Continuous hydrothermal oxidation of phenol for small molecule organic acids production

Abstract:

With formic and acetic acids as the main objective products, the experimental research hydrothermal oxidation of phenol for producing small molecule organic acids was conducted by using a self-developed continuous-flow hydrothermal reaction apparatus. The results show that the addition of alkali promotes formic and acetic production but excess alkali decreases formic and acetic acids yields. Formic and acetic acids yields increase first and then decrease with the increasing in the oxygen supply, reaction time and temperature. The highest yields of up to 9.5% and 11.2% for formic and acetic acids, respectively, are obtained at the temperature of 300 oC with the concentration of 1.0 mol•L-1 NaOH and oxygen supply of 70% for 60 s. Based on the products recognization, production pathways of the small molecule organic acids, especially formic and acetic acids, are discussed.

Key words:hydrothermal oxidation; phenol; continuous-flow hydrothermal reaction apparatus; formic acid; acetic acid