Process Simulation And Optimization Of Catalytic Distillation For Hydrolysis Of Sec-butyl Acetate

Sec-butyl alcohol(SBA)is an important organic chemical material,and it is widely used in industry.SBA is often used as solvent because of its solubility,and it can also be a component of gasoline dissolved with methanol to improve the octane number.SBA is raw materials of emulsifier and spice,too.But more than 90% of the SBA is used for the synthesis of methyl ethyl ketone(MEK),which is excellent chemical materials.The demand of SBA is rising as the market demand of MEK shows a growing trend recently.At present,the methods for preparing SBA mainly composed of indirect hydration,hydration,transesterification of SBAC,etc.However,there are many problems,such as etching equipment or harsh reaction conditions and so on.The industrial sec-butyl acetate(SBAC)is synthesized by the reaction of acetic acid and n-butene in the C4 component which is a cheap by-product in the refinery and obtained easily.This thesis puts forward a new process of preparing SBA by the hydrolysis of SBAC in a distillation column for the first time.The hydrolysis conditions of catalytic distillation are mild,the process is simple and the raw materials are cheap.The kinetic study of SBAC hydrolysis was carried on in a batch stirred tank reactor,and suitable catalysts and reaction condition were screened.The hydrolysis rate of SBAC was investigated with the change of reaction temperature and the kinetic model of two stage homogeneous phase was established,dynamics equation was obtained.On the basis of results above,the chemical process simulation software Aspen Plus was used to simulate the catalytic distillation process of SBAC hydrolysis.Based on the analysis of the basic physical properties of the system,a suitable process was established.The effects of the number of theoretical plates,the molar ratio of reactants were investigated,and optimization results were obtained.Theoretical plates numbers of rectifying section,reaction section and stripping section are 14,21 and 2 respectively,and the feed molar ratio of reactants is 6:1.The conversion of SBAC reached 96.87%,the mass fraction of SBA in the top product reached 71.85%,and reached 99.00% after purification.The mass fraction of acetic acid and water meet the industrial standard.A set of continuous catalytic distillation lab test tower made of stainless steel is built,and it is connected by several tower segments.The catalyst packing style are designed,and the rectifying section and stripping section are full of 3×3 mm 316 L stainless steel helices.Based on the simulation results,experimental research about the feed position of water and SBAC,feed mole ratio of reactants were carried on.It showed that water and SBAC were fed from the top and the bottom of the reaction zone respectively and mole ratio of reactants was 6:1.The mass fraction of SBA reached 71.35% at the top product,and the mass fraction of acetic acid reached 44.91% at the bottom product.The experimental results are in good agreement with the simulation results,which verifies the reliability of the simulation.