Pilot run, plant design and cost analysis for reductive ozonolysis of methyl soyate

Abstract

Preparation of methyl azelaaldehydate dimethyl acetal (MAzDA) from methyl soyate was investigated on a pilot scale via the sequence ozonization, hydrogenation, acetalization and fractional distillation. A water-methyl soyate emulsion for the ozonization step was preferred to methanolic solution or neat methyl soyate for reasons of cost and safety. Ozonization of the water-methyl soyate emulsion (1.63:1 ratio) in a six-plate sieve tower produced 1271 lb aqueous peroxidic emulsion during 12 days of continuous operation. Because a continuous hydrogenation facility was not available, reduction was done in 200 lb batches. Since batch hydrogenation of the peroxidic emulsion in this quantity was difficult to control and optimum conditions were difficult to maintain, maximum yield of the product was only 56%. The average yield for seven batches was 48.3%. However laboratory hydrogenation under optimum conditions of periodic samples taken from the sieve tower discharge indicated an overall yield of 74.5% (average of eight monitor samples). A plant designed to produce 10 million lb annually should be capable of producing MAzDA at a total manufacturing cost of 39 cents/lb or a net manufacturing cost of 27 cents/lb with byproduct credit conservatively estimated. Methyl soyate ozonolysis products are not sensitive to detonation, and their exothermic decomposition is greatly moderated by the presence of water.