Decomposition of a long chain saturated fatty acid with some additives in hot compressed water

Stearic acid (C17H35COOH: C17-acid) was treated using a batch reactor with supercritical water (SCW) of 673 K and 0.17 g/cm3 for 30 min. In SCW, C17-acid was stable (2% conversion) and the main products were CO2 and C16 alkene. An addition of alkali hydroxide (NaOH and KOH) in the SCW reaction enhanced the decarboxylation of C17-acid with the main products being CO2 and C17 alkane. Metal oxides (CeO2, Y2O3 and ZrO2) enhanced the decarboxylation of C17-acid and the main products were CO2 and C16 alkene. Based on the results, the reaction mechanism was proposed.