scholarly journals HETEROGENEOUS CATALYTIC CONVERSIONS OF ACETYLENE

2021 ◽  
pp. 45-57
Keyword(s):  
Acetic Acid ◽  
Water Vapor ◽  
Hydrofluoric Acid ◽  
Heterogeneous Catalysts ◽  
Ammonium Fluoride ◽  
Catalyst Carrier ◽  
Heterogeneous Catalytic ◽  
Pyridine Bases ◽  
Cadmium Zinc ◽  
Selection Of

The reactions of interaction of acetylene with water vapor, acetic acid and ammonia in the presence of heterogeneous catalysts have investigated. Depending on the nature of the starting components used, acetaldehyde and acetone, vinyl acetate, pyridine bases and pyrrole synthesized. Heterogeneous catalysts selected for each studied reaction based on some scientific prerequisites for the selection of catalysts. Active catalysts for the investigated reactions were determined, which contain compounds of cadmium, zinc, bismuth, chromium, iron and copper, in general, d-group metals. γ-Al2O3, bentonite and kaolin used as a catalyst carrier. Hydrofluoric acid, acetic acid, ammonium fluoride and others used for peptization. Some hypothetical mechanisms for the formation of target products for each reaction have proposed.

scholarly journals Experiments on the Release of CMOS-Micromachined Metal Layers

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Daniel Fernández ◽  
Jordi Ricart ◽  
Jordi Madrenas
Keyword(s):  
Acetic Acid ◽  
Silicon Dioxide ◽  
Hydrogen Fluoride ◽  
Hydrofluoric Acid ◽  
Ammonium Fluoride ◽  
Cmos Technology ◽  
Multilayer Structures ◽  
Structural Elements ◽  
Mems Devices ◽  
Metal Layers

We present experimental results on the release of MEMS devices manufactured using the standard CMOS interconnection metal layers as structural elements and the insulating silicon dioxide as sacrificial layers. Experiments compare the release results of four different etching agents in a CMOS technology (hydrofluoric acid, ammonium fluoride, a mixture of acetic acid and ammonium fluoride, and hydrogen fluoride), describe various phenomena found during the etching process, and show the release results of multilayer structures.

scholarly journals Chemocatalytic Production of Lactates from Biomass-Derived Sugars

2018 ◽  
Vol 2018 ◽  
pp. 1-18 ◽  
Author(s):  
Heng Zhang ◽  
Yulin Hu ◽  
Liying Qi ◽  
Jian He ◽  
Hu Li ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Heterogeneous Catalysts ◽  
Catalytic Performance ◽  
Green Solvents ◽  
Separation And Purification ◽  
Sustainable Resources ◽  
Base Catalysts ◽  
Heterogeneous Catalytic ◽  
Acid And Base ◽  
Relative Separation

In recent decades, a great deal of attention has been paid to the exploration of alternative and sustainable resources to produce biofuels and valuable chemicals, with aims of reducing the reliance on depleting confined fossil resources and alleviating serious economic and environmental issues. In line with this, lignocellulosic biomass-derived lactic acid (LA, 2-hydroxypropanoic acid), to be identified as an important biomass-derived commodity chemical, has found wide applications in food, pharmaceuticals, and cosmetics. In spite of the current fermentation of saccharides to produce lactic acid, sustainability issues such as environmental impact and high cost derived from the relative separation and purification process will be growing with the increasing demands of necessary orders. Alternatively, chemocatalytic approaches to manufacture LA from biomass (i.e., inedible cellulose) have attracted extensive attention, which may give rise to higher productivity and lower costs related to product work-up. This work presents a review of the state-of-the-art for the production of LA using homogeneous, heterogeneous acid, and base catalysts, from sugars and real biomass like rice straw, respectively. Furthermore, the corresponding bio-based esters lactate which could serve as green solvents, produced from biomass with chemocatalysis, is also discussed. Advantages of heterogeneous catalytic reaction systems are emphasized. Guidance is suggested to improve the catalytic performance of heterogeneous catalysts for the production of LA.

scholarly journals Isolation and selection of microorganisms in cocoa fermentation

2019 ◽  
Vol 18 (4) ◽  
pp. 51-61
Author(s):  
Phong X. Huynh
Keyword(s):  
Acetic Acid ◽  
Theobroma Cacao ◽  
Acetic Acid Bacteria ◽  
Aerobic Bacteria ◽  
Bacterial Isolates ◽  
Fermentative Capacity ◽  
Selection Of Microorganisms ◽  
Cocoa Fermentation ◽  
Selection Of ◽  
Microbial Quantities

The objectives of this study were to investigate the change of microorganisms involved in cocoa (Theobroma cacao) fermentation and then to isolate, characterize and select the important microorganisms in cocoa fermentation. The results showed that microbial quantities continuously changed during cocoa fermentation and the highest quantity of dominant microorganisms at different stages of fermentation process as 8.03 log cfu/g of yeast, 6.34 log cfu/g of mold, 7.77 log cfu/g of lactic acid bacteria, 7.87 log cfu/g of acetic acid bacteria, 7.25 log cfu/g of Bacillus, and 10.93 log cfu/g of the total aerobic bacteria. There were nine yeast isolates belonging 5 genera of Saccharomyces, Kluyveromyces, Brettanomyces, Candida and Cystofilobasidium; 9 mould isolates belonging to 2 genera of Rhizopus and Aspergillus; 11 acetic acid bacteria isolates belonging to Acetobacter; and 13 spore-forming bacterial isolates belonging to Bacillus isolates. Three isolates of yeast (CY-1a, CY-1b, CY-2a) belonging to Kluyveromyces possessed the high fermentative capacity and 4 Acetobacter isolates (CAAB-1d, CAAB-1a, CAAB-1e and CAAB-2d) produced high amounts of acetic acid.

Heterogeneous catalytic wet peroxide oxidation of simulated phenol wastewater by copper metal–organic frameworks

RSC Advances ◽  
2015 ◽  
Vol 5 (41) ◽  
pp. 32795-32803 ◽  
Author(s):  
Kai Huang ◽  
Yang Xu ◽  
Lianguang Wang ◽  
Dongfang Wu
Keyword(s):  
Heterogeneous Catalysts ◽  
Metal Organic Frameworks ◽  
Peroxide Oxidation ◽  
Copper Metal ◽  
Heterogeneous Catalytic ◽  
Wet Peroxide Oxidation ◽  
Porous Copper ◽  
Metal Organic ◽  
Catalytic Wet Peroxide Oxidation ◽  
Phenol Wastewater

Two different porous copper metal–organic frameworks (Cu-MOFs) named as Cu3(BTC)2 and Cu(BDC) were synthesized and applied as heterogeneous catalysts for the catalytic wet peroxide oxidation (CWPO) of simulated phenol wastewater (100 mg L−1).

The Varieties of Scrubbers, Tubing, and Tubing Connectors

2018 ◽  
pp. 221-231
Author(s):  
John R. B. Lighton
Keyword(s):  
Carbon Dioxide ◽  
Water Vapor ◽  
Correct Selection ◽  
Flow Rates ◽  
Intended Application ◽  
Metabolic Measurement ◽  
Air Streams ◽  
Selection Of ◽  
Selective Membranes

This chapter discusses several often-neglected areas of respirometry infrastructure. These include the correct selection of scrubber chemicals for removing water vapor and/or carbon dioxide from air streams, without undesirable interactions; chemical-free scrubbing techniques such as selective membranes, thermal condensing systems, and mathematical correction for water vapor dilution; selecting tubing for metabolic measurement; evaluating the different tubing chemistries in light of the intended application; selecting appropriate tubing diameters for the flow rates that will be used; selecting tubing connectors; maintaining connector gender conventions to minimize plumbing confusion; and other related topics.

scholarly journals A Review of Pyrolisis of Eceng Gondok (Water hyacinth) for Liquid Smoke

2018 ◽  
Vol 73 ◽  
pp. 05010
Author(s):  
Rita Dwi Ratnani ◽  
Widiyanto
Keyword(s):  
Acetic Acid ◽  
Water Vapor ◽  
Activated Charcoal ◽  
Water Hyacinth ◽  
Combustion Process ◽  
Pyrolysis Process ◽  
Temperature Range ◽  
Liquid Smoke ◽  
16Th World ◽  
Co Gas

The growth of eceng gondok (Water hyacinth) in Rawa Pening Lake showed rapid increase.. Based on the mandate of the National Lake conference in Bali and the 16th World Lake Conference, Rawa Pening is one of the fifteen national lakes which need to be treated for its conservation. Reducing number of eceng gondok plants is one of the alternatif. However, further processing is required to treat the waste of eceng gondok. One attempt is to convert eceng gondok (water hyacinth) into liquid smoke product. This article reviewes the potency of eceng gondok for liquid smoke through pyrolisis method. The liquid smoke can be used for various applications such as preservatives, antioxidants, biopesticides and perisa disinfectants. Pyrolysis is a combustion process in the absence of oxygen to produce liquid and charcoal activated charcoal products called activated charcoal. The pyrolysis process is generally carried out at a temperature range between 200-700 °C. The pyrolysis process is one of the methods chosen in order to strive for development that suppresses the formation of CO gas but releases water vapor. Pyrolysis at a temperature of 300-700 ° C, produces the most dominant compounds 1.6 Anhyro-beta-d-glucopyranose, phenol, and acetic acid. The reaction that occurs during pyrolysis of this temperature is the release of water vapor instead of carbon gas so that it is safe for the environment. The discussion on this article focused on the production of liquid smoke from eceng gondok biomass.

scholarly journals Selection of Saccharomyces cerevisiae Starter Strain for Merwah Wine

Fermentation ◽  
2020 ◽  
Vol 6 (2) ◽  
pp. 43
Author(s):  
Nadine Feghali ◽  
Angela Bianco ◽  
Giacomo Zara ◽  
Edouard Tabet ◽  
Chantal Ghanem ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Pilot Scale ◽  
Molecular Monitoring ◽  
Technological Parameters ◽  
Sensorial Analysis ◽  
Spontaneous Fermentation ◽  
Wine Production ◽  
Wild Yeasts ◽  
Selection Of

In order to select Saccharomyces cerevisiae starter strains for ‘‘Merwah’’ wine production, three strains (M.6.16, M.10.16, and M.4.17) previously isolated from ‘‘Merwah’’ must and characterized at the lab scale were tested in pilot-scale fermentation in a Lebanese winery during the 2019 vintage. The three inoculated musts were compared to that obtained with a spontaneous fermentation. During the fermentations, must samples were taken to evaluate the dominance of the inoculated strains, and at the end of fermentation, the obtained wines were subjected to chemical and sensorial characterization. Molecular monitoring by interdelta analysis revealed that only M.4.17 was able to complete the fermentation and dominate over the wild yeasts. Based on the analysis of principal technological parameters (i.e., residual sugar, fermentative vigor, sulfur production, and acetic acid) and sensorial analysis of the wines obtained, M.4.17 was selected as an adequate starter for the production of typical ‘‘Merwah’’ wine.

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