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Auswahl der wissenschaftlichen Literatur zum Thema „Industrially important solvents“
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Zeitschriftenartikel zum Thema "Industrially important solvents"
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McDermott, Catherine, und James J. A. Heffron. „Toxicity of Industrially Relevant Chlorinated Organic Solvents In Vitro“. International Journal of Toxicology 32, Nr. 2 (März 2013): 136–45. http://dx.doi.org/10.1177/1091581813482006.
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The cytotoxic effects of 4 industrially important chlorinated organic solvents, dichloromethane (DCM), 1,2-dichloroethane (DCE), trichloroethylene (TCE), and tetrachloroethylene (PERC) in vitro, were investigated. Jurkat T cells were exposed to the solvents individually for 72 hours and changes in reactive oxygen species (ROS) formation, cell proliferation, intracellular free calcium concentration ([Ca2+]), and caspase-3 activity were measured. There was a concentration-dependent increase in the ROS formation and intracellular free [Ca2+] following exposure to each of the solvents. This was accompanied by a decrease in the cell proliferation. Solvent potency decreased in the following order: PERC > TCE > DCM > DCE. Caspase-3 activity was increased in a concentration-dependent manner by TCE and PERC but was not significantly altered by DCM or DCE. n-Acetyl-l-cysteine pretreatment showed that changes in the intracellular free [Ca2+] and caspase-3 activity were independent of ROS formation. However, increased ROS formation did play a causal role in the decreased cell proliferation observed.
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An, Suna, Dahye Kwon, JeongHyun Cho und Ji Chul Jung. „Effect of the Solvent on the Basic Properties of Mg–Al Hydrotalcite Catalysts for Glucose Isomerization“. Catalysts 10, Nr. 11 (25.10.2020): 1236. http://dx.doi.org/10.3390/catal10111236.
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We suggested the existence of a relationship between the base properties of Mg–Al hydrotalcite catalysts and the solvents employed in the industrially important isomerization of glucose produce fructose. We prepared Mg–Al hydrotalcite catalysts with different Mg/Al atomic ratios to tune the basic properties of the catalyst. The prepared catalysts were used in the glucose isomerization conducted in various solvents. Experimental results confirmed that the catalysts exhibited different activities in the different solvents. We also implemented the Hammett indicator method, which allows to analyze the basic properties of the catalysts in various solvents. According to evidence, the basic properties of the catalysts varied substantially in different solvents. Notably, increases in the catalysts’ base properties matched the observed increases in fructose yield of the glucose isomerization. Consequently, we suggested that, in order to prepare efficient Mg–Al hydrotalcite catalysts for glucose isomerization, the interaction between the solvent used to conduct the reaction and the basic properties of the catalyst, which are in turn influenced by the solvent, should be considered.
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Hall, T. F., R. C. Waterfall, G. J. Kakabadse, E. O. Olatoye, R. Perry und A. E. Tipping. „Computer-Controlled On-Line Moisture Measurement in Organic Solvents Using a Novel Potentiometric Technique“. Measurement and Control 22, Nr. 8 (Oktober 1989): 240–44. http://dx.doi.org/10.1177/002029408902200803.
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A microcomputer-based monitoring system for the determination of residual water in organic solvents using ion-selective electrodes in a novel potentiometric method, called the proton iso-concentration technique (PICT), has been developed at UMIST. In the monitor, a sample stream is bled off and mixed with a buffer solution before passing through a cell containing a pH glass electrode, a reference electrode and an automatic temperature compensation probe. The instrument is calibrated with standard solutions containing water in the same solvent. The automatic monitoring system comprises a microcomputer and slave microprocessor system, the former performing system control and data analysis, the latter controlling a number of discrete electronic devices. Results obtained on selected industrially important solvents demonstrate a satisfactory performance of PICT in continuous monitoring, showing it to be accurate, reproducible and sensitive. On-line determination of moisture in solvents is important for process control in industry.
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Venkatramana, L., K. Sivakumar, V. Govinda und K. Dayananda Reddy. „Study on solution properties of some industrially important solvents with an aromatic alcohol“. Journal of Molecular Liquids 186 (Oktober 2013): 163–70. http://dx.doi.org/10.1016/j.molliq.2013.04.026.
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Peng, Shu Ge, Yong Ke Guo, Xiao Fei Liu und Jun Zhang. „The Effects of Organic Solvents on Catalytic Behavior of Immobilized Hemoglobin Nanocomposites: Functional Groups and Molecular Constitution“. Advanced Materials Research 233-235 (Mai 2011): 1556–59. http://dx.doi.org/10.4028/www.scientific.net/amr.233-235.1556.
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The use of organic solvents as reaction media for enzymatic reactions provides numerous industrially attractive advantages compared to traditional aqueous reaction systems. Hemoglobin (Hb) intercalated magadiite nano-composites was successfully prepared by exfoliation-reassembly method at room temperature and pH=7, and was used to catalyze the oxidation of o-phenylenediamine in organic solvents. Catalytic activity of immobilized Hb in organic solvents with different hydrophobicity and different functional groups were investigated detailedly. The results showed that functional groups and molecular constitution of the organic solvents were both important factors to determine catalytic activity of immobilized Hb in organic media except hydrophobicity of organic solvents.
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Orha, László, József M. Tukacs, László Kollár und László T. Mika. „Palladium-catalyzed Sonogashira coupling reactions in γ-valerolactone-based ionic liquids“. Beilstein Journal of Organic Chemistry 15 (03.12.2019): 2907–13. http://dx.doi.org/10.3762/bjoc.15.284.
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It was demonstrated that the γ-valerolactone-based ionic liquid, tetrabutylphosphonium 4-ethoxyvalerate as a partially bio-based solvent can be utilized as alternative reaction medium for copper- and auxiliary base-free Pd-catalyzed Sonogashira coupling reactions of aryl iodides and functionalized acetylenes under mild conditions. Twenty-two cross-coupling products were isolated with good to excellent yields (72–99%) and purity (>98%). These results represent an example which proves that biomass-derived safer solvents can be utilized efficiently in common, industrially important transformations exhibiting higher chemical and environmental efficiency.
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Sokoli, Hülya U., Morten E. Simonsen und Erik G. Søgaard. „Investigation of degradation products produced by recycling the solvent during chemical degradation of fiber-reinforced composites“. Journal of Reinforced Plastics and Composites 36, Nr. 17 (27.04.2017): 1286–96. http://dx.doi.org/10.1177/0731684417707060.
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Recycling of fiber-reinforced thermoset composites using chemical solvolysis has been investigated thoroughly in recent years, where solvents such as water, alcohols and ketones have been used. However, high costs are related to the use of organic solvents, decreasing the sustainability of the process. In this study, acetone has been used as the organic solvent. To increase the sustainability of the process, the solvent was recycled in eight consecutive batches using new glass fiber-reinforced composites in each recycling. No additional amount of acetone was added, resulting in a reduction of solvent consumption by 88%. It was found that the recycled solvent became increasingly more concentrated with degradation products from the epoxy resin and compounds produced by acetone aldol reactions. These degradation products promoted and enhanced the degradation of the composite. Among the compounds produced by acetone aldol reaction, the industrially important bulk chemical mesityl oxide accounted for 68–79% of the total chromatographic peak area. Simultaneously, with the optimization of a process for converting composite waste into its constituent (fibers and resin), valuable bulk chemicals can be produced to increase the overall commercial interest.
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Weidlich, Tomáš, und Barbora Kamenická. „Utilization of CO2-Available Organocatalysts for Reactions with Industrially Important Epoxides“. Catalysts 12, Nr. 3 (06.03.2022): 298. http://dx.doi.org/10.3390/catal12030298.
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Recent knowledge in chemistry has enabled the material utilization of greenhouse gas (CO2) for the production of organic carbonates using mild reaction conditions. Organic carbonates, especially cyclic carbonates, are applicable as green solvents, electrolytes in batteries, feedstock for fine chemicals and monomers for polycarbonate production. This review summarizes new developments in the ring opening of epoxides with subsequent CO2-based formation of cyclic carbonates. The review highlights recent and major developments for sustainable CO2 conversion from 2000 to the end of 2021 abstracted by Web of Science. The syntheses of epoxides, especially from bio-based raw materials, will be summarized, such as the types of raw material (vegetable oils or their esters) and the reaction conditions. The aim of this review is also to summarize and to compare the types of homogeneous non-metallic catalysts. The three reaction mechanisms for cyclic carbonate formation are presented, namely activation of the epoxide ring, CO2 activation and dual activation. Usually most effective catalysts described in the literature consist of powerful sources of nucleophile such as onium salt, of hydrogen bond donors and of tertiary amines used to combine epoxide activation for facile epoxide ring opening and CO2 activation for the subsequent smooth addition reaction and ring closure. The most active catalytic systems are capable of activating even internal epoxides such as epoxidized unsaturated fatty acid derivatives for the cycloaddition of CO2 under relatively mild conditions. In case of terminal epoxides such as epichlorohydrin, the effective utilization of diluted sources of CO2 such as flue gas is possible using the most active organocatalysts even at ambient pressure.
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Kótai, László, Vladimir M. Petruševski, Laura Bereczki und Kende Attila Béres. „Catalytic Properties of the Spinel-Like CuxMn3−xO4 Copper Manganese Oxides—An Overview“. Catalysts 13, Nr. 1 (06.01.2023): 129. http://dx.doi.org/10.3390/catal13010129.
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Copper manganese oxide spinels and related (multiphase) materials with the formula CuxMn3−xO4 are the active catalysts in a wide variety of industrially important processes due to their great diversity in their phase relations, metal ion valence/site distribution, and chemical properties. In this review, we summarize the preparation methods and their effects on the composition, properties, and catalytic properties of various CuxMn3−xO4 catalysts with various Cu/Mn ratios. The main summarized catalytic reactions are the oxidation of carbon monoxide, nitrogen oxide, and hydrogen sulfide and the oxidative removal of organic solvents such as benzene, toluene, and xylene from the air. Some industrially important reactions (steam reforming of methanol or synthesis gas) and the manufacture of organic chemicals (methyl formate, propylene oxide, and benzyl alcohol) catalyzed by CuxMn3−xO4 spinels are also reviewed.
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Roy, Mahendra Nath, Rajani Dewan, Deepak Ekka und Ishani Banik. „Probing molecular interactions of ionic liquid in industrially important solvents by means of conductometric and spectroscopic approach“. Thermochimica Acta 559 (Mai 2013): 46–51. http://dx.doi.org/10.1016/j.tca.2013.02.022.
Der volle Inhalt der QuelleDissertationen zum Thema "Industrially important solvents"
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Pradhan, Rajendra. „Molecular interactions in mixtures of some industrially important solvents: a physico-chemical study“. Thesis, University of North Bengal, 2018. http://ir.nbu.ac.in/handle/123456789/2698.
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Banik, Ishani. „Physico-Chemical studies on interaction of biologically active solutes and ionic salts in some industrially important solvent media“. Thesis, University of North Bengal, 2014. http://ir.nbu.ac.in/handle/123456789/1491.
Der volle Inhalt der QuelleBücher zum Thema "Industrially important solvents"
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Bochove, Gerard Van. Two and Three-Liquid Phase Equilibria in Industrial Mixed Solvent Electrolyte Solutions: Experiments & Modelling of Systems of Importance for the Extraction of Caprolactam. Delft Univ Pr, 2003.
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Bäck, Thomas. Evolutionary Algorithms in Theory and Practice. Oxford University Press, 1996. http://dx.doi.org/10.1093/oso/9780195099713.001.0001.
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This book presents a unified view of evolutionary algorithms: the exciting new probabilistic search tools inspired by biological models that have immense potential as practical problem-solvers in a wide variety of settings, academic, commercial, and industrial. In this work, the author compares the three most prominent representatives of evolutionary algorithms: genetic algorithms, evolution strategies, and evolutionary programming. The algorithms are presented within a unified framework, thereby clarifying the similarities and differences of these methods. The author also presents new results regarding the role of mutation and selection in genetic algorithms, showing how mutation seems to be much more important for the performance of genetic algorithms than usually assumed. The interaction of selection and mutation, and the impact of the binary code are further topics of interest. Some of the theoretical results are also confirmed by performing an experiment in meta-evolution on a parallel computer. The meta-algorithm used in this experiment combines components from evolution strategies and genetic algorithms to yield a hybrid capable of handling mixed integer optimization problems. As a detailed description of the algorithms, with practical guidelines for usage and implementation, this work will interest a wide range of researchers in computer science and engineering disciplines, as well as graduate students in these fields.
Buchteile zum Thema "Industrially important solvents"
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Yogesh, B. J., und S. Bharathi. „Industrial Aspects of Microbes“. In Industrial Applications of Soil Microbes, 59–76. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9789815039955122010007.
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This chapter deals with the significance of soil microbes from an industrial perspective. Soil microbes are the most diverse populations to exist on earth, and they are known to have played a prominent role in the development of soil chemistry, soil texture, and soil suitability to sustain plant life. The chapter deals with the significance of cultural techniques for the isolation of desired microbial strains from the soil. The importance of screening techniques for isolates is emphasized, wherein the potential strains are tested for their physiological characteristics that are industrially beneficial. A few criteria are mentioned for judging the soil isolate’s capability to become an industrial strain. The difference between natural isolates and potential industrial strains is discussed. Useful strains are categorized based on their ability to produce primary and secondary metabolites with commercial applications in terms of economic, agricultural, and environmental significance. Industrially important microbes are listed with emphasis on the types of metabolites they produce and their applications. Knowledge of metabolic pathways involved in metabolite production and their regulation in terms of various feedback control systems are discussed. Strain improvement and its role in improving industrial aspects of microbes are highlighted. Bacillus sp. are given their due importance as the most diverse and dynamic forms of bacteria, contributing immensely to our knowledge and being the most beneficial forms of soil microbes. A few metabolites are discussed in detail, with emphasis given to enzymes, microbial polymers, amino acids, solvents, organic acids, and antibiotics. Microbial bioleaching mostly employs bacteria that could help in the recovery of metals from low-grade ores, and industries based on biomining have shown a renewed interest in this economically viable process.
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Manke, Charles W., und Esin Gulari. „Rheological Properties of Polymers Modified with Carbon Dioxide“. In Green Chemistry Using Liquid and Supercritical Carbon Dioxide. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195154832.003.0016.
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Use of supercritical fluids (SCFs), particularly supercritical carbon dioxide, as alternative solvents in polymer synthesis and processing is a rapidly growing research area with successful industrial applications (McCoy, 1999). In some cases, the need for alternative solvents is based on environmental concerns, with regulations mandating replacement solvents. An environmentally mandated example is the 1995 ban of the use of chlorofluorocarbons (CFCs) as physical blowing agents in the manufacture of polymeric foams after CFCs were classified as class-I-ozone-depleting substances (ODPs). Among the alternative blowing agents are gases like CO2 and N2 and refrigerants such as 1,1-difluoroethane (R152a) and 1,1,1,2-tetrafluoroethane (R134a). Under the foaming conditions, at temperatures above the glass transition temperature of a polymer, and at pressures required for flow of highly viscous polymer melts, these alternative blowing agents are frequently supercritical. When polymers are formed into final products by various melt-processing techniques, such as extrusion, injection molding, blow molding, foaming, and spin-coating, extremely high melt viscosity presents a major difficulty. A common method to moderate the processing conditions is to add a liquid solvent or plasticizer to the melt. Solvents and plasticizers lower the glass transition temperature, Tg, of the polymer so that the polymer can be made to flow at lower pressures and temperatures. Replacing liquid solvents with SCFs presents unique processing advantages. Higher diffusivity and lower viscosity of SCFs, compared with liquid solvents, increase rates of dissolution and mixing. The properties of polymer–SCF solutions are tunable via pressure or temperature changes, thus allowing efficient downstream separations. Most importantly, dissolution of an SCF produces very large reductions in melt viscosity compared with a liquid solvent dissolved in the melt. Whether the interest in using SCFs in polymer synthesis and processing is driven by environmental concerns or processing advantages, it is important to understand the rheological behavior of polymer–SCF mixtures. In this chapter, we describe rheological measurements of polymer melts containing dissolved gases for two polymers, polydimethylsiloxane (PDMS) swollen with CO2 at 50 °C and 80 °C and polystyrene (PS) swollen with CO2, R152a, and R134a at 150 °C and 175 °C.
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Nelson, William M. „Green Solvents for Industrial Chemistry“. In Green Solvents for Chemistry, 198–251. Oxford University PressNew York, NY, 2003. http://dx.doi.org/10.1093/oso/9780195157369.003.0007.
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Abstract Environmental concerns have raised public awareness of environmental issues and are driving forces for regulation; the impact of regulation on the cost of production is expected to become important in determining the international competitiveness of the U.S. chemical industry (Pereira, 1999). In response to cost pressures, industry has launched a number of initiatives aimed at improving efficiency and reducing environmental impact. Some of these environmental success stories are receiving increased national attention due to programs such as the Presidential Green Chemistry Challenge Awards program. In addition to traditional metrics for evaluating process performance, such as productivity, environmental considerations increasingly are important in process development. Chemical processes evolve through life-cycle phases, beginning with research, and then moving to process engineering, plant operation, and eventually, decommissioning (see fig. 7.1). The number of technology options available for reducing environmental impact are highest early on in the life cycle and then decrease drastically. In contrast, costs associated with resolving an environmental problem typically increase exponentially as the process matures and the scale of equipment gets larger. There is, therefore, a considerable incentive to address and resolve environmental issues early in the life cycle (Bollinger et al., 1996).
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G. Montalbán, Mercedes, und Gloria Víllora. „Supercritical Fluids: Properties and Applications“. In Phase Equilibria With Supercritical Carbon Dioxide - Application to the Components of a Biocatalytic Process. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.105485.
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Currently, both humanity and the whole planet are living in a critical time, which leads us to look for more sustainable formulas to interact with the environment. One of the important changes in the design and operation of chemical processes is the search for environmentally friendly technologies. Many industrial processes are carried out under severe conditions or with reactants that involve the use of strong acids, toxic metal catalysts, organic solvents, and processes at high temperatures and/or pressures. Supercritical fluids (SCFs) and, among these, supercritical carbon dioxide (scCO2), have been revealed as promising environmentally friendly solvents, energy-efficient, selective, and capable of reducing waste, constituting an alternative to conventional organic solvents. The use of SCF, such as solvents and reaction media, makes it possible to work in less severe and more environmentally friendly conditions, even considerably increasing the efficiency of the processes. This chapter provides a brief review of the most important properties of SCF, with special emphasis on scCO2, as well as some of the most important applications.
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Nelson, William M. „Philosophy of the Environment“. In Green Solvents for Chemistry, 3–19. Oxford University PressNew York, NY, 2003. http://dx.doi.org/10.1093/oso/9780195157369.003.0001.
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Abstract Let us put chemical usage in context. There is justifiably a concern over the adverse effects of chemicals on human health and the environment. The source of chemicals may be industrial, commercial, or adventitious. Environmental quality is a concern in the United States and throughout the world. This concern is important today. Our world has heightened environmental awareness, fueled by public interest groups and the media. Public awareness is growing of the processes involved in the use, manufacturing, and effect of many chemicals on the environment, including the generation of waste, the disruption of ecosystems, and the depletion of natural resources. Current patterns of chemical development threaten to exceed the limits of sustainability in terms of resource utilization and waste management, and also pose potential threats to global climate, vegetation, and agriculture. According to the U.S. Environmental Protection Agency (EPA), about 123 billion tons of industrial wastes are generated annually in the United States, and more than a third of this is hazardous waste. This presents a challenge to the chemical industry. Although the EPA has striven to reduce the impact of toxic chemicals, the efforts have focused primarily on exposure-based approaches. Within the United States, the Pollution Prevention Act of 1990 introduced a new era in regulatory philosophy and policy. The emphasis became the prevention of toxic substances at their source. Green chemistry aims at accomplishing pollution prevention through the design of safer chemicals and the use of more environmentally friendly chemical processes.
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Dhariwal, Jyoti, Gaurav Choudhary, Dipti Vaya, Srikanta Sahu, Manish Shandilya, Poonam Kaswan, Ambrish Kumar, Shruti Trivedi, Manoj K. Banjare und Kamalakanta Behera. „Self-Assembled Nanostructures within Ionic Liquids-based Media“. In Ionic Liquids: Eco-friendly Substitutes for Surface and Interface Applications, 111–59. BENTHAM SCIENCE PUBLISHERS, 2023. http://dx.doi.org/10.2174/9789815136234123010011.
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Ionic liquids (ILs) have shown immense potential as suitable alternatives to environmentally damaging volatile organic solvents (VOS). These unique materials possess very unusual physicochemical properties, such as low melting point, high boiling point, excellent thermal and chemical stability, large electrochemical window, very low volatility and high conductivity. One of the most important features associated with ILs is that their physicochemical properties, like viscosity, density, hydrophobicity, solubility, polarity, etc., can be effectively tuned for desired applications just by tuning the structures of cations and/or anions. Further, these designer solvents show dual behavior, i.e., electrolytes and solvents. In the last two decades, these unique materials have shown tremendous application potential in various interdisciplinary research areas, such as synthesis, catalysis, separation, extraction, nanoscience, and pharmaceutics, among many others. Further, the formation of surfactant self-assembled nanostructures (micelles and microemulsions (ME)) within ionic liquid-based systems of immense importance due to the vast utility of these nanostructures well as ILs in various fields of science and technology. These microheterogeneous systems can be effectively used as greener alternatives to those environmentally harmful volatile organic solvents which are largely used for academic and industrial research purposes.atile organic solvents which are largely used for academic and industrial research purposes. The IL-based self-assembled nanostructures show major advantages due to their affinity to solubilize many chemical and biochemical solutes (both hydrophilic as well as hydrophobic), thereby expanding their potential application as solubilizing media, media for synthesis, catalysis and biocatalysis, separation and extraction, drug delivery vehicles, and media for biochemical stability (e.g., protein and enzyme stability). This book chapter will highlight the formation and utility of various types of self-assembled nanostructures formed by surfactants, polymers, etc., within Ils-based media.
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Wilson, G. R., P. A. Nee, J. S. Watson und R. K. Harrison. „High-pressure injection injuries“. In Emergency Management of Hand Injuries, 63–64. Oxford University PressNew York, NY, 1997. http://dx.doi.org/10.1093/oso/9780192628244.003.0013.
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Abstract Uncommon but important industrial injury frequently affecting the index fingertip of the non-dominant hand. High pressure injection of foreign material (e.g. wax, grease, paint, solvent, oil). The patient has frequently been cleaning the nozzle of a high-pressure gun when material is inadvertently injected.
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„Pyrrole Synthesis“. In Greener Organic Transformations, 125–28. The Royal Society of Chemistry, 2022. http://dx.doi.org/10.1039/9781837670895-00125.
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Pyrroles are prominent heterocycles with a central role in life processes. Two important natural pigments, haem and chlorophyll, contain a porphyrin core that contains four modified pyrrole subunits. This chapter discusses the uses and industrial synthesis of pyrroles. Green chemistry developments, including solvent-free approaches, the use of ionic liquids and the use of deep eutectic fluids, are covered.
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de Aguiar, Ana Carolina, Arthur Luiz Baião Dias und Juliane Viganó. „Green Extraction Techniques to Obtain Bioactive Concentrates Rich in Terpenoids“. In Terpenoids: Recent Advances in Extraction, Biochemistry and Biotechnology, 17–38. BENTHAM SCIENCE PUBLISHERS, 2022. http://dx.doi.org/10.2174/9781681089645122010004.
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Terpenoids, also called isoprenoids or terpenes, are a large class of natural products which display a wide range of biological activities. They are major constituents of essential oils produced by aromatic plants and tree resins. Due to their notable biological activities, these compounds have enormous economic importance, being widely used as bioactive ingredients in the food, cosmetic, and pharmaceutical industries. The growing demand from consumers and regulatory agencies to develop green sustainable industrial processes has resulted in the emergence of new technologies for obtaining bioactive compounds from natural sources. Thus, many works have been reported in the literature regarding the development and application of new methods for obtaining terpenoids from natural sources that meet the demands of green processes, with reduced consumption of solvent and energy, less waste generation, and use of non-toxic solvents. This chapter proposes to present the main methods of green extraction to obtain terpenoids-rich extracts, with an emphasis on low-pressure methods, such as microwave-assisted extraction (MAE) and ultrasound assisted extraction (UAE); and high-pressure methods (here considered as pressures greater than 5 bar), including extraction with supercritical fluids (SFE), subcritical water (SWE) and liquefied petroleum gas extraction (LPG). In addition, the future perspectives and the main challenges regarding the development of alternative methods for the recovery of terpenoids are presented and discussed.
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Cesar Ribeiro Nunes, Julio, Ricardo de Freitas Fernandes Pontes, Fabio Rodolfo Miguel Batista und Rafael M. Matricarde Falleiro. „Evaluation of the Best Operating Conditions in Distillation Columns: A Case Study for the Separation between Nonylphenol and Dinonylphenol“. In Solvents - Dilute, Dissolve, and Disperse [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1003801.
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Nonylphenol is a very important product for the chemical industry due to its widespread use as a base for several other chemical products. Among the major industrial sectors that use nonylphenol is the production of non-ionic surfactants, which are used from the home and personal care industry to the agrochemical industry. This study aims to define the optimal or quasi-optimal operating conditions for the separation system, which is composed of packed columns. Using simulation tools, the best operating conditions are attained, and the dinonylphenol subproduct generation is minimized. The commercial simulator Aspen Plus® was used for this study as the analysis tool for the mentioned objectives. The developed model is validated with technical data, measures are taken in a nonylphenol plant, and parameters are used in the same plant. From the obtained data from the plant, the best process performance is evaluated regarding cost-benefit analysis and safety concerns. The study shows a potential to reduce the subproduct production by 30% and the reboilers’ heat loads by 2%.
Konferenzberichte zum Thema "Industrially important solvents"
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Narayanasamy, R., H. Ibrahim, M. Kamali und M. Fabrik. „CCUS and Geothermal Energy Activities in Saskatchewan, Canada: Novel Technologies in Carbon Capture and Storage Related the University of Regina's Clean Energy Technologies Research Institute and the PTRC's Aquistore Deep Saline Storage Project“. In ADIPEC. SPE, 2023. http://dx.doi.org/10.2118/216727-ms.
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Abstract The province of Saskatchewan in Canada has two of the largest CCUS projects in the world - the Weyburn CO2-EOR flood and the Aquistore Deep Saline CO2 Storage Project. Learnings from these operations have powered significant research in capture, storage, and (inadvertently) geothermal energy production. This work will examine how these commercial operations have fostered important research into solvents for less expensive capture technologies, and reservoir characterization and monitoring that has enhanced CO2 storage while simultaneously enhancing geothermal production. The 23-year history of CO2 EOR and deep saline storage in Saskatchewan has led to a material advantage for research groups in the province - both in the areas of CO2 capture research, and CO2 deep geological storage. The SaskPower Boundary Dam Capture Facility, and the Aquistore site have both facilitated R&D programs at Saskatchewan's universities and research organizations into reactive solvent capture technologies, and at PTRC in novel measurement, monitoring and verification tools. The accumulated data from those two industrial scale projects (capture and storage) have facilitated unique findings worth sharing with other planned CCS projects now in development. Over 30 different kinds of measurement, monitoring and verification technologies for storage have been examined and compared at the Aquistore Deep Saline Storage Project. The results on plume monitoring and surveillance, using both DAS and DTS (fibre optic) deployment has shown a surprising repeatability of results as compared to the site's permanent geophone array. Novel deep fluid sampling to examine brine-CO2 interactions, and ongoing extensive sometimes surprising data related to second-by-second injection at the wellhead has revealed salt precipitation and pressure data that is crucial for planned projects globally, particularly those that may experience stop-and-start injection regimes. In relation to reactive solvent development in the field of capture, CETRI (U of R) has developed a synergistic combination of novel solvent and catalytic packing in its facility that significantly reduces energy requirements and equipment size for CO2 capture, resulting in a lower cost process. This next generation capture technology provides decarbonization across many challenging applications and industrial sources. The research at CETRI, which has played an important role in the optimization of the Boundary Dam facility in the past, is building on that experience. Both the real-time data at Aquistore, and the catalyst-aided solvent development at the University of Regina draw from industrial scale CCUS in Saskatchewan. Interestingly, the saline formation characterization that informed Aquistore, has now provided crucial data for southern Saskatchewan about temperatures and fluid flow that is encouraging geothermal heating in cities like Regina and Estevan, offering insight into how research into emissions reduction technologies can help inform and expand additional low carbon projects.
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Elmously, Mohamed A., Ahmed Emara und Osayed S. M. Abu-Elyazeed. „Conversion of Glucose Into 5-Hydroxymethylfurfural in DMSO as Single Organic Solvent“. In ASME 2014 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/imece2014-37316.
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Nowadays, 5-Hydroxymethylfurfural (HMF) is considered an important compound due to its economic importance, and due to the energy and waste crisis. It could provide a biofuel and alternatives of petrochemicals for various industrial applications. In the present work, 5-HMF was successfully produced with high yield by the dehydration of glucose in DMSO as organic solvent. DMSO was approved that it is highly selectivity of HMF (5-Hydroxymethylfurfural), and reducing the side reactions compared to water/DMSO as solvent. And the 5-HMF formation reaction was found to be faster in DMSO system than in water/DMSO. The influence of temperature and reaction time on the selectivity of DMSO was investigated over small range, to clarify the relation between temperature and time.
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Simić, Zoran. „Analysis of different possibilities for determining tie lines in liquid-liquid equilibria“. In 35th International Congress on Process Industry. SMEITS, 2022. http://dx.doi.org/10.24094/ptk.022.319.
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Due to the global trend of increasing environmental pollution, green solvents are being implemented in various branches of the chemical industry to, which would replace standard industrial solvents with harmful characteristics. In order to examine the possibilities of using green solvents, the possibility of appropriate replacement and process design, it is necessary to determine thermodynamic data such as liquid-liquid equilibria, i.e. tie lines in liquid- liquid extraction (LLE), and the corresponding binodal curve. Solubility of components are of great importance for the separation processes (especially for extraction) applied in the chemical industry. Tie lines are a very important thermodynamic data, which are mostly determined by chromatographic analysis depending on the nature of the components in the mixture. Tie lines are mostly determined by chromatographic analysis. Chromatographic analysis is one of the methods that not every laboratory can afford, due to the high cost of the apparatus and high operational costs. In this paper some of the alternative methods for determining tie lines in liquid-liquid equilibria are presented. On the example of the ternary system water+dimethyl adipate+2-propanol, the determination of tie lines via the refractive index and the density of the mixture are shown. These analytical methods are often used in various branches of industry. Based on the obtained results, a mutual comparison of the results obtained through these three methods is performed.
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Cai, Shaowei, Chuan Luo und Haochen Zhang. „From Decimation to Local Search and Back: A New Approach to MaxSAT“. In Twenty-Sixth International Joint Conference on Artificial Intelligence. California: International Joint Conferences on Artificial Intelligence Organization, 2017. http://dx.doi.org/10.24963/ijcai.2017/80.
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Maximum Satisfiability (MaxSAT) is an important NP-hard combinatorial optimization problem with many applications and MaxSAT solving has attracted much interest. This work proposes a new incomplete approach to MaxSAT. We propose a novel decimation algorithm for MaxSAT, and then combine it with a local search algorithm. Our approach works by interleaving between the decimation algorithm and the local search algorithm, with useful information passed between them. Experiments show that our solver DeciLS achieves state of the art performance on all unweighted benchmarks from the MaxSAT Evaluation 2016. Moreover, compared to SAT-based MaxSAT solvers which dominate industrial benchmarks for years, it performs better on industrial benchmarks and significantly better on application formulas from SAT Competition. We also extend this approach to (Weighted) Partial MaxSAT, and the resulting solvers significantly improve local search solvers on crafted and industrial benchmarks, and are complementary (better on WPMS crafted benchmarks) to SAT-based solvers.
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Zhu, Liyang, Wuhua Duan, Jingming Xu und Yongjun Zhu. „Extraction of Actinides and Lanthanides by Supercritical Fluid“. In 18th International Conference on Nuclear Engineering. ASMEDC, 2010. http://dx.doi.org/10.1115/icone18-29914.
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Reprocessing of used nuclear fuel and treatment of nuclear waste are important issues for the sustainable development of nuclear energy. It is necessary to develop novel nuclear waste treatment technologies to meet the goal of minimizing the secondary liquid waste. Supercritical fluids are considered green solvents in chemical engineering process. It gains growing interest to treat nuclear waste using supercritical fluid extraction recently, because it can greatly decrease the secondary liquid waste with high radioactivity. During the past two decades, extraction of actinides and lanthanides by supercritical fluid has been intensively studied in some countries, and many important progresses have been made. However, the prospect of industrial application of supercritical fluid extraction technology in reprocessing of used nuclear fuel and treatment of nuclear waste is still unclear. In this paper, extraction of actinides and lanthanides from various matrixes or from their oxides by supercritical fluid including the experimental results, extraction mechanism and kinetic process was reviewed. The engineering demonstration projects were introduced. The trend of industrial application of supercritical fluid extraction technology in nuclear waste management was also discussed.
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Lei, Zhendong, und Shaowei Cai. „Solving (Weighted) Partial MaxSAT by Dynamic Local Search for SAT“. In Twenty-Seventh International Joint Conference on Artificial Intelligence {IJCAI-18}. California: International Joint Conferences on Artificial Intelligence Organization, 2018. http://dx.doi.org/10.24963/ijcai.2018/187.
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Partial MaxSAT (PMS) generalizes SAT and MaxSAT by introducing hard clauses and soft clauses. PMS and Weighted PMS (WPMS) have many important real world applications. Local search is one popular method for solving (W)PMS. Recent studies on specialized local search for (W)PMS have led to significant improvements. But such specialized algorithms are complicated with the concepts tailored for hard and soft clauses. In this work, we propose a dynamic local search algorithm, which exploits the structure of (W)PMS by a carefully designed clause weighting scheme. Our solver SATLike adopts a local search framework for SAT and does not need any specialized concept for (W)PMS. Experiments on PMS and WPMS benchmarks from the MaxSAT Evaluations (MSE) 2016 and 2017 show that SATLike significantly outperforms state of the art local search solvers. Also, SATLike significantly narrows the gap between the performance of local search solvers and complete solvers on industrial benchmarks, and performs better than the complete solvers on the MSE2017 benchmarks.
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Peixoto, Bárbara Pereira, José Walkimar de M. Carneiro und Rodolfo Goetze Fiorot. „Substituição nucleofílica alifática: qual o mecanismo preferencial? Estudo computacional dos efeitos da estrutura do substrato e solvente“. In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol2020122.
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Nucleophilic aliphatic substitution reactions constitute important steps in the synthesis of substances with biological activity and industrial appeal, beyond to participating in steps in biosynthetic routes of natural products. Unimolecular (SN1) and bimolecular (SN2) pathways can be understood as limiting cases of a mechanistic continuum. In between them, borderline mechanisms are proposed. The preference for one path over another depends on several factors, such as the structure of the substrate, the nucleophile and the solvent used. This plurality is still a topic of discussion and needs further understanding. In this context, the present work aims to rationalize the preferential reaction pathway for nucleophilic aliphatic substitutions, whose substrates do not fit only in the uni- and bimolecular models, by identifying lower energy reaction pathways due to the structural and electronic characteristics. The evaluation was carried out by molecular modeling at the Density Functional Theory (DFT) level, simulating substrates with the nucleofuge (Cl and NH3 + ) connected to secondary carbon atoms, with the computational method M06-2X/aug-cc-pVTZ, previously validated according to geometrical and energetic parameters. Besides, we checked the effect of a polar solvent with high dielectric constant in the reaction pathways. The analyzed substrates demonstrated preference for the bimolecular mechanism and the influence of a solvent in these reactions was evident.
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Chiou, Richard Y., Michael G. Mauk, Irina C. Husanu, Tzu-Liang (Bill) Tseng und Sowrirajan Sowmithran. „Virtual Reality Laboratory: Green Robotic Ultrasonic Welding“. In ASME 2019 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/imece2019-11912.
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Abstract This paper describes recent developments in an ongoing project to develop a series of virtual reality (VR) based robotic ultrasonic welding laboratory simulations, designed to impress upon users the importance of proper laboratory safety procedures and the potential consequences of not doing so. Robotic ultrasonic welding virtual reality laboratory is developed as an educational project and laboratory component for undergraduate engineering curricula. Ultrasonic welding is a relatively fast, clean process that does not require adhesives, binding agents, solders, fluxes, or solvents. However, it can only be done either by an experienced welder or a welding robot since it is difficult to weld due to high-frequency mechanical vibration and complex welding path. This paper explores the use of virtual reality simulation of industrial robots and its application in the field of industrial design and automation with lab-on-a-chip devices. With a virtual reality based welding simulator, learning ultrasonic welding can be made easier and faster. Accordingly, educational approaches that combine and integrate multiple disciplines afford more efficient and effective use of time and resources. A concluding section discusses the student learning outcomes during this project.
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Huang, Yuhao, Zane Morris, Tim Sirola, Andrew Hardman, Yifan Shi, Il Yong Kim, Manish Pamwar und Balbir Sangha. „Frequency-Constrained Multi-Material Topology Optimization: Commercial Solver Integrable Sensitivities“. In WCX SAE World Congress Experience. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2023. http://dx.doi.org/10.4271/2023-01-0029.
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<div class="section abstract"><div class="htmlview paragraph">Numerical tools such as topology optimization (TO) have seen large development in both academic and industrial settings, enabling the optimization of structural objectives and/or attributes, subject to a wide range of constraints, pertinent to the engineering and design problems of automotive and aerospace industries. Classical TO methods assume the use of a single material (SMTO), however, a recent and important advancement in this field is that of multi-material topology optimization (MMTO), capable of simultaneous material existence and selection optimization. This is of heightened importance in the aforementioned industries, where many costly engineering materials can be used, but their selection is delegated to engineer experience. Consideration of modal characteristics (i.e., natural frequencies) in MMTO efforts have seen marginal development in recent years, yet is vital to both industries, who’s products are each subject to uncontrolled environments and vibratory motion. Where frequency has been considered in MMTO, mathematical frameworks require the usage of model attributes that are not extractable from commercial finite element analysis (FEA) solvers, leading to reduced computational efficiency. This paper presents an advancement of the frequency-constrained MMTO sensitivities previously utilized in SMTO, enabling the use of commercial solvers, thus inheriting computational improvements. A derivation of sensitivities, a detailed discussion, and analysis of two case studies have been included, so as to provide the reader with a sound understanding of the nature of the constraint sensitivities, and how they may be able to intuit results.</div></div>
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Fadil MOUSA, Enaam, und Ibtissam Khalifa JASSIM. „SYNTHESIS ,CHARACTERIZATION AND BIOLOGICAL ACTIVITY STUDY OF SOME HETEROCYCLIC COMPOUNDS“. In IV.International Scientific Congress of Pure,Appliedand Technological Sciences. Rimar Academy, 2022. http://dx.doi.org/10.47832/minarcongress4-18.
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Heterocycles are an important class of organic compounds because of their applications in medicines and industrial fields. Therefore our study included preparation of these compound such as oxazepine and quinazoline rings, which were prepared through two steps: The first step included the reaction of the Schiff bases derived from sulfamethaxazole (1-4) with each of phthalic anhydride and 3- nitrophthalic anhydride for the preparation of oxazepines (5-12) .While the second step included the preparation of quinazoline compounds (13-16) from the reaction of Schiff bases (1-4) with anthranilic acid using dry benzene as a medium and solvent for the reaction. All prepared compounds were characterized by using infrared,proton- nuclear magnetic resonance, mass techniques and melting points, and their purity was determined by thin layer chromatography technique also screened the biological activity of some of these prepared compounds by using two types of bacteria Gram-positive and negative . The results showed that these compounds have a good inhibition against these organisms