Journal articles on the topic 'Gases from plants Measurement'
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1
Hämäläinen, K. M., H. Jungner, O. Antson, J. Räsänen, K. Tormonen, and J. Roine. "Measurement of Biocarbon in Flue Gases Using 14C." Radiocarbon 49, no. 2 (2007): 325–30. http://dx.doi.org/10.1017/s0033822200042259.
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A preliminary investigation of the biocarbon fraction in carbon dioxide emissions of power plants using both fossil- and biobased fuels is presented. Calculation of the biocarbon fraction is based on radiocarbon content measured in power plant flue gases. Samples were collected directly from the chimneys into plastic sampling bags. The 14C content in CO2 was measured by accelerator mass spectrometry (AMS). Flue gases from power plants that use natural gas, coal, wood chips, bark, plywood residue, sludge from the pulp factory, peat, and recovered fuel were measured. Among the selected plants, there was one that used only fossil fuel and one that used only biofuel; the other investigated plants burned mixtures of fuels. The results show that 14C measurement provides the possibility to determine the ratio of bio and fossil fuel burned in power plants.
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Grigorieva, Elena V., Valery V. Chernyshev, Sergei V. Kulichkov, and Larisa V. Andreeva. "Impact of Particulate Matter Emissions from Ship Power Plants on the Port City Environment." E3S Web of Conferences 320 (2021): 01010. http://dx.doi.org/10.1051/e3sconf/202132001010.
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The paper deals with one of the methods for assessing anthropogenic impact of the operation of ship power plants in port areas on the environment. The measurement of mass concentration of particulate matters (PM) in the open air was carried out during summer and winter in eight points of the city that were selected depending on the conditions of orographic characteristics of the area. Moreover, vessel traffic in coastal waters was assessed and information on the number and type of vessels was collected. Based on the data obtained, the total PM volume emitted with exhaust gases from ship power plants in the port areas during a year was calculated.
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Burgués, Javier, María Deseada Esclapez, Silvia Doñate, Laura Pastor, and Santiago Marco. "Aerial Mapping of Odorous Gases in a Wastewater Treatment Plant Using a Small Drone." Remote Sensing 13, no. 9 (April 30, 2021): 1757. http://dx.doi.org/10.3390/rs13091757.
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Wastewater treatment plants (WWTPs) are sources of greenhouse gases, hazardous air pollutants and offensive odors. These emissions can have negative repercussions in and around the plant, degrading the quality of life of surrounding neighborhoods, damaging the environment, and reducing employee’s overall job satisfaction. Current monitoring methodologies based on fixed gas detectors and sporadic olfactometric measurements (human panels) do not allow for an accurate spatial representation of such emissions. In this paper we use a small drone equipped with an array of electrochemical and metal oxide (MOX) sensors for mapping odorous gases in a mid-sized WWTP. An innovative sampling system based on two (10 m long) flexible tubes hanging from the drone allowed near-source sampling from a safe distance with negligible influence from the downwash of the drone’s propellers. The proposed platform is very convenient for monitoring hard-to-reach emission sources, such as the plant’s deodorization chimney, which turned out to be responsible for the strongest odor emissions. The geo-localized measurements visualized in the form of a two-dimensional (2D) gas concentration map revealed the main emission hotspots where abatement solutions were needed. A principal component analysis (PCA) of the multivariate sensor signals suggests that the proposed system can also be used to trace which emission source is responsible for a certain measurement.
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Cerqueira, Joaci Dos Santos, Helder Neves de Albuquerque, Mário Luiz Farias Cavalcanti, and Francisco De Assis Salviano de Sousa. "Use of portable environmental sensors in the monitoring of the thermoelectric power plants operation." Revista Ibero-Americana de Ciências Ambientais 11, no. 6 (July 6, 2020): 178–201. http://dx.doi.org/10.6008/cbpc2179-6858.2020.006.0016.
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Thermoelectric power plants can directly cause environmental impacts with respect to emissions of atmospheric gases caused by combustion for operation, being the main agents: unburned hydrocarbons, carbon oxides, sulfur oxides, nitrogen oxides, volatile organic compounds and material particulate. Thus, this research aimed to measure and compare the instantaneous levels of the chemical compounds CO2, CO, SO2, noise, air temperature, relative humidity, dew point temperature, wind speed and luminescence in two peri-urban areas of the surrounding a thermoelectric power plant in the interior of Paraíba, Brazil. To this end, data were collected using environmental sensors (a Garmin Gpsmap 62sc GPS camera 5mp; a Canon powershot SX60HS 16.1MP LCD 3.0 semi-professional digital camera, 65x optical zoom; an ITMCO2-600 meter for measuring CO2 and CO; one ITMP-600 multifunctional meter for AVG/MAX/MIN/DIF measurement, temperature measurement, humidity measurement, sound level measurement, luminescence measurement and wind speed measurement; and a GasAlert Extreme SO2 Gas detector to measure concentrations of sulfur in the environment), from October 2015 to March 2017, during daytime, between 7:00am to 9:00am, with weekly frequency, with instantaneous sampling measurements being collected at the collection points, near the thermoelectric power plant (Area 1) and close to the BR/104 highway (Area 2). The results showed that the records through the environmental sensors were not significant among the areas surveyed regarding the values of CO, CO2, SO2, air temperature, relative humidity, dew point temperature and luminescence. Regarding the wind speed, the two areas showed little variation. The noise levels in Area 1, on the other hand, during the operation of the thermoelectric power plant in its fullness, there was an increase above the permitted level, according to current Brazilian regulations, causing damage to the health of the inhabitants of its surroundings, in addition to harming the fauna of the surrounding area. around, mainly, the birds that are driven away by the noise, and, consequently, reducing the diversity of the avifauna surrounding the Thermoelectric. Thus, the use of environmental sensors to monitor the air quality of this area is very important, thus serving as a comparative support for future studies, as well as establishing the genesis for an environmental database in this metropolitan region of Campina Grande/PB, Brazil.
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Stelmach, Wioleta, Paweł Szarlip, and Andrzej Trembaczowski. "Changes of Isotopic Composition in Gases Emitted from Wastewater Treatment Plant - Preliminary Study." Ecological Chemistry and Engineering S 21, no. 2 (July 8, 2014): 245–54. http://dx.doi.org/10.2478/eces-2014-0019.
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Abstract Investigations of processes occurring during wastewater treatment have progressed beyond the stage of technology. Currently, great numbers of representatives of diverse specialist research apply increasingly sophisticated measurement methods that have not been employed in this field of science. One of the methods is IRMS (Isotope Ratio Mass Spectrometry). Tracking changes in the ratios of biogenic element isotopes is useful in eg identification and monitoring of investigated processes. Since the IRMS technique has hardly been used for investigations of the wastewater treatment process, pilot research should be instigated to determine the isotope ratios occurring naturally in the process. The aim of the study was to determine changes in carbon and nitrogen isotope ratios at the successive stages of the technological line in wastewater treatment plants. The study material comprised: i) suspensions of raw sewage and mixtures of wastewater and activated sludge; ii) gases sampled from the volume of the suspensions; iii) gases sampled from the air above the suspension surface. The research material originated from the facilities of “Hajdow” municipal wastewater treatment plant in Lublin (SE Poland). The samples were analysed for the carbon and nitrogen isotope ratios, and the concentrations of the gases as well as total organic carbon (TOC), inorganic carbon (IC), Kjeldahl nitrogen (KN), dry weight, pH, and Eh were determined. The results obtained suggest that: i) the IRMS technique can be successfully applied in investigations of processes occurring during wastewater treatment; ii) isotope ratios in the carbon and nitrogen compounds (CO2 and N2) both in the suspensions and gases contained therein and in the air above them differ from each other and change at the different stages of the treatment process; iii) further research is indispensable in order to identify processes responsible for fractionation of carbon and nitrogen isotopes.
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Och, Andreas, Jochen O. Schrattenecker, Stefan Schuster, Patrick A. Hölzl, Philipp F. Freidl, Stefan Scheiblhofer, Dominik Zankl, and Robert Weigel. "Accuracy Bounds and Measurements of a Contactless Permittivity Sensor for Gases Using Synchronized Low-Cost mm-Wave Frequency Modulated Continuous Wave Radar Transceivers." Sensors 19, no. 15 (July 31, 2019): 3351. http://dx.doi.org/10.3390/s19153351.
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A primary concern in a multitude of industrial processes is the precise monitoring of gaseous substances to ensure proper operating conditions. However, many traditional technologies are not suitable for operation under harsh environmental conditions. Radar-based time-of-flight permittivity measurements have been proposed as alternative but suffer from high cost and limited accuracy in highly cluttered industrial plants. This paper examines the performance limits of low-cost frequency-modulated continuous-wave (FMCW) radar sensors for permittivity measurements. First, the accuracy limits are investigated theoretically and the Cramér-Rao lower bounds for time-of-flight based permittivity and concentration measurements are derived. In addition, Monte-Carlo simulations are carried out to validate the analytical solutions. The capabilities of the measurement concept are then demonstrated with different binary gas mixtures of Helium and Carbon Dioxide in air. A low-cost time-of-flight sensor based on two synchronized fully-integrated millimeter-wave (MMW) radar transceivers is developed and evaluated. A method to compensate systematic deviations caused by the measurement setup is proposed and implemented. The theoretical discussion underlines the necessity of exploiting the information contained in the signal phase to achieve the desired accuracy. Results of various permittivity and gas concentration measurements are in good accordance to reference sensors and measurements with a commercial vector network analyzer (VNA). In conclusion, the proposed radar-based low-cost sensor solution shows promising performance for the intended use in demanding industrial applications.
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Sumiyati, Sri, Haryono Setiyo Huboyo, and Bimastyaji Surya Ramadan. "Potential Use of Banana Plant (Musa spp.) as Bio-sorbent Materials for Controlling Gaseous Pollutants." E3S Web of Conferences 125 (2019): 03015. http://dx.doi.org/10.1051/e3sconf/201912503015.
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The use of organic waste as bio-sorbent has been carried out by many researchers in the world. Furthermore, the utilization of plants for treating wastewater is also commonly found in various environmental applications. Nevertheless, a review of the ability of banana plants (Musa spp.) as bio-sorbent to eliminate gaseous pollutants is rarely found and has not been fully understood. In this paper, lignocellulosic biomass from banana plants (bark, stem, leaves, peels, etc) was identified and reviewed. Sorption potential was discussed and taken from various literature which then evaluated to discuss the potential and ability of banana plants as sorbent material for treating gaseous pollutants. Assessment and measurement methods were also discussed to obtain the best sorbent in removing gaseous pollutants. This research was conducted by reviewing scientific articles that discussed the use of lignocellulosic materials derived from banana plants for absorbing various gases. Almost all articles described the manufacture of adsorbents from banana plants that were used to treat wastewater but not many researchers have tried to develop a commercially adsorbent for gas-shaped pollutants. This research is expected to provide essential information for the readers to develop advanced materials used to control environmental pollution especially gaseous pollutants.
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Dekhtyareva, Alena, Mark Hermanson, Anna Nikulina, Ove Hermansen, Tove Svendby, Kim Holmén, and Rune Grand Graversen. "Springtime nitrogen oxides and tropospheric ozone in Svalbard: results from the measurement station network." Atmospheric Chemistry and Physics 22, no. 17 (September 9, 2022): 11631–56. http://dx.doi.org/10.5194/acp-22-11631-2022.
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Abstract. Svalbard is a remote and scarcely populated Arctic archipelago and is considered to be mostly influenced by long-range-transported air pollution. However, there are also local emission sources such as coal and diesel power plants, snowmobiles and ships, but their influence on the background concentrations of trace gases has not been thoroughly assessed. This study is based on data of tropospheric ozone (O3) and nitrogen oxides (NOx) collected in three main Svalbard settlements in spring 2017. In addition to these ground-based observations and radiosonde and O3 sonde soundings, ERA5 reanalysis and BrO satellite data have been applied in order to distinguish the impact of local and synoptic-scale conditions on the NOx and O3 chemistry. The measurement campaign was divided into several sub-periods based on the prevailing large-scale weather regimes. The local wind direction at the stations depended on the large-scale conditions but was modified due to complex topography. The NOx concentration showed weak correlation for the different stations and depended strongly on the wind direction and atmospheric stability. Conversely, the O3 concentration was highly correlated among the different measurement sites and was controlled by the long-range atmospheric transport to Svalbard. Lagrangian backward trajectories have been used to examine the origin and path of the air masses during the campaign.
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Andreão, Willian Lemker, Taciana Toledo de Almeida Albuquerque, Lucas de Almeida Chamhum Silva, and Carlos Augusto de Lemos Chernicharo. "Part B: Advances in gas emission control techniques for anaerobic-based STPs Technical Note 8 – Emission and mathematical models of dispersion of odorants gases generated in the STPs." Cadernos Técnicos Engenharia Sanitária e Ambiental 1, no. 2 (2021): 107–22. http://dx.doi.org/10.5327/276455760102008.
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Companies related to environmental sanitation, such as sewage treatment plants (STP), especially those based on anaerobic effluent treatment, are faced with the need to evaluate their odorous gaseous emissions, aiming to reduce any impacts on the environment and on the surrounding community, since odorant gases emission has a real impact on people and their well-being, in addition to being one of the main reasons related to complaints and nuisance around the STP. In this context, this Technical Note discusses: (i) the application of the dynamic flux chamber for the direct measurement of volatile gas in units that have quiescent liquid surfaces (low degree of agitation); (ii) the use of algebraic mathematical models to estimate the emission rate of odorants gases in the units of a STP; and (iii) the use of dispersion models as tools to evaluate the concentration of pollutants after their emission. The required input data from each model is highlighted as well as the limitations of each process.
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Jeon, Min-Gyu, Jeong-Woong Hong, Deog-Hee Doh, and Yoshihiro Deguchi. "Temperature measurement of turbulent flame using CT-TDLAS (computed tomography-tunable diode laser absorption spectroscopy)." International Journal of Modern Physics B 35, no. 14n16 (May 14, 2021): 2140012. http://dx.doi.org/10.1142/s0217979221400129.
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In order to satisfy the requirements of high-quality and high-performance optimal material manufacturing process, it is essential to control the gas system of the manufacturing process. In the actual industry, the quality of products is improved by controlling various gases in the manufacturing process. The tunable laser absorption spectroscopy (TDLAS) technique can be measured by the temperature and concentration of target gas simultaneously. Among the more advanced technologies, CT-TDLAS is the most crucial technique for measuring temperature and concentration distributions across two-dimensional planes. This study suggests a three-dimensional useful measurement of irregular flow or exhaust gases. Furthermore, an optical measurement method has been adopted to measure temperature distribution at a cross-section of the Methane Air premixed turbulent flame. The equivalence ratio of fuel can control this system. The burner system consists of two sections (main flame, sub-flame) for a turbulent flame. In the CT-TDLAS technique, it is essential to set the wavelength for target gases. There is a limit to high-temperature measurement in temperature estimation using a single laser-specific wavelength. Therefore, compared measurement performance was made using a mixed type laser (1388 nm, 1343 nm) and a single type laser (1388 nm). The temperatures obtained by using the optical measurement results were relatively evaluated with those obtained by the thermocouples. It was confirmed that the relative error of the temperature occurred at the central position of the burner. It was about 13.33% by the mixed laser system and 38.33% by the single laser system in most close to point from the burner.
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Zhao, Y., B. F. Wu, and Y. Zeng. "Spatial and temporal aspects of greenhouse gas emissions from Three Gorges Reservoir, China." Biogeosciences Discussions 9, no. 10 (October 18, 2012): 14503–35. http://dx.doi.org/10.5194/bgd-9-14503-2012.
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Abstract. Before completion of the Three Gorges Reservoir (TGR), China, there was growing apprehension that it would become a major emitter of greenhouse gases (GHG): Carbon Dioxide (CO2), Methane (CH4) and Nitrous Oxide (N2O). We report monthly measurements for one year of the fluxes of these gases at multiple sites within the TGR, Yangtze River, China, and from several major tributaries, and immediately downstream of the dam. The tributary areas have lower CO2 fluxes than the main storage; CH4 fluxes to the atmosphere after passage through the turbines are negligible. Overall, TGR showed significantly lower CH4 emission rates than most new reservoirs in temperate and tropical regions. We attribute this to the well-oxygenated deep water and high water velocities which produce oxic mainstem conditions inimical to CH4 emission. TGR's CO2 fluxes were lower than most tropical reservoirs and higher than most temperate systems. This is due to the high load of metabolizable soil carbon delivered through erosion to the Yangtze River. Compared to fossil fuelled power plants of equivalent power output TGR is a very small GHG emitter, annual CO2-equivalent emissions are approximately 1.7% of a coal-fired generating plant of comparable power output.
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Merlaud, Alexis, Livio Belegante, Daniel-Eduard Constantin, Mirjam Den Hoed, Andreas Carlos Meier, Marc Allaart, Magdalena Ardelean, et al. "Satellite validation strategy assessments based on the AROMAT campaigns." Atmospheric Measurement Techniques 13, no. 10 (October 15, 2020): 5513–35. http://dx.doi.org/10.5194/amt-13-5513-2020.
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Abstract. The Airborne ROmanian Measurements of Aerosols and Trace gases (AROMAT) campaigns took place in Romania in September 2014 and August 2015. They focused on two sites: the Bucharest urban area and large power plants in the Jiu Valley. The main objectives of the campaigns were to test recently developed airborne observation systems dedicated to air quality studies and to verify their applicability for the validation of space-borne atmospheric missions such as the TROPOspheric Monitoring Instrument (TROPOMI)/Sentinel-5 Precursor (S5P). We present the AROMAT campaigns from the perspective of findings related to the validation of tropospheric NO2, SO2, and H2CO. We also quantify the emissions of NOx and SO2 at both measurement sites. We show that tropospheric NO2 vertical column density (VCD) measurements using airborne mapping instruments are well suited for satellite validation in principle. The signal-to-noise ratio of the airborne NO2 measurements is an order of magnitude higher than its space-borne counterpart when the airborne measurements are averaged at the TROPOMI pixel scale. However, we show that the temporal variation of the NO2 VCDs during a flight might be a significant source of comparison error. Considering the random error of the TROPOMI tropospheric NO2 VCD (σ), the dynamic range of the NO2 VCDs field extends from detection limit up to 37 σ (2.6×1016 molec. cm−2) and 29 σ (2×1016 molec. cm−2) for Bucharest and the Jiu Valley, respectively. For both areas, we simulate validation exercises applied to the TROPOMI tropospheric NO2 product. These simulations indicate that a comparison error budget closely matching the TROPOMI optimal target accuracy of 25 % can be obtained by adding NO2 and aerosol profile information to the airborne mapping observations, which constrains the investigated accuracy to within 28 %. In addition to NO2, our study also addresses the measurements of SO2 emissions from power plants in the Jiu Valley and an urban hotspot of H2CO in the centre of Bucharest. For these two species, we conclude that the best validation strategy would consist of deploying ground-based measurement systems at well-identified locations.
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Uddin, Jasim, Rod Smith, Nigel Hancock, and Joseph Foley. "Evaluation of Sap Flow Sensors to Measure the Transpiration Rate of Plants during Canopy Wetting and Drying." Journal of Agricultural Studies 2, no. 2 (August 14, 2014): 105. http://dx.doi.org/10.5296/jas.v2i2.6134.
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Accurate measurement of transpiration is required to estimate the various components of evaporation losses during sprinkler irrigation. Among the methods, sap flow measurements have widely used for direct measurements of transpiration rate in plant. To evaluate the applicability of this method to field experiments involving canopy wetting (by sprinkler irrigation), stem flow measurements were compared with transpiration values estimated from successive mass measurements of small potted plants using pre-calibrated mini-lysimeters in a glasshouse at the University of Southern Queensland, during the period August–October 2010. From this study it was found that when the canopy was dry, the sap flow measurements mirrored the transpiration rate of plants with reasonable accuracy, overestimating the transpiration rate by about 11%. The measurements showed no evidence of time lag between sap flow and transpiration. Following wetting of the plant canopy the sap flow declined rapidly reflecting a decline in the transpiration rate transpiration and sap flow. Location of the sap flow gage on the stem was seen to be a factor with gages at different heights giving different sap flow rates again due to the buffering capacity of the stem.
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Vance, J. M., and R. S. French. "Measurement of Torsional Vibration in Rotating Machinery." Journal of Mechanisms, Transmissions, and Automation in Design 108, no. 4 (December 1, 1986): 565–77. http://dx.doi.org/10.1115/1.3258771.
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Five techniques for measurement of torsional vibration in a drive train are described, along with the advantages and disadvantages of each. Two laboratory test rigs, designed and constructed for experimental evaluation of various torsional vibration measurement techniques, are described. The measurement techniques investigated fall into three categories: a) those using signals from strain gages, b) those using signals from a magnetically transduced gear, and c) using signals optically transduced from a special tape applied to the shaft. One of the techniques described requires no specialized instrumentation other than a spectrum analyzer, which is now typically available in plants with rotating machinery. Another technique is capable of producing a detailed time history of torsional oscillations during acceleration of the drive train (i.e., startup), using a time interval measurement system. A comparison of results from the various techniques is given, and recommendations are made for several types of applications.
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Chałupnik, S., A. Smoliński, and M. Wysocka. "Calibration of the Method for Measuring 14C in Combustion Gases." Radiocarbon 56, no. 3 (2014): 1207–14. http://dx.doi.org/10.2458/56.17779.
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Much recent effort has been focused on the development of monitoring methods to calculate the percentage of biomass in the fuel used for energy generation in power plants. One possible method is based on measurements of radiocarbon concentration in combustion gases by liquid scintillation (LS) spectrometry. Fossil fuels contain no 14C due to their age. Therefore, after the combustion of such fuels, the resulting CO2 contains no 14C as well. The only source of 14C comes from the admixture of biomass containing modern carbon. 14C is a beta-emitting radionuclide with a maximum beta energy of 156 keV. There is no emission of gamma rays during decay; therefore, no possibility of gamma spectrometry exists. A difficult task thus is to validate the method and to calibrate it in agreement with the known amount of biomass in the fuel. For this purpose, a set of samples was prepared that were mixtures of hard coal and biomass with a known percentage of carbon. The oxycombustion method was applied for sample preparation in which the combustion of the fuel is done in pure oxygen; therefore, the combustion gas contains mostly CO2 and steam. The CO2 from the gas sample is then adsorbed by 3-methoxypropylamine. A known amount of this absorbent was mixed with a scintillation cocktail and measured in the LS spectrometer. In this way, a calibration curve has been obtained, allowing quantitative measurements of biomass content in the fuel.
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Iswanto, Iswanto, Alfian Ma’arif, Bilah Kebenaran, and Prisma Megantoro. "Design of gas concentration measurement and monitoring system for biogas power plant." Indonesian Journal of Electrical Engineering and Computer Science 22, no. 2 (May 1, 2021): 726. http://dx.doi.org/10.11591/ijeecs.v22.i2.pp726-732.
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Biogas is a gas obtained from the breakdown of organic matter (such as animal waste, human waste, and plants) by methanogenic bacteria in an oxygen-free (anaerobic) state. The biogas produced mainly consists of 50-70% methane, 30-40% carbon dioxide, and other gases in small amounts. The gas produced has a different composition depending on the type of animal that produces it. It is challenging to obtain biogas concentration data because the monitoring equipment is currently minimal. Therefore, this research discusses how to make a monitoring system for biogas reactors. Sensors are installed in the digester tank and storage tank. The installed sensors are the MQ-4 sensor to detect methane gas (CH<sub>4</sub>), MG-811 sensor to detect carbon dioxide (CO<sub>2</sub>) gas, MQ-136 sensor to detect sulfide acid gas (H<sub>2</sub>S), and Thermocouple Type-K to detect temperature. The sensor will send a signal to the control unit in Arduino Mega 2560, then processed and displayed on the liquid crystal display (LCD). The sensor calculation results' accuracy is not much different from the reference based on the sensor readings. The sensor deviation standard is below 5.0, indicating that the sensor is in precision. The sensor's linearity of MQ-4 is 0.7%, the MG-811 is 0.17%, the MQ-136 is 0.29%, and the Type-K Thermocouple is 1.19%. The installed sensor can be used to monitor gas concentration and temperature in a biogas reactor.
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Yarmolchick, Yu P. "Formation Mechanisms and Methods for Calculating Pollutant Emissions from Natural Gas Combustion Depending on the Burner Emission Class." ENERGETIKA. Proceedings of CIS higher education institutions and power engineering associations 62, no. 6 (November 29, 2019): 565–82. http://dx.doi.org/10.21122/1029-7448-2019-62-6-565-582.
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The combustion of hydrocarbon fuels in the chambers of heat generating plants is one of the main sources of pollutant emissions. Environmental standards and rules that limit emissions are becoming more stringent and their implementation requires the introduction of advanced technologies and equipment. The main device in combustion systems are blow burners, the design of which largely determines the level of emission. The article considers factors that intensify the formation of normalized pollutants, provides global chemical reactions, various types of mechanisms, and kinetic schemes. Based on the analysis of modern methods for reducing harmful emissions, the most effective design solutions for mixing devices, nozzles and systems for distributing the flow of fuel and air supplied to combustion are determined. A comparative analysis of the methods and conditions for determining the emission class of the burner device is carried out depending on the selected units of measure, the coefficient of excess air (oxygen concentration in flue gases), air humidity and the initial composition of natural gas using examples of EU and EAC standards. The methodology for calculating the emissions of nitrogen oxides depending on the measurement conditions is given. The conversion factors for the values of pollutant emissions from the accepted units in the EU (mg/(kW×h)) into the units indicated according to the EAC environmental rules (mg/m3) taking into account the respectively normalized coefficient of excess air are obtained. As a result of the calculations, the types of burners were determined by emission classes corresponding to the applicable environmental standards and rules in the Republic of Belarus, depending on the heat output of the boiler plants.
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Liu, Fei, Bryan N. Duncan, Nickolay A. Krotkov, Lok N. Lamsal, Steffen Beirle, Debora Griffin, Chris A. McLinden, Daniel L. Goldberg, and Zifeng Lu. "A methodology to constrain carbon dioxide emissions from coal-fired power plants using satellite observations of co-emitted nitrogen dioxide." Atmospheric Chemistry and Physics 20, no. 1 (January 3, 2020): 99–116. http://dx.doi.org/10.5194/acp-20-99-2020.
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Abstract. We present a method to infer CO2 emissions from individual power plants based on satellite observations of co-emitted nitrogen dioxide (NO2), which could serve as complementary verification of bottom-up inventories or be used to supplement these inventories. We demonstrate its utility on eight large and isolated US power plants, where accurate stack emission estimates of both gases are available for comparison. In the first step of our methodology, we infer nitrogen oxides (NOx) emissions from US power plants using Ozone Monitoring Instrument (OMI) NO2 tropospheric vertical column densities (VCDs) averaged over the ozone season (May–September) and a “top-down” approach that we previously developed. Second, we determine the relationship between NOx and CO2 emissions based on the direct stack emissions measurements reported by continuous emissions monitoring system (CEMS) programs, accounting for coal quality, boiler firing technology, NOx emission control device type, and any change in operating conditions. Third, we estimate CO2 emissions for power plants using the OMI-estimated NOx emissions and the CEMS NOx∕CO2 emission ratio. We find that the CO2 emissions estimated by our satellite-based method during 2005–2017 are in reasonable agreement with the US CEMS measurements, with a relative difference of 8 %±41 % (mean ± standard deviation). The broader implication of our methodology is that it has the potential to provide an additional constraint on CO2 emissions from power plants in regions of the world without reliable emissions accounting. We explore the feasibility by comparing the derived NOx∕CO2 emission ratios for the US with those from a bottom-up emission inventory for other countries and applying our methodology to a power plant in South Africa, where the satellite-based emission estimates show reasonable consistency with other independent estimates. Though our analysis is limited to a few power plants, we expect to be able to apply our method to more US (and world) power plants when multi-year data records become available from new OMI-like sensors with improved capabilities, such as the TROPOspheric Monitoring Instrument (TROPOMI), and upcoming geostationary satellites, such as the Tropospheric Emissions: Monitoring Pollution (TEMPO) instrument.
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Fix, Andreas, Axel Amediek, Christian Büdenbender, Gerhard Ehret, Christoph Kiemle, Mathieu Quatrevalet, Martin Wirth, et al. "CH4 and CO2 IPDA Lidar Measurements During the Comet 2018 Airborne Field Campaign." EPJ Web of Conferences 237 (2020): 03005. http://dx.doi.org/10.1051/epjconf/202023703005.
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Installed onboard the German research aircraft HALO, the integrated-path differential-absorption (IPDA) lidar CHARM-F measures weighted vertical columns of both greenhouse gases (GHG) below the aircraft and along its flight track, aiming at high accuracy and precision. Results will be shown from the deployment during the CoMet field campaign that was carried out in spring 2018, with its main focus on one of the major European hot spots in methane emissions: the Upper Silesian Coal Basin (USCB) in Poland. First analyses reveal a measurement precision of below 0.5% for 20-km averages and also low bias, which was assessed by comparison with in-situ instruments. The measurements flights were designed to capture individual CH4 and CO2 plumes from e.g. coal mine venting and coal-fired power plants, respectively, but also to measure large and regional scale GHG gradients and to provide comparisons with the Total Carbon Column Observing Network (TCCON). Many other different instruments, both airborne and ground-based, complemented the lidar measurements to provide a comprehensive dataset for model analyses. CHARM-F also acts as the airborne demonstrator for MERLIN, the “Methane Remote Lidar Mission”, conducted by the German and French space agencies, DLR and CNES, with launch foreseen in ~ 2024. In this context, the airborne lidar data are likewise important for mission support such as for e.g. algorithm development and improvement and, moreover, the CoMet mission was also an important step for MERLIN validation preparation.
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Millet, D. B., A. Guenther, D. A. Siegel, N. B. Nelson, H. B. Singh, J. A. de Gouw, C. Warneke, et al. "Global atmospheric budget of acetaldehyde: 3-D model analysis and constraints from in-situ and satellite observations." Atmospheric Chemistry and Physics Discussions 9, no. 6 (November 12, 2009): 24225–79. http://dx.doi.org/10.5194/acpd-9-24225-2009.
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Abstract. We construct a global atmospheric budget for acetaldehyde using a 3-D model of atmospheric chemistry (GEOS-Chem), and use an ensemble of observations to evaluate present understanding of its sources and sinks. Hydrocarbon oxidation provides the largest acetaldehyde source in the model (130 Tg a−1), with alkanes, alkenes, ethanol, and isoprene the main precursors. We use an updated chemical mechanism for GEOS-Chem, and photochemical acetaldehyde yields are consistent with the Master Chemical Mechanism. We apply SeaWiFS satellite observations to define the global distribution of light absorption due to marine dissolved organic matter (DOM), and estimate the corresponding sea-to-air acetaldehyde flux based on measured photoproduction rates from DOM. The resulting net ocean emission is 58 Tg a−1, the second largest global source of acetaldehyde. Quantitative model evaluation over the ocean is complicated by known measurement artifacts in clean air. Simulated concentrations in surface air over the ocean generally agree well with aircraft measurements, though the model tends to overestimate the vertical gradient. PAN:NOx ratios are well-simulated in the marine boundary layer, providing some support for the modeled ocean source. A key uncertainty is the acetaldehyde turnover time in the ocean mixed layer. We introduce the Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) for acetaldehyde and ethanol and use it to quantify their net flux from living terrestrial plants. Including emissions from decaying plants the total direct acetaldehyde source from the land biosphere is 22 Tg a−1. Other terrestrial acetaldehyde sources include biomass burning (3 Tg a−1) and anthropogenic emissions (2 Tg a−1). Simulated concentrations in the continental boundary layer are generally unbiased and capture the spatial gradients seen in observations over North America, Europe, and tropical South America. However, the model underestimates acetaldehyde levels in urban outflow, suggesting a missing source in polluted air. Ubiquitous high measured concentrations in the free troposphere are not captured by the model, and based on present understanding are not consistent with concurrent measurements of PAN and NOx. We find no compelling evidence for a widespread missing acetaldehyde source in the free troposphere. We estimate the current US source of ethanol and acetaldehyde (primary+secondary) at 1.3 Tg a−1 and 7.0 Tg a−1, approximately 60% and 400% of the corresponding increases expected for a national transition from gasoline to ethanol fuel.
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Millet, D. B., A. Guenther, D. A. Siegel, N. B. Nelson, H. B. Singh, J. A. de Gouw, C. Warneke, et al. "Global atmospheric budget of acetaldehyde: 3-D model analysis and constraints from in-situ and satellite observations." Atmospheric Chemistry and Physics 10, no. 7 (April 12, 2010): 3405–25. http://dx.doi.org/10.5194/acp-10-3405-2010.
Full textAbstract:
Abstract. We construct a global atmospheric budget for acetaldehyde using a 3-D model of atmospheric chemistry (GEOS-Chem), and use an ensemble of observations to evaluate present understanding of its sources and sinks. Hydrocarbon oxidation provides the largest acetaldehyde source in the model (128 Tg a−1, a factor of 4 greater than the previous estimate), with alkanes, alkenes, and ethanol the main precursors. There is also a minor source from isoprene oxidation. We use an updated chemical mechanism for GEOS-Chem, and photochemical acetaldehyde yields are consistent with the Master Chemical Mechanism. We present a new approach to quantifying the acetaldehyde air-sea flux based on the global distribution of light absorption due to colored dissolved organic matter (CDOM) derived from satellite ocean color observations. The resulting net ocean emission is 57 Tg a−1, the second largest global source of acetaldehyde. A key uncertainty is the acetaldehyde turnover time in the ocean mixed layer, with quantitative model evaluation over the ocean complicated by known measurement artifacts in clean air. Simulated concentrations in surface air over the ocean generally agree well with aircraft measurements, though the model tends to overestimate the vertical gradient. PAN:NOx ratios are well-simulated in the marine boundary layer, providing some support for the modeled ocean source. We introduce the Model of Emissions of Gases and Aerosols from Nature (MEGANv2.1) for acetaldehyde and ethanol and use it to quantify their net flux from living terrestrial plants. Including emissions from decaying plants the total direct acetaldehyde source from the land biosphere is 23 Tg a−1. Other terrestrial acetaldehyde sources include biomass burning (3 Tg a−1) and anthropogenic emissions (2 Tg a−1). Simulated concentrations in the continental boundary layer are generally unbiased and capture the spatial gradients seen in observations over North America, Europe, and tropical South America. However, the model underestimates acetaldehyde levels in urban outflow, suggesting a missing source in polluted air. Ubiquitous high measured concentrations in the free troposphere are not captured by the model, and based on present understanding are not consistent with concurrent measurements of PAN and NOx: we find no compelling evidence for a widespread missing acetaldehyde source in the free troposphere. We estimate the current US source of ethanol and acetaldehyde (primary + secondary) at 1.3 Tg a−1 and 7.8 Tg a−1, approximately 60{%} and 480% of the corresponding increases expected for a national transition from gasoline to ethanol fuel.
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Xu, Zhengtian, Hong Sun, Xueqing Li, and Eiji Motoda. "A new solution for destruction of PCDD/Fs by a catalytic filter system at waste incinerators." E3S Web of Conferences 118 (2019): 04046. http://dx.doi.org/10.1051/e3sconf/201911804046.
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Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) are emitted from high temperature combustion processes such as municipal waste incinerators, hazardous waste incinerators, medical waste incinerators, and secondary metal processing plants. Due to their extreme toxicity, stringent regulations on PCDD/Fs emissions have been in effect around the world since the early 1990s. W. L. Gore & Associates, Inc. developed a catalytic filter system in 1997 that can effectively remove and destroy PCDD/Fs in the industrial flue gases. The REMEDIATM Catalytic Filter System has been installed in various industrial facilities around the world. The dioxin emission measurements in these plants achieve more than 98% PCDD/Fs removal efficiencies and reach the European standard. In this paper, three case studies will be presented on the performance of the REMEDIA Catalytic Filter System at municipal, medical, and hazardous waste incinerators. Three cases in the paper demonstrate the efficiency and results.
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Opacka, Beata, Jean-François Müller, Trissevgeni Stavrakou, Diego G. Miralles, Akash Koppa, Brianna Rita Pagán, Mark J. Potosnak, Roger Seco, Isabelle De Smedt, and Alex B. Guenther. "Impact of Drought on Isoprene Fluxes Assessed Using Field Data, Satellite-Based GLEAM Soil Moisture and HCHO Observations from OMI." Remote Sensing 14, no. 9 (April 22, 2022): 2021. http://dx.doi.org/10.3390/rs14092021.
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Biogenic volatile organic compounds (BVOCs), primarily emitted by terrestrial vegetation, are highly reactive and have large effects on the oxidizing potential of the troposphere, air quality and climate. In terms of global emissions, isoprene is the most important BVOC. Droughts bring about changes in the surface emission of biogenic hydrocarbons mainly because plants suffer water stress. Past studies report that the current parameterization in the state-of-the-art Model of Emissions of Gases and Aerosols from Nature (MEGAN) v2.1, which is a function of the soil water content and the permanent wilting point, fails at representing the strong reduction in isoprene emissions observed in field measurements conducted during a severe drought. Since the current algorithm was originally developed based on potted plants, in this study, we update the parameterization in the light of recent ecosystem-scale measurements of isoprene conducted during natural droughts in the central U.S. at the Missouri Ozarks AmeriFlux (MOFLUX) site. The updated parameterization results in stronger reductions in isoprene emissions. Evaluation using satellite formaldehyde (HCHO), a proxy for BVOC emissions, and a chemical-transport model, shows that the adjusted parameterization provides a better agreement between the modelled and observed HCHO temporal variability at local and regional scales in 2011–2012, even if it worsens the model agreement in a global, long-term evaluation. We discuss the limitations of the current parameterization, a function of highly uncertain soil properties such as porosity.
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Dindoruk, Birol, Ram R. Ratnakar, and Sanyal Suchismita. "Phase Equilibria of Acid-Gas Aqueous Systems (CO2, H2S, CH4, Water) and In-Situ pH Measurements in Application to Top-of-Line Corrosion." SPE Journal 26, no. 04 (February 22, 2021): 2364–79. http://dx.doi.org/10.2118/201341-pa.
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Summary We present thermodynamic modeling and pH measurements of fluid systems containing acid-gases (e.g., CO2 and H2S), water, and hydrocarbons—replicating the production and shutdown conditions in sour fields—for the purpose of evaluating top-of-line corrosion (TLC) and wellbore integrity and screening/selection of the proper wellbore materials. In particular: An equation of state (EOS) model using Peng-Robinson EOS in combination with the Huron-Vidal (HV) mixing rule for an aqueous subsystem is developed. In the model, subject EOS parameters are calibrated against existing thermodynamic data (saturation data for pure components and solubility data for binary systems) in literature. New in-situ pH measurement data are presented for a model system corresponding to a sour field. It was found that the wellbore can be subjected to pH levels as low as 2.7 with reservoir fluid containing 12 mol% CO2 and 88 mol% CH4 with downhole flowing conditions of 200 bar and 150°C and wellhead shut-in conditions of 300 bar and 4°C, as observed from the experiments. A modeling workflow is developed to estimate pH of the condensed water as a function of temperature and composition of the aqueous phase. The comparison between prediction and experimental measurement shows a very good match between the two (within pH ±0.1). Such studies (pH measurements and prediction) are not available in the literature but play important roles in material screening and assuring wellbore integrity for sour fields. More importantly, sensitivity analysis can be performed to investigate the effects of various factors (such as reservoir temperature/pressure, shutdown conditions, and compositions or extent of souring) on pH prediction. Furthermore, the methodologies developed through this work can also be extended to reservoir facilities, pipelines, sour gas disposal/handling units, and downstream systems such as water utilities, reactor plants, and refineries. The work can also support regulation/licensing for these sour systems.
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Wang, K., C. Liu, X. Zheng, M. Pihlatie, B. Li, S. Haapanala, T. Vesala, et al. "Comparison between eddy covariance and automatic chamber techniques for measuring net ecosystem exchange of carbon dioxide in cotton and wheat fields." Biogeosciences 10, no. 11 (November 2, 2013): 6865–77. http://dx.doi.org/10.5194/bg-10-6865-2013.
Full textAbstract:
Abstract. Static and transparent automatic chamber (AC) technique is a necessary choice for measuring net ecosystem exchange (NEE) of carbon dioxide (CO2) in circumstances where eddy covariance (EC) technique is not applicable. However, a comparison of the two techniques for measurements on croplands has seldom been undertaken. We carried out NEE observations in a cotton field (for one year) and a winter wheat field (for one cropping season) using both AC and EC techniques, to (a) compare the NEE fluxes measured using each technique, and (b) test the NEE measurement performance of an automatic chamber system (AMEG), which was designed for simultaneous flux measurements of multiple gases. The half-hourly NEE fluxes measured with the two techniques were in approximate agreement, with the AC fluxes being 0.78 (cotton) and 1.06 (wheat) times the size of the EC fluxes. When integrated to daily timescale, the fluxes of the two techniques were in better agreement, showing an average ratio of 0.94 and 1.00 for the cotton and wheat, respectively. During the periods with comparable field conditions and normal performance of both instruments, the cumulative NEE fluxes revealed small differences between the two techniques (−9.0% ~ 7%, with a mean of 0.1%). The measurements resulted in an annual cumulative NEE of −40 g C m−2 yr−1 (EC) and −42 g C m−2 yr−1 (AC) in the cotton field, and a seasonal cumulative NEE of −251 g C m−2 (EC) and −205 g C m−2 (AC) in the wheat field. Our results indicate that, for cropland populated by short plants, the AMEG system and the data processing procedures applied in this study are able to provide NEE estimates comparable to those from EC measurements.
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Rajkumar, V., and R. Sundararajan. "Significance of Flyash in Producing Durable Eco-Friendly Concrete with Corrosion Inhibitor." Advanced Materials Research 347-353 (October 2011): 4069–73. http://dx.doi.org/10.4028/www.scientific.net/amr.347-353.4069.
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The production of Portland cement, the principal binder in concrete, is a major contributor for 6-8% of human generated green house gases that are involved in global warming and climate change. But when flyash, which is the residue from coal-fired power plants is used as partial replacement of cement in concrete, results in the reduction of environmental load and concrete production cost besides enhancing strength and protection of embedded steel in concrete from corrosive agents. This paper investigates the influence of 30% replacement of cement by flyash on the strength and corrosion resistive properties of concrete along with Triethanolamine as corrosion inhibiting admixture at the dosage of 1%, 2%, 3% and 4% by weight of cement. The specimens were tested for compressive strength, split tensile strength, flexural strength and bond strength. The resistance to corrosion is evaluated based on the performance of the concrete for the penetration of chloride ions by means of impressed current technique, half cell potential measurement and weight loss method. From the results obtained, it is found that flyash blended cement concrete increases the strength, reduces the permeability by the pozzolonic reaction, offers very good resistance against chemical attack and increases corrosion resistance with the addition of inhibitors.
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Khan, Bilal Ahmed, Longsheng Cheng, Aves A. Khan, and Haris Ahmed. "Healthcare waste management in Asian developing countries: A mini review." Waste Management & Research 37, no. 9 (July 3, 2019): 863–75. http://dx.doi.org/10.1177/0734242x19857470.
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Healthcare waste encompasses a significant quantity of hazardous substances. Poor healthcare waste management can result in serious environmental and human health risks. Asian developing countries are densely populated, and some are highly resource constrained. These countries commonly fail to practice appropriate healthcare waste management. Moreover, facilities in these countries extensively lack proper waste segregation, collection, safe storage, transportation, and disposal. This mini-review recapitulates key issues of healthcare waste management confronting Asian developing countries. Regulations, legislation, and policies are found to be recent, and their implementation varies from one another. Variation in waste generation rate is common. Contradictory methods of waste measurement used by researchers leave these variations questionable. The absence of waste management training programmes roots ignorance among staff and handlers, which leads to unsafe waste handling and causes different health risks. Unsafe and illegal recycling of hazardous waste is a threat to human health, also landfilling is often confused with open dumping, causing environmental damage. Outdated incineration plants need to be replaced with autoclaving, steam sterilisation, and comparatively reasonable new practice of pyrolysis to avoid the emission of toxic gases. The significance of proper healthcare waste management cannot be ignored, especially in Asian developing countries; substantial improvements are required in order to protect the environment and human health from serious risks.
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., Ohwofadjeke, and Paul Ogheneochuko. "TECHNO-ECONOMIC STUDY OF ELECTRICITY GENERATING POTENTIALS OF FLARED GASES IN KOKORI TOWN OF DELTA STATE, NIGERIA." International Journal of Engineering Applied Sciences and Technology 7, no. 4 (August 1, 2022): 233–38. http://dx.doi.org/10.33564/ijeast.2022.v07i04.037.
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According to the Department of Petroleum resource (DPR) in its 2018 annual report, 11% of total gas production in Nigeria was flared that year, which translate into about 88.06 BSCF (billions standard cubic feet) of gases that could have been delivered to power plants. This work aims to study the economic benefits of utilizing flared gases for power generation in Nigeria using Kokori Island in Delta State as a case study. Data such as flare volumes and gas turbines fuel consumption were obtained from July to December 2018. The research work was carried out using a five steps methodology which include; Intensive literature review, Site visits, Data collection, Data classification and analysis using payback period. Primary data used were collected through direct measurement of related parameters, The following findings were made; (1)That about 86 % ($5, 002, 391.844) of the total annual operating and maintenance cost goes into purchasing of natural gas for fuelling the turbines to generate electricity, (2) That the average daily gas flaring volume is about 7.2 mmscf/d (Million Standard Cubic Feet per Day) which translates into about 2,625 million mmscf per year, (3) Hitachi H25 gas turbine generator requires about 3.5657 mmscf of natural gas per day to generate 22.9 Mega Watts of electricity which translates into about 1,301 mmscf per year. The following are the recommendations;(1) That the federal government through its Department of Petroleum resource (DPR) should enforce a total ban on gas flaring in Nigeria, (2) That the federal government of Nigeria should decentralize electricity generation and distribution to encourage more investors through a competitive market system, (3) That more indigenous engineers and scientists should undertake researches in electricity generation, transmission and distribution so as to make the commodity available and affordable to Nigerian citizens in the nearest future.
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Aaltonen, H., J. Pumpanen, H. Hakola, T. Vesala, S. Rasmus, and J. Bäck. "Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest." Biogeosciences Discussions 9, no. 1 (January 16, 2012): 527–55. http://dx.doi.org/10.5194/bgd-9-527-2012.
Full textAbstract:
Abstract. Soil forms an important source for volatile organic compounds (VOCs), but in boreal forests these fluxes and their seasonal variations have not been characterized in detail, especially wintertime fluxes, which are almost completely unstudied. In this study, we measured the VOC concentrations inside a snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m−3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from the soil surface towards the snow surface, suggesting soil as being the source for terpenoids. Forest damages resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are also active and efficient VOC sources during winter and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, basically plants, have lower activity.
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Aaltonen, H., J. Pumpanen, H. Hakola, T. Vesala, S. Rasmus, and J. Bäck. "Snowpack concentrations and estimated fluxes of volatile organic compounds in a boreal forest." Biogeosciences 9, no. 6 (June 7, 2012): 2033–44. http://dx.doi.org/10.5194/bg-9-2033-2012.
Full textAbstract:
Abstract. Soil provides an important source of volatile organic compounds (VOCs) to atmosphere, but in boreal forests these fluxes and their seasonal variations have not been characterized in detail. Especially wintertime fluxes are almost completely unstudied. In this study, we measured the VOC concentrations inside the snowpack in a boreal Scots pine (Pinus sylvestris L.) forest in southern Finland, using adsorbent tubes and air samplers installed permanently in the snow profile. Based on the VOC concentrations at three heights inside the snowpack, we estimated the fluxes of these gases. We measured 20 VOCs from the snowpack, monoterpenes being the most abundant group with concentrations varying from 0.11 to 16 μg m−3. Sesquiterpenes and oxygen-containing monoterpenes were also detected. Inside the pristine snowpack, the concentrations of terpenoids decreased from soil surface towards the surface of the snow, suggesting soil as the source for terpenoids. Forest damages (i.e. broken treetops and branches, fallen trees) resulting from heavy snow loading during the measurement period increased the terpenoid concentrations dramatically, especially in the upper part of the snowpack. The results show that soil processes are active and efficient VOC sources also during winter, and that natural or human disturbance can increase forest floor VOC concentrations substantially. Our results stress the importance of soil as a source of VOCs during the season when other biological sources, such as plants, have lower activity.
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Hofman, Paul, Eric May, Guillaume Watson, Brendan Graham, and Mark Trebble. "Dynamic column breakthrough measurements for increasing LNG production efficiency with cryogenic pressure swing adsorption." APPEA Journal 50, no. 2 (2010): 738. http://dx.doi.org/10.1071/aj09102.
Full textAbstract:
The use of natural gas as a primary energy source is rapidly increasing on a global scale. To economically transport natural gas over long distances and satisfy this increase in demand, efficient production of liquefied natural gas (LNG) is required. Prior to the liquefaction of natural gas to produce LNG, it is highly desirable to remove N2 and CO2 impurities from the reservoir feed gas. Typically, CO2 is removed using a water-based amine solution. The regeneration of this amine solution is both energy intensive and costly. Furthermore, the amine solutions used are undesirable from health and environmental standpoints. Nitrogen is generally not removed prior to the liquefaction and must be separated from the end-flash vapor produced with the LNG. Conventionally this requires the construction of distillation towers operating at cryogenic conditions. In the environment of a cryogenic gas plant, adsorption-based processes for separating gases have several natural advantages over other methods. However, very little work has been done studying the efficiency of adsorption processes at the pressures and temperatures found in LNG plants. We have constructed a dynamic column breakthrough apparatus capable of measuring equilibrium adsorption and kinetics of adsorption at temperatures between 190 and 298 K and pressures to 1 MPa. This system was used to study the adsorption behaviour of N2, CO2 and CH4 on carbon molecular sieves and zeolites. This presentation will describe the measurement results and the challenges that were overcome as well as future plans to construct a larger scale apparatus.
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Oliveira, Bárbara Cristina Santos de, Alessandro Carioca de Araújo, Carlos Alberto Dias Pinto, Cleo Marcelo de Araújo Souza, Alailson Venceslau Santiago, and Ivanildo Alves Trindade. "Characterization of seasonal variation of atmospheric CO2 in the iLPF system in eastern Amazonia." Ciência e Natura 40 (March 22, 2018): 181. http://dx.doi.org/10.5902/2179460x30756.
Full textAbstract:
In the face of the human impacts caused mainly after Industrial Revolution, such as the burning of fossil fuels, deforestation and intensive soil preparation, there has been an increase in the emission of greenhouse gases (GHG). Among the forms of GHG mitigation, there are those carried out through agriculture, such as the adequate management of the soil and the removal of CO2 by plants through the consortium systems. Studies indicate that a viable alternative is the crop-livestock integration (CLI), which is composed of tree and forage species. Measurement of the atmospheric CO2 concentration ([CO2]) in CLI may indicate responses that will serve as a basis for monitoring this ecosystem in the Amazon region. Measures of the vertical profile of [CO2] were obtained in intensive campaigns during the periods less rainy of 2016, more and less rainy of 2017, in the municipality of Terra Alta, PA. There was greater amplitude in the [CO2] measured in the less rainy period of 2017 and higher daytime concentrations in relation to the other periods. Seasonality is a factor that influences [CO2] in the CLI. The [CO2] only begins to rise and accumulate below the canopy from 20:00 hours, when the atmosphere is more stable.
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Warneke, Carsten, Michael Trainer, Joost A. de Gouw, David D. Parrish, David W. Fahey, A. R. Ravishankara, Ann M. Middlebrook, et al. "Instrumentation and measurement strategy for the NOAA SENEX aircraft campaign as part of the Southeast Atmosphere Study 2013." Atmospheric Measurement Techniques 9, no. 7 (July 18, 2016): 3063–93. http://dx.doi.org/10.5194/amt-9-3063-2016.
Full textAbstract:
Abstract. Natural emissions of ozone-and-aerosol-precursor gases such as isoprene and monoterpenes are high in the southeastern US. In addition, anthropogenic emissions are significant in the southeastern US and summertime photochemistry is rapid. The NOAA-led SENEX (Southeast Nexus) aircraft campaign was one of the major components of the Southeast Atmosphere Study (SAS) and was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. Here we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign. The aircraft, its capabilities and standard measurements are described. The instrument payload is summarized including detection limits, accuracy, precision and time resolutions for all gas-and-aerosol phase instruments. The inter-comparisons of compounds measured with multiple instruments on the NOAA WP-3D are presented and were all within the stated uncertainties, except two of the three NO2 measurements. The SENEX flights included day- and nighttime flights in the southeastern US as well as flights over areas with intense shale gas extraction (Marcellus, Fayetteville and Haynesville shale). We present one example flight on 16 June 2013, which was a daytime flight over the Atlanta region, where several crosswind transects of plumes from the city and nearby point sources, such as power plants, paper mills and landfills, were flown. The area around Atlanta has large biogenic isoprene emissions, which provided an excellent case for studying the interactions between biogenic and anthropogenic emissions. In this example flight, chemistry in and outside the Atlanta plumes was observed for several hours after emission. The analysis of this flight showcases the strategies implemented to answer some of the main SENEX science questions.
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Wang, K., C. Liu, X. Zheng, M. Pihlatie, B. Li, S. Haapanala, T. Vesala, et al. "Comparison between eddy covariance and automatic chamber techniques for measuring net ecosystem exchange of carbon dioxide in cotton and wheat fields." Biogeosciences Discussions 10, no. 5 (May 22, 2013): 8467–503. http://dx.doi.org/10.5194/bgd-10-8467-2013.
Full textAbstract:
Abstract. Static and transparent automatic chamber (AC) technique is a~necessary choice for measuring net ecosystem exchange (NEE) of carbon dioxide (CO2) in circumstances where eddy covariance (EC) technique is not applicable. However, a comparison of the two techniques for measurements on croplands has seldom been undertaken. We carried out NEE observations in a cotton field (for one year) and a winter wheat field (for one cropping season) using both AC and EC techniques, to (a) compare the NEE fluxes measured using each technique, and (b) test the NEE measurement performance of an automatic chamber system (AMEG), which was designed for simultaneous flux measurements of multiple gases. The half-hourly NEE fluxes measured with the two techniques were in approximate agreement, with the AC fluxes being 0.78 (cotton) and 1.06 (wheat) times those of the EC. When integrated to daily timescale, the fluxes of the two techniques were in better agreement, showing an average ratio of 0.94 and 1.00 for the cotton and wheat, respectively. During the periods with comparable field conditions and normal performance of both instruments, the cumulative NEE fluxes revealed small differences between the two techniques (–9.0 ~ 6.7%, with a mean of 0.1%). The measurements resulted in annual cumulative NEE of –40 g C m–2 yr–1 (EC) and –42 g C m–2 yr–1 (AC) in the cotton field and seasonal cumulative NEE of –251 g C m–2 (EC) and –205 g C m–2 (AC) in the wheat field. Our results indicate that, for cropland populated by short plants, the AMEG system and the data processing procedures applied in this study are able to provide NEE estimates comparable to those from EC measurements, although either technique may lead to an overestimation of the loss rate (or underestimation of the gain rate) of the soil organic carbon stock of an ecosystem, in particular with calcareous soils exposed to increasing atmospheric acid deposition.
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Zhao, Y., B. F. Wu, and Y. Zeng. "Spatial and temporal patterns of greenhouse gas emissions from Three Gorges Reservoir of China." Biogeosciences 10, no. 2 (February 26, 2013): 1219–30. http://dx.doi.org/10.5194/bg-10-1219-2013.
Full textAbstract:
Abstract. Anthropogenic activity has led to significant emissions of greenhouse gas (GHG), which is thought to play important roles in global climate changes. It remains unclear about the kinetics of GHG emissions, including carbon dioxide (CO2), methane (CH4) and nitrous Oxide (N2O) from the Three Gorges Reservoir (TGR) of China, which was formed after the construction of the famous Three Gorges Dam. Here we report monthly measurements for one year of the fluxes of these gases at multiple sites within the TGR region, including three major tributaries, six mainstream sites, two downstream sites and one upstream site. The tributary areas have lower CO2 fluxes than the main storage; CH4 fluxes in the tributaries and upper reach mainstream sites are relative higher. Overall, TGR showed significantly lower CH4 emission rates than most new reservoirs in temperate and tropical regions. We attribute this to the well-oxygenated deep water and high water velocities that may facilitate the consumption of CH4. TGR's CO2 fluxes were lower than most tropical reservoirs and higher than most temperate systems. This could be explained by the high load of labile soil carbon delivered through erosion to the Yangtze River. Compared to fossil-fuelled power plants of equivalent power output, TGR is a very small GHG emitter – annual CO2-equivalent emissions are approximately 1.7% of that of a coal-fired generating plant of comparable power output.
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Sandhu, Shahbeg S., and W. R. Lower. "In Situ Assessment of Genotoxic Hazards of Environmental Pollution." Toxicology and Industrial Health 5, no. 1 (January 1989): 73–83. http://dx.doi.org/10.1177/074823378900500107.
Full textAbstract:
The potential impact of the environmental pollutants on human health can be evaluated by the laboratory analysis of the environmental samples or by the measurement of the biological effects on indigenous populations and/or specific test organisms placed in the environment to be monitored. A canary in a cage, used by 19th century miners as a biological indicator for rising levels of toxic gases, is a classical example of in situ hazard identification. The induced toxic effects are often the result of synergistic and antagonistic interactions among various physical and chemical factors that are difficult to reproduce in the laboratory. Therefore, conceivably the biological effects measured on or near the impacted site have greater relevancy for hazard assessment to man than from the data derived from the environmental samples analyzed in the lab. The organisms most commonly employed for the assessment of mutagenicity under real-world conditions are: (1) flowering plants, (2) wild and captive mammals, and (3) aquatic vertebrates. Plant species such as Tradescantia paludosa, Zea mays, and Osmunda regalis have been used for monitoring ambient air quality around several major industrial cities in the U.S.A., nuclear power plants, and industrial waste sites, and also for the assessment of potential health effects of municipal sewage sludges. Domestic animals such as dogs can be used as sentinels to provide information on the effects of contaminants in the environment and have been used to a limited extent to evaluate the environmental influences on the occurrence of breast cancer and osteosarcoma. Cytogenetic analysis from feral and wild animals has been employed for assessing the health hazards and prioritizing the clean-up efforts at hazardous waste sites. Aquatic animals have been used more often than terrestrial animals or plants to identify and characterize the genotoxic effects of environmental pollution. Since 1970, a number of studies has been reported on the mutagenic and neoplastic effects on aquatic animals from coastal areas and continental rivers, lakes, and ponds. The limitations of in situ environmental assessment are lack of control over the physical environmental components, inherent variability and interactions of test organisms, lack of control of exposure doses, and difficulty of finding concurrent experimental controls. Nevertheless, flowering plants, terrestrial, and aquatic animals may serve as useful sentinels and biomarkers of environmental pollution.
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Cignini, Fabio, Antonino Genovese, Fernando Ortenzi, Stefano Valentini, and Alberto Caprioli. "Performance and Emissions Comparison between Biomethane and Natural Gas Fuel in Passenger Vehicles: results of the third testing campaign." Journal of Physics: Conference Series 2385, no. 1 (December 1, 2022): 012061. http://dx.doi.org/10.1088/1742-6596/2385/1/012061.
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Abstract This paper shows the results of the third (and last) campaign in the BiomethER project (EU-LIFE). It aimed to achieve two newest bio-methane production plants in the Emilia Romagna region (Italy). This manuscript reports the measurements of emission and performance for the vehicles tested, as widely described in the previous papers. So, three passenger cars are fuelled with conventional natural gas and bio-methane from a BiomethER plant. The emissions and performances on the chassis dynamometer for each vehicle have been measured. Inspecting the combustion chambers of the engines allows for evaluating their wear condition. This campaign confirms the results achieved in the previous two campaigns; there are no appreciable deviations for fuel consumption, greenhouse gas and other pollutant emissions between the two gases. The inspection reveals that biomethane reduces the carbon deposits in combustion chambers compared to natural gas in national infrastructure.
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Kamal Mahmood, Abdulkhaleq, and Ali Abdulkhaleq Kamal. "Study and evaluation the air pollution around the thermal power plant of Zebadiah city, Wassit province, Iraq." International Journal of Engineering & Technology 7, no. 4 (September 24, 2018): 2494. http://dx.doi.org/10.14419/ijet.v7i2.18.12162.
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This study focused on gaseous pollution caused by exhaust gas from AL-Zubaydiah thermal power plant. Study gases included sulfur dioxide (SO2), nitrogen oxide (NO), carbon oxide (CO) and hydrocarbon (HC). The concentration of gas measurement is conducted during six months from January until June 2017. Nova 600 series portable devise and G450 confined space gas detector was used for measuring gas concentration, which emitted from the chimney of the thermal power station with an interval of 100m and into the path of smoke for a distance of 1400 m. The prevailing wind direction and temperature were taken into consideration during the study and their impact on the gas distribution. Four readings have been taken in each station during each month for all gases under study. The results showed that less gas concentrations were near the power station and then getting more gas concentration away from the station and higher concentrations are obtained at a distance of 900 m from the power station at ground level. Results indicated that sulfur dioxide concentrations recorded were higher than allowed in the Iraqi and American standards in most locations around the station. The highest concentration recorded at 900 m from the power station with value 597.3968 μg/m3, which is higher than the limitation of Iraqi and international specifications (150 μg/m3). This high concentration of SO2 is due to the crude oil from the Ahdab field with high rates of Sulphur that used as fuel in the generation process. These high concentrations of sulfur dioxide cause problems on the growth of plants and human health and viability of the soil in the coming years. Nitrogen oxide gas concentrations also were high and outside the upper limits allowed and were worth 131.38 μg/m3. The rest of the gas concentration (CO and HC) were acceptable and within the Iraqi standard. To preserve the environment in the region and within the limits of the allowed values globally requires a search for another source of fuel with a low percentage of sulfur and using modern technology for burning to reduce emissions of nitrogen oxides.
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Vernooij, Roland, Ulrike Dusek, Maria Elena Popa, Peng Yao, Anupam Shaikat, Chenxi Qiu, Patrik Winiger, et al. "Stable carbon isotopic composition of biomass burning emissions – implications for estimating the contribution of C<sub>3</sub> and C<sub>4</sub> plants." Atmospheric Chemistry and Physics 22, no. 4 (March 3, 2022): 2871–90. http://dx.doi.org/10.5194/acp-22-2871-2022.
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Abstract. Landscape fires are a significant contributor to atmospheric burdens of greenhouse gases and aerosols. Although many studies have looked at biomass burning products and their fate in the atmosphere, estimating and tracing atmospheric pollution from landscape fires based on atmospheric measurements are challenging due to the large variability in fuel composition and burning conditions. Stable carbon isotopes in biomass burning (BB) emissions can be used to trace the contribution of C3 plants (e.g. trees or shrubs) and C4 plants (e.g. savanna grasses) to various combustion products. However, there are still many uncertainties regarding changes in isotopic composition (also known as fractionation) of the emitted carbon compared to the burnt fuel during the pyrolysis and combustion processes. To study BB isotope fractionation, we performed a series of laboratory fire experiments in which we burned pure C3 and C4 plants as well as mixtures of the two. Using isotope ratio mass spectrometry (IRMS), we measured stable carbon isotope signatures in the pre-fire fuels and post-fire residual char, as well as in the CO2, CO, CH4, organic carbon (OC), and elemental carbon (EC) emissions, which together constitute over 98 % of the post-fire carbon. Our laboratory tests indicated substantial isotopic fractionation in combustion products compared to the fuel, which varied between the measured fire products. CO2, EC, and residual char were the most reliable tracers of the fuel 13C signature. CO in particular showed a distinct dependence on burning conditions; flaming emissions were enriched in 13C compared to smouldering combustion emissions. For CH4 and OC, the fractionation was the other way round for C3 emissions (13C-enriched) and C4 emissions (13C-depleted). This indicates that while it is possible to distinguish between fires that were dominated by either C3 or C4 fuels using these tracers, it is more complicated to quantify their relative contribution to a mixed-fuel fire based on the δ13C signature of emissions. Besides laboratory experiments, we sampled gases and carbonaceous aerosols from prescribed fires in the Niassa Special Reserve (NSR) in Mozambique, using an unmanned aerial system (UAS)-mounted sampling set-up. We also provided a range of C3:C4 contributions to the fuel and measured the fuel isotopic signatures. While both OC and EC were useful tracers of the C3-to-C4 fuel ratio in mixed fires in the lab, we found particularly OC to be depleted compared to the calculated fuel signal in the field experiments. This suggests that either our fuel measurements were incomprehensive and underestimated the C3:C4 ratio in the field or other processes caused this depletion. Although additional field measurements are needed, our results indicate that C3-vs.-C4 source ratio estimation is possible with most BB products, albeit with varying uncertainty ranges.
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Kunt, Fatma, and Şükran Erdoğan. "Evaluation of Outdoor Environment PM10 Concentration in an Organized Industrial Zone Using Geographical Information System." Atmosphere 13, no. 11 (November 17, 2022): 1918. http://dx.doi.org/10.3390/atmos13111918.
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Air pollution adversely affects human health, visibility distance, materials, plants and animal health. Air pollution’s impact on human health arises from inhaling high amounts of harmful substances in the atmosphere. Notably, our understanding of the damage caused by PM10 pollutants is improving daily. This study aims to measure and analyze PM10 pollution in the Konya Organized Industrial Zone at certain times and places. Measurements were taken at twenty-four locations in the morning, noon and evening hours. The results were compared with the Turkish Air Quality Assessment and Management Regulation, and pollution maps of the regions were created with Surfer Software and ArcGIS 10.1 programs. With the measurements, it was observed that the times at which the limit was exceeded were mainly the evening hours. While no limit exceedance was recorded in the morning hours, the average concentration value was observed once in those hours, and around noon the maximum value was observed five times. In this study, we correlated the measurement results, the values of the measurement points located in the city center and the average number of vehicles passing through the region. It was observed that the PM10 -induced air pollution in the Konya Organized Industrial Zone was caused by dense traffic during evening hours. To prevent traffic-related pollution in the region, it is recommended to increase the number of entrance and exit gates in the industrial zone and to plant trees in appropriate sections.
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Holmes, R. I. "Mitigating Ventilation Air Methane Cost-Effectively from a Colliery in Australia." Journal of Applied Engineering Sciences 6, no. 1 (May 1, 2016): 41–50. http://dx.doi.org/10.1515/jaes-2016-0005.
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Abstract Methane has been controlled in collieries in the past only for safety and statutory compliance reasons; however concerns over greenhouse gas emissions mean that this is now changing. About 65% of greenhouse emissions associated with underground coal mining come from ventilation air methane (VAM). The machinery to mitigate these fugitive emissions once the VAM exits the mine fans is expensive, has safety concerns and is not widely used at present. Consider these factors; more collieries are mining lower seams, methane content increases with depth, VAM mitigation plants are not widely used, most mine emissions are VAM, and widespread concern over greenhouse gases mean that it is desirable to lower VAM emissions now. One solution would be a method to prevent more methane from entering the mine airstream and becoming VAM in the first place. Recently, in a colliery in the Hunter Valley, this mitigation method underwent a 12-month trial, and involved six different measures. Measurements were taken to assess the emissions mitigation which was achieved, and the cost of the works; all the results are detailed herein. A reduction in fugitive emissions of 80,307 t/CO2-e below that which was projected for the next 12-month period was quantified, at an average cost of A$1.28c t/CO2-e. The mitigation measure outlined here represent a first attempt to the author’s knowledge, in an operating mine, to lower a collieries’ environmental footprint by preventing methane from entering the mine airstream and becoming VAM gas by the deliberate use of mitigation measures.
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Буланин, В., and V. Bulanin. "METHOD OF ANALYSIS OF ENERGY POTENTIAL OF THERMAL ENERGY SOURCE FOR HEAT SUPPLY." Bulletin of Belgorod State Technological University named after. V. G. Shukhov 4, no. 10 (November 7, 2019): 74–83. http://dx.doi.org/10.34031/article_5db3dec6d4a347.72433966.
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The main sources of thermal energy for the heat supply of cities and settlements are fuel-based thermal power plants and boilers. The article provides an analysis of the energy balance of a power plant in connection with the need to minimize the cost of fuel and electricity for heat supply. New analytical expressions comprehensively characterizing the efficiency of a power plant are developed. The analytical assessment of the impact of energy costs for the boiler needs on the energy balance of thermal power plant is made; methods for constructing schemes of the energy balance of thermal power plant and assessment of fuel efficiency in the boiler are designed. Attention is paid to errors arising from the use of the calculated values of air suction in the gas path of the boiler, and not the actual ones. Therefore, it is proposed to change the method of measuring heat loss with flue gases in order to eliminate or reduce the effect of air suction on the measurement results, taking into account the part of the flue gas heat received by the air in the air heater and returned to the boiler through the burner. The methods increasing accuracy of calculations of energy efficiency of the technological processes which are key in the centralized heat supply of the cities and settlements are developed.
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Thieringer, Julia R. D., Julia Szabadi, Jörg Meyer, and Achim Dittler. "Impact of Residential Real-World Wood Stove Operation on Air Quality concerning PM2.5 Immission." Processes 10, no. 3 (March 11, 2022): 545. http://dx.doi.org/10.3390/pr10030545.
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In Germany, the number of small wood-burning combustion plants was around 11 million in 2020. The PM2.5 immissions caused by the operation of these combustion plants are already about as high as those from traffic exhaust gases. Thus, particulate matter immissions occur not only on busy roads but also in residential areas. Since there are few official measuring stations for PM2.5 in residential areas and suburbs, this study determined PM2.5 concentrations from November 2020 to June 2021 at three stations (urban, suburban, and residential) in the Karlsruhe area. Simultaneous measurements of PM2.5 at the three locations have been implemented to determine short-term (peaks), medium-term, and long-term particulate matter levels and to assign them to sources by observation, considering wind direction. Illustratively, PM2.5 immission levels in January and May 2021 were compared in this paper. The comparison of the particulate matter immissions measured in the urban and residential area in January revealed that PM2.5 concentration peaks of up to 60 µg/m3 occurred for short periods in the residential area, especially on Fridays and in the evenings, which could be assigned to wood stove operation. In the urban and suburban areas, the number of the immission peaks was lower by 70–80%, and the peak concentrations were also lower by an average of 13–18%. However, the high short-term peaks have no significant impact when calculating the PM2.5 annual average according to the current limit value regulation (39. BImSchV).
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Vasconez Barrera, Fabian, and Fernando Molina Granja. "Diseño de un sistema de control gerencial de plantas avícolas utilizando redes de sensores inalámbricos con tecnología Open Hardware / Design of a management control system for poultry plants using wireless sensor networks with Open Hardware technology." Ciencia Unemi 9, no. 21 (May 10, 2017): 143. http://dx.doi.org/10.29076/issn.2528-7737vol9iss21.2016pp143-156p.
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Se presenta el diseño del control automatizado de una planta avícola utilizando tecnología Open Hardware Arduino y cómo fue implementado en la Planta Académica Avícola de la Facultad de Ciencias Pecuarias de la Escuela Superior Politécnica de Chimborazo, Ecuador, además, de qué manera se acopla una tarjeta microcontroladora a otra diseñada para la conexión de los sensores y actuadores. Los sensores se seleccionaron en base a las características técnicas del proceso de crianza de pollos de engorde, utilizados para medir temperatura, humedad, intensidad de luz, amoníaco, monóxido de carbono y gases inflamables. Según el presente estudio, este módulo debe colocarse a una altura entre 0,80 y 1,5 m. y fuera de influencia directa de calefactores o ventiladores, de esta forma, se optimiza el envío de mediciones de manera inalámbrica, utilizando protocolo ZigBee a un computador que, mediante software desarrollado, las compara con parámetros considerados normales. También se desarrolló una aplicación web e implementó, para el monitoreo y control desde cualquier lugar. Utilizando este sistema se obtuvo una tasa de mortalidad de 0,2% y promedios de ganancia de peso superiores a 2600 g., lo que justifica el proyecto y es una opción a considerar por las avícolas, debido al ahorro de recursos obtenido. ABSTRACTThe design of the automated control of a poultry plant using Open Hardware Arduino technology and how it was implemented in the Poultry Academic Plant of the Faculty of Animal Sciences of the Polytechnic School of Chimborazo, Ecuador is presented. Microcontroller to another designed for the connection of sensors and actuators is also illustrated. The sensors were selected based on the technical characteristics of broilers breeding process, used to measure temperature, humidity, light intensity, ammonia, carbon monoxide and flammable gases. According to the present study, this module should be placed at a height between 0.80 and 1.5 m. and out of direct influence of heaters or fans, this way; it is optimized to send measurements wirelessly, using ZigBee protocol to a computer that, using developed software, compares them with parameters considered normal. It was also developed a web application and implemented, for monitoring and control from anywhere. Using this system, a mortality rate of 0.2% and weight gain averages above 2600 g were obtained, which justifies the project and is an option to be considered by poultry, due to the savings of resources obtained.
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Gerilowski, K., A. Tretner, T. Krings, M. Buchwitz, P. P. Bertagnolio, F. Belemezov, J. Erzinger, J. P. Burrows, and H. Bovensmann. "MAMAP – a new spectrometer system for column-averaged methane and carbon dioxide observations from aircraft: instrument description and performance assessment." Atmospheric Measurement Techniques Discussions 3, no. 4 (August 2, 2010): 3199–276. http://dx.doi.org/10.5194/amtd-3-3199-2010.
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Abstract. Carbon dioxide (CO2) and Methane (CH4) are the two most important anthropogenic greenhouse gases. CH4 is furthermore one of the most potent present and future contributors to global warming because of its large global warming potential (GWP). Our knowledge of CH4 sources and sinks is based primarily on sparse in-situ local point measurements from micro sites and surface networks and more recently on low spatial resolution satellite observations. There is a need for measurements of the dry columns of CO2 and CH4 having high spatial resolution and spatial coverage. In order to fill this gap a new passive airborne 2-channel grating spectrometer instrument for remote sensing of small scale and mesoscale column-averaged CH4 and CO2 observations has been developed. This Methane Airborne MAPper (MAMAP) instrument measures reflected and scattered solar radiation in the short wave infrared (SWIR) and near-infrared (NIR) parts of the electro-magnetic spectrum at moderate spectral resolution. The SWIR channel yields measurements of atmospheric absorption bands of CH4 and CO2 in the spectral range between 1.59 and 1.69 μm at a spectral resolution of 0.82 nm. The NIR channel around 0.76 μm measures the atmospheric O2-A-band absorption with a resolution of 0.46 nm. MAMAP has been designed for flexible operation aboard a variety of airborne platforms. The instrument design and performance, together with some results from on-ground and in-flight engineering tests are presented. The instrument performance has been analyzed using a retrieval algorithm applied to the SWIR channel nadir measured spectra. The signal-to-noise ratio (SNR) of the SWIR channel is approximately 1000 for integration times (tint) in the range of 0.6–0.8 s for scenes with surface spectral reflectances of around 0.18. At these integration times the ground scene size is about 23×33 m2 for an aircraft altitude of 1 km and a ground speed of 200 km/h. For these scenes the CH4 and CO2 column retrieval precisions are typically about 1% (1 σ). Elevated levels of CH4 have been retrieved above a CH4 emitting landfill. Similarly the plume of CO2 from coal-fired power plants can be well detected and tracked. The measurements by the MAMAP sensor enable estimates of anthropogenic, biogenic and geological emissions of localized intense CH4 and CO2 sources such as anthropogenic fugitive emissions from gas industry and waste, emissions from coal-fired power plants or geologic emissions from seepage and volcanoes. Appropriate analysis of the measurements of MAMAP potentially also yields CH4 emissions from less intense but extensive sources such as wetlands.
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Zanke, Ulrich, Aron Roland, and Andreas Wurpts. "Roughness Effects of Subaquaeous Ripples and Dunes." Water 14, no. 13 (June 24, 2022): 2024. http://dx.doi.org/10.3390/w14132024.
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Numerous questions and problems on Earth and questions with respect to other planets arise from morphodynamic processes caused by sediment movements driven by flows of fluids, such as water, air and other gases. A sediment surface opposes the current with a resistance that is determined by its skin or grain roughness. As soon as sand waves, such as ripples and/or dunes, are formed, these bedforms cause a further resistance to the flow, the so-called form roughness. Dependent on the dimensions of the ripples and dunes, the form roughness can be much more pronounced than the skin roughness. The relevant literature provides a large number of solution approaches based on different basic ideas and different result quality. The aim of this paper is a comparative analysis of solution approaches from the literature. For this purpose, 14 approaches to bedform-related friction in the subaqueous case are evaluated using 637 measurements from laboratory and natural settings. We found that all approaches were significantly more accurate for ripples than for dunes. Since this was equally the case for all approaches tested, it is reasonable to assume that this is caused by measurement inaccuracies for dunes in the natural case rather than due to the approaches themselves. The approach of Engelund 1977 proved to be most accurate among all approaches investigated here. It is based on the Borda–Carnot formulation and an additional empirical term. An analytical derivation and justification is provided for this additional term.
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Pelić, Vladimir, Tomislav Mrakovčić, Ozren Bukovac, and Marko Valčić. "Development and Validation of 4 Stroke Marine Diesel Engine Numerical Model." Journal of Maritime & Transportation Science 3, no. 3 (June 2020): 359–72. http://dx.doi.org/10.18048/2020.00.27.
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Increasing demands on energy efficiency and environmental acceptance are being imposed on marine propulsion plants. The fulfilment of the conditions set by the MARPOL Convention, Annex VI, regarding the emissions from exhaust gases of marine diesel engines is of particular interest. This paper presents the development and validation of a zero-dimensional, single-zone diesel engine numerical model. Presented numerical model is based on the law of conservation of energy and mass and solving the resulting differential equations. The single-zone model will serve as the basis for a model where the cylinder space is divided into two or three zones during combustion. In this way, the multi-zone model will allow the modelling of nitrogen oxide emissions with satisfactory accuracy. Validation of the diesel engine model was carried out for the Wärtsilä 12V50DF 11700 kW motor designed to drive a synchronous alternator. Obtained results and deviations of certain parameters in the operation of the engine with respect to the data obtained from the measurements on the test bed, are more than satisfactory regarding complexity of the numerical model. This confirmed the usability of the model for research purposes to optimize the marine diesel engine.
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Heckel, A., S. W. Kim, G. J. Frost, A. Richter, M. Trainer, and J. P. Burrows. "Influence of under-sampled a priori data on tropospheric NO<sub>2</sub> satellite retrievals." Atmospheric Measurement Techniques Discussions 4, no. 2 (March 18, 2011): 1893–934. http://dx.doi.org/10.5194/amtd-4-1893-2011.
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Abstract. The retrieval of tropospheric columns of NO2 and other trace gases from satellite observations of backscattered solar radiation relies on the use of accurate a priori information. The spatial resolution of current space sensors is often significantly higher than that of the a priori datasets used, introducing uncertainties from spatial misrepresentation. In this study, the effect of spatial under-sampling of a priori data on the retrieval of NO2 columns was studied for a typical coastal area (around San Francisco). High-resolution (15 × 15 km2) NO2 a priori data from the WRF-Chem model in combination with high-resolution MODIS surface reflectance and aerosol data were used to investigate the uncertainty introduced by applying a priori data at typical global chemical transport model resolution. The results show that the relative uncertainties can be large (more than a factor of 2) for individual measurements, mainly due to spatial variations in NO2 profile and surface albedo, with smaller contributions from aerosols and surface height changes. Similar sensitivities are expected for other coastal regions and localised sources such as power plants, highlighting the need for high-resolution a priori data in quantitative analysis of the spatial patterns retrieved from satellite observations of tropospheric pollution.
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Heckel, A., S. W. Kim, G. J. Frost, A. Richter, M. Trainer, and J. P. Burrows. "Influence of low spatial resolution a priori data on tropospheric NO<sub>2</sub> satellite retrievals." Atmospheric Measurement Techniques 4, no. 9 (September 9, 2011): 1805–20. http://dx.doi.org/10.5194/amt-4-1805-2011.
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Abstract. The retrieval of tropospheric columns of NO2 and other trace gases from satellite observations of backscattered solar radiation relies on the use of accurate a priori information. The spatial resolution of current space sensors is often significantly higher than that of the a priori datasets used, introducing uncertainties from spatial misrepresentation. In this study, the effect of spatial under-sampling of a priori data on the retrieval of NO2 columns was studied for a typical coastal area (around San Francisco). High-resolution (15 × 15 km2) NO2 a priori data from the WRF-Chem model in combination with high-resolution MODIS surface reflectance and aerosol data were used to investigate the uncertainty introduced by applying a priori data at typical global chemical transport model resolution. The results show that the relative uncertainties can be large (more than a factor of 2 if all a priori data used is at the coarsest resolution) for individual measurements, mainly due to spatial variations in NO2 profile and surface albedo, with smaller contributions from aerosols and surface height changes. Similar sensitivities are expected for other coastal regions and localised sources such as power plants, highlighting the need for high-resolution a priori data in quantitative analysis of the spatial patterns retrieved from satellite observations of tropospheric pollution.
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Qin, Jiayao, Xiuying Zhang, Linjing Zhang, Miaomiao Cheng, and Xuehe Lu. "Spatiotemporal Variations of XCH4 across China during 2003–2021 Based on Observations from Multiple Satellites." Atmosphere 13, no. 9 (August 25, 2022): 1362. http://dx.doi.org/10.3390/atmos13091362.
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Atmospheric methane (CH4) is an important greenhouse gas that can reflect variations of CH4 emissions and sinks. This study aimed to detect spatial and temporal variations of atmospheric CH4 concentrations in China during 2003–2021 based on CH4 column-averaged dry-air mole fraction (XCH4) products from three satellites, namely, Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY), Greenhouse Gases Observing Satellite (GOSAT), and Copernicus Sentinel-5 Precursor (S5P). The results revealed that XCH4 observed from three satellites showed high agreement in spatiotemporal variations and demonstrated good consistency with ground station measurements. The correlation coefficients (r) between the three satellites were 0.72 and 0.73, and the correlation coefficients for the ground stations were 0.79, 0.66, 0.03, 0.21, 0.70, and 0.80. The spatial distribution of XCH4 in China was generally high in the east and low in the west and close to that of CH4 emissions, indicating that CH4 emission sources dominated the spatial variations of atmospheric XCH4. From 2003 to 2006, XCH4 remained stable with an annual growth rate of 0.51 ppb·yr−1 and then abruptly increased with an overall growth rate of 6.96 ppb·yr−1. There were obvious seasonal changes in XCH4, with peaks in autumn and summer and nadir in winter and spring. These seasonal variations of XCH4 were related to CH4 emissions from rice planting. Rice cultivation areas generally had high XCH4 concentrations, and the growth cycle of rice plants significantly contributed to seasonal variations of XCH4 in the main rice planting areas. These results provide scientific data that could encourage decision-makers to enact policies and processes to reduce methane emissions.