Research On Biodiesel Production Technology Use Cottonseed Oil Soapstock

Objective:In this research, biodiesel production technology are based on traditional manufacturing technology of fatty acid,and use cottonseed oil soapstock as raw material, through improvement and optimization each reaction process to obtain the best reaction conditions, reduce waste of catalyst and raw material, cut down energy depletion and waste discharge. At the same time, through experimental to study purification of glycerol come from the production process and get high purity glycerol products.Methods:In this research,three methods of biodiesel production technology are used,the first is called saponification acidolysis esterification technology (also called the one-step technology), it means saponify cottonseed oil soapstock first,then by means of acidolysis and esterification reaction,the soapstock is converted fatty acid methyl ester.The second method is called acidic oil technology, it means through direct acidification process to get acidic oil, then by means of esterification and ester exchange reaction,acidic oil is converted fatty acid methyl ester. The third method is called extraction separation technology,it means through extraction technology to segregate neutral oil and soap,then through two different metheds produce biodiesel respectively use neutral oil and soap as raw material.Experiment with single factor and orthogonal experiment optimization reaction conditions, and using high performance liquid chromatography and thin-layer chromatography qualitative and quantitative analysis biodiesel components and purity.Results:1.Saponification acidolysis esterification technology.Through single factor and orthogonal experiment optimization reaction conditions, the optimum conditions is reaction temperature 60℃, reaction time 2h, ratio of methanol to soap(v/w) is 4.5:1, ratio of sulfuric acid to soap (v/w) is 0.75:1.2.Acidic oil technology. Through optimization experiment obtained the optimum conditions,the optimum parameters is:(1)In the esterification reaction the amount of sulfuric acid to soap (v/w) is 1.5%, the amount of methanol to soap (v/w) is 200%, reaction temperature is 65℃,reaction time is 2h. (2)In the ester exchange reaction the dosage of sulfuric acid is 0.5%, methanol dosage is 20%, reaction temperature is 60℃, reaction time is 45min.3.Extraction separation technology. Through optimization experiment obtained the optimum conditions,the optimum parameters is:(1)The dosage of petroleum ether is 200%, the time of extraction and separation is 4h.(2) In the ester exchange reaction, molar ratio of methanol to neutral oil is 5:1, reaction temperature is 40℃, reaction time is 60min, the dosage of NaOH is 1.54%.(3)After hydrolysis reaction,soap was converted to fatty acid, the optimum condition of fatty acid produce biodiesel is:methanol dosage is 150%, sulfuric acid dosage is 2%,reaction temperature is 65℃,reaction time is 6h.Conclusion:1.The technology.of saponification acidolysis esterification for biodiesel faster is more easier than other technology, but during reaction process the consumption of acid and alkali very large, unfavorable mass industrial production.2.The technology of acidic oil for biodiesel can be completed only by two steps of acidolysis and esterification,compare with the patent CN1931961A the technology is more concise,and can reduce energy and reagent consumption,cut down waste exhaust discharge.3.The technology of extraction separation is still in preparation, haven't seen industrialization. This process require long reaction time, consume large extraction agent, but the process consume little acid and alkali,and can obtained more superior quality biodiesel.4.The colour of biodiesel obtained from soapstock is dark, and diffuse special odor, through the high vacuum distillation measures can obtain higher quality of the products.