title: Formation of formic acid, acetic acid and lactic acid from decomposition of citric acid by coal ash particles at room temperature.
abstract: It was found for the first time that citric acid was decomposed to formic acid, acetic acid and lactic acid in the presence of coal ash particles at pH 3 at 20 degrees C, while it was not decomposed at more than pH 5. The yield of organic acid at stirring time of 60 min is in the order of formic acid>acetic acid>lactic acid. Since citric acid dissociates to citric anion at more than pH 5, it was suggested that citric anion and negatively charged coal ash particles repelled electrically each other at more than pH 5, resulting in that citric acid could not be adsorbed and not be decomposed on coal ash. Based on the obtained results, the decomposition of citric acid at pH 3 was suggested to be due to catalytic effects of coal ash. Since formic acid and acetic acid can be used as a material of hydrogen fermentation, coal ash could be used as a catalyst to synthesize the important material for hydrogen fermentation from wastewater of citric acid.
authors.affiliation: Technology Development Center, Electric Power Development Co, Ltd, Chigasaki, Kanagawa, Japan. hiroyuki_nakui@jpower.co.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakui
authors.forename: Kenji
authors.initials: K
authors.lastname: Okitsu
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Maeda
authors.forename: Rokuro
authors.initials: R
authors.lastname: Nishimura
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D002244:Carbon; D002264:Carboxylic Acids / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry*; D003031:Coal; D060729:Coal Ash; D005561:Formates / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000737:chemistry; D052638:Particulate Matter; D013696:Temperature
chemical_list: D002264:Carboxylic Acids; D003031:Coal; D060729:Coal Ash; D005561:Formates; D052638:Particulate Matter; C030544:formic acid; D019343:Citric Acid; D019344:Lactic Acid; D002244:Carbon; D019342:Acetic Acid