J.C. Craig

Technical new feature

A continuous process for the commercial production of isopropenyl stearate (IPS) from triple pressed stearic acid and a stabilized form of propyne has been developed. Cost estimates, including capital costs, operating costs, and profitability, for commercial scale plant production which show the process to be economically feasible are presented. This potentially profitable process offers the advantages of reliable raw material sources, minimal external thermal requirements, and usable process waste streams. For a plant producing 5 million pounds of IPS per year, the selling price range is 80 to 107 cents/lb IPS, corresponding to a raw material cost range of 27 to 54 cents/lb of IPS. For a 20 million pound per year plant, the selling price range is 58 to 85 cents/lb IPS. The selling prices include a 20% annual return on fixed capital investment. Fixed capital requirement ranges from 2.7 to 10.9 million dollars (3rd quarter, 1975) for plants ranging in size from 5 to 50 million pounds of IPS per year, respectively.

Development of a continuous process for enol esters of fatty acids

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.