ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Base-catalysed reduction of pyruvic acid in near-critical water

Li Gang Luo, Zhi Qiang Hoau, Yuan Yuan Wang, and Li Yi Dai

Department of Chemistry, East China Normal University, 200241, Shanghai, China

E-mail: yywang@chem.ecnu.edu.cn

Abstract: The reduction of pyruvic acid in near-critical water has successfully been conducted under conditions of various temperatures, pressures, reaction time and the presence of formic acid as the reducing agent. In this work, additives (K₂CO₃, KHCO₃, and sodium acetate) used in the reduction of pyruvic acid were also investigated. The results showed that by adding K₂CO₃ (25 mole %) a markedly higher lactic acid yield (70.7 %) was obtained than without additives (31.3 %) at 573.15 K, pressure of 8.59 MPa, 60 min, and in the presence of 2 mol L⁻¹ formic acid. As a base catalyst, K₂CO₃ definitely accelerated the reduction of pyruvic acid. The reaction rate constants, average apparent activation energy and pre-exponential factor were evaluated in accordance with the Arrhenius equation. The reaction mechanism of the reduction was proposed on the basis of the experimental results.

Keywords: near-critical water – additives – pyruvic acid – reduction – lactic acid

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0308-x

Chemical Papers 67 (5) 509–516 (2013)