The Study Of Purification Of Isostearic Acid By Urea Inclusion And Its Economic Valuation

Isostearic acid is a C₁₈saturated fatty acid with alkyl branch chain.It has a lower melting point and better oxidation stability than stearic acid.Therefore,it's widely used in cosmetics,medicine,lubricants and many other industries,and it shows a high commercial value.In the preparation method of isostearic acid,zeolite-catalyzed oleic acid isomerization method has high conversion rate and good selectivity,but the purity of the reaction product prepared by this method is not high.In order to obtain high purity isostearic acid,the mixed fatty acids need to be further separated and purified.The technological parameters of tartaric acid assisted urea inclusion method for the separation and purification of isostearic acid in the above mixed fatty acids were investigated.The recovery technology of urea and tartaric acid were explored.The process of separation and purification of isostearic acid by tartaric acid assisted urea inclusion method and process of urea inclusion complexes recovery was developed and the economic analysis was performed.Main tasks as follows.Tartaric acid assisted urea inclusion method was used to purify isostearic acid.The effects of inclusion temperature,urea/mixed fatty acids mass ratio and methanol/mixed fatty acids mass ratio on the separation of isostearic acid were investigated by orthogonal experiment.The research shows:?1?The purity of isostearic acid in the mixed fatty acids can be improved from 78.35%to about 95.00%;hydroxystearic acid can be completely removed;palmitic acid content can be reduced to less than 0.50%and basically removed;stearic acid content can be reduced to less than 1.00%from 9.03%.?2?The factors affecting the purity of isostearic acid are as follows:inclusion temperature>methanol/mixed fatty acids mass ratio>urea/mixed fatty acids mass ratio.The process condition with the highest purity is inclusion temperature 2?,urea/mixed fatty acids mass ratio 3:1,methanol/mixed fatty acids mass ratio 8:1.The factors affecting the yield of isostearic acid are as follows:urea/mixed fatty acid mass ratio>methanol/mixed fatty acid mass ratio>inclusion temperature.The process condition with the highest yield is inclusion temperature 215?,urea/mixed fatty acids mass ratio 1.5:1,methanol/mixed fatty acids mass ratio 10:1.The purity and yield of isostearic acid cannot be maximized under the same process conditions,and the appropriate process conditions can be selected according to the requirements for the purity or yield of isostearic acid.Tartaric acid assisted urea inclusion method to separate isostearic acid requires a large amount of urea and tartaric acid,the methanol-cyclohexane binary solvent method was used to recover urea and tartaric acid.The results showed that:9.0445 g of urea tartaric acid and0.7038 g of fatty acids can be recovered from 10 g of urea inclusion complexes,the recovery rate is 97.48%.The recovered urea tartaric acid can be reused once and has a good separation effect.According to the aforementioned research results,the process of separation and purification of isostearic acid by tartaric acid assisted urea inclusion method was developed.A preliminary economic analysis of the separation process with an annual output of 3,000 tons is carried out,the fixed asset investment is estimated to be 7.6536 million yuan,and the cost of material consumption in the separation process is 4254 yuan/ton.It is of reference significance to the separation and purification process of isostearic acid in the technical route of zeolite-catalyzed isomerization of oleic acid to prepare isostearic acid.