China
Africa
Explore chapters and articles related to this topic
Metabolic Engineering for the Production of a Variety of Biofuels and Biochemicals
Published in Kazuyuki Shimizu, Metabolic Regulation and Metabolic Engineering for Biofuel and Biochemical Production, 2017
D-Glucaric acid is found in fruits, vegetables, and mammals. It may be used as a dietary supplement in the form of calcium D-glucarate, and it has been investigated for a variety of therapeutic purposes such as cholesterol reduction (Walaszek et al. 1996), diabetes treatment (Bhattachaya et al. 2013), and cancer chemotherapy (Gupta and Singh 2004). D-Glucaric acid is also identified as a top value-added chemical from biomass (Werpy and Petersen, 2004). D-Glucaric acid is a highly functionalized compound with four chiral carbons, and is currently produced by chemical oxidation of glucose, a nonselective, expensive, and environmentally not friendly process using nitric acid as the solvent and oxidant (Werpy and Petersen, 2004). Biological production may be able to avoid costly catalyst and harsh reaction conditions, and offers the potential for a cheaper and more environmentally friendly process.
Valorization of Hemicelluloses
Published in Jean-Luc Wertz, Magali Deleu, Séverine Coppée, Aurore Richel, Hemicelluloses and Lignin in Biorefineries, 2017
Jean-Luc Wertz, Magali Deleu, Séverine Coppée, Aurore Richel
C6 building blocks (Table 9.7) mainly include adipic, saccharic, 2,5-furan dicarboxylic acid, caprolactam, and sorbitol. Adipic acid is known to be a monomer of nylon 6,6. Biobased adipic acid developed by Verdezyne is produced by fermentation. It is also a monomer of polyurethane, and its esters are PVC plasticizers.Saccharic (also called glucaric) acid is obtained by oxidation of glucose with nitric acid. It leads to new nylons (polyhydroxypolyamides). Saccharic acid (and its esters) leads also to the production of new polyester types. In addition, it could find applications in the market of laundry surfactants.2,5-Furan dicarboxylic acid is obtained by selective oxidation of hydroxymethylfurfural. It is a potential substitute of terephthalic in the manufacture of polyesters such as PET. The Dutch company Avantium works in partnership with Coca-Cola to produce a 100% biobased PEF (polyethylene furanoate). Virent and Gevo also work in partnership with Coca-Cola to produce a 100% biobased PET.Polycaprolactam can be produced from lysine, biobutadiene, bioacrylonitrile, and biobenzene. It is a monomer of nylon 6.Sorbitol, a sweetener, is obtained by chemical reduction of glucose. It is also produced from sucrose or from mixtures of fructose and glucose. It is an intermediate in the production of hydrocarbons and is a starting material for many products going from ethylene glycol to propylene glycol, lactic acid, glycerol, isosorbide, 1,4-sorbitan, and polyesters.
Green Chemistry
Published in Paul Mac Berthouex, Linfield C. Brown, Chemical Processes for Pollution Prevention and Control, 2017
Paul Mac Berthouex, Linfield C. Brown
Another non-petrochemical-based method of producing adipic acid is shown in Figure 10.16. First, biomass is converted to glucose. Glucose is converted to glucaric acid using selective oxidation, and glucaric acid is converted to adipic acid via selective hydrogenation.
Kinetic modeling of advanced starch oxidation with ozone in basic solutions
Published in Ozone: Science & Engineering, 2023
Alejandro Ávila-Sierra, José M. Vicaria, Juan F. Martínez-Gallegos, Sara Cañadas, Encarnación Jurado-Alameda
Previous works have shown that ozone can modify the composition and structure of starch, given its ability to break the glucosidic bonds that bind glucose molecules, causing starch depolymerization, and oxidizing its hydroxyl and carbonyl groups to carboxyl groups (Castanha, Matta Junior, Augusto 2017; Catal and Ibanoglu, 2014). Similarly, it has been observed how hydroxyl radicals react with oligosaccharides and polysaccharides, being capable of breaking glucosidic bonds (Dai et al. 2017). The glucose oxidation by ozone generates different products, including acidic sugars, such as uronic (glucuronic acid), aldonic (gluconic acid) and aldaric acids (glucaric acid). The subsequent oxidation of these substances gives rise to other organic acids and compounds with fewer carbon atoms, the latter arising from their decarboxylation causing the release of CO2 (Marcq, Barbe, Trichet, Guilard 2009). Analogously, successive oxidations of starch by hydroxyl radicals during its ozonation at alkaline pH are foreseeable and would be justified by the observed reduction of COD (Figure 5), being this COD reduction also found in previous works on cleaning of starchy deposits (Ávila-Sierra, Vicaria, Jurado-Alameda, Martínez-Gallegos 2020; Avila-Sierra et al. 2021). Likewise, these oxidations and depolymerizations may change the properties of starch after ozonation, e.g., gelatinization, pasting, retrogradation and solubility (Catal and Ibanoglu, 2014), likely affecting the cleaning process of starches.