Development of a continuous process for enol esters of fatty acids

Abstract

Abstract and SummaryA continuous process for the production of iso‐propenyl stearate from stearic acid and propyne was developed. The reaction proceeds at elevated pres‐sures and temperatures (∼550 psig and 400 F, respec‐tively) in about l0 min. A slower, second reaction produces stearic anhydride from the isopropenyl stearate. A recovery section was devised, wherein the liquid product stream is chilled, recovered as flakes, and extracted with a solvent, e.g. Skelly B. Reaction studies were scaled‐up from 10 to 40 lb feed/hr using triple pressed stearic acid and MAPP® gas (AIRCO, Inc., Montvale, NJ), a commercially available gas con‐taining a nominal 1/3 propyne, 1/3 propadiene, and 1/3 stabilizing, saturated hydrocarbons. The acid and propyne are reacted in the presence of zinc stearate in a continuous stirred tank reactor (CSTR). The reac‐tion is “finished” in a short tubular reactor. Data are presented on the effect of pressure, temperature, catalyst level, dwell in the reactors, and solvent ratio during extraction. The product is about 92% iso‐propenyl ester, contaminated with unconverted stearic acid and by‐product stearic anhydride.