scholarly journals Efficient chemical fixation and defixation cycle of carbon dioxide under ambient conditions

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Saumen Hajra ◽  
Anurag Biswas
Keyword(s):  
Flue Gas ◽  
Room Temperature ◽  
Irreversible Process ◽  
Value Added ◽  
Chemical Transformations ◽  
Chemical Fixation ◽  
Ambient Conditions ◽  
Combustion Technology ◽  
Capture And Release ◽  
Value Added Products

Abstract Chemical fixation of CO2 as a C1 feedstock for producing value-added products is an important post-combustion technology reducing the CO2 emission. As it is an irreversible process, not considered for the CO2 capture and release. Overall, these chemical transformations also do not help to mitigate global warming, as the energy consumed in different forms is much higher than the amount of CO2 fixed by chemical reactions. Here we describe the development of re-generable chemical fixation of CO2 by spiroaziridine oxindole, where CO2 is captured (chemical fixation) under catalyst-free condition at room temperature both in aqueous and non-aqueous medium even directly from the slow stream of flue gas producing regioselectively spirooxazolidinyl oxindoles, a potential drug. The CO2-adduct is reversed back to the spiroaziridine releasing CO2 under mild conditions. Further both the fixation-defixation of CO2 can be repeated under near ambient conditions for several cycles in a single loop using a recyclable reagent.

Efficient chemical fixation of CO2 from direct air under environment-friendly co-catalyst and solvent-free ambient conditions

2021 ◽  
Author(s):  
Rajesh Das ◽  
THIRUMAVALAVAN EZHIL ◽  
Athulya S. Palakkal ◽  
Devaraj Muthukumar ◽  
Renjith S. Pillai ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Value Added ◽  
Solvent Free ◽  
Chemical Fixation ◽  
Ambient Conditions ◽  
Energy Sustainability ◽  
Environment Friendly ◽  
Co Catalyst ◽  
Mild Conditions ◽  
Value Added Products

The capture and conversion of CO2 from direct air into value-added products under mild conditions represents a promising step towards environmental remediation and energy sustainability. Consequently, herein, we report application...

Purification of Eucalyptus globulus water prehydrolyzates using the HiTAC process (high-temperature adsorption on activated charcoal)

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Jenny Sabrina Gütsch ◽  
Herbert Sixta
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Adsorption Process ◽  
Value Added ◽  
Sustainable Utilization ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Charcoal Adsorption ◽  
Increasing Temperature ◽  
Value Added Products

Abstract The implementation of biorefinery concepts into existing pulp and paper mills is a key step for a sustainable utilization of the natural resource wood. Water prehydrolysis of wood is an interesting process for the recovery of xylo-oligosaccharides and derivatives thereof, while at the same time cellulose is preserved to a large extent for subsequent dissolving pulp production. The recovery of value-added products out of autohydrolyzates is frequently hindered by extensive lignin precipitation, especially at high temperatures. In this study, a new high-temperature adsorption process (HiTAC process) was developed, where lignin is removed directly after the autohydrolysis, which enables further processing of the autohydrolyzates. The suitability of activated charcoals as a selective adsorbent for lignin under process-relevant conditions (150 and 170°C) has not been considered up to now, because former experiments showed decreasing efficiency of charcoal adsorption of lignin with increasing temperature in the range 20–80°C. In contrast to these results, we demonstrated that the adsorption of lignin at 170°C directly after autohydrolysis is even more efficient than after cooling the hydrolyzate to room temperature. The formation of lignin precipitation and incrustations can thus be efficiently prevented by the HiTAC process. The carbohydrates in the autohydrolysis liquor remain unaffected over a wide charcoal concentration range and can be further processed to yield valuable products.

Implementing a sustainable photochemical step to produce value-added products in flue gas desulfurization

2022 ◽  
Vol 430 ◽  
pp. 133072
Author(s):  
Raúl E. Orozco-Mena ◽  
Raúl A. Márquez ◽  
Kenya I. Mora-Domínguez ◽  
Virginia H. Collins-Martinez ◽  
Eduardo F. Herrera-Peraza ◽  
...  
Keyword(s):  
Flue Gas ◽  
Value Added ◽  
Flue Gas Desulfurization ◽  
Value Added Products

Chemical transformations of glucose to value added products using Cu-based catalytic systems

2013 ◽  
Vol 15 (29) ◽  
pp. 12165 ◽  
Author(s):  
Alfonso Yepez ◽  
Antonio Pineda ◽  
Angel Garcia ◽  
Antonio A. Romero ◽  
Rafael Luque
Keyword(s):  
Value Added ◽  
Chemical Transformations ◽  
Catalytic Systems ◽  
Value Added Products

scholarly journals Ammonia borane enabled upgrading of biomass derivatives at room temperature

2020 ◽  
Vol 22 (18) ◽  
pp. 5972-5977
Author(s):  
Wenfeng Zhao ◽  
Sebastian Meier ◽  
Song Yang ◽  
Anders Riisager
Keyword(s):  
Room Temperature ◽  
Value Added ◽  
Ammonia Borane ◽  
Efficient Catalyst ◽  
Free System ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Value Added Products

An efficient catalyst-free system composed of ammonia borane in water or alcohol was developed to selectively convert biomass-derived feedstock into four value-added products under extremely mild conditions.

scholarly journals Rigor index, fillet yield and proximate composition of cultured striped catfish (Pangasianodon hypophthalmus) for its suitability in processing industries in Bangladesh

2014 ◽  
Vol 2 (3) ◽  
pp. 157 ◽  
Author(s):  
Salma Noor-E Islami ◽  
Md. Shaheed Reza ◽  
Md. Abul Mansur ◽  
Md. Ismail Hossain ◽  
Fatema Hoque Shikha ◽  
...  
Keyword(s):  
Proximate Composition ◽  
Room Temperature ◽  
Value Added ◽  
Composition Analysis ◽  
Tail Region ◽  
Pangasianodon Hypophthalmus ◽  
Fish Fillets ◽  
Striped Catfish ◽  
Fillet Yield ◽  
Value Added Products

Rigor-index in market-size striped catfish (Pangasianodon hypophthalmus, locally called Thai-Pangas) was determined to assess fillet yield for production of value-added products. In whole fish, rigor started within 1 hr after death under both iced and room temperature conditions while rigor-index reached a maximum of 72.23% within 8 hr and 85.5% within 5 hr at room temperature and iced condition, respectively, which was fully relaxed after 22 hr under both storage conditions. Post-mortem muscle pH decreased to 6.8 after 2 hr, 6.2 after 8 hr and sharp increase to 6.9 after 9 hr. There was a positive correlation between rigor progress and pH shift in fish fillets. Hand filleting was done post-rigor and fillet yield experiment showed 50.4±2.1% fillet, 8.0±0.2% viscera, 8.0±1.3% skin and 32.0±3.2% carcass could be obtained from Thai-Pangas. Proximate composition analysis of four regions of Thai-Pangas viz., head region, middle region, tail region and viscera revealed moisture 78.36%, 81.14%, 81.45% and 57.33%; protein 15.83%, 15.97%, 16.14% and 17.20%; lipid 4.61%, 1.82%, 1.32% and 24.31% and ash 1.09%, 0.96%, 0.95% and 0.86%, respectively indicating suitability of Thai-Pangas for production of value-added products such as fish fillets.

Observations of thick and thin sections in a field-emission SEM

1994 ◽  
Vol 52 ◽  
pp. 1018-1019
Author(s):  
W. P. Wergin ◽  
S. Roy ◽  
E. F. Erbe ◽  
C. A. Murphy ◽  
C. D. Pooley
Keyword(s):  
Electron Microscope ◽  
Field Emission ◽  
Room Temperature ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Chemical Fixation ◽  
Thin Sections ◽  
Transmission Electron ◽  
Conventional Transmission Electron Microscope ◽  
Scanning Electron

Larvae of the nematode, Steinernema carpocapsae Weiser strain All, were cryofixed and freezesubstituted for 3 days in acetone containing 2% osmium tetroxide according to established procedures. Following chemical fixation, the nematodes were brought to room temperature, embedded in Spurr's medium and sectioned for observation with a Hitachi S-4100 field emission scanning electron microscope that was equipped with an Oxford CT 1500 Cryotrans System. Thin sections, about 80 nm thick, similar to those generally used in conventional transmission electron microscope (TEM) studies were mounted on copper grids and stained with uranyl acetate for 30 min and lead citrate for 5 min. Sections about 2 μm thick were also mounted and stained in a similar fashion. The grids were mounted on an Oxford grid holder, inserted into the microscope and onto a cryostage that was operated at ambient temperature. Thick and thin sections of the larvae were evaluated and photographed in the SEM at different accelerating voltages. Figs. 4 and 5 have undergone contrast conversion so that the images would resemble transmitted electron micrographs obtained with a TEM.

OPPORTUNITIES FOR STRATEGIC DEVELOPMENT OF BIO-ECONOMY IN THE FOOD AND TOURISM INDUSTRY

2018 ◽  
Vol 28 (5) ◽  
pp. 1681-1684
Author(s):  
Georgi Toskov ◽  
Ana Yaneva ◽  
Stanko Stankov ◽  
Hafize Fidan
Keyword(s):  
National Level ◽  
Value Added ◽  
Tourism Industry ◽  
Small Companies ◽  
Food Sector ◽  
Strategic Development ◽  
Innovation Potential ◽  
Wide Range ◽  
Foreign Brands ◽  
Value Added Products

The European Commission defines the bioeconomy as "the production of renewable biological resources and the conversion of these resources and waste streams into value added products, such as food, feed, bio-based products and bioenergy. Its sectors and industries have strong innovation potential due to their use of a wide range of sciences, enabling and industrial technologies, along with local and implied knowledge." The Bulgarian food industry faces a lot of challenges on the local and national level, which have direct influence on the structure of the production companies. Most of the enterprises from the food sector produce under foreign brands in order to be flexible partners to the large Bulgarian retail chains. The small companies from the food sector are not able to develop as an independent competitive producer on the territory of their local markets. This kind of companies rarely has a working strategy for positioning on new markets. In order to consolidate their already built positions for long period of time, the producers are trying to optimize their operations in a short term. However, the unclear vision of the companies for the business segment does not allow them to fully develop. Tourism in Bulgaria is a significant contributor to the country's economy.

Oxidized indium with transformable dimensions for CO2 electroreduction toward formate aided by oxygen vacancies

2020 ◽  
Vol 4 (7) ◽  
pp. 3726-3731
Author(s):  
Fenghui Ye ◽  
Jinghui Gao ◽  
Yilin Chen ◽  
Yunming Fang
Keyword(s):  
Crucial Role ◽  
Oxygen Vacancies ◽  
Value Added ◽  
Promising Technique ◽  
Co2 Electroreduction ◽  
Value Added Products

Electroreduction of CO2 into value-added products is a promising technique in which the structure of the catalyst plays a crucial role.

scholarly journals β-Galactosidases from a Sequence-Based Metagenome: Cloning, Expression, Purification and Characterization

2020 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
María Florencia Eberhardt ◽  
José Matías Irazoqui ◽  
Ariel Fernando Amadio
Keyword(s):  
Bacterial Species ◽  
Value Added ◽  
Raw Material ◽  
Activity Levels ◽  
Treatment Technology ◽  
Catalytic Domains ◽  
Stabilization Ponds ◽  
Cazy Database ◽  
Genes Encoding ◽  
Value Added Products

Stabilization ponds are a common treatment technology for wastewater generated by dairy industries. Large proportions of cheese whey are thrown into these ponds, creating an environmental problem because of the large volume produced and the high biological and chemical oxygen demands. Due to its composition, mainly lactose and proteins, it can be considered as a raw material for value-added products, through physicochemical or enzymatic treatments. β-Galactosidases (EC 3.2.1.23) are lactose modifying enzymes that can transform lactose in free monomers, glucose and galactose, or galactooligosacharides. Here, the identification of novel genes encoding β-galactosidases, identified via whole-genome shotgun sequencing of the metagenome of dairy industries stabilization ponds is reported. The genes were selected based on the conservation of catalytic domains, comparing against the CAZy database, and focusing on families with β-galactosidases activity (GH1, GH2 and GH42). A total of 394 candidate genes were found, all belonging to bacterial species. From these candidates, 12 were selected to be cloned and expressed. A total of six enzymes were expressed, and five cleaved efficiently ortho-nitrophenyl-β-galactoside and lactose. The activity levels of one of these novel β-galactosidase was higher than other enzymes reported from functional metagenomics screening and higher than the only enzyme reported from sequence-based metagenomics. A group of novel mesophilic β-galactosidases from diary stabilization ponds’ metagenomes was successfully identified, cloned and expressed. These novel enzymes provide alternatives for the production of value-added products from dairy industries’ by-products.

Sign in / Sign up

Export Citation Format

Share Document