Low-molecular-weight carboxylic acids produced from hydrothermal treatment of organic wastes.
This article reports production of low-molecular-weight carboxylic acids from the hydrothermal treatment of representative organic wastes and compounds (i.e. domestic sludge, proteinaceous, cellulosic and plastic wastes) with or without oxidant (H(2)O(2)). Organic acids such as acetic, formic, propionic, succinic and lactic acids were obtained in significant amounts. At 623 K (16.5 MPa), acetic acid of about 26 mg/g dry waste fish entrails was obtained. This increased to 42 mg/g dry waste fish entrails in the presence of H(2)O(2). Experiments on glucose to represent cellulosic wastes were also carried out, getting acetic acid of about 29 mg/g glucose. The study was extended to terephthalic acid and glyceraldehyde, reaction intermediates of hydrothermal treatment of polyethylene terephthalate (PET) plastic wastes and glucose, respectively. In addition, production of lactic acid, one of the interesting low-molecular-weight carboxylic acids, was discussed on the viewpoint of resources recovery. Studies on temperature dependence of formation of organic acids showed thermal stability of acetic acid, whereas, formic acid decomposed readily under hydrothermal conditions. In general, results demonstrated that the presence of oxidants favored formation of organic acids with acetic acid being the major product.
Quitain
Armando T
AT
Department of Ecological Engineering (G-614), Toyohashi University of Technology, Tempaku-cho, 441-8580, Toyohashi, Japan.
Faisal
Muhammad
M
Kang
Kilyoon
K
Daimon
Hiroyuki
H
Fujie
Koichi
K
D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry*; D002482:Cellulose; D006861:Hydrogen Peroxide / Q000737:chemistry; D008970:Molecular Weight; D009930:Organic Chemicals; D016877:Oxidants / Q000737:chemistry; D010969:Plastics; D011506:Proteins; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry; D013696:Temperature; D014867:Water
D002264:Carboxylic Acids; D009930:Organic Chemicals; D016877:Oxidants; D010969:Plastics; D011506:Proteins; D012722:Sewage; D014867:Water; D002482:Cellulose; D006861:Hydrogen Peroxide