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1
Theliander, Hans, and Urban Greiz. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 1, no. 3 (August 1, 1986): 32–40. http://dx.doi.org/10.3183/npprj-1986-01-03-p032-040.
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Theliander, Hans, and Urban Grén. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 1, no. 3 (August 1, 1986): 41–46. http://dx.doi.org/10.3183/npprj-1986-01-03-p041-046.
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Theliander, Hans, and Urban Grh. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 2, no. 3 (August 1, 1987): 101–8. http://dx.doi.org/10.3183/npprj-1987-02-03-p101-108.
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Theliander, Hans, and Urban Grén. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 2, no. 3 (August 1, 1987): 109–15. http://dx.doi.org/10.3183/npprj-1987-02-03-p109-115.
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Theliander, Hans. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 3, no. 2 (May 1, 1988): 60–67. http://dx.doi.org/10.3183/npprj-1988-03-02-p060-067.
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Theliander, Hans, and Oystein Aksnes. "A system analysis of the chemical recovery plant of the sulfate pulping process." Nordic Pulp & Paper Research Journal 4, no. 4 (December 1, 1989): 263–71. http://dx.doi.org/10.3183/npprj-1989-04-04-p263-271.
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He, Jie, and Bing Yue Liu. "Acid Extracting Pectin from Guangyechu White Bast and Subsequent Ammonium Sulfate Pulping." Advanced Materials Research 236-238 (May 2011): 1301–6. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1301.
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In this paper, the process of acid extracting pectin from Guangyechu white bast and subsequent ammonium sulfate pulping was optimized by condition test. Under optimal conditions, the pectin yield was 3.99%, the screened pulp yield was 52.61%, KMnO4 value was 9.84 and whiteness was 51.7%ISO. And chemical compositions of Guangyechu white bast in each treatment stage were compared and analyzed.
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Rintala, J., J. L. Sanz Martin, and G. Lettinga. "Thermophilic Anaerobic Treatment of Sulfate-Rich Pulp and Paper Integrate Process Water." Water Science and Technology 24, no. 3-4 (August 1, 1991): 149–60. http://dx.doi.org/10.2166/wst.1991.0471.
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Anaerobic treatment of sulfate - rich (COD/SO4 ratio 1.4-2.1) clarified Whitewater from a thermomechanical pulping (TMP) process was studied in three laboratory-scale upflow anaerobic sludge blanket (UASB) reactors at 55°C and in batch digesters at 55° and 65°C. Different seed materials were used in the UASB reactors. The highest COD removal efficiency (effluent sulfide stripped) achieved was approximately 65 % in the UASB reactors. About 55 % COD removal efficiency was obtained at a loading rate of about 41 kgCODm−3d−1 in the UASB reactor seeded with thermophilic sludge cultivated with volatile fatty acids (VFAs). The total sulfide present in the liquid phase after anaerobic treatment accounted for approximately 65-78 % and 15-61 % of the removed COD in the batch digesters and the UASB reactors, respectively. Sulfate reduction was almost complete in the batch digesters, whereas about 24-64 % of sulfate was reduced in the UASB reactors. Acetate utilization for sulfate reduction was apparent in the batch digesters, whereas that could not be demonstrated in the UASB reactors. Sulfate reduction in the UASB reactors was obviously substrate limited. In conclusion, thermophilic anaerobic treatment is an alternative for the treatment of warm sulfate rich TMP process water.
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Felissia, Fernando E., Maria C. Area, Olga M. Barboza, and Dora I. Bengoechea. "Anti-scaling agents in kraft pulping." BioResources 2, no. 2 (May 4, 2007): 252–64. http://dx.doi.org/10.15376/biores.2.2.252-264.
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Scale formation in the digester during kraft pulping represents a great problem in pulp mills. Scaling reduces pulping control and efficiency, increasing energy costs and leading to cleaning breakdowns, with subsequent losses in productivity. The kraft process promotes CaCO3 scaling due to high calcium ion and carbonate concentrations, as well as high alkalinity and temperature levels, which increase the speed with which liquors reach a state of supersaturation. This work examines the action of diethylene triamine penta(methylene phosphonic acid) (DTPMPA), either alone or combined with commercial anti-scaling agents, as an inhibitor of calcium carbonate precipitation in the kraft pulping of Pinus taeda. The theoretical amount of calcium deposited in the digester was obtained by mass balance. Soluble calcium was stable throughout cooking when using the phosphonates alone or combined with anti-scaling agents. When adding only DTPMPA, calcium stays in the pulp, rather than forming deposits.
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Qiu, Rongchu, J. F. Ferguson, and M. M. Benjamin. "Sequential Anaerobic and Aerobic Treatment of Kraft Pulping Wastes." Water Science and Technology 20, no. 1 (January 1, 1988): 107–20. http://dx.doi.org/10.2166/wst.1988.0014.
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A study of sequential anaerobic and aerobic treatment was conducted with combinations of kraft evaporator condensate (KEC) and caustic extraction (CE) stage bleaching effluent. In addition to conventional measures of treatment efficiency, the transformations and removal of sulfur compounds from the KEC and changes in molecular size fraction of organic carbon and organic chlorine were measured. A large fraction of the BOD in the combined waste could be removed in the anaerobic stage at loadings of up to at least 15 kg COD/m3-d. The overall process produced an effluent with <30 mg/l BOD and SS and with varying amounts of COD, depending on the CE fraction being treated. Fractional removals of organic carbon and COD were approximately equal and were significantly greater than that of organic chlorine. Removal efficiencies were higher for the low molecular weight fraction. One third of the influent sulfur was removed as H2S gas in the anaerobic stage. The remaining sulfur was largely oxidized to sulfate in the aerobic stage, with nearly complete elimination of odors.
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Chaurasia, Shardesh, Prakashchandra Mervana, Satyapal Singh, and Sanjay Naithani. "Biological Pretreatment of Lignocellulosic Material for Biopulping: A Review." Journal of Non Timber Forest Products 23, no. 1 (March 1, 2016): 1–12. http://dx.doi.org/10.54207/bsmps2000-2016-mir5p1.
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Biopulping has the potential to improve pulp quality, paper properties and to reduce energy costs and environmental impact relative to traditional pulping approaches. The technology has focused on the white rot fungi that are known to be degrader of wood constituents. This group of fungi have complex extracellular ligninolytic enzyme systems that can selectively degrade/ alter lignin structure and allow cellulose fibres to be relatively unaffected. It colonizes either on living or dead wood and decomposes almost all plant cell wall polymers including lignin and extractives making it to be extremely potential to be used in biopulping. Biopulping reduces the chemical load in paper industry and thus partially limiting environmental threats caused by conventional pulping. It has been advised that energy savings alone could make the process economically viable. Other benefits include improved burst strength and tear indices of product and reduced pitch deposition.
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Strunk, Peter, Åsa Lindgren, Roland Agnemo, and Bertil Eliasson. "Properties of cellulose pulps and their influence on the production of a cellulose ether." Nordic Pulp & Paper Research Journal 27, no. 1 (January 1, 2012): 24–34. http://dx.doi.org/10.3183/npprj-2012-27-01-p024-034.
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Abstract Several grades of cellulose pulps were investigated for their influence on the product quality of a cellulose ether, ethyl-hydroxy-ethyl cellulose (EHEC). The selection of the pulps was based on pulping process, original wood type and intrinsic viscosity. In total, five sulfite pulps and four sulfate pulps were chosen, of which all but one sulfate pulp were of dissolving grade. The physical and chemical properties of the pulps were analyzed as well as important qualitative parameters of the final product EHEC. The influence of pulp properties on EHEC quality was investigated by multivariate data analyses. Principal component analysis showed that due to the influence of all variables, the pulps aligned in groups in accordance to the selection criteria pulping process and wood type. Partial least square regression revealed that high gel formation in EHEC is explained by the pulp properties high intrinsic viscosity and high Mw in combination with high caustic absorption rate and high total caustic absorption. The amount of hemicelluloses, in particular xylose, also contributed to gel formation. High cloud point for an EHEC solution was explained by a high MSEO and low DSEt of the EHEC molecules, where in turn a high MSEO could be predicted by a high pore area, high PD and a low caustic absorption rate. A low DSEt could on the other hand be predicted by a low hemicellulose content and hence a high R18. In a separate model, the same pulp properties explaining MSEO and DSEt also predicted cloud point directly. Fock reactivity and viscose dope filterability, both test methods originating from the viscose manufacturing, were shown to predict cloud point but have low predictability on other EHEC quality parameters. The models achieved can thus be utilized to predict final EHEC product qualities for new pulps within the design set of the chosen pulps.
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Tripathy, Upendra Prasad, and Sunil Kumar Bishoyi. "Reduction of Colour from effluents of Pulp and Paper Industry by Ozonation: A Review." Research Journal of Chemistry and Environment 25, no. 12 (November 25, 2021): 170–74. http://dx.doi.org/10.25303/2512rjce170174.
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Pulp and paper making is the major old process industry in India which is water intensive and generates heavy water pollution. Pulp and paper industries are the fifth largest contributor to industrial water pollution. Waste water is generated from each and every section of paper making process and depends upon the type of pulping and bleaching process. Presently, primary and secondary (Biological) treatment systems based on activated sludge process are widely used by paper industry for effluent treatment. The process requires high energy and chemical inputs and involves high operational costs. One of the novel processes for treating effluent is its oxidation through ozonation which is a greener way of degrading pollutants. Ozonation of intermediate stage effluents having high colour load is more effective for industrial application and re-utilization.
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Hruška, Michal, Miroslav Variny, Juma Haydary, and Ján Janošovský. "Sulfur Recovery from Syngas in Pulp Mills with Integrated Black Liquor Gasification." Forests 11, no. 11 (November 3, 2020): 1173. http://dx.doi.org/10.3390/f11111173.
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Research Highlights: As to fill the current knowledge gap and to deliver important findings to the scientific community, efficient sulfur recovery from black liquor gasifier syngas, comprising both gas cleaning and returning sulfur to the pulping process, was modeled and assessed from a techno-economic viewpoint. This manuscript proves that the associated investment and operational costs cannot be neglected and that they impact the black liquor gasification feasibility significantly. To prove its gasification as a sustainable and more efficient processing route over its combustion in recovery boilers, a substantial process efficiency improvement and operating costs reduction must be targeted in future research. Background and Objectives: Sulfur compounds found in black liquor partly turn into hydrogen sulfide during gasification and exit the gasifier in the syngas. Their efficient recovery in their sulfidic form to the pulping process is of utmost importance. Current studies focus on black liquor gasifier syngas desulfurization only. Materials and Methods: A mathematical model of two H2S absorption units from a 66.7 tDS/h (1600 tons dry solids per day) black liquor gasification process to 20 ppm H2S content in cleaned syngas using either white liquor plus NaOH or N-methyldiethanolamine (MDEA) was created using the Aspen Plus simulation software. Results: The results show that CO2 co-absorption significantly increases the lime kiln load: +20% in the MDEA alternative and +100% in the other one. The MDEA alternative requires almost the same investment costs but by around USD 9.7 million (>50%) lower annual operating costs compared to the other one. Economic evaluation was based on the assumed discount rate of 5% and on the expected plant operation time of 25 years. The estimated total investment cost of the whole plant is around USD 170 million for both alternatives. The whole plant including this alternative exhibits a positive net present value (over USD 19 million), an internal rate of return of 5% and a profitability index of 1.12, whereas that with the other alternative is economically infeasible. Conclusions: The MDEA-based syngas cleaning technology represents a more efficient and economically feasible option of sulfur recovery. A major drawback of both modeled syngas cleaning technologies is that their estimated annual operating costs significantly reduce the expected profit margin of gasification over the traditional black liquor combustion in a recovery boiler. Syngas cleaning and sulfur recovery have to be further optimized to reach a significant cut down in operational costs to improve the economic feasibility of black liquor gasification.
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Hossini, H., A. Rezaee, M. Shirmardi, and A. Naeimabadi. "Sulfate removal from wastewater using electrocoagulation process: evaluation of effective parameters and costs." Journal of North Khorasan University of Medical Sciences 6, no. 4 (March 1, 2015): 787–96. http://dx.doi.org/10.29252/jnkums.6.4.787.
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Chambers, Paul GS, and Nuno MG Borralho. "A simple model to examine the impact of changes in wood traits on the costs of thermomechanical pulping and high-brightness newsprint production with radiata pine." Canadian Journal of Forest Research 29, no. 10 (October 1, 1999): 1615–26. http://dx.doi.org/10.1139/x99-127.
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A number of functions were investigated that related the costs of thermomechanical pulp (TMP) and high-brightness newsprint production, using Pinus radiata D. Don, to important pulp and paper quality (breeding objective) variables, including specific energy consumption and pulp handsheet tear and tensile strength, brightness, and opacity. Pulp handsheet quality traits were considered to be reasonable two-dimensional predictors of paper quality traits in this context. A specific production process that requires the use of a reinforcement kraft pulp and an artificial clay filler to improve the quality of paper produced from the bleached TMP fibres was investigated, similar to the production process used by Australian Newspaper Mills' Boyer Mill in Tasmania, Australia. Pulp and pulp handsheet quality variables could be explained by significant (P > 0.05) wood traits using multiple linear regression equations. This provided a method to predict the economic importance of each wood trait in relation to the thermomechanical production process investigated. The results showed that tracheid length, wood density, wood brightness, and tracheid coarseness were the best predictors of costs. Increases in tracheid length, wood density, and wood brightness and decreases in tracheid coarseness resulted in decreasing the total costs of TMP and high-brightness newsprint production.
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Han, Xiao Fang, and Hong Qing Hu. "Application of Bleaching Reed Pulp by Xylanase-Producing Alkalophilic Bacillius." Advanced Materials Research 830 (October 2013): 207–10. http://dx.doi.org/10.4028/www.scientific.net/amr.830.207.
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The reeds are the reeds of the Gramineae Lo bamboo family and they are major non-wood papermaking raw materials. Based on the importance of the reed in the papermaking, many useful discussions have been carried out about its pulping and bleaching processes (Shatalov et al.,2001).Finnish scholars reported a pulp by the xylanase treatment could reduce the segment of chloride to chlorine consumption of 25% for the first time in 1986 (Viikari et al., 1986),and it was soon put into industrial production after then. Xylanase can reduce the amount of chemical additives by improving the bleach ability of the pulp, thereby reducing environmental pollution and reduce production costs, and increase the brightness of the paper (Anatoly et al., 2007).Although many scholars have done a lot of research in biobleaching, and have made some progress, but most of the selection of microorganisms are fungi and neutrophilic bacteria, the production of xylanase is usually in the pH 5 - 7, 40-50°C which often leads to maximal activity, thus lack of compatibility with the conventional chemical pulping process. In recent years, the thermal stability of alkaline xylanase has been paid much attention (Shatalov et al.,2003). Alkalophilic bacteria secreted extracellular enzyme with heat, basophilic characteristics, can be used directly to the biopulping pretreatment and bleaching of wood and non wood raw materials. The recent study on organic solventbased pulping of giant reed showed that competitive papermaking fibres could be produced using this advanced pulping technology (Shatalov and Pereira, 2001). The amount of enzyme not only directly affects the size of pulp hardness, degree of polymerization and brightness, but also was the basis for investigating the economic of dealing with enzyme.The results of alkaline bacteria xylanase bleaching ramie fiber have been reported previously (Zheng et al., 2000). In this study, the xylanase of alkalophilic Bacillus is used in reed pulp bleaching pretreatment, and the physical and chemical properties of the enzyme to deal with the reed pulp are analyzed.
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Bosco, Mtweve, Ekael Mbise, and Rwaichi Minja. "Production of Paper Pulp Using Sisal Fiber Waste from Sisal Spinning Processes." Tanzania Journal of Engineering and Technology 41, no. 2 (June 30, 2022): 150–57. http://dx.doi.org/10.52339/tjet.v41i2.788.
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Disposal of large volumes of textile waste is an escalating problem for textile industries. Sisal spinning industry is the one of the textile industries releasing large volumes of textile waste in the landfills. The rising costs, and reduction of available space together with increasing stringent environmental measures are making burying and land filling of textile waste, a declining option. This study therefore explores recycling options where the potential of using sisal fiber waste produced during sisal spinning processes as raw materials for the production of paper pulp was investigated. Sampling was done at 21stCentury Holdings Limited allocated at Chang’ombe industrial street Dar es Salaam mainly dealer of sisal yarns production. Materials were prepared and cut into small pieces of about ½ inches to reduce the fiber into unit lengths so as to achieve pulping required performance. Pulping process was achieved through Soda pulping techniques with two different effective alkali charges (EA-20% and EA-24%) for 240 minutes under maximum temperature 140 C, and liquor to fiber ratio 4:1by using Mathis Labomat dyeing Machine. The kappa number obtained was (25.5, 34.5) for material treated under EA 24% and EA 20% respectively, Percentage pulp yield were (47.1, 54.4) for EA 24% and EA20% pulp respectively. Freeness (630CFS, 555CSF) after refining at 4500rpm. Finally, the resulting pulp was used for hand sheet making and the sheets were tested for their mechanical properties; Grammage (61.1, 61.1) g/m2, Tensile index (9.9, 22.3) Nm/g, Tear index (13.3, 17.4) Nm2/g, burst index (1.7, 3.7 and 1.6) k.pa.m2/g and Elongation at break (2.02, 2.22) % for EA24% pulp, EA20% pulp respectively. The findings shows that sisal fiber wastes have a promising potential for paper pulp production compared to other non-wood raw material.
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Zhang, Ze Biao, Wan Kun Wang, and Jin Hui Peng. "Innovative Process of Leaching of Nickel Supported Activated Carbon in Ammonium Sulfate." Advanced Materials Research 201-203 (February 2011): 1774–79. http://dx.doi.org/10.4028/www.scientific.net/amr.201-203.1774.
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The leaching tests of nickel supported activated carbon under normal pressure in (NH4)2SO4were studied. The effects of experimental condition, such as initial concentration of (NH4)2SO4, liquid-to-solid ratio, leaching time and leaching temperature on the leaching rate of nickel, were investigated. The results show that the leaching rate of nickel is 96.12% with initial concentration of (NH4)2SO4of 7.5%, liquid-to-solid ratio of 2, leaching time of 5h and leaching temperature of 25°C. The morphology of nickel supported activated carbon before and after leaching was characterized by XRD, which proved the effective separation of nickel and activated carbon. The leaching rate of nickel was also shown better at room temperature and atmospheric pressure. Moreover, it needn’t equipments enduring high-pressure and high temperature in the leaching process, thus reducing the costs of leaching equipments greatly. This work provides a new way to the comprehensive utilization of nickel-containing activated carbon.
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Franzmann, P. D., J. J. Plumb, J. T. Wylie, W. J. Robertson, G. B. Douglas, T. P. Bastow, A. H. Kaksonen, and J. A. Puhakka. "Treatment of saline, acidic, metal-contaminated groundwater from the Western Australian Wheatbelt." Water Science and Technology 58, no. 12 (December 1, 2008): 2353–64. http://dx.doi.org/10.2166/wst.2008.582.
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Managing acidic, metal-containing saline ground and drainage waters in the Wheatbelt of Western Australia is an environmental and economic challenge. Sulfate-reducing fluidised bed bioreactors are shown to be technically capable of treating high salt, low pH, metal containing waters from the town of Narembeen in the Wheatbelt so as to reduce acidity and to remove most of the undesirable metal contaminants. The hydraulic residence time (HRT) limit for a stable process with groundwater from the region of Narembeen was >16 hours. The maximal rate of sulfate reduction in the laboratory system treating Narembeen groundwater was similar to rates observed in comparable applications of the process at other sites, ca. 3 g sulfate (L-reactor)−1 day−1. Salts that are relatively free of metal contaminants can be produced from water that has been treated by the sulfate-reducing fluidised bed bioreactor. It is unlikely that metal precipitates, captured from Wheatbelt waters by the process, would be of economic value. If sulfate-reducing fluidised bed reactors were considered technologically appropriate at larger scale, the decision to use them would be based on the necessity to take action, the comparative effectiveness of competing technologies, and the relative costs of competing technologies.
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Khanramaki, Fereshte, Jaber Safdari, Amir S. Shirani, and Rezvan Torkaman. "Investigations on the complete removal of iron(III) interference on the uranium(VI) extraction from sulfate leach liquor using Alamine 336 in kerosene." Radiochimica Acta 106, no. 8 (August 28, 2018): 631–43. http://dx.doi.org/10.1515/ract-2017-2906.
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Abstract Uranyl sulfate obtained by uranium ore leaching of an industrial sample deposit of Gachin site was used for uranium separation by the solvent extraction technique. The presence of other elements in the sulfate leach liquors has a negative impact on the uranium extraction process using Alamine 336; therefore, the operating costs are increased. In this study, the separation of uranium(VI) and iron(III) by Alamine 336 and kerosene have been examined as an extractant and a diluent, respectively. For this purpose, the effects of operating parameters on the extraction process such as Alamine 336 concentration, modifier concentration, contact time, initial aqueous pH, sulfate ion concentration, temperature, and stripping agents were investigated. Also, the complete removal of iron(III) interference from the sulfate leach liquor before the extraction step has been studied with reducing agents. The equilibrium constants and stoichiometric coefficients for uranium and iron extraction with Alamine 336 in the sulfate leach liquors were calculated. Likewise, the values of the thermodynamic parameters such as Gibbs energy, enthalpy and entropy were determined to prove the exothermic and spontaneous reactions. The mentioned procedure is proposed for the uranium separation from the impurities in the sulfate ores using tertiary amine for production of purified uranium.
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Anwar, Sohaib Waseem, and Wendong Tao. "Cost benefit assessment of a novel thermal stripping – acid absorption process for ammonia recovery from anaerobically digested dairy manure." Water Practice and Technology 11, no. 2 (June 1, 2016): 355–64. http://dx.doi.org/10.2166/wpt.2016.041.
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Thermal stripping – acid absorption is a novel technology recently developed to recover ammonia as marketable ammonium sulfate granules from anaerobic digester effluent. Taking a large-size dairy farm in New York State, USA, as an example, this study evaluates the costs and benefits of ammonia recovery from a recirculation line of mesophilic anaerobic digesters. Option 1 is the baseline without ammonia recovery. Option 2 is to draw digester effluent at 28% of the liquid manure loading rate, heat to 101 °C for ammonia recovery, and return the ammonia-recovered dairy manure to the digesters. Under option 2, the returned hot manure eliminates the need to heat the digesters. Option 3 is similar to Option 2, but the recirculation rate is only 14% of the manure loading rate. In this case, additional heating is needed for the digesters. Engineering unit cost and revenue models are developed for the thermal stripping – acid absorption process. Options 2 and 3 have benefit/cost ratios of 1.90 and 1.86, respectively. Option 2 produces greater net present value (NPV) ($1.34 million) than Option 2 ($0.72 million), while Option 1 yields a negative NPV (−$0.23 million). Ammonia recovery on this farm can create 1.5–3 jobs. Labor costs account for 62–70% of the total operating costs. Option 2 can generate a benefit of $0.018/L manure digestate or $0.50/d/cow. Any uncertainties relating to NPV and benefit/cost ratio are mainly associated with the sale price of ammonium sulfate and hourly wage rate.
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Atamanyuk, V. M., V. V. Kochubei, D. P. Kindzera, and N. Y. Tsiura. "Investigation of the dehydration process of iron(II) sulfate heptahydrate by filtration method." Voprosy Khimii i Khimicheskoi Tekhnologii, no. 5 (October 2022): 24–32. http://dx.doi.org/10.32434/0321-4095-2022-144-5-24-32.
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The filtration method of dehydrating iron(II) sulfate heptahydrate was proposed to involve the formed compounds in the production process of fabrication of iron oxide pigments. Using the method of complex thermal analysis, the influence of the heating rate on the temperature limits and the intensity of the dehydration process was revealed. Based on the results of the differential thermal analysis, the heat agent temperature was chosen to be 3350.5 K, which is lower than the melting point of the sample. The effects of increasing the speed of the heat agent on the kinetics of dehydration of iron(II) sulfate heptahydrate by the filtration method and on the intensity of the heat exchange process were determined. The values of the heat transfer coefficients were calculated based on experimental data in a thin layer and from the calculated dependence. The calculated coefficients were generalized using a dimensionless dependence within the range of Reynolds numbers of 20 to 100. The equation for forecasting heat energy costs at the stage of designing equipment for dehydration was proposed.
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Puke, Maris, Daniela Godina, Mikelis Kirpluks, Janis Rizikovs, and Prans Brazdausks. "Residual Birch Wood Lignocellulose after 2-Furaldehyde Production as a Potential Feedstock for Obtaining Fiber." Polymers 13, no. 11 (May 31, 2021): 1816. http://dx.doi.org/10.3390/polym13111816.
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From birch wood, it is possible to obtain both acetic acid and 2-furaldehyde as valuable value-added products. The main objective of this study was to develop a new wasteless technology for obtaining 2-furaldehyde, acetic acid, and lignocellulose (LC) residue usable as feedstock in further processing such as thermomechanical (TMP), alkaline peroxide mechanical (APMP), and sulfate pulping processes. To achieve this objective several screening tests were performed, and a further experimental plan was developed using DesignExpert11. Process yields were analyzed both in terms of total yield and at individual time increments. In addition, the obtained LC residue was also characterized. A unique bench-scale reactor system was used to obtain an LC material without pentoses and with maximum preservation of cellulose fiber for further research. Studies on the deacetylation and dehydration of birch wood hemicelluloses of pentose monosaccharides to 2-furaldehyde and acetic acid using orthophosphoric acid as a catalyst were carried out. Results showed that, depending on the used pre-treatment conditions, the 2-furaldehyde yield was from 0.04% to 10.84% oven dry mass (o.d.m.), the acetic acid yield was from 0.51% to 6.50% o.d.m., and the LC residue yield was from 68.13% to 98.07% o.d.m. with minimal content of admixtures. Process optimization using DesignExpert11 revealed that the main pre-treatment process parameters that influenced the yield of 2-furaldehyde in the pre-treatment process were process temperature (53.3%) and process duration (29.8%).
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BROGDON, BRIAN N. "Optimization of elemental chlorine-free bleaching for a softwood kraft pulp – part 1: impact of oxidative extraction on chlorine dioxide stoichiometry." August 2010 9, no. 8 (September 1, 2010): 27–35. http://dx.doi.org/10.32964/tj9.8.27.
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The present investigation meticulously analyzes how oxidative alkaline extraction can be augmented through process changes, and how these augmentations can be leveraged to optimize chlorine dioxide usage with elemental chlorine-free (ECF) sequences for a conventional softwood kraft pulp. Bleaching data from Basta and co-workers (1992 TAPPI Pulping Conference) are re-examined and re-interpreted in this study. We determined that ~60% to 65% of the overall ClO2 charge should be applied in the D0-stage. Peroxide addition to an (EOP) can replace 0.6 to 2.5 Kg. ClO2 per Kg H2O2. Boosting the (EO) temperature to 80°C is equivalent to a 70°C (EOP) with 0.25% to 0.30% H2O2,whereas a 90°C (EO) is equivalent to 0.50% – 0.75% H2O2 in a 70°C (EOP). The stoichiometric bleaching data from this study can guide decision-making for lowering chemical usage and minimize costs to reach target brightness levels with three- and five-stage sequences.
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Zhu, Yanjun, Shidong Yang, Weizhuo Wang, Lingwei Meng, and Jingbo Guo. "Applications of Sponge Iron and Effects of Organic Carbon Source on Sulfate-Reducing Ammonium Oxidation Process." International Journal of Environmental Research and Public Health 19, no. 4 (February 17, 2022): 2283. http://dx.doi.org/10.3390/ijerph19042283.
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The typical characteristics of wastewater produced from seafood, chemical, textile, and paper industries are that it contains ammonia, sulfate, and a certain amount of chemical oxygen demand (COD). The sulfate-reducing ammonium oxidation process is a biochemical reaction that allows both ammonia and sulfate removal, but its low growth rate and harsh reaction conditions limit its practical application. Due to the adsorption properties of the iron sponge and its robust structure, it provides a suitable living environment for microorganisms. To reduce the negative impact on the environment, we employed 4.8 kg of sponge iron in a 2.0 dm3 anaerobic sequencing batch reactor (ASBR). We investigated the effects of the type and concentration of carbon sources on the performance of the sulfate-reducing ammonium oxidation (SRAO) process. The results demonstrated that during a start-up period of 90 days, the average ammonium removal efficiency and the sulfate conversion efficiency of the reactor containing the sponge iron were 4.42% and 8.37% higher than those of the reactor without the sponge iron. The addition of the sponge iron shortens the start-up time of this greenhouse gas-free denitrification process and reduces future costs in practical applications. The removal of total nitrogen (TN) significantly increased after adding organic carbon sources and then declined sharply, while the most considerable reduction of ammonium removal efficiency from 98.4% to 30.5% was observed with adding phenol. The performance of the group employing glucose as the carbon source was recovered on the 28th day, with the average ammonium removal efficiency increasing from 49.03% to 83.5%. The results of this simulation study will help the rapid start-up of SRAO in the water treatment industry and can precisely guide the application of the SRAO process for wastewater containing different organic carbon sources.
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Xu, Ya-Nan, and Yinguang Chen. "Advances in heavy metal removal by sulfate-reducing bacteria." Water Science and Technology 81, no. 9 (May 1, 2020): 1797–827. http://dx.doi.org/10.2166/wst.2020.227.
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Abstract Industrial development has led to generation of large volumes of wastewater containing heavy metals, which need to be removed before the wastewater is released into the environment. Chemical and electrochemical methods are traditionally applied to treat this type of wastewater. These conventional methods have several shortcomings, such as secondary pollution and cost. Bioprocesses are gradually gaining popularity because of their high selectivities, low costs, and reduced environmental pollution. Removal of heavy metals by sulfate-reducing bacteria (SRB) is an economical and effective alternative to conventional methods. The limitations of and advances in SRB activity have not been comprehensively reviewed. In this paper, recent advances from laboratory studies in heavy metal removal by SRB were reported. Firstly, the mechanism of heavy metal removal by SRB is introduced. Then, the factors affecting microbial activity and metal removal efficiency are elucidated and discussed in detail. In addition, recent advances in selection of an electron donor, enhancement of SRB activity, and improvement of SRB tolerance to heavy metals are reviewed. Furthermore, key points for future studies of the SRB process are proposed.
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Mysov, Oleg, Igor Levchuk, Kseniia Fesenko, Mariia Savchenko, and Olena Gnatko. "DEVELOPMENT OF A COMPUTER MODEL FOR OBTAINING A SOLUTION OF COPPER SULFATE ADAPTED FOR SOLVING CONTROL PROBLEMS." HERALD OF KHMELNYTSKYI NATIONAL UNIVERSITY 299, no. 4 (October 2021): 59–66. http://dx.doi.org/10.31891/2307-5732-2021-299-4-59-66.
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Copper sulfate is an inorganic compound that is currently widely used in the chemical industry, medicine and agriculture. When developing systems for automated control of the process of obtaining copper sulfate, there is a need for simple, high-speed and at the same time accurate mathematical models that are used both in improving algorithms for optimal control of this process, and in developing operator interfaces and debugging control algorithms. At the same time, the development of full-fledged mathematical models of technological processes is a very laborious task that requires significant material and time costs. The subject of study in the article is a computer model of the process of obtaining a solution of copper sulfate, implemented in the software environment of the universal modeling program ChemCAD. The aim of the work is to develop in a software environment a universal modeling program ChemCAD, a computer model of the process of obtaining a solution of copper sulphate, adapted for solving problems of control and integration into modern SCADA systems. Objectives: to develop a computer model of the process of obtaining a solution of copper sulfate in the ChemCAD simulation program; explore the process using a computer model, get graphical dependencies that describe the main technological parameters of the process; perform a comparative analysis of the data obtained by calculation with the experimental data of the laboratory setup and draw a conclusion about the functionality of the developed computer model; adapt the computer model to solve the control problem and develop the principles of two-way information exchange of the computer model based on OPC technology with the modern SCADA system TRACE-MODE 6. The methods used are: computer modeling of technological processes; OPC technology; SCADA. Conclusions: the novelty of the results obtained is as follows. In the ChemCAD software environment, a computer model of the process of obtaining a solution of copper sulfate has been developed, adapted for solving control problems and integration into existing SCADA systems. The principles and structure of two-way information exchange of a computer model with external control programs based on OPC technology have been developed.
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Plugge, Caroline M., João A. B. Sousa, Stephan Christel, Mark Dopson, Martijn F. M. Bijmans, Alfons J. M. Stams, and Martijn Diender. "Syngas as Electron Donor for Sulfate and Thiosulfate Reducing Haloalkaliphilic Microorganisms in a Gas-Lift Bioreactor." Microorganisms 8, no. 9 (September 22, 2020): 1451. http://dx.doi.org/10.3390/microorganisms8091451.
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Biodesulfurization processes remove toxic and corrosive hydrogen sulfide from gas streams (e.g., natural gas, biogas, or syngas). To improve the efficiency of these processes under haloalkaline conditions, a sulfate and thiosulfate reduction step can be included. The use of H2/CO mixtures (as in syngas) instead of pure H2 was tested to investigate the potential cost reduction of the electron donor required. Syngas is produced in the gas-reforming process and consists mainly of H2, carbon monoxide (CO), and carbon dioxide (CO2). Purification of syngas to obtain pure H2 implies higher costs because of additional post-treatment. Therefore, the use of syngas has merit in the biodesulfurization process. Initially, CO inhibited hydrogen-dependent sulfate reduction. However, after 30 days the biomass was adapted and both H2 and CO were used as electron donors. First, formate was produced, followed by sulfate and thiosulfate reduction, and later in the reactor run acetate and methane were detected. Sulfide production rates with sulfate and thiosulfate after adaptation were comparable with previously described rates with only hydrogen. The addition of CO marginally affected the microbial community in which Tindallia sp. was dominant. Over time, acetate production increased and acetogenesis became the dominant process in the bioreactor. Around 50% of H2/CO was converted to acetate. Acetate supported biomass growth and higher biomass concentrations were reached compared to bioreactors without CO feed. Finally, CO addition resulted in the formation of small, compact microbial aggregates. This suggests that CO or syngas can be used to stimulate aggregation in haloalkaline biodesulfurization systems.
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MARKLUND, MAGNUS, RIKARD GEBART, and RAGNAR TEGMAN. "Comparisons of Initial Experiments and Reactor Model Predictions in High Temperature Black Liquor Gasification." February 2009 8, no. 2 (March 1, 2009): 12–18. http://dx.doi.org/10.32964/tj8.2.12.
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Pressurized high temperature black liquor gasification might significantly improve the efficiency of the energy and chemical recovery cycle in kraft pulping. The process, which is based on the entrained-flow principle, is under development, and a scale-up from an existing pilot gasifier is planned. We developed a self-consistent com-putational fluid dynamic (CFD) model, in conjunction with pilot gasifier experiments, as a tool for scale-up. This report compares model predictions against experimental pilot gasifier data. The agreement between model and experiments is encouraging in certain areas, but significant discrepancies resulted for other areas. Model predic-tions of global performance parameters, such as sulfate reduction efficiency and carbon conversion, are in reason-able agreement with the experiments, but the predicted gas composition differed significantly from results of the experiments. Direct measurements of quantities to validate the current model validation are difficult to obtain because of severe conditions in the gasifier, and many of the model comparisons are based on indirect values. Hence, it is difficult to judge whether the errors come from the experiment or the simulation. Before we can draw a definite conclusion about the model’s validity, improved in-situ measurements inside the gasifier are necessary and are currently under development.
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Karimov, Kirill A., Aleksei V. Kritskii, and Sergey E. Polygalov. "Investigation of Flotation Separation of Elemental Sulfur and Sulfides from Lead Sulfate from Low-Temperature Leaching of Lead Concentrates." Materials Science Forum 989 (May 2020): 537–42. http://dx.doi.org/10.4028/www.scientific.net/msf.989.537.
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Monometallic ore that is mostly lead found in nature is extremely rare. The main natural raw material for the lead production is sulfide polymetallic ores. In this study the filter cake processing after the low-temperature autoclave leaching of the lead concentrate to produce a sulphide concentrate and lead tailings was investigated The study of component separation was carried out using the methods of mathematical planning of the second order experiment. The following optimal costs of reagents, g/t: 140-200 potassium xanthate, 70-100 foaming agent, 100 copper sulfate; the concentrate yield is 41-43 %; it is extracted to, %: 95 Fe, 49 Cu, 96 Zn, 98 S0, 18-19 Pb. At flotation 18,7% of lead goes into flotation concentrate and 80.5% is lead sulfate. The rectification of the obtained concentrate by flotation did not give acceptable results, since the yield of the foam product in all experiments was 93-96%. For the separation of lead sulphate from sulphur-sulfide concentrate was used in the granulation of sulfur in the following conditions: t = 145 °C, Po2 = 0,0-0,5 MPa, τ = 60 to 120 min. In the granulation process of the flotation concentrate is a division of lead sulfate and elemental sulfur, the sulfate lead content in sulphur-sulfide phase is decreased from 28.44 % to 3.5 %, its recovery in a sulfate filter cake has reached 90.6 %
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Bandiera, Nataly Simões, Samera Rafaela Bruzaroski, Raúl Jorge Hérnan Castro Gomez, Elsa Helena Walter de Santana, Cínthia Hoch Batista de Souza, Caio Casale Aragon, Tatiana Colombo Pimentel, and Lina Casale Aragon-Alegro. "Probiotic powder: Optimization of the process parameters and influence of the drying method." Research, Society and Development 10, no. 16 (December 16, 2021): e420101623796. http://dx.doi.org/10.33448/rsd-v10i16.23796.
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This research paper aimed to optimize the process parameters and to select the most suitable drying method in order to obtain probiotic powder at reduced cost. The influence of the addition of growth promoters (glucose, sucrose, cheese whey, peptone, yeast extract or ammonium sulfate), incubation parameters (time and temperature) and drying method (freeze-drying or oven-drying) on the viability of the probiotic cultures Lactobacillus casei or Lactobacillus acidophilus was evaluated. The effect of the growth promoters was evaluated using a fractional factorial experimental design 26-4 and the concentration of the growth promoters and the incubation temperature were optimized through Box-Behnken experimental matrix (33). Cheese whey (16% w/v) plus ammonium sulfate (2.5% w/v) and cheese whey (12% w/v) plus yeast extract (7% w/v) promoted a higher multiplication of L. casei and L. acidophilus, respectively. The best temperature for L. casei was 35 ºC and for L. acidophilus 39 ºC, without influence of the incubation time (24 or 48 h). The oven-drying resulted in the highest populations of the probiotic cultures (above 9 log cfu/mL). This study proved that cheese whey can be a suitable growth promoter for both probiotic cultures and oven-drying could be the drying method, which can decrease the production costs. The influence of the temperature and growth promoters is strain specific, demonstrating that the growth conditions should be evaluated for each probiotic strain.
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Rodríguez, Mallerliny Quintero, Jaiver Osorio Grisales, Henry Reyes Pineda, and Jhon Rodríguez Espinosa. "Degradation of Dyes in Real Textile Industry Wastewater Samples by Fenton Process." Journal of Hunan University Natural Sciences 49, no. 6 (June 30, 2022): 151–66. http://dx.doi.org/10.55463/issn.1674-2974.49.6.16.
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This research proposes a solution to the problem of industrial safety and the improvement of environmental processes in the textile industry through the degradation of dyes from its processes using the Fenton reaction. This advanced oxidation technology makes it possible to reduce the possible environmental impacts caused by the organic matter generated in industrial activity. Sampling was conducted under real operating conditions in the homogenization tank of the Industrias Printex SAS wastewater treatment plant. Advanced oxidation was carried out applying the Fenton process using iron from ferrous sulfate heptahydrate as a catalyst and hydrogen peroxide at different concentrations in a 6-post flocculator. Among the results obtained, an optimal dose of 571 ppm of iron and 38 ppm of hydrogen peroxide was found through statistical analysis with the STATGRAPHICS program using the 2k factorial design and constructing response surfaces. A comparative study between the Fenton treatments, treatment with hydrogen peroxide, and treatment with ferrous sulfate heptahydrate showed the Fenton reaction at neutral pH, attributed to the presence of some organic acids such as citric acid, used as a chelating agent (Fenton modified). The proposed treatment was compared with the one that uses chlorine, applying it in three (3) different tanks through a multifactorial ANOVA with the data collected when scaling the treatment, finding that the proposed Fenton treatment is more efficient. This research was innovative because it demonstrated the feasibility of scaling up the Fenton process to neutral pH in a textile wastewater treatment plant, reducing operating costs and minimizing environmental impact.
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Tang, Mingliang, Xuerun Li, Yusheng Shen, and Xiaodong Shen. "Kinetic model for calcium sulfate α-hemihydrate produced hydrothermally from gypsum formed by flue gas desulfurization." Journal of Applied Crystallography 48, no. 3 (May 9, 2015): 827–35. http://dx.doi.org/10.1107/s1600576715007141.
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Modeling of the kinetics of the synthesis process for calcium sulfate α-hemihydrate from gypsum formed by flue gas desulfurization (FGD) is important to produce high-performance products with minimal costs and production cycles under hydrothermal conditions. In this study, a model was established by horizontally translating the obtained crystal size distribution (CSD) to the CSD of the stable phase during the transformation process. A simple method was used to obtain the nucleation and growth rates. A nonlinear optimization algorithm method was employed to determine the kinetic parameters. The model can be successfully used to analyze the transformation kinetics of FGD gypsum to α-hemihydrate in an isothermal batch crystallizer. The results showed that the transformation temperature and stirring speed exhibit a significant influence on the crystal growth and nucleation rates of α-hemihydrate, thus altering the transformation time and CSD of the final products. The characteristics obtained by the proposed model can potentially be used in the production of α-hemihydrate.
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Diffo Teguia, Cedric, Sophie D'Amours, Rod Albers, and Paul Stuart. "Decision-making process for the identification of preferred lignin-based biorefinery strategies." April 2017 16, no. 04 (2017): 229–40. http://dx.doi.org/10.32964/tj16.4.229.
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The lignin biorefinery is emerging; there has been significant progress in recent years regarding lignin extraction and conversion processes, their implementation at the commercial scale, and the validation of lignin substitution potential in various applications. In this paper, seven strategies for implementing the lignin-based biorefinery into a kraft pulp mill were considered, and different performance metrics for these strategies were calculated in order to identify the “most preferred”. The different options addressed two distinctly different objectives that companies can consider regarding their biorefinery strategy, either (1) a near-term mill-level profitability improvement vision, or (2) a longer-term revenue growth-oriented vision. A phased-implementation approach was systematically defined for each option in order to mitigate technology and market risks. Lignin product applications that were considered included phenol replacement in phenol-formaldehyde (PF) resins, polyols replacement in polyurethane (PU) foams, and polyacrylonitrile (PAN) replacement in carbon fiber. A Multi-Criteria Decision-Making (MCDM) panel was executed for evaluating the seven lignin-based biorefinery strategies, using a set of economic, market risk, and competitiveness criteria. Although the panel selected Internal Rate of Return (IRR) as the most important criterion, Competitiveness on Production Costs (CPC) appeared to be the most important factor for distinguishing between lignin strategy options. CPC reflects the robustness of the biorefinery strategy relative to an aggressive price-cutting strategy from the competition. Overall, strategies involving lignin precipitation were more attractive economically, while those involving larger-scale solvent pulping processes and the associated larger revenue streams were considered better long-term strategies. The most preferred strategy considered by the panel was for precipitated lignin sold for both PF resin and PU foam applications. The next preferred strategy considered lignin sales to the same market segments, but at larger volumes. The next closely-ranked strategy considered the production of a lignin-based PF resin at the host mill. These three strategies were identified as “preferred,” for further, more detailed assessment.
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Can, İlkay Bengü, Özlem Bıçak, Seda Özçelik, Metin Can, and Zafir Ekmekçi. "Sulphate Removal from Flotation Process Water Using Ion-Exchange Resin Column System." Minerals 10, no. 8 (July 23, 2020): 655. http://dx.doi.org/10.3390/min10080655.
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Water chemistry is one of the most important parameters affecting flotation performance. Various types of ions can dissolve and accumulate in process water depending on ore mineralogy, reagent scheme, grinding medium and chemistry of mine site water. Sulfur-based ions (sulfate, thiosulfate, polythionate) are generally observed in flotation of sulfide ores. High concentrations of these ions may reduce efficiency of the flotation process, causing scale problems. Removal of these ions from process water often requires complex water treatment plants with high capital and operating costs. In this study, partial cleaning of water was investigated as an alternative approach for decreasing high sulphate concentrations of 3000–3800 mg/L down to 1000–1500 mg/L, an acceptable concentration for most sulfide ore flotation plants, by using an ion-exchange resin. For this purpose, detailed adsorption tests were performed using a laboratory-scale column system to determine the most suitable type of resin for adsorption of sulfate and thiosalts, kinetics of adsorption and regeneration of the resins. A strong base anion ion exchange resin (Selion SBA2000) was used in the experiments. The findings from the laboratory scale studies were validated in a Cu-Pb-Zn Flotation Plant in an Iberian mine using a larger scale of column set-up. The results showed that 60–70% of sulphates could be successfully removed from process water. Adsorption capacity of the resin was determined as 80.3 mg SO4/g resin. Concentrations of thiosalts and polythionates were also reduced to nearly zero value from 500 mg/L and 1000 mg/L, respectively. Flowrate of water had a significant effect on adsorption performance. The resin could be regenerated successfully using 2% (w/v) NaOH solution and used multiple times for water treatment.
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Chen, Ze Min, Zhi Li Wu, and Qiao Yun Zhang. "The Study of Color Film Phosphating Process in Steel before Coating." Advanced Materials Research 581-582 (October 2012): 1088–91. http://dx.doi.org/10.4028/www.scientific.net/amr.581-582.1088.
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This study through a lot of theoretical analysis and experimental exploration, come to add phytic acid and chromium alum in the traditional zinc phosphating solution for phosphating solution film-forming speed and improve the film density has a distinct effect, and further by orthogonal experiments and the final assessment of preferred a group of environmental, low-temperature, and no sediment of new phosphating process. The composition of the phosphating solution is as follow: zinc oxide 0.5g/L; phosphating acid 5.0mL/L; tartaric acid 0.75g/L; sodium molybdate 0.6g/L; Ma Jif salt 2.0g/L; NaF 0.25g/L; phytic acid 0.4mL/L; chromium alum 1.0g/L; free acidity 2-4 points; total acidity 15-18 points. The experimental results show that: the new phosphating process of this study reduces the handling costs, the stability bath performance, little changes in acidity, in the case of do not need to adjust the surface at room temperature, to forming a completed, dense, strong corrosion-resistant color phosphate crystal film on metal surface within 5 minutes, the copper sulfate bit time is 2.5mins, with good adhesion to 0, the impact resistance is 50kg/cm, it can be used in conjunction with a variety of coating processes.
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Kopra, Riku, and Olli Dahl. "Determining wash loss levels in the brownstock pulp washing line using different methods." May 2017 16, no. 05 (2017): 253–59. http://dx.doi.org/10.32964/tj16.5.253.
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The purpose of brownstock pulp washing is to recover the maximum amount of dissolved inorganic and organic material using a minimal amount of water. Brownstock washing is a notable subprocess in chemical pulping because it has effects on the subsequent treatments of the pulp and is also the first step in the chemical recovery cycle. Without effective washing, the economic viability of chemical pulp production is affected. The performance of washing can be described in two main ways: using wash loss, which describes the amount of washable compounds in the pulp suspension that could have been removed in washing; or the dilution factor, which represents the net amount of water that is added during washing. The amount of sodium in the pulp suspension after washing has typically been used as an indicator of wash loss, usually expressed as kg sodium sulfate/ovendry ton of washed pulp. Other common measurement methods are conductivity, chemical oxygen demand (COD), total organic carbon (TOC), dissolved dry solids (DDS), and lignin concentration. Scandinavian pulp mill softwood and hardwood fiber lines were investigated using various measurement methods in the pulp phases to gain better understanding of wash loss. The concentration of DDS in the streams was measured using a refractometer and laboratory scale. The pH, conductivity, lignin content, TOC, and COD were measured to look for any correlations. Using different methods, the level differences remain constant, but it is difficult to control the washing process with sufficient precision using individual measurements. The measurement methods must also be continuous and reliable to be used to monitor and control washing.
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Oliveira, Nágilla, Maria de la Luz Cádiz-Gurrea, Ana Margarida Silva, Catarina Macedo, Francisca Rodrigues, and Paulo Costa. "Development and Optimization of a Topical Formulation with Castanea sativa Shells Extract Based on the Concept “Quality by Design”." Sustainability 14, no. 1 (December 23, 2021): 129. http://dx.doi.org/10.3390/su14010129.
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The proposed study aims to develop and optimize a topical formulation with Castanea sativa shells extract considering the concept of Quality by Design, focusing on a planned development that consider the vulnerabilities of the entire process through risk analysis tools and design of experiments (DoE). A Box–Behnken design with three factors and three levels was used as a statistical tool for the execution of the DoE and the analysis of the response surface methodology responses. The independent variables studied were the quantity of sodium lauryl sulfate (%) (X1), beeswax (%) (X2) and macadamia oil (%) (X3); the dependent variables were pH (Y1), viscosity (Y2) and adhesiveness (Y3). According to the mathematical model, the optimal formulation contains 0.93% of sodium lauryl sulfate, 5.00% of beeswax and 10.00% of macadamia oil. The optimal formulation with the extract was prepared and characterized over the time, regarding organoleptic and technological characteristics, allowing conclusions to be reached regarding its stability. The formulation presented a pleasant odor and was light brown in color, it also demonstrated pseudoplastic-thixotropic behavior and a small reduction in the formulation consistency after 30 days of storage. This study demonstrated the efficiency of the Quality by Design methodology to understand the product variability, supporting that this approach favors a better understanding of the whole process and enables to design a robust development stage, reducing costs and generating high-quality products.
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Zimmermann. "The Potential of Encapsulated Iron Compounds in Food Fortification: A Review." International Journal for Vitamin and Nutrition Research 74, no. 6 (November 1, 2004): 453–61. http://dx.doi.org/10.1024/0300-9831.74.6.453.
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Iron (Fe) encapsulation has the potential to help overcome several major challenges in Fe fortification of foods. It may decrease unwanted sensory changes in fortified products and reduce interactions of Fe with food components that lower Fe bioavailability. However, the effect of encapsulation per se on Fe bioavailability is a concern. Rat studies comparing encapsulated ferrous sulfate, ferric ammonium citrate, and ferrous fumarate to non-encapsulated compounds indicate that a ratio of capsule:substrate of _ 60:40 may decrease the relative bioavailability (RBV) of the Fe by approximately 20%. At a ratio of capsule:substrate of _ 50: 50, the RBV of encapsulated ferrous sulfate appears to be similar to ferrous sulfate. Even minor changes in capsule composition may influence Fe bioavailability. Encapsulated ferrous fumarate given with ascorbic acid as a complementary food supplement and encapsulated ferrous sulfate fortified into salt have been shown to be efficacious in anemic children. For salt fortification, further refinements in Fe capsule design are needed to increase resistance to moisture and abrasion, while maintaining bioavailability. Studies evaluating the potential efficacy of encapsulated Fe in staple cereals (wheat and maize flours) are needed. A potential barrier to use of encapsulated forms of Fe in staple food fortification is the relatively low melting point of the capsules, which may cause unwanted sensory changes during food preparation. Research and development efforts to improve the quality of coatings and their resistance to high temperatures are ongoing. Process costs for encapsulation can be high, and unless they can be reduced, may limit applications. Further research is needed to determine which encapsulation technologies are most effective in ensuring iron bioavailability from encapsulated compounds.
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Moldoveanu, Georgiana, and Vladimiros Papangelakis. "Chelation-Assisted Ion-Exchange Leaching of Rare Earths from Clay Minerals." Metals 11, no. 8 (August 11, 2021): 1265. http://dx.doi.org/10.3390/met11081265.
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The effect of biodegradable chelating agents on the recovery of rare earth elements (REE) from clay minerals via ion-exchange leaching was investigated, with the aim of proposing a cost-effective, enhanced procedure that is environmentally benign and allows high REE recovery while reducing/eliminating ammonium sulfate usage. A processing route employing a lixiviant system consisting of simulated sea water (equivalent to about 0.5 mol/L NaCl) in conjunction with chelating agents was also explored, in order to offer a process alternative for situations with restricted access to fresh water (either due to remote location or to lower the operating costs). Screening criteria for the selection of chelating agents were established and experiments were conducted to assess the efficiency of selected reagents in terms of REE recovery. The results were compared to extraction levels obtained during conventional ion-exchange leaching procedures with ammonium sulfate and simulated sea water only. It was found that stoichiometric addition of N,N′-ethylenediaminedisuccinic acid (EDDS) and nitrilotriacetic acid-trisodium form (NTA-Na3) resulted in 10–20% increased REE extraction when compared to lixiviant only, while achieving moderate Al co-desorption and maintaining neutral pH values in the final solution.
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Gurinenko, N. S., and E. I. Batyanovskiy. "Influence of Polyfunctional Additive on Hardening Process and Properties of Cement Concrete." Science & Technique 18, no. 4 (August 13, 2019): 330–38. http://dx.doi.org/10.21122/2227-1031-2019-18-4-330-338.
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The paper presents results of research aimed at developing a new semi-functional concrete additive that provides an increase in rate and level of its strength growth while reducing energy costs to accelerate hardening process, as a basis for reducing energy intensity in manufacturing of concrete and reinforced concrete products and structures. Experimentally a rational ratio of components for a polyfunctional additive has been found of mass cement: a superplasticizer based on polycarboxylate resins (for example, “Stachement 2000” or “Relamiks PC”) – 0.5 %, ultradispersed microsilica (SiO2) – 1.0 %, sodium sulfate (Na2SO4), hardening accelerator – 0.5 %, aluminum sulfate (Al2(SO4)3), sealing additive structure ‒ 0.25 %. The mentioned components ensure the largest increase in strength of cement stone and structural heavy concrete. Results of derivatographic and X-ray phase analyses have shown that strength growth is based on formation of a fine-crystalline form of low-base crystalline silicates of CSH-silicate group, which complements traditionally formed C2SH by the reaction of threeand two-calcium silicate cement with water, as well as it is based on an increase in the number of neoplasms due to the reaction of Ca(OH)2 with amorphous SiO2 and ettringite 3CaO × Al2O3 × 3CaSO4 × 32H2O, being formed due to reactions with cement aluminates these are accelerating-compacting additive components, that in total provides an increase in density and strength of cement stone. While having the case with concrete, the effect is complemented by hardening the zone of contact between aggregate surface and cement stone due to the reaction between Ca(OH)2 and SiO2. These effects have been confirmed by growth (up to 38 %) of water which is chemically bound with cement in presence of a multifunctional additive in samples of cement stone, which is characterized by the largest strength. While using standardized testing methods, effectiveness of a multifunctional additive has been experimentally confirmed and it has been expressed in growth of quality characteristics and properties of structural heavy concrete: compressive strength – up to 40–60 %, flexural strength – up to 15 %, reduction of shrinkage – up to 50 % and water absorption – by 1.5–2 times, increase in frost resistance from brand F250 to F500, water resistance – from W6–W8 to W20.
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Kolesnyk, V. V., V. M. Orlyk, V. A. Zhaivoronok, V. V. Sobchenko, and H. O. Sobchenko. "PURIFICATION OF SINTERING GASES FROM SULFUR DIOXIDE." Energy Technologies & Resource Saving, no. 1 (March 18, 2022): 51–61. http://dx.doi.org/10.33070/etars.1.2022.05.
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Under the terms limited knowledge of the kinetics of the processes of chemisorption of sulfur oxides, an approach to qualitative determination of the chemisorption capacity of limestone-based adsorbents is proposed, which allows to optimize the hardware-technological design of the sulfur oxide capture process at the design stage. To take into account the high cost of effective fine adsorbents, it is proposed to recycle part of the source product, which contains an adsorbent with a residual adsorption capacity. Dependences for calculation of economy of fresh adsorbent are resulted. To reduce the effect of CaSO4 ballast product on the efficiency of sulfur oxide capture and reduce energy costs for recycling, it is proposed to segregate the recycle stream into unreacted or partially unreacted adsorbent and completely converted into calcium sulfate, followed by recirculation of the adsorbent only.
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Wang, Dan, Yihui Wu, Fang Guo, Zhiping Li, and Guangxue Wu. "Comprehensive assessment of system performance in a full-scale wastewater treatment plant with an anaerobic/anoxic/aerobic membrane bioreactor combined with the ozonation process." Water Science and Technology 78, no. 3 (July 31, 2018): 690–98. http://dx.doi.org/10.2166/wst.2018.344.
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Abstract The system performance, economic cost and environmental impact of a full-scale anaerobic/anoxic/aerobic/membrane bioreactor (3AMBR) combined with the ozonation process were evaluated. The 3AMBR/ozonation process removed biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids, NH4-N and total phosphorus efficiently, with removal percentages above 94%, while the total nitrogen removal percentage was only 70%. The multiple linear regression analysis showed that hydraulic retention time (HRT) had a significant effect on nitrogen removal. A low HRT benefited nitrogen removal. Ferrous sulfate dosage close to the optimal value and a high mixed liquid suspended solid could enhance the phosphorus removal. The electricity cost accounted for 88% of the total economic costs. Greenhouse gas (GHG) emissions from the BOD oxidation and endogenous decay accounted for more than 50% of total emissions. The second largest GHG emission source was electricity consumption, accounting for 41%. The key to reduce the eutrophication was to enhance nitrogen removal. The composite cost of the 3AMBR/ozonation process was 251 CNY/t CODeq removed, among which economic cost accounted for 82.5%, while environmental impact cost accounted for a small proportion.
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Gomes, José Cosme Cunha, C. P. Souza, Uilame Umbelino Gomes, Jean R. Gavarri, Jean P. Dallas, and C. Leroux. "Leaching Process of Cerium Extraction from Mixture of Cerite-Monazite Mineral." Materials Science Forum 514-516 (May 2006): 1653–57. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.1653.
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Rare earth oxides have been widely investigated in catalysis as structured and electronic promoters to improve the activity and thermal stability of catalysts. Cerium has an important role in three-way catalysis and fluid catalytic cracking, two significant catalytic processes by their economic relevance and tonnage. Cerium and other rare earths have been studied as possible heterogeneous catalysts at selective oxidation of hydrocarbons. Cerite and monazite are minerals with high concentration of cerium element. Extraction of cerium metal using conventional leaching processes has shown low yields or high costs. The main purpose of this research work is to optimize the parameters in cerium purification stage from this mineral using leaching process. To separate particles with different granulometries, the mineral is ground and fractioned with sieves of 80, 200, 250 and 400 mesh. In order to put off organic components and oxidize cerium(III) to cerium(IV), samples were roasted at 1073K by twenty-four hours. The roasted samples were solubilized by acid attack (leaching) for approximately twenty-four hours; according to the acid used hydrochloric or sulfuric), cerium and other trivalent elements are solubilized as chloride or sulfate solution. Cerium was extracted by selective precipitation at pH~3,4 using ammonium or natrium hydroxide as pH changer. After filtration and drying, the precipitated product was characterized by XRD (x-ray diffraction), and then process efficiency was determined (cerium percentage and the different phases in the powder). Particles granulometry, roasting process (time and temperature), as well as leaching parameters (acid used, time, temperature and concentration of reagents) were the main variables studied.
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Figueiredo, A., L. Amaral, and J. Pacheco. "Forecasting saltwater intrusion volume and sulfate content in a wastewater collection system. Case study: Barreiro/Moita WWTP, Portugal." Journal of Water and Climate Change 12, no. 8 (October 27, 2021): 3648–60. http://dx.doi.org/10.2166/wcc.2021.375.
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Abstract The presence of salt water from the Tagus Estuary has been identified in the influent at Barreiro/Moita Wastewater Treatment Plant (WWTP), Portugal. The intrusion occurs throughout damaged sections and direct vectors in the wastewater collection system, during high tide levels, changing the wastewater characteristics and impacting the WWTP process. This study designed models to quantify this problem, enabling more effective countermeasures within the right timing. The proposed models estimate the average volume of salt water and sulfate () load for each high tide period. The laboratory results show strong correlations between the influent electrical conductivity (EC) and percentage of salt water in WWTP inflow (0.9909), and between EC and concentration in WWTP influent (0.9797). The forecast models also show good correlation between the high tide levels with volume of salt water (0.9145) and load (0.9162) entering the system. Considering the total monthly inflow, the highest percentage of salt water registered in WWTP inflow was 3.6%. During high tide periods, critical situations have been assessed with up to 53.9% of salt water in the WWTP inflow, increasing energy consumption and costs in pumping stations.
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Ladeira, Bruno Loureiro, Janaína Fernandes de Medeiros Burkert, and Carlos André Burkert. "Experimental Design as a Tool for the Optimization of Lipid Production by Meyerozyma guilliermondii in a Crude Glycerol-based Medium." Journal of Applied Biotechnology 5, no. 2 (August 16, 2017): 88. http://dx.doi.org/10.5296/jab.v5i2.11497.
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Biodiesel production, which has been increasing worldwide, transformed crude glycerol, the main byproduct of the reaction, into a commodity of low commercial value, especially due to the high costs involved in its purification process and to the fact that the market cannot account for its generation. Therefore, this study aims at contributing to the search for technological alternatives to the use of surplus crude glycerol so as to add value to this byproduct by using it as the carbon source for the yeast Meyerozyma guilliermondii, in order to yield lipids. The Central Composite Rotational Design was proposed to establish empirical models, codified for lipid content, production and productivity as the result of concentrations of Magnesium Sulfate Heptahydrate (MgSO4.7H2O) and yeast extract. In the optimized conditions, the lipid content in dry basis, lipid production and lipid productivity were 8.25%, 1.10 g.L-1 and 0.0092 g.L-1.h-1, respectively obtained.
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Turek, Marian, Krzysztof Mitko, Paweł Skóra, Piotr Dydo, Agata Jakóbik-Kolon, Aleksa Warzecha, and Klaudia Tyrała. "Improving the Performance of a Salt Production Plant by Using Nanofiltration as a Pretreatment." Membranes 12, no. 12 (November 25, 2022): 1191. http://dx.doi.org/10.3390/membranes12121191.
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The Dębieńsko plant in Czerwionka-Leszczyny, Poland, producing evaporated salt from the saline mine water, faces increasing operating costs due to its high energy consumption. To improve the performance of the plant, a two-pass nanofiltration with intermediate crystallization of gypsum was proposed as a pretreatment. Based on the results of pilot-scale research, it was found that the removal of most of the calcium, magnesium, and sulfate allows a substantial reduction in the concentration of these components in the concentrated brine, which is then directed to a sodium chloride crystallization evaporator. This makes it possible to increase salt yield from the current 58.8% to 76.1% and indirectly reduce energy consumption from 1350 kWh/t to 1068 kWh/t. At the same time, the volume of the highly saline post-crystallization lyes is decreased by 66%, and a new stream is obtained: a Mg-rich solution, which could be used for magnesium hydroxide recovery.
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Rumky, Jannatul, Ekaterina Bandina, and Eveliina Repo. "Behavior of Sludge Dewaterability and Nutrient Contents after Treatment with Cellulose-Based Flocculants with Combined PTS and Catalytic Behavior of Sludge towards Tetracycline Degradation." Resources 12, no. 2 (January 17, 2023): 17. http://dx.doi.org/10.3390/resources12020017.
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Wastewater treatment plants are increasingly interested in adopting inorganic coagulants and organic flocculants in their sludge treatment process since sludge disposal costs more than half of the overall operational costs. This study synthesized poly titanium sulfate (PTS) by different molar ratios and used the best one with cellulose-based flocculants for sludge conditioning. PTS synthesized with a 1:2 molar ratio showed the lowest capillary suction time (CST) of sludge and was selected for further studies with cellulose-based flocculants. As bio-based flocculants have gained popularity due to current environmental problems, cationized cellulose-based flocculants (Ce-CTA) were used in this work with or without PTS for sludge treatment. After coagulation–flocculation, dewaterability of sludge enhanced, and the Lowry and Anthrone method was used to assess proteins and polysaccharides. Next, metal content and nutrients such as total phosphorus, phosphate, and nitrate were measured by ICP-OES and IC, and we found promising results of phosphate especially at pH 3. Higher total phosphorus content was found at pH 3 and 9, and even at pH 6 after PTS or PTS+Ce-CTA treatment. In addition, PTS-treated sludge materials also showed catalytic behavior, suggesting a new research avenue for future development. Based on this study, the PTS+Ce-CTA combination is promising for sludge treatment and nutrient recovery, along with the possibility for the further valorization of the sludge materials.
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Menta, Venkata Gireesh K., Irfan Tahir, and Abdulaziz Abutunis. "Effects of Blending Tobacco Lignin with HDPE on Thermal and Mechanical Properties." Materials 15, no. 13 (June 23, 2022): 4437. http://dx.doi.org/10.3390/ma15134437.
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Depletion of fossil fuels and the detrimental environmental impacts of synthetic plastics have prompted a global interest in bio-based polymers. Lignin is an abundant, unused, and low-value byproduct of pulping and biochemical operations that has the potential to decrease the need for plastics derived from petroleum. Melt blending is one of the easiest strategies for expanding the commercial applications of lignin. Concerns remain, however, regarding the negative effects of lignin on the final composite material’s performance, and the increase in manufacturing costs. This study investigates the effects of blending lignin extracted from tobacco using a novel one-step processing technique on injection molding parameters, and the mechanical, physical, and thermal properties of high-density polyethylene (HDPE). By extruding HDPE pellets and lignin powder, varying blend concentrations (0, 5, 10, 15, and 30% wt.) were produced. Scanning electron microscopy (SEM) and optical microscopy were used to investigate the compatibility of the blend morphology. Results indicated that interfacial interactions were achieved as particles of tobacco lignin were well dispersed and uniformly distributed throughout HDPE. Intermolecular interactions between HDPE and lignin were also discovered through Fourier-transform infrared (FTIR) spectral analyses. The tensile test results showed that increase in lignin content up to 15% wt. had little effect on tensile strength, but at 30% wt., a 19% reduction was observed. With the addition of 5, 10, 15, and 30% wt. of lignin, the tensile modulus increased by 4%, 29%, 25%, and 8%, respectively. TGA results demonstrated that at 15% and 30% wt., tobacco lignin acted as a thermal stabilizer. The processability study revealed that tobacco lignin could be processed easily using injection molding without requiring significant changes to the process parameters. Overall, tobacco lignin showed great promise as a biodegradable HDPE filler.