The hydrolysis of cellulose into saccharides using a range of solid catalysts is investigated for potential application in the environmentally benign saccharification of cellulose. Crystalline pure cellulose is not hydrolyzed by conventional strong solid Brønsted acid catalysts such as niobic acid, H-mordenite, Nafion and Amberlyst-15, whereas amorphous carbon bearing SO 3H, COOH, and OH function as an efficient catalyst for the reaction. The apparent activation energy for the hydrolysis of cellulose into glucose using the carbon catalyst is estimated to be 110 kJ mol (-1), smaller than that for sulfuric acid under optimal conditions (170 kJ mol (-1)). The carbon catalyst can be readily separated from the saccharide solution after reaction for reuse in the reaction without loss of activity. The catalytic performance of the carbon catalyst is attributed to the ability of the material to adsorb beta-1,4 glucan, which does not adsorb to other solid acids.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja803983h | DOI Listing |
Polymers (Basel)
December 2024
Department of Chemical, Environmental and Materials Engineering, Higher Polytechnical School of University of Jaén, Avda. de la Universidad s/n, 23700 Linares, Spain.
A sequential valorization process of sunflower stalks was carried out using nitric acid (0.1-2 mol dm) as a hydrolytic agent and fermenting the hydrolysate of higher sugar concentration in the presence of the non-conventional yeast . Values reached for ethanol yield (0.
View Article and Find Full Text PDFMolecules
December 2024
Department of Material Science and Engineering, University of Ioannina, 45110 Ioannina, Greece.
Biomass valorization and bio-based material development are of major research interest following the spirit of the circular economy. Aloe vera cultivation is a widespread agricultural activity oriented toward supplement production because of its well-known antioxidant and antimicrobial properties. Aloe vera juice production also produces a large amount of biomass byproducts that are usually landfilled.
View Article and Find Full Text PDFMaterials (Basel)
December 2024
Department of Drug Form Technology, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland.
The aim of this study was to develop and optimize polymeric films based on cellulose derivatives-hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), and sodium carboxymethylcellulose (NaCMC)-as well as pullulan, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and glycerol (GLY) as plasticizer incorporating extract for potential use in periodontal and gum disease treatment. Over 80 formulations were fabricated using the solvent-casting method, 6 of which were selected for further investigation based on their mechanical properties, mucoadhesion, and disintegration profiles, including three placebo films (OP1 (PVA/PVP/MC400CP/NaCMC/GLY), OP2 (PVA/PVP/MCA15C/NaCMC/GLY), and OP3 (PVA/PVP/HPMC/NaCMC/GLY)) and three films containing extract (OW1, OW2, and OW3). The films demonstrated uniform structural characteristics, with the formulations containing PVA with a high hydrolysis degree (98-99%) and methylcellulose derivatives showing prolonged dissolution times due to physical cross-linking, while the inclusion of NaCMC reduced dissolution time without compromising mucoadhesiveness.
View Article and Find Full Text PDFFEBS J
January 2025
Department of Biosciences and Bioengineering, IIT Bombay, Mumbai, India.
Cellulases are an ensemble of enzymes that hydrolyze cellulose chains into fermentable glucose and hence are widely used in bioethanol production. The last enzyme of the cellulose degradation pathway, β-glucosidase, is inhibited by its product, glucose. The product inhibition by glucose hinders cellulose hydrolysis limiting the saccharification during bioethanol production.
View Article and Find Full Text PDFBBA Adv
December 2024
Novonesis, 2 Biologiens Vej, DK-2800 Lyngby Denmark.
Cellulases are of paramount interest for upcoming biorefineries that utilize residue from agriculture and forestry to produce sustainable fuels and chemicals. Specifically, cellulases are used for the conversion of recalcitrant plant biomass to fermentable sugars in a so-called saccharification process. The vast literature on enzymatic saccharification frequently refers to low catalytic rates of cellulases as a main bottleneck for industrial implementation, but such statements are rarely supported by kinetic or thermodynamic considerations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!