The Process Simulation And Optimization Of Epichlorohydrin

The high temperature chlorination of propylene is widely used to produce Epichlorohydrin(ECH).The process mainly includes three parts of propylene,chlorohydrin and epoxy.The method is flexible in production process,mature in technology and stable in operation,but inevitably there is a large energy consumption problem.It is necessary to take effective measures to save energy and increase efficiency.In this paper,a mathematical model for the extraction of epoxy chloropropane by high temperature chlorination of propylene was established,and the heat transfer network of the device was analyzed and optimized on the basis of pinch technique.In this paper,Aspen Plus is used to simulate the whole process of the production of epichlorohydrin by high temperature chlorination.According to the different properties of the various parts of the process,the suitable physical property method is selected;the towers in the process are selected to be simulated by Rad Frac,and the heat exchange equipments are simulated by Heater and HeatX.At the same time,a suitable convergence method is selected to specify the process parameters of each module,and the simulation of epichlorohydrin plant is realized.The results of the process simulation are in good agreement with the design data.It shows that the accurate and reliable unit operation model and the appropriate physical property method are used to simulate the epichlorohydrin unit,which can provide accurate basic data for the energy-saving research of the devices.The sensitivity analysis is used to optimize the operating parameters of the main distillation columns.Based on the optimized simulation results,the logistics data needed for the design of the pinch point are extracted.The setup temperature difference of the system is 20 ?,and the maximum heat recovery network of the device is designed according to the pinch design principles.The thermal utility consumption of the scheme is 8637.72 kW and the consumption of cold utilities is 17839.10 kW.Compared with the existing heat exchanger network,it can save 3150.64 kW of thermal utility project and 3223.50 kW of cold utility project.The energy efficiency of the thermal utility project is 26.73%,the energy efficiency of the cold utility project is 15.30%,and the investment recovery period is 0.16 years.Based on the process simulation results of devices,the heat transfer network is analyzed on the basis of the transformation of the heat exchanger network without changing the process flow,and the heat transfer process which is contrary to the pinch point design is reconstructed by using pinch technology.Under the condition that the temperature difference of the pinch point is 20°C,the existing heat exchange network is reformed according to the pinch point technology.The amount of hot public utilities required by this scheme is 8913.23 kW,and the cold public utilities is 18187.47 kW.Compared with the existing heat transfer network,the utility model can separately save 2875.13 kW for the cold and hot public projects,and the energy saving for the hot and cold public utilities is 24.39% and.13.65% Respectively,the investment recovery period is 0.18 years.