Portal de Periódicos da CAPES

Reaction Kinetics of Amino Acid Decomposition in High-Temperature and High-Pressure Water

2004; American Chemical Society; Volume: 43; Issue: 13 Linguagem: Inglês

10.1021/ie020733n

1520-5045

Nobuaki Sato, Armando T. Quitain, Kil-Yoon Kang, Hiroyuki Daimon, Koichi Fujie,

Catalysts for Methane Reforming

Decomposition behavior of five selected amino acids in high-temperature and high-pressure water was studied using a continuous-flow tubular reactor. The reaction was carried out in the temperature range of 200−340 °C at a pressure of 20 MPa. Alanine and its derivatives leucine, phenylalanine, serine, and aspartic acid were used as model amino acids. The effect of temperature on reaction products, pathway, and rate was determined as a function of reaction time. Alanine decomposed into lactic acid and pyruvic acid, then finally mineralized to carbon dioxide with an activation energy of 154 [kJ/mol] at 20 MPa. The degradation rate decreased in the following order: aspartic acid, serine, phenylalanine, leucine, and alanine. The general reaction network of amino acids under hydrothermal conditions takes two main paths: deamination to produce ammonia and organic acids, and decarboxylation to produce carbonic acid and amines. Deamination was the predominant reaction in the decomposition of aspartic acid, an acidic amino acid. Production of glycine and alanine from serine, an oxy amino acid, was also observed.