Energy-saving Research On Epichlorohydrin Produced Via Propylene Acetate Method

Epichlorohydrin (ECH) known as chlorine alcohol is an important chemicalintermediate. It is the main raw material for epoxy resins, and it also can be used forproducing epichlorohydrin rubber, electrical insulation products and surface activeagent.The methods of epichlorohydrin production are high temperature chlorination,propylene acetate and glycerine. More than90percent of manufactuers produceepichlorohydrin by the way of high temperature chlorination; however the method ofpropylene acetate also has many advantages, such as low material consumption andlow energy consumption.A chemical plant produces ECH by using the propylene acetate method. Theannual production is sixty thousand tons, with the first part24000t/a, the second part36000t/a. In order to reduce energy consumption and realize the comprehensiveutilization of energy, the improvement of the current flowsheet has great sigifiance. Inthe work, the propylene acetate flowsheet was simulated and analyzed using thechemical process software Aspen plus, and some energy-saving methods andtransformations to the devices were put forward.This paper firstly introduced the flowsheet of the ECH production via propyleneacetate. According to the feature of the process, the appropriate module and thethermodynamic model were chosen in ASPEN PLUS. Then the flowsheet wassimulated, and the sensitivity of the process was analyzed, next the parameters for asingle tower were optimized. According to the pinch technology and the heatexchanger network simulation software ASPEN ENENRGY ANALYZER, the heatexchanger network was analyzed to find the bottleneck of the existing flowsheet andan optimized heat-exchange network was proposed. According to the new heatexchanger network, some energy-saving methods were put forward. Considering theactual layout and production conditions, comparing the input with output, theenergy-saving measures were decided. The project was expected to invest10millonyuan, which can save steam1.5t/t product,9000tons per year, that is16.2millionyuan per year.The static payback period is0.62year. Finally, a steam ejector wasdesigned in order to leap the pinch point.