Journal articles: 'HTL reaction conditions'

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Jatoi, Abdul Sattar, Ayaz Ali Shah, Jawad Ahmed, Shamimur Rehman, Syed Hasseb Sultan, Abdul Karim Shah, Aamir Raza, et al. "Hydrothermal Liquefaction of Lignocellulosic and Protein-Containing Biomass: A Comprehensive Review." Catalysts 12, no. 12 (December 9, 2022): 1621. http://dx.doi.org/10.3390/catal12121621.

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Hydrothermal liquefaction (HTL) is a thermochemical depolymerization technology, also known as hydrous pyrolysis, that transforms wet biomass into biocrude and valuable chemicals at a moderate temperature (usually 200–400 °C) and high pressure (typically 10–25 MPa). In HTL, water acts as a key reactant in HTL activities. Several properties of water are substantially altered as the reaction state gets closer to the critical point of water, which can result in quick, uniform, and effective reactions. The current review covers the HTL of various feedstocks, especially lignocellulosic and high protein-containing feeds with their in-depth information of the chemical reaction mechanisms involved in the HTL. Further, this review gives insight and knowledge about the influencing factors such as biomass pretreatment, process mode, process conditions, etc., which could affect the efficiency of the hydrothermal process and biocrude productivity. In addition, the latest trends, and emerging challenges to HTL are discussed with suitable recommendations.

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Nonchana, Thanakrit, and Kulachate Pianthong. "Bio-oil synthesis from cassava pulp via hydrothermal liquefaction: Effects of catalysts and operating conditions." International Journal of Renewable Energy Development 9, no. 3 (May 30, 2020): 329–37. http://dx.doi.org/10.14710/ijred.9.3.329-337.

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The influence of catalysts and operating conditions on the conversion and yield of bio-crude oil from CP via the hydrothermal liquefaction technique (HTL) were studied. HTL is commonly used to convert CP to bio-crude oil (BCO). Three independent factors—reaction temperatures (250–350 °C), reaction times (30–90 min), and CP concentrations (5–20 wt.%)—were investigated. Proximate analysis showed that CP comprises 84.61% volatile matter and 13.59% fixed carbon. The ultimate analysis demonstrated that CP has carbon and oxygen levels of 44.86% and 46.91%, respectively. Thermogravimetric analysis showed that CP begins to decompose at temperatures between 250–350 °C. The results show that KOH is the most suitable catalyst because it provides the highest BCO yield when compared to other catalysts under the same operating conditions. We found that the ideal operating conditions for maximizing BCO performance are 250 °C, pressure of 17.0 MPa, 90 min, 5 wt.%. Under these conditions, Fourier transforms infrared analysis showed that the most abundant chemical bonds found in BCO were CH3-O, CH3-C, and CH3. The findings of the CHNS analysis showed that BCO has an H/C ratio of 2.25, similar to that of petroleum and bio-diesel. Results from a gas chromatograph-mass spectrometer indicate that a fatty acid group is the main component of BCO. ©2020. CBIORE-IJRED. All rights reserved

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Han, Yang, Kent Hoekman, Umakanta Jena, and Probir Das. "Use of Co-Solvents in Hydrothermal Liquefaction (HTL) of Microalgae." Energies 13, no. 1 (December 25, 2019): 124. http://dx.doi.org/10.3390/en13010124.

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This study reviewed and summarized the literature regarding the use of alcohols during hydrothermal liquefaction (HTL) of algal biomass feedstocks. The use of both pure alcohols and alcohol-water co-solvents were considered. Based upon this review, laboratory experiments were conducted to investigate the impacts of different alcohol co-solvents (ethanol, isopropanol, ethylene glycol, and glycerol) on the HTL treatment of a specific saltwater microalga (Tetraselmis sp.) at two temperatures: 300 °C and 350 °C. Based on their performance, two co-solvents, isopropanol and ethylene glycol, were selected to explore the effects of varying solvent concentrations and reaction temperatures on product yields and biocrude properties. The type and amount of added alcohol did not significantly affect the biocrude yield or composition. Biocrude yields were in the range of 30–35%, while a nearly constant yield of 21% insoluble products was observed, largely resulting from ash constituents within the algal feedstock. The benefits of using alcohol co-solvents (especially isopropanol) were the reduced viscosity of the biocrude products and reduced rates of viscosity increase with biocrude aging. These effects were attributed mainly to the physical properties of the co-solvent mixtures (solubility, polarity, density, etc.) rather than chemical processes. Under the reaction conditions used, there was no evidence that the co-solvents participated in biocrude production by means of hydrogen donation or other chemical processes. Recovery and recycling of the co-solvent present various challenges, depending upon the type and amount of the co-solvent that is used. For example, glycol solvents are recovered nearly completely within the aqueous product stream, whereas simple alcohols are partitioned between the biocrude and aqueous product streams. In commercial applications, the slight benefits provided by the use of co-solvents must be balanced by the challenges of co-solvent recovery and recycling.

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Wei, Xuan, and Dengfei Jie. "Optimization to Hydrothermal Liquefaction of Low Lipid Content Microalgae Spirulina sp. Using Response Surface Methodology." Journal of Chemistry 2018 (2018): 1–9. http://dx.doi.org/10.1155/2018/2041812.

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The production and nature of the biocrude obtained from Spirulina sp. by hydrothermal liquefaction (HTL) technology is focused in this investigation. Our aim is to evaluate the interaction of different factors on the bio-oil production through HTL using microalgae that contains relatively low lipid content and high protein. Optimization of three key parameters—concentration (mass of algae per mass of solvent), reaction temperature, and holding time—was carried out by response surface methodology (RSM). In this work, we used central composite design to conduct the experiment process. Graphical response surface and contour plots were used to locate the optimum point. The final results showed that the optimum concentration, temperature, and holding time were 10.5%, 357°C, and 37 min, respectively. Under the optimum conditions established, yield of the biocrude (41.6 ± 2.2%) was experimentally obtained using the fresh microalgae. This study showed the potential of bio-oil production of Spirulina sp. by HTL technology, but it still needs more improvement of the biocrude for utilization.

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Halleraker, Hilde V., Solmaz Ghoreishi, and Tanja Barth. "Investigating reaction pathways for formic acid and lignin at HTL conditions using 13C-labeled formic acid and 13C NMR." Results in Chemistry 2 (January 2020): 100019. http://dx.doi.org/10.1016/j.rechem.2019.100019.

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Ong, Mei Yin, and Saifuddin Nomanbhay. "Optimization Study on Microwave-Assisted Hydrothermal Liquefaction of Malaysian Macroalgae Chaetomorpha sp. for Phenolic-Rich Bio-Oil Production." Energies 15, no. 11 (May 27, 2022): 3974. http://dx.doi.org/10.3390/en15113974.

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There are several methods of biomass conversion, including hydrothermal liquefaction (HTL). The implementation of microwave technology in the HTL process is still new, especially on the conversion of marine biomass into bio-crude. In this work, the macroalgae Chaetomorpha sp. was used as the biomass feedstock to produce phenolic-rich bio-oil through microwave-assisted HTL. Chaetomorpha sp. was abundantly found in Malaysia, creating a green tides issue. By utilizing these algae, the green tide issue can be solved and value-added bio-oil is obtained. However, bio-oil from macroalgae has a relatively low heating value, restricting its fuel application. Therefore, it is suggested to be used for bio-polymer synthesis, including bio-based phenol formaldehyde. In this study, the effect of different parameters, such as reaction temperature, preloaded pressure, water-to-algal biomass ratio, and holding time, on both the bio-oil yield and phenolic yield was evaluated. Folin–Ciocalteu method was introduced as the phenolic determination method and the optimal conditions were located by using Response Surface Methodology (RSM). As a results, an optimal biodiesel yield and phenolic yield of 21.47 wt% and 19.22 wt% Gallic Acid Equivalent was obtained at a reaction temperature of 226 °C, 42 bar preloaded pressure and 30:1 water-to-algal biomass ratio after 79 min. Sensitivity analysis also concluded that the water-to-algal biomass ratio is the most influential factor, followed by the preloaded pressure. The FTIR spectrum of the bio-oil produced indicated the presence of different functional group of compounds. In short, Chaetomorpha sp. has been successfully converted into valuable bio-oil through microwave-assisted HTL.

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Eladnani, Ikram, Maria Paola Bracciale, Martina Damizia, Seyedmohammad Mousavi, Paolo De Filippis, Rajae Lakhmiri, and Benedetta de Caprariis. "Catalytic Hydrothermal Liquefaction of Brachychiton populneus Biomass for the Production of High-Value Bio-Crude." Processes 11, no. 2 (January 19, 2023): 324. http://dx.doi.org/10.3390/pr11020324.

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The current study focused on the heterogenous catalytic hydrothermal liquefaction (HTL) of Brachychiton populneus biomass seed, using Ni as hydrogenation catalyst and Fe as active hydrogen producer. The activity of Ni metal and of Ni/Al2O3 in the HTL of seed (BS) and of a mixture of seed and shell (BM) was studied. To establish the best operating process conditions, the influence of variation of temperature and reaction time on the product yields was also examined. The highest bio-crude yields of 57.18% and 48.23% for BS and BM, respectively, were obtained at 330 °C and 10 min of reaction time, in the presence of Ni/Al2O3 as catalyst and Fe as hydrogen donor. Elemental analysis results showed that at these operative conditions, an increase of the higher heating value (HHV) from 25.14 MJ/kg to 38.04 MJ/kg and from 17.71 MJ/kg to 31.72 MJ/kg was obtained for BS and BM biomass, respectively, when the combination of Fe and Ni/Al2O3 was used. Gas chromatography–mass spectrometry (GC-MS) and Fourier transform infrared spectroscopy (FT-IR), used to determine the oils’ chemical compositions, showed that the combined presence of Fe and Ni/Al2O3 favored the hydrodeoxygenation of the fatty acids into hydrocarbons, indeed their amount increased to ≈20% for both biomasses used. These results demonstrate that the obtained bio-crude has the capacity to be a source of synthetic fuels and chemical feedstock.

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Rizzo, Andrea Maria, and David Chiaramonti. "Blending of Hydrothermal Liquefaction Biocrude with Residual Marine Fuel: An Experimental Assessment." Energies 15, no. 2 (January 10, 2022): 450. http://dx.doi.org/10.3390/en15020450.

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As with all transport modes, the maritime sector is undergoing a drastic transition towards net zero, similar to the path in which Aviation is already engaged through global decarbonization programs such as CORSIA for the International Civil Aviation Organization, or the Emission trading Scheme of the European Union). Maritime indeed shares with Aviation a common element: the difficulty of shifting to electric in the short to medium term. Therefore, the use of sustainable fuels represents the main and only relevant option in this timeframe. As sustainable biofuels will be used as blend components in the case of large-scale deployment, it is necessary to investigate the behavior of bio- and fossil-based fuels when mixed in various percentages, in particular for low quality products such as HTL (HydroThermal Liquefaction) and fast pyrolysis oils from lignocellulosic biomass and waste. Biocrude from subcritical hydrothermal liquefaction of undigested sewage sludge, produced at reaction conditions of 350 °C and 200 bar in a continuous HTL pilot scale unit, was manually mixed at 70 °C with residual marine fuel (low-sulphur type F-RMG-380 per ISO 8217) at two different nominal biocrude shares, respectively 10 wt.% and 20 wt.% in the mixture. While the former blend resulted in the technically complete dissolution of biocrude in the fossil component, the latter sample formed biocrude agglomerates and only partial dissolution of the biocrude aliquot in marine fuel could be achieved (calculated between 14–16 wt.%). The blend with 10 wt.% of SS biocrude in the mixture resulted in compliance with limits of total acid number (TAN), inorganics (in particular vanadium, sodium, silicon and aluminum) and sulphur content, while only the ash content was slightly above the limit.

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Mani, Devendra, Ricardo Pérez de Tudela, Raffael Schwan, Nitish Pal, Saskia Körning, Harald Forbert, Britta Redlich, et al. "Acid solvation versus dissociation at “stardust conditions”: Reaction sequence matters." Science Advances 5, no. 6 (June 2019): eaav8179. http://dx.doi.org/10.1126/sciadv.aav8179.

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Chemical reactions at ultralow temperatures are of fundamental importance to primordial molecular evolution as it occurs on icy mantles of dust nanoparticles or on ultracold water clusters in dense interstellar clouds. As we show, studying reactions in a stepwise manner in ultracold helium nanodroplets by mass-selective infrared (IR) spectroscopy provides an avenue to mimic these “stardust conditions” in the laboratory. In our joint experimental/theoretical study, in which we successively add H2O molecules to HCl, we disclose a unique IR fingerprint at 1337 cm−1 that heralds hydronium (H3O+) formation and, thus, acid dissociation generating solvated protons. In stark contrast, no reaction is observed when reversing the sequence by allowing HCl to interact with preformed small embryonic ice-like clusters. Our ab initio simulations demonstrate that not only reaction stoichiometry but also the reaction sequence needs to be explicitly considered to rationalize ultracold chemistry.

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Arunan, E., R. Rengarajan, and D. W. Setser. "Infrared chemiluminescence studies of the reactions of H atoms with CCl3, CF2Cl, and CH2CH2Cl radicals at 300 and 475 K: recombination–elimination vs. abstraction mechanisms." Canadian Journal of Chemistry 72, no. 3 (March 1, 1994): 568–76. http://dx.doi.org/10.1139/v94-080.

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The reactions of H atoms with CCl3, CF2Cl, and CH2CH2Cl radicals have been studied in a flow reactor at 300 and 475 K by observation of the infrared emission from the HCl and HF products. These reactions were observed as secondary reactions from the H + CCl3Br, CF2ClBr, and CH2Cl–CH2I chemical systems. The conditions in the flow reactor were controlled so that the nascent vibrational distributions of HCl and HF were recorded. The pattern of vibrational energy disposal to HCl was used to differentiate between Cl atom abstraction and recombination–elimination mechanisms. The H atom reactions with CCl3 and CF2Cl radicals occur only via a recombination–elimination mechanism and give HCl(υ) or HF(υ) in a unimolecular step. Thus, the Cl atom abstraction reactions must have ≥3.0 kcal mol−1 higher activation energy than the recombination reaction. From observation of the ratio of the HCl and HF products from CHF2Cl*, the difference in threshold energies for HF and HCl elimination was determined to be ∼13 kcal mol−1. On the other hand, Cl atom abstraction does compete with recombination–elimination in the H + CH2CH2Cl reaction, the branching fraction is ∼0.3 at 300 K and ∼0.6 at 475 K.

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Chin, Terence, Rong Yan, David Tee Liang, and Joo Hwa Tay. "Hydrated Lime Reaction with HCl under Simulated Flue Gas Conditions." Industrial & Engineering Chemistry Research 44, no. 10 (May 2005): 3742–48. http://dx.doi.org/10.1021/ie040206z.

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Tagi, Rawa M., Raad J. Al-Timimi, Muna M. Hassan, and Mohammed J. Hamzah. "Spectrophotometric determination of promethazine HCl in pure and dosage forms." Journal of Biotechnology Research Center 13, no. 1 (January 1, 2019): 52–57. http://dx.doi.org/10.24126/jobrc.2019.13.1.568.

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Background: The research is involved development a new spectrophotometric method based on the oxidative coupling reactions for determination of important phenothiazine drug which is promethazine HCl in pure solutions and local pharmaceutical preparations. Materials and methods: The Standard promethazine HCl was treated with organic reagent of P-Chloroaniline as a coupling reagent in the presence of oxidizing agent Ammonium Cerric (IV) Sulphate, the reaction leads to the formation a blue –greenish color product that has a maximum absorption at 603nm. Results: The variables of reaction conditions including optimum volumes of both reagent and oxidizing agent, acidity of the reaction medium, order of addition and stability time were studied. The obtained results of the purposed method shows that a Beer law is obeyed in the range of 7-40ppm with a correlation coefficient (r2) of 0.9981. While the molar absorptivity (ξ) of 1.861x103 L.mol-1.cm-1, sandal sensitivity(s) of 0.172μg.cm-2, limit of detection (LOD) of 4.02ppm and limit of quantification (LOQ) of 13.39ppm were obtained. The developed method was compared with the standard method adopted by USP using F and t-tests and the results shows no significant deferent between both methods. Conclusion: The analytical method was also applied successfully for pharmaceutical preparations containing promethazine HCl.

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Duczynski, Jeremy A., Rebecca Fuller, and Scott G. Stewart. "tert-Butyldimethylsilyl Amine (TBDMS-NH2): A Mild and Green Reagent for the Protection of Benzyl Alcohols, Phenols, and Carboxylic Acids under Solvent-Free Conditions." Australian Journal of Chemistry 69, no. 10 (2016): 1172. http://dx.doi.org/10.1071/ch16097.

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Herein, we present the use of the tert-butyldimethylsilyl amine (TBDMS-NH2) as a silylating reagent for phenols, benzyl alcohols, and carboxylic acids. Unlike other silyl protection reactions, this reported process with TBDMS-NH2 does not involve the formation of HCl. Importantly, we report the efficacy of this reagent in operating under solvent-free conditions and enabling short reaction times.

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Rajaram, Vijayaragavan, Bharathi Varadharaj, and Prakash Jayavel. "Impact of electroosmotic flow on a Casson fluid driven by chemical reaction and convective boundary conditions." Heat Transfer 50, no. 5 (March 11, 2021): 4993–5019. http://dx.doi.org/10.1002/htj.22113.

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Peng, Cheng, Benaiah U. Anabaraonye, John P. Crawshaw, Geoffrey C. Maitland, and J. P. Martin Trusler. "Kinetics of carbonate mineral dissolution in CO2-acidified brines at storage reservoir conditions." Faraday Discussions 192 (2016): 545–60. http://dx.doi.org/10.1039/c6fd00048g.

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We report experimental measurements of the dissolution rate of several carbonate minerals in CO₂-saturated water or brine at temperatures between 323 K and 373 K and at pressures up to 15 MPa. The dissolution kinetics of pure calcite were studied in CO₂-saturated NaCl brines with molalities of up to 5 mol kg⁻¹. The results of these experiments were found to depend only weakly on the brine molality and to conform reasonably well with a kinetic model involving two parallel first-order reactions: one involving reactions with protons and the other involving reaction with carbonic acid. The dissolution rates of dolomite and magnesite were studied in both aqueous HCl solution and in CO₂-saturated water. For these minerals, the dissolution rates could be explained by a simpler kinetic model involving only direct reaction between protons and the mineral surface. Finally, the rates of dissolution of two carbonate-reservoir analogue minerals (Ketton limestone and North-Sea chalk) in CO₂-saturated water were found to follow the same kinetics as found for pure calcite. Vertical scanning interferometry was used to study the surface morphology of unreacted and reacted samples. The results of the present study may find application in reactive-flow simulations of CO₂-injection into carbonate-mineral saline aquifers.

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Alferiev, Ivan S., and Sergey Yu Bobkov. "Cyclic Oligophosphonic Anhydrides Stable in Aqueous Media." Zeitschrift für Naturforschung B 47, no. 9 (September 1, 1992): 1213–24. http://dx.doi.org/10.1515/znb-1992-0902.

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Depending on reaction conditions, the phosphonylation of N-alkylacetamides with H3PO3– PCl3 in B · HCl media (B = Py, Bu3N) gives either 1-alkylaminoethylidene-1,1-bisphosphonic acids (la–e) or previously unknown 1-alkylaminobutane-1,1,3,3-tetrayl-tetrakisphosphonic dianhydrides (2a–e). The latter convert into monocyclic forms (3a–e) under mild acidic hydrolysis. Acyclic forms (4a–e) cannot be isolated. In the presence of higher N,N-dialkylamides the phosphonylation of acetamides affords the higher dianhydrides (2f–h). Strong acidic hydrolysis of 2 or 3 yields 3,3-diphosphonocarboxylic acids (5a–c). Reacting with H3PO3–PHal3 in B · HHal (Hal = Cl, Br), the amides R1CONHR2 (R1 ≠ H, Me; R2 = Alk, H) give both N-alkyl- (or N-unsubstituted) 1-aminoalkylidene-1,1-bis-phosphonic acids (6a–j) and their cyclic dimeric anhydrides (7a–g, i, j).

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Wohltmann, Ingo, Ralph Lehmann, and Markus Rex. "A quantitative analysis of the reactions involved in stratospheric ozone depletion in the polar vortex core." Atmospheric Chemistry and Physics 17, no. 17 (September 8, 2017): 10535–63. http://dx.doi.org/10.5194/acp-17-10535-2017.

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Abstract. We present a quantitative analysis of the chemical reactions involved in polar ozone depletion in the stratosphere and of the relevant reaction pathways and cycles. While the reactions involved in polar ozone depletion are well known, quantitative estimates of the importance of individual reactions or reaction cycles are rare. In particular, there is no comprehensive and quantitative study of the reaction rates and cycles averaged over the polar vortex under conditions of heterogeneous chemistry so far. We show time series of reaction rates averaged over the core of the polar vortex in winter and spring for all relevant reactions and indicate which reaction pathways and cycles are responsible for the vortex-averaged net change of the key species involved in ozone depletion, i.e., ozone, chlorine species (ClOx, HCl, ClONO2), bromine species, nitrogen species (HNO3, NOx) and hydrogen species (HOx). For clarity, we focus on one Arctic winter (2004–2005) and one Antarctic winter (2006) in a layer in the lower stratosphere around 54 hPa and show results for additional pressure levels and winters in the Supplement. Mixing ratios and reaction rates are obtained from runs of the ATLAS Lagrangian chemistry and transport model (CTM) driven by the European Centre for Medium-Range Weather Forecasts (ECMWF) ERA-Interim reanalysis data. An emphasis is put on the partitioning of the relevant chemical families (nitrogen, hydrogen, chlorine, bromine and odd oxygen) and activation and deactivation of chlorine.

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Oikonomopoulos, Panagiotis, Varvara Pagkali, Evangelia Kritikou, Anthi Panara, Marios G. Kostakis, Nicolaos S. Thomaidis, Thomais G. Tziotzi, Anastasios Economou, Christos Kokkinos, and Giannis S. Papaefstathiou. "Oxalamide Based Fe(II)-MOFs as Potential Electrode Modifiers for Glucose Detection." Chemistry 5, no. 1 (December 20, 2022): 19–30. http://dx.doi.org/10.3390/chemistry5010002.

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In an attempt to expand the coordination chemistry of N,N’-bis(2,4-dicarboxyphenyl)-oxalamide (H6L) ligand, we isolated and structurally characterized two new Fe(II) Metal-Organic Frameworks (MOFs), namely [Fe2(H2L)(H2O)5] (3D-Fe-MOF) and [Fe(H4L)(H2O)2]∙2H2O, (2D-Fe-MOF) by carefully adjusting the reaction conditions to achieve the optimal degree of deprotonation of the bridging ligand. Both MOFs were found stable in water, as evidenced by powder X-ray diffraction data and their ability to sorb glucose (GLU) from either an aqueous solution or artificial sweat was investigated only to show negligible sorption. Α graphite paste sensor (GPE) using the 3D-Fe-MOF as a modifier was fabricated. Τhe 3D-Fe-MOF modified GPE was assessed for non-enzymatic GLU detection in aqueous solution at pH 6 via differential pulse voltammetry and the preliminary results were discussed.

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Cheng, Kui, Zhong-Lu You, and Hai-Liang Zhu. "New Method for the Synthesis of a Mononucleating Cyclic Peptide Ligand, Crystal Structures of its Ni, Zn, Cu, and Co Complexes, and Their Inhibitory Bioactivity Against Urease." Australian Journal of Chemistry 60, no. 5 (2007): 375. http://dx.doi.org/10.1071/ch06479.

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A novel cyclic peptide complex, NiL 1 (H2L = 12,24-dihydroxy-1,6-dioxo-2,5,14,17-tetraaza[6*6]metacyclophane-13,17-diene has been synthesized for the first time under solvothermal conditions through a one-pot synthetic procedure using nickel ion as the template reagent. It was found that other metal ions were not suitable for the direct template reagent in this reaction. The nickel ion was eliminated from the complex and the metal-free cyclic peptide ligand H2L was obtained through a series of reactions. Then, ZnII, CuII, and CoII were coordinated with H2L under the same solvothermal conditions to produce three isomorphous complexes ZnL 2, CuL 3, and CoL 4. Their inhibitory bioactivities against urease were then studied. The copper(ii) complex 3 was the strongest inhibitor against jack bean urease, while H2L, 2, and 4 showed weak or no inhibitory activity against this enzyme.

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Gallagher, MJ, MJ Gallagher, H. Noerdin, and H. Noerdin. "The Synthesis and Photochemistry of p-Dimethylamino-p′-nitrodiphenylethyne: a Push-Pull Acetylene." Australian Journal of Chemistry 38, no. 6 (1985): 997. http://dx.doi.org/10.1071/ch9850997.

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The title compound (2) was prepared as a possible precursor to a push- pull cyclobutadiene, and its photochemistry examined under a wide range of conditions. The principal reaction observed was loss of a methyl group, and no evidence for bimolecular reactions was observed. The alkyne (2) readily added water, acetic acid and HCl to give the expected products, but failed to react with Fe2(CO)9. 1H and 13C n.m.r , data are reported.

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Carruthers, Chris, and Heshel Teitelbaum. "Non-equilibrium kinetics of bimolecular reactions. Part 6. Transient rate coefficients." Canadian Journal of Chemistry 72, no. 3 (March 1, 1994): 714–20. http://dx.doi.org/10.1139/v94-096.

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The master equation is solved numerically for the time dependence of the vibrational level populations of HCl (treated as a simple harmonic oscillator) during the bimolecular exchange reaction, Br + HCl → HBr + Cl, taking into account the competition between reaction and vibrational equilibration subject to Landau–Teller T–V excitation. Strong deviations from Boltzmann distributions are found. A wide range of reactant concentrations, diluent concentrations and temperatures were explored. It was found that no significant reaction occurs before the establishment of a steady vibrational population distribution, confirming that the rate coefficient for non-equilibrium bimolecular exchange reactions can be determined from a simple analytical steady state treatment (J. Chem. Soc. Faraday Trans. 87, 229 (1991)). The rate of an isolated elementary bimolecular reaction, A + BC → AB + C, under non-equilibrium conditions can deviate seriously from the standard expression, Keq [A][BC], and is better given by the law[Formula: see text]where [R] is the concentration of the collisional equilibrator, R, and a and g are constants depending only on temperature. This generalized rate law describes not only the initial rate but also the rate all the way up to completion, in the absence of the reverse reaction.

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Wang, Jei-Pil, Dong-Hun Lee, Min-Seok Go, and Eun-Kyu So. "A Study on the Wet Process Conditions That Affect the Selective Recovery of Si from Photovoltaic Cells by Using the Cavitation Effect." Metals 12, no. 2 (January 25, 2022): 222. http://dx.doi.org/10.3390/met12020222.

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In this research, a study to selectively recover Si from end-of-life photovoltaic cells by using acid solutions (HNO3 and HCl) and the cavitation effect of an ultrasonic cleaner was carried out. To selectively recover Si from an end-of-life photovoltaic cell, after a leaching process was conducted by using an acid solution, the photovoltaic cell that had completed the reaction was cleaned with distilled water and dried in a drying oven (100 °C) for 24 h. The experiment was conducted with acid solution concentration, reaction temperature, reaction time, and ultrasonic intensity as variables. In the results of the experiment, the optimal process was determined to be a concentration of 3M, a reaction temperature of 60 °C, a reaction time of 90 min, and an ultrasonic intensity of 150 W when using the HNO3 solution and a concentration of 3M, a reaction temperature of 60 °C, a reaction time of 120 min, and an ultrasonic intensity of 150 W when using the HCl solution. At this time, Si purity was 99.78% for HNO3 and 99.85% for HCl and the Si recovery rate was 98.9% for HNO3 and 99.24% for HCl.

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Zupanc, Anže, and Marjan Jereb. "NaSH-HCl mediated reduction of sulfoxides into sulfides under organic solvent-free reaction conditions." Green Chemistry Letters and Reviews 13, no. 4 (October 1, 2020): 341–48. http://dx.doi.org/10.1080/17518253.2020.1838625.

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Nacca, Francesca Giulia, Bonifacio Monti, Eder João Lenardão, Paul Evans, and Claudio Santi. "A Simple Zinc-Mediated Method for Selenium Addition to Michael Acceptors." Molecules 25, no. 9 (April 26, 2020): 2018. http://dx.doi.org/10.3390/molecules25092018.

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In this work, we focused our attention on seleno-Michael type reactions. These were performed using zinc-selenolates generated in situ from diphenyl diselenide 1, 1,2-bis(3-phenylpropyl)diselenide 30, and protected selenocystine 31 via an efficient biphasic Zn/HCl-based reducing system. Alkenes with a variety of electron-withdrawing groups were investigated in order to gauge the scope and limitations of the process. Results demonstrated that the addition to acyclic α,β-unsaturated ketones, aldehydes, esters amides, and acids was effectively achieved and that alkyl substituents at the reactive β-centre can be accommodated. Similarly, cyclic enones undergo efficient Se-addition and the corresponding adducts were isolated in moderate to good yield. Vinyl sulfones, α,β-unsaturated nitriles, and chalcones are not compatible with these reaction conditions. A recycling experiment demonstrated that the unreacted Zn/HCl reducing system can be effectively reused for seven reaction cycles (91% conversion yield at the 7° recycling rounds).

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Wurfel, M. M., E. Hailman, and S. D. Wright. "Soluble CD14 acts as a shuttle in the neutralization of lipopolysaccharide (LPS) by LPS-binding protein and reconstituted high density lipoprotein." Journal of Experimental Medicine 181, no. 5 (May 1, 1995): 1743–54. http://dx.doi.org/10.1084/jem.181.5.1743.

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We have recently shown that lipopolysaccharide (LPS)-binding protein (LBP) is a lipid transfer protein that catalyzes two distinct reactions: movement of bacterial LPS (endotoxin) from LPS micelles to soluble CD14 (sCD14) and movement of LPS from micelles to reconstituted high density lipoprotein (R-HDL) particles. Here we show that LBP facilitates a third lipid transfer reaction: movement of LPS from LPS-sCD14 complexes to R-HDL particles. This action of LBP is catalytic, with one molecule of LBP enabling the movement of multiple LPS molecules into R-HDL. LBP-catalyzed movement of LPS from LPS-sCD14 complexes to R-HDL neutralizes the capacity of LPS to stimulate polymorphonuclear leukocytes. Our findings show that LPS may be transferred to R-HDL either by the direct action of LBP or by a two-step reaction in which LPS is first transferred to sCD14 and subsequently to R-HDL. We have observed that the two-step pathway of LPS transfer to R-HDL is strongly favored over direct transfer. Neutralization of LPS by LBP and R-HDL was accelerated more than 30-fold by addition of sCD14. Several observations suggest that sCD14 accelerates this reaction by serving as a shuttle for LPS: addition of LBP and sCD14 to LPS micelles resulted in LPS-sCD14 complexes that could diffuse through a 100-kD cutoff filter; LPS-sCD14 complexes appeared transiently during movement of LPS to R-HDL facilitated by purified LBP; and sCD14 could facilitate transfer of LPS to R-HDL without becoming part of the final LPS-R-HDL complex. Complexes of LPS and sCD14 were formed transiently when LPS was incubated in plasma, suggesting that these complexes may play a role as intermediates in the neutralization of LPS under physiological conditions. These findings detail a new activity for sCD14 and suggest a novel mechanism for lipid transfer by LBP.

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Liu, Zong-liang, Ren-mei Zhang, Ye Liu, Yan Guo, and Qing-guo Meng. "The Effects of Different Catalysts, Substituted Aromatic Aldehydes on One-Pot Three-Component Biginelli Reaction." Current Organic Synthesis 16, no. 1 (February 4, 2019): 181–86. http://dx.doi.org/10.2174/1570179416666181122100405.

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Aim and Objective: The Biginelli reaction, first reported in 1893, is one great example of the important multicomponent reactions reported from 1893. Under the same conditions, the influence of the common catalysts on the yield of the Biginelli reaction was investigated. </P><P> Materials and Method: To a round-bottom flask equipped with a spherical condenser were added 1,3- dicarbonyl compound (1.0 eq), urea (1.45 eq), aromatic aldehyde (1.0 eq), catalyst and methanol. The mixture was heated at reflux for 16 h. After cooling off, the mixture was filtered and washed with cold methanol to give DHPMs. Reaction solution was further purified by recrystallization with petroleum ether and ethyl acetate. Six catalytic systems, different 1,3-dicarbonyl compounds and different substituted aromatic aldehydes with varied substitutions are described for the Biginelli reaction. An analysis was also performed to study the factors that affect the yield of the reaction. </P><P> Results: When 1,3-dicarbonyl compound was ethyl acetoacetate, the CuCl/ conc.H2SO4 system gave the highest yield (90.5%). While when acetoacetamide was used, the yields of DHPMs in presence of PTSA/conc. HCl, conc. HCl or FeCl3•6H2O were all over 90%. Nine DHPMs with different substituents were obtained. Conclusion: The Lewis acid or mixed catalyst had no significant advantage over a single protonic acid as catalyst. Conc. HCl as the catalyst was found to be the most effective condition for the preparation of DHPMs. The aromatic aldehyde with weak electron-withdrawing substituent such as Br resulted in the best yield.

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Amonova, Dilnoza Mukhtarovna, Bakhtiyor Ikromovich Mukhitdinov, Abbaskhan Sabirkhanovich Turaev, Khusniddin Khasanbaevich Kirgizbayev, Azizbek Anvarzhanovich Boydedayev, Bobur Aktamovich Sindarov, and Zhakhongir Nematullaevich Bekmirzayev. "OBTAINING LOW-MOLECULAR WEIGHT GALACTOMANNANES AND STUDYING THEIR PHYSICO-CHEMICAL CHARACTERISTICS." chemistry of plant raw material, no. 2 (June 10, 2022): 51–60. http://dx.doi.org/10.14258/jcprm.2022029551.

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The aim of this study was studying the effect of acidic hydrolysis conditions on the molecular parameters of galactomannan, such as weight average degree of polymerization (DPw), weight average molecular weight (Mw), product yield, depolymerization reaction rate, and mannose/galactose (Man/Gal) ratio in the presence of hydrochloric acid and obtaining low molecular weight oligogalactomannans soluble in water. A preparing possibility low molecular weight galactomannans by acid hydrolysis of guar galactomannan (DPw=1160, Mw=563.8 kDa, Man/Gal=1.89) in the presence of hydrochloric acid was studied. The studies were carried out in hydrochloric acid solutions with various concentrations (0.05–1.0 mol/L) for different times (10–240 min) at a constant temperature (80 °C). In the course of the studies, effects of the reaction conditions on the molecular parameters of the product obtained were analyzed. The conducted reactions yielded low molecular weight galactomannans and oligogalactomannans with different molecular parameters (DPw=6–1021, Mw=2.6–505.1 kDa, Man/Gal=1.90–3.19) and yields (2.8–97.1%). Based on the results obtained, the optimal reaction conditions (HCl 0.1 mol/L, 240 min, 80 °C) were supposed for the preparation of galactomannan oligosaccharides. The structural studies of the products indicated that products with reduced galactose residues could be prepared by this method.

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GEORGE, STEVEN M., and FRANK E. LIVINGSTON. "DYNAMIC ICE SURFACE IN THE POLAR STRATOSPHERE." Surface Review and Letters 04, no. 04 (August 1997): 771–80. http://dx.doi.org/10.1142/s0218625x97000754.

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Heterogeneous reactions on polar stratospheric clouds (PSCs), such as ClONO2+HCl — Cl2+HNO3 , are important for an understanding of the production of active chlorine species (HOCl, Cl2 ) and Antarctic ozone depletion. H2O -ice forms the Type II PSCs and the nature of H2O -ice surfaces under stratospheric conditions may affect the heterogeneous chemistry. This review focuses on recent measurements of H2O adsorption kinetics on ice, H2O desorption kinetics from ice, H2O surface diffusion on ice and H2O diffusion into ice. These measurements reveal that the ice surface is extremely dynamic under polar stratospheric conditions. For example, the residence time for an H2O molecule on an ice surface at 188 K is only ~20 milliseconds before desorption and only ~0.4 milliseconds before diffusion into the ice bulk. The dynamic nature of the ice surface may significantly affect the adsorption, solvation, diffusion and reaction of the chlorine reservoir molecules ( ClONO2 , HCl). The dynamic ice surface may also serve as a model for the surfaces of other molecular solids.

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Liang, Xiaolei, Jinmei Qian, Yonggang Liu, Zhengmei Zhang, and Daqiang Gao. "Efficient electrocatalyst of α-Fe2O3 nanorings for oxygen evolution reaction in acidic conditions." RSC Advances 10, no. 49 (2020): 29077–81. http://dx.doi.org/10.1039/d0ra04262e.

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Chen, Xiao, Huawei Hu, Zhaoming Xia, Wei Gao, Wangyan Gou, Yongquan Qu, and Yuanyuan Ma. "CsPbBr3 perovskite nanocrystals as highly selective and sensitive spectrochemical probes for gaseous HCl detection." Journal of Materials Chemistry C 5, no. 2 (2017): 309–13. http://dx.doi.org/10.1039/c6tc04136a.

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31

Petrova, Irina M., Yury I. Lyakhovetsky, Nikolai S. Ikonnikov, and Nataliya N. Makarova. "The Influence of HCl Concentration on the Rate of the Hydrolysis–Condensation Reaction of Phenyltrichlorosilane and the Yield of (Tetrahydroxy)(Tetraphenyl)Cyclotetrasiloxanes, Synthesis of All Its Geometrical Isomers and Thermal Self-Condensation of Them under “Pseudo”-Equilibrium Conditions." Molecules 26, no. 14 (July 20, 2021): 4383. http://dx.doi.org/10.3390/molecules26144383.

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The rate of hydrolysis–condensation reaction of phenyltrichlorosilane in water-acetone solutions and the product yields were shown to significantly depend on the concentration of HCl (CHCl) in the solutions. The main product of the reaction was all-cis-(tetrahydroxy)(tetraphenyl)cyclotetrasiloxane. This was different from the earlier published results of analogous reactions of m-tolylSiCl3, m-ClPhSiCl3, and α-naphtylSiCl, in which some products of other types were formed. For example, trans-1,1,3,3-tetrahydroxy-1,3-di-α-naphtyldisiloxane was obtained in the case of α-naphtylSiCl3. All-cis-(tetrahydroxy)(tetraphenyl)cyclotetrasiloxane was treated in acetone with HCl to give the other three geometric isomers (cis-cis-trans-, cis-trans-, and all-trans-). The thermal self-condensation of these four isomers under “pseudo”-equilibrium conditions (under atmospheric pressure) was investigated in different solvents, in quartz or molybdenum glass flasks. The compositions of the products were monitored by APCI-MS and 29Si NMR spectroscopy. It was shown that all-cis- and cis-cis-trans-isomers in toluene or anisole mostly gave the cage-like Ph-T8,10,12,14 and uncompleted cage-like Ph-T10,12OSi(HO)Ph compounds. In contrast to these two isomers, the cis-trans–isomer in toluene mainly formed dimers with the loss of one or two molecules of water. However, in acetonitrile, significant amounts of Ph-T10,12 and Ph-T10,12OSi(HO)Ph species were formed along with the dimers. All-trans-isomer did not enter into the reaction at all.

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32

Muliani, Lia, and Bambang Sunendar. "Synthesis and Characterization of Nanocrystalline TiO₂ by Non-Aqueous Sol-Gel in Acidic Condition for Dye-Sensitized Solar Cells." Advanced Materials Research 789 (September 2013): 171–75. http://dx.doi.org/10.4028/www.scientific.net/amr.789.171.

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Nanocrystalline TiO2 has been synthesized through non-aqueous sol-gel using acetic acid (HOAc) and hydrochloric acid (HCl) as a catalyst. Titanium isopropoxide (TTIP) as precursor was prepared by reaction between TiCl4 with isopropyl alcohol (IPA) in concentration of 0.3 M. The sol-gel process employed at around 60°C using tert-butanol as solvent and HOAc was added as ligand to stabilize the reaction. Controlled hydrolysis and condensation reactions were achieved through in-taking of water molecules released from the esterification reaction of HOAc with tert-butanol. In this paper, the influence of acidic catalyst was described at the volume ratio of HOAc:HCl are 0:2 ; 1:1 and 2:0. The crystallinity and crystal phase of the samples were characterized by X-ray Diffraction and nanocrystalline TiO2 with anatase phase was resulted. The morphology of the TiO2 powder was analyzed by Scanning Electron Microscopy. Pore size and the BET surface area were determined by Brunauer-Emmett-Teller (BET) analysis. Nanocrystalline TiO2 produced was applied for photoelectrode of dye-sensitized solar cell. The optical properties of the TiO2 photoelectrodes were measured using by UV-Vis Spectrophotometer. The performance of the cell was measured using a solar simulator with light at an intensity of 50 mW/cm2 generated by a xenon lamp. The best efficiency of 0.5% was achieved for active area of 0.48 cm2.

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33

Lehmusto, Juho, Patrik Yrjas, Bengt Johan Skrifvars, and Mikko Hupa. "Detailed Studies on the High Temperature Corrosion Reactions between Potassium Chloride and Metallic Chromium." Materials Science Forum 696 (September 2011): 218–23. http://dx.doi.org/10.4028/www.scientific.net/msf.696.218.

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Recovery of energy from biomass and various waste–derived fuels by combustion has become important due to reduction of detrimental CO2 emissions. Biomass does, however, release significant amounts of chlorine and alkali metals, as e.g. HCl(g), KCl(g), KOH(g) and NaCl(g), into the gas phase during combustion. The alkali chlorides may cause deposits on superheater tubes, which interfere with operation and can lead to corrosion and/or blockage of the gas path. To prevent and diminish the problems mentioned above, better and more detailed knowledge of the reactions between potassium chloride and the tube materials during combustion is needed. These materials commonly contain, among other metals, chromium, which is thought to protect the rest of the material since it forms a very dense but thin oxide layer on the surface of the tube material. It has been suggested that the reaction between solid or partly molten KCl and chromium oxide is the one responsible for starting the complex series of corrosion reactions. In this work, the overall reaction between potassium chloride and chromium was studied through partial reactions with compounds known to participate to the overall reaction or to be formed during it. The reactions were studied in synthetic air by heating sample mixtures in a DTA/TGA (Differential Thermal Analysis/ Thermogravimetric Analysis) apparatus. Selected samples were also studied and analyzed with a scanning electron microscope equipped with an energy dispersive x-ray analyzer (SEM/EDXA). Under the used conditions both potassium chloride and potassium chromate reacted with pure chromium and chromium oxide. In the case of chromium, chromium oxide was formed via the formation of potassium chromate. In reactions including chromium oxide as reactant also potassium dichromate was detected.

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Yu, Xiaolin, Dmitry I. Pavlov, Alexey A. Ryadun, Andrei S. Potapov, and Vladimir P. Fedin. "Variable Dimensionality of Europium(III) and Terbium(III) Coordination Compounds with a Flexible Hexacarboxylate Ligand." Molecules 27, no. 22 (November 14, 2022): 7849. http://dx.doi.org/10.3390/molecules27227849.

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A reaction between 4,4′,4″-(benzene-1,3,5-triyltris(oxy))triphthalic acid (H6L) and lanthanide(III) nitrates (Ln = Eu3+, Tb3+) in water under the same conditions gave a molecular coordination compound [Tb(H4.5L)2(H2O)5]∙6H2O in the case of terbium(III) and a one-dimensional linear coordination polymer {[Eu2(H3L)2(H2O)6]∙8H2O}n in the case of europium(III). The crystal structures of both compounds were established by single-crystal X-ray diffraction, and they were further characterized by powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. The compounds demonstrated characteristic lanthanide-centered photoluminescence. The lanthanide-dependent dimensionality of the synthesized compounds, which are the first examples of the coordination compounds of hexacarboxylic acid H6L demonstrates its potential as a linker for new coordination polymers.

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35

Sutradhar, Manas, Elisabete Alegria, M. Guedes da Silva, Cai-Ming Liu, and Armando Pombeiro. "Peroxidative Oxidation of Alkanes and Alcohols under Mild Conditions by Di- and Tetranuclear Copper (II) Complexes of Bis (2-Hydroxybenzylidene) Isophthalohydrazide." Molecules 23, no. 10 (October 19, 2018): 2699. http://dx.doi.org/10.3390/molecules23102699.

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Bis(2-hydroxybenzylidene)isophthalohydrazide (H4L) has been used to synthesize the dinuclear [Cu2(1κNO2:2κN′O′2-H2L)(NO3)2(H2O)2] (1) and the tetranuclear [Cu4(μ-1κNO2:2κN′O2-H2L)2(μ-NO3)2(H2O)4]·2C2H5OH (2) complexes. The solvent plays an important role in determining the ligand behaviour in the syntheses of the complexes. An ethanol-acetonitrile mixture of solvents favours partials enolization in the case of 2. Both complexes have been characterized by elemental analysis, infrared radiation (IR), single crystal X-ray crystallography and electrochemical methods. The variable temperature magnetic susceptibility measurements of 2 show strong antiferromagnetic coupling between the central nitrato-bridged Cu (II) ions. The catalytic activity of both 1 and 2 has been screened toward the solvent-free microwave-assisted oxidation of alcohols and the peroxidative oxidation of alkanes under mild conditions. Complex 1 exhibits the highest activity for both oxidation reactions, leading selectively to a maximum product yield of 99% (for the 1-phenylethanol oxidation after 1 h without any additive) and 13% (for the cyclohexane oxidation to cyclohexyl hydroperoxide, cyclohexanol and cyclohexanone after 3 h).

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Zhang, Ji Ku, Lu Lu Dai, and Wei Tan. "Study of Manufacturing High Pure Chlorine Dioxide with Multi-Stage Compound Chlorine Dioxide Generator." Advanced Materials Research 550-553 (July 2012): 3125–30. http://dx.doi.org/10.4028/www.scientific.net/amr.550-553.3125.

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Based on the status that conversion rate of Single-stage compound chlorine dioxide generator is not high in the market，we designed a multi-stage compound chlorine dioxide generator and discussed the best reaction conditions. At the same time ,we also focused on the reaction temperature, reactor pressure, concentration of raw materials and raw materials ratio on the performance of generator. The results show that the best reaction conditions of water bath temperature was 70°C、gas pressure was 60 ml • min-1、mass fraction of HCl was 24%、mass fraction of NaClO3 was 26%、Molar ratio of HCl and NaClO 3was 3. Under these conditions, the Index ,such as production of ClO2、production of effective chlorine、yield and purity of ClO2、consumption rate of NaClO3 and the ratio of ClO2/Cl2,reached a higher level, providing the technical basis for the mass production of Multi-stage compound chlorine dioxide generator.

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37

Chang, Meng-Yang, and Kuan-Ting Chen. "MeONH2·HCl-Mediated α-Methylenation/Conjugate Addition of α-Sulfonyl o-Hydroxyacetophenones with Methyl Sulfoxides: Route to 3-Sulfonylchroman-4-ones." Synthesis 53, no. 01 (August 19, 2020): 135–45. http://dx.doi.org/10.1055/s-0040-1707245.

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A novel and efficient route for the synthesis of 3-sulfonylchroman-4-ones from α-sulfonyl o-hydroxyacetophenones with methyl sulfoxides via a MeONH2·HCl-mediated sequential methylenation/ conjugate addition is described. Plausible reaction mechanisms are proposed and discussed. Various reaction conditions for this novel, one-pot, environmentally friendly conversion were investigated.

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38

Akkus, Meryem Sena. "Investigation of Hydrogen Production Performance Using Nanoporous NiCr and NiV Alloys in KBH4 Hydrolysis." Energies 15, no. 24 (December 16, 2022): 9547. http://dx.doi.org/10.3390/en15249547.

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Studies of storage and production of hydrogen, which is an alternative to fossil fuels, have been intensified. Hydrogen production from metal borohydrides via catalyst is very attractive because of its advantages, such as controlled production, high hydrogen content, nontoxicity, etc. In this study, the catalytic performances of nanoporous nickel–chromium alloy and nickel–vanadium alloy catalysts prepared with magnetron sputtering in hydrolysis of potassium borohydride, which is a hydrogen storage material, were investigated. Parameters that affected the hydrolysis reaction rate, such as the temperature, the amount of catalyst, and the volume of 0.5 M HCl solution were investigated using response surface methodology. In addition, the prepared catalysts were characterized with XRD and FE-SEM analysis, and the remaining solutions after the reactions were characterized with FE-SEM/EDS analysis. Using response surface methodology, optimum conditions for the maximum hydrogen production rate were determined to be 1.65 g of catalyst, 6% KBH4, 3% NaOH, and 7 mL of 0.5 M HCl at 333 K. Under these conditions, the hydrogen production rates were calculated as 68.9 L·min−1·gcat−1 and 76.5 L·min−1·gcat−1 for NiCr and NiV, respectively.

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39

Zoorob, Hanafi H., Wafaa S. Hamama, Osama M. Abd El-Magid, and Mamdoh S. Soliman. "Intermolecular double Michael reaction to construct 4-benzyl-5-imino-3-phenyl-6-oxa-1-aza-tricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile." Journal of Chemical Research 2005, no. 10 (October 2005): 669–72. http://dx.doi.org/10.3184/030823405774663075.

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1-azabicyclo[2.2.2]octan-3-one. HCl (1) reacts with ylidene nitrile through photo- thermal reaction conditions to give 4-benzyl-5-imino-3-phenyl-6-oxa-1-aza-tricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile. (3) via intermolecular double Micheal reaction, whereas, 5-imino-3-phenyl-6-oxa-1-azatricyclo[6.2.2.02,7]dodec-2(7)-ene-4-carbonitrile (4) was achieved via thermal conditions only.

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40

Sridhar, Narasi, and Andrzej Anderko. "Electrolyte Based Modeling of Corrosion Processes in Sulfuric Acid Mixtures, Part 1: Nonoxidizing Conditions." Corrosion 77, no. 9 (June 29, 2021): 935–48. http://dx.doi.org/10.5006/3872.

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The corrosion behavior of stainless steels and Ni-based alloys in nonoxidizing sulfuric acid mixtures at concentrations below approximately 30 mol/kg H2O is modeled. The redox potential in sulfuric acid across a broad concentration range, from 0 to 80 mol% (0 to 95.6 wt%), is determined by the proton reduction reaction. Thus, in the absence of other oxidizing species, sulfuric acid behaves as a nonoxidizing (reducing) acid. The calculated corrosion rates, using an electrochemical model up to about 30 mol/kg H2O (about 75 wt%), are in agreement with experimental values. The predicted polarization curves of anodic and cathodic processes show that the alloys in these environments are in active dissolution regime, consistent with experimental data. The model predictions of corrosion rates in H2SO4+HCl, H2SO4+HF, and H2SO4+HCl+HF mixtures are in agreement with weight-loss corrosion data. The corrosion rate of alloys in the nonoxidizing sulfuric acid mixtures correlated to an equivalent alloy composition given by (Ni0.7-Cr0.1+Mo+0.5 W). The effect of alloying elements under these conditions may be related to their beneficial effect on active dissolution and proton reduction reaction rates.

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Mpofu, Brendon, Hembe E. Mukaya, and Diakanua B. Nkazi. "Mineral carbonation process of carbon dioxide using animal bone." Science Progress 104, no. 2 (April 2021): 003685042110196. http://dx.doi.org/10.1177/00368504211019644.

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Carbon dioxide has been identified as one of the greenhouse gases responsible for global warming. Several carbon capture and storage technologies have been developed to mitigate the large quantities of carbon dioxide released into the atmosphere, but these are quite expensive and not easy to implement. Thus, this research analyses the technical and economic feasibility of using calcium leached from cow bone to capture and store carbon dioxide through the mineral carbonation process. The capturing process of carbon dioxide was successful using the proposed technique of leaching calcium from cow shinbone (the tibia) in the presence of HCl by reacting the calcium solution with gaseous carbon dioxide. AAS and XRF analysis were used to determine the concentration of calcium in leached solutions and the composition of calcium in cow bone respectively. The best leaching conditions were found to be 4 mole/L HCl and leaching time of 6 h. Under these conditions, a leaching efficiency of 91% and a calcium conversion of 83% in the carbonation reaction were obtained. Other factors such as carbonation time, agitation rate, and carbonation reaction temperature had little effect on the yield. A preliminary cost analysis showed that the cost to capture 1 ton of CO2 with the proposed technique is about US$ 268.32, which is in the acceptable range of the capturing process. However, the cost of material used and electricity should be reviewed to reduce the preliminary production cost.

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42

Möller, Maren, Herbert Over, Bernd Smarsly, Nikolay Tarabanko, and Sven Urban. "Electrospun ceria-based nanofibers for the facile assessment of catalyst morphological stability under harsh HCl oxidation reaction conditions." Catalysis Today 253 (September 2015): 207–18. http://dx.doi.org/10.1016/j.cattod.2015.02.027.

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Mokhlis, Hafida, and Abdeljabbar Attaoui. "PERCENTAGE OF COMPOUNDS CONSTITUTING THE TARFAYAS OIL SHALE (MOROCCO) REACTING TO ACID ATTACK (HCL)." International Journal of Advanced Research 10, no. 06 (June 30, 2022): 611–23. http://dx.doi.org/10.21474/ijar01/14929.

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The mastery of a number of chemical reactions can give us information on the constitution of compounds in the solid state. As an example, acid etching (HCl) is used for oil shale to separate the organic matrix by destroying the mineral matrix. (The use of the soxhlet). Similarly, by ashing at low temperatures (LTH) in combustion of the organic material, the mineral matrix can be kept to a minimum (A.Attaoui et al: 2022).Another way of using acid etching (HCl) at given concentrations can be carried out for oil shale in order to give the composition of the majority constituents of the latter, namely organic matter and carbonates (calcite and dolomite discerned). The objective of this study, which is carried out in a back-assay mode using the Tacussel pH meter, is to establish a table of compositions in mass percentages of the different constituents reacting to the acid attack of oil shale from the first three layers of the Tarfaya deposit (Morocco), which are Z0, Z1 and Z2.Calcite CaCO3 is taken as a control, it was used under the same conditions as the oil shale, i.e. combustion in an isothermal regime, followed by acid attack.

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CHU, L. T., M. T. LEU, and L. F. KEYSER. "ChemInform Abstract: Heterogeneous Reactions of HOCl + HCl → Cl2 + H2O (1) and ClONO2 + HCl → Cl2 + HNO3 (2) on Ice Surfaces at Polar Stratospheric Conditions." ChemInform 25, no. 11 (August 19, 2010): no. http://dx.doi.org/10.1002/chin.199411292.

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45

Zhang, Xiaoping, Rong-Mei Kong, Huitong Du, Lian Xia, and Fengli Qu. "Highly efficient electrochemical ammonia synthesis via nitrogen reduction reactions on a VN nanowire array under ambient conditions." Chemical Communications 54, no. 42 (2018): 5323–25. http://dx.doi.org/10.1039/c8cc00459e.

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A VN nanowire array on carbon cloth (VN/CC) as a high-performance catalyst for the nitrogen reduction reaction (NRR) affords high ammonia yield (2.48 × 10⁻¹⁰ mol⁻¹ s⁻¹ cm⁻²) and faradaic efficiency (3.58%) at −0.3 V versus RHE in 0.1 M HCl.

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46

Lee, Joo Chan, Se-Won Park, Hyun Sub Kim, Tanvir Alam, and Sang Yeop Lee. "Oxidation Enhancement of Gaseous Elemental Mercury Using Waste Steel Slag under Various Experimental Conditions." Sustainability 15, no. 2 (January 11, 2023): 1406. http://dx.doi.org/10.3390/su15021406.

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In this study, the oxidation characteristics of elemental mercury were assessed based on the input gas environment, temperature, and particle size distribution of the steel slag. Experiments were performed at room temperature, 100 °C and 200 °C, under air and simulated gas environments. The oxidation reaction of elemental mercury was conducted using steel slag samples of 1 mm, 2.36 mm, and 4.75 mm at various conditions. From the basic characteristic analysis of the steel slag, it was found that the steel slag exhibits a similar composition to that of fly ash, and it can be utilized as an oxidizing agent. Results show that regardless of the temperature and the particle size distribution of steel slag, the oxidation reaction of elemental mercury rarely occurred in the air environment. However, in the case of the HCl gas environment, it was observed that the smaller the steel slag particle size, the stronger the oxidation reaction. It is believed that the oxidation efficiency of the steel slag increased as the contact area between the gas and particles increased. The oxidation reactivity was nearly two times higher in the temperature range of 100 °C to 200 °C than it was at room temperature. It is advised that further research be undertaken in order to determine the precise temperature range at which the oxidation reaction occurs.

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Chaudhary, Karan, Manoj Trivedi, D. T. Masram, Abhinav Kumar, Girijesh Kumar, Ahmad Husain, and Nigam P. Rath. "A highly active copper catalyst for the hydrogenation of carbon dioxide to formate under ambient conditions." Dalton Transactions 49, no. 9 (2020): 2994–3000. http://dx.doi.org/10.1039/c9dt04662c.

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Catalytic conversion of CO₂via hydrogenation using in situ gaseous H₂ (granulated tin metal and concentrated HCl) to produce the formate salt (HCO₂⁻) with turnover number (TON) values of 326 to 1.065 × 10⁵ in 12 h to 48 h of reaction at 25 °C to 80 °C has been reported.

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Abdelgawad, Khaled Z., Mohamed Mahmoud, Salaheldin Elkatatny, Abdulazeez Abdulraheem, and Shirish Patil. "Reaction Kinetics and Coreflooding Study of High-Temperature Carbonate Reservoir Stimulation Using GLDA in Seawater." Energies 12, no. 18 (September 4, 2019): 3407. http://dx.doi.org/10.3390/en12183407.

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Well stimulation using hydrochloric acid (HCl) is a common practice in carbonate reservoirs to overcome formation damage in the near wellbore area. Using HCl for matrix acidizing has many limitations at high-temperature (HT) conditions, such as tubulars corrosion and face dissolution due to the fast reaction rate. Chelating agents, such as L-glutamic acid-N,N-diacetic acid (GLDA), are alternatives to HCl to overcome these problems. We studied the effect of diluting GLDA in seawater on the reaction kinetics with carbonate rocks under HT conditions at low pH (3.8). Results of the reaction of carbonate at 1000 psi and 150, 200, and 250 °F with GLDA prepared in both fresh and seawater, GLDA/DI and GLDA/SW, respectively, are presented. The reaction kinetics experiments were carried out in HT rotating disk apparatus (RDA) at rotational speeds ranging from 500 to 2000 revolutions per minute (RPM) at a fixed temperature. Indiana limestone and Austin chalk were used to studying the effect of rock facies on the reaction of GLDA with rock samples. In both GLDA/DI and GLDA/SW, the reaction regime of 20 wt% GLDA (3.8 pH) with Indiana limestone was mass transfer limited. The reaction rate and diffusion coefficient were highly dependent on the temperature. For Austin chalk, at 200 °F and 1000 psi the diffusion coefficient of GLDA/SW is an order of magnitude of its value with Indiana limestone using the same fluid. Diffusion coefficients were used to estimate the optimum injection rate for stimulating HT carbonate formation and compared with coreflooding results. The data presented in this paper will support the numerical simulation of the acid flow in carbonate reservoirs.

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Wang, Nan, and Julian Tyson. "Non-chromatographic speciation of inorganic arsenic by atomic fluorescence spectrometry with flow injection hydride generation with a tetrahydroborate-form anion-exchanger." J. Anal. At. Spectrom. 29, no. 4 (2014): 665–73. http://dx.doi.org/10.1039/c3ja50376c.

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Pak, Jeong W., Kyle L. Knoke, Daniel R. Noguera, Brian G. Fox, and Glenn H. Chambliss. "Transformation of 2,4,6-Trinitrotoluene by Purified Xenobiotic Reductase B from Pseudomonas fluorescensI-C." Applied and Environmental Microbiology 66, no. 11 (November 1, 2000): 4742–50. http://dx.doi.org/10.1128/aem.66.11.4742-4750.2000.

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ABSTRACT The enzymatic transformation of 2,4,6-trinitrotoluene (TNT) by purified XenB, an NADPH-dependent flavoprotein oxidoreductase fromPseudomonas fluorescens I-C, was evaluated by using natural abundance and [U-14C]TNT preparations. XenB catalyzed the reduction of TNT either by hydride addition to the aromatic ring or by nitro group reduction, with the accumulation of various tautomers of the protonated dihydride-Meisenheimer complex of TNT, 2-hydroxylamino-4,6-dinitrotoluene, and 4-hydroxylamino-2,6-dinitrotoluene. Subsequent reactions of these metabolites were nonenzymatic and resulted in predominant formation of at least three dimers with an anionic m/z of 376 as determined by negative-mode electrospray ionization mass spectrometry and the release of ∼0.5 mol of nitrite per mol of TNT consumed. The extents of the initial enzymatic reactions were similar in the presence and in the absence of O2, but the dimerization reaction and the release of nitrite were favored under aerobic conditions or under anaerobic conditions in the presence of NADP+. Reactions of chemically and enzymatically synthesized and high-pressure liquid chromatography-purified TNT metabolites showed that both a hydroxylamino-dinitrotoluene isomer and a tautomer of the protonated dihydride-Meisenheimer complex of TNT were required precursors for the dimerization and nitrite release reactions. The m/z 376 dimers also reacted with either dansyl chloride or N-1-naphthylethylenediamine HCl, providing evidence for an aryl amine functional group. In combination, the experimental results are consistent with assigning the chemical structures of them/z 376 species to various isomers of amino-dimethyl-tetranitrobiphenyl. A mechanism for the formation of these proposed TNT metabolites is presented, and the potential enzymatic and environmental significance of their formation is discussed.

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Journal articles on the topic 'HTL reaction conditions'

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