Study On Clean Synthesis Process Of Fatty Acid Ethyl Ester

With petrochemical resources increasingly depleted,the energy issue has become a bottleneck restricting the development of society.As an alternative to fossil fuel,biodiesel is clean and renewable using biomass as raw material that has become the focus of attention about energy industry.Ethanol production of biodiesel can be based entirely on renewable agricultural resources,fatty acid ethyl ester with higher cetane number and calorific value,the lesser emissions of nitrogen oxide and carbon monoxide,burning less particulate matter,biodegradable.It not only can be used as biodiesel,and also has a high application value in the field of printing.In this study,with soybean oil as material,soybean oil fatty acid ethyl ester was synthesized by transesterification of alkali catalytic as the mainline.Transesterification focuses on homogeneous base catalyst KOH and sodium methoxide and heterogeneous catalytic reactions using glycerin calcium.Eutectic solvent is a new type of green solvent mixture can be used to exploring study of the product purification refining process after transesterification.The purpose is to avoid the polluted water from wash process of the traditional production process.And thermodynamic calculation and analysis has been done for the transesterification reaction system,in order to provide direction for process improvement.In the homogeneous reaction system of KOH and sodium methoxide as catalyst respectively by adopting the orthogonal test and the response surface analysis to optimize process.The best preparation conditions were determined as follows: In KOH catalysis reaction system,catalyst amount1.3%,molar ratio of ethanol to oil 8:1,reaction temperature 75 ?,and reaction time 2.5 h,then,conversion reached 99.38%;in sodium methoxide catalysis reaction system,catalyst amount1.26 wt%,molar ratio of ethanol to oil 8.94,reaction temperature 63.88 ?,and reaction time 2.65 h,the conversion of validation experiments reached 99.27%,and consist with the prediction results 99.38%.In addition,with glycerol calcium(solid alkali)as catalyst,using single factor experiment,respectively,to investigate the influence of various factors and the laws of catalyst recycling use in the heterogeneous reaction system.The results as follows: 8 wt% of catalyst,molar ratio of ethanol to oil 12:1,reaction time 5 h under the reflux temperature,then,the conversion was 84.6 %,and the catalyst can be recycled more than five times.Deep eutectic solvent is biodegradable,cheap,easy soluble in water,and have a wide range of solubility property.This research mainly is that the soybean oil fatty acid ethyl ester from transesterification was purified by deep eutectic solvent synthetized by choline chloride and urea.The purification conditions were optimized by orthogonal experiment as follows: volume ratio of DES to soybean oil fatty acid ethyl ester 1:1,temperature is70 ?,and washing time 6 min.Under these conditions,the residue content of glycerol in the purified product was 0.01007 %,and the pH was 7.0,meanwhile,there was no wastewater emission in the purification process.The transesterification of ethanol and soybean oil as a model reaction,to estimate thermodynamic data of complex molecules using a variety of group contribution such as Benson,Fedors,Rozicka-Domalski,C-G and so on.On this basis,calculate the standard molar Gibbs function and equilibrium constant of the transesterification,in order to provide theoretical basis and guidance for the improvement of subsequent process,the determination of operating conditions and process control.