Gasification of aliphatic alcohols in aqueous solution plasma: mechanism explaining why product gas composition remains similar despite different alcohol type

Abstract Aqueous solution plasma was studied as a hydrogen production method from organic resources, including alcohols that can be derived from biomass. To elucidate the decomposition and gasification mechanisms, C 1 –C 6 normal aliphatic alcohols were treated with aqueous solution plasma. The primary gaseous products were H 2 , CO, and CO 2 , with similar relative compositions regardless of the carbon chain length of the feedstock alcohol. In contrast, the formation of hydrocarbon gases was minimal. Detailed chemical analyses of the aqueous phase revealed the presence of polyhydric alcohols, aldehydes, and carboxylic acids as intermediates. Based on these findings, we propose a reaction pathway in which hydroxyl radicals (·OH) derived from water oxidize the alkyl chain, forming polyhydric alcohols. Subsequent oxidation of primary alcohols generates aldehydes, which undergo decarbonylation to produce H 2 and CO. Further oxidation of aldehydes leads to carboxylic acids, which decompose via decarboxylation, yielding H 2 and CO 2 .