Methyl esters directly from acidulated cottonseed soapstock. Preliminary cost study

A product containing from 80 to 95% of the methyl esters of cottonseed, soybean, and corn oil is produced commercially in the United States directly from the respective acidulated soapstocks of these oils, using a process developed at the Southern Utilization Research and Development Division. The product is marketed as a high‐energy additive for poultry and livestock feed, and its ready acceptance indicates that it has nutritional and handling advantages over other by‐product fats for this purpose, which, in 1958, represented a ready and expanding market for almost 600 million pounds of animal and vegetable fats and oils. A flow sheet for the process is given, and hypothetical plants with capacities of 15,000 and 60,000 lbs. of acidulated foots per 24 hrs. are described for the continuous production of up to 21 million pounds of methylated foots product annually. The lowest manufacturing costs are realized for each plant when operating 24 hrs. a day, 250 days annually, averaging five days per week. For these optimum operations the estimated capital investment for the small plant is $223,000, and for the large plant $410,000. Manufacturing costs range from a high of 11.2¢ per pound of product at an annual production of 11/4 million pounds to 6.5¢ at an annual production of 15.3 million pounds. The cost of the raw materials, although only 3.4¢ per pound of product and chiefly the cost of foots, is the largest single item of unit cost in producing methyl esters; and, for the higher productions covered by this study, raw material costs account for more than one‐half of total unit manufacturing cost. Surplus cottonseed foots can be economically converted into a low‐cost feed additive with improved nutritional and handling properties. The process is already a commercial success.