China
Africa
Explore chapters and articles related to this topic
Noble Metal Nanoparticles in Organic Catalysis
Published in Varun Rawat, Anirban Das, Chandra Mohan Srivastava, Heterogeneous Catalysis in Organic Transformations, 2022
Laxmi Devi, Komal, Sunita Kanwar, Kamal Nayan Sharma, Anirban Das, Jyotirmoy Maity
Gluconic acid and gulonic acid were produced on oxidizing D-sorbitol using gold-platinum group metal on carbon support (Au-PGM/C) as a catalyst (Figure 3.3) [15]. It was seen that bimetallic catalysts exhibited improved selectivity as well as improved resistance to poisoning in comparison to monometallic catalysts. Selectivity observed for gluconate and gulonate on Au and Au/Pt were 60% and 62%, respectively [15, 16]. For the oxidation of glycerol, Au was found to be resistant to the poisoning of oxygen than PGMs. The oxidation of glycerol in the liquid phase using Au/charcoal, activated carbon, and Au/graphite was reported. It was found that glyceric acid was obtained by oxidation of glycerol with high selectivity and quantitative conversion in mild conditions using water as a solvent (Figure 3.4) [17].
Chemical Reactions of Glycerine
Published in Eric Jungermann, Norman O.V. Sonntag, Glycerine, 2018
Oxidation of glycerine with bromine and sodium carbonate results in the formation of a mixture of glyceraldehyde and dihydroxacetone; this mixture is often called glycerose. The aldehyde is the predominant component in this mixture. These compounds are the simplest aldose and ketose, and as such are the forerunners of the carbohydrates. Dihydroxyacetone, can also be formed by the microbiological oxidation of glycerine by the sorbose bacterium which exclusively attacks secondary hydroxyl groups [41]. Dihydroxyacetone is a skin-tanning agent and is used in cosmetic formulations designed for this purpose. Anodic oxidation of glycerol at a silver oxide electrode yields glyceric acid [42]. Glycerine is also converted into glyceric acid by the reaction of concentrated nitric acid.
Utilization of Biodiesel By-Products in Various Industrial Applications
Published in Bhaskar Singh, Ramesh Oraon, Advanced Nanocatalysts for Biodiesel Production, 2023
Glyceric acid is a naturally occurring organic acid with a molecular formula of C3H6O4 (2R, 3-hydroxy propanoic acid) (Handa et al., 1986). Its chemical synthesis is very costly and hence restricts it usage value. Chemically, it is synthesized either by a microbial fermentation process or by metallic oxidation of glycerol (Bianchi et al., 2005). It is used in the chemical, cosmetic and pharmaceutical industries (Habe et al., 2009; Rosseto et al., 2008; Sile et al., 2013).
Efficient production of dihydroxyacetone from glycerol over a Pt/CeO2-ZrO2-Bi2O3/SBA-16 catalyst
Published in Journal of Asian Ceramic Societies, 2018
Pil-Gyu Choi, Naoyoshi Nunotani, Nobuhito Imanaka
Glycerol is generated as a byproduct in the production of bio-diesel from lipids, such as vegetable oils, animal oils, and waste fats [1,2]. Today’s increasing production of bio-diesel is fueling growth in the supply of glycerol, leading to surplus production of glycerol. It is, therefore, important to transform the excess glycerol to valuable chemicals, such as dihydroxyacetone (DHA), glyceric acid, tartronic acid, and lactic acid. DHA is one of the especially important compounds due to its skin-browning effect without UV irradiation (i.e. its sunless tanning effect). Since this tanning is nontoxic and poses no risk of skin cancer derived from UV rays, DHA has been widely used for cosmetics.