Process Simulation And Optimization Of Propylene Distillation For Dushanzi Petrochemical Company

Since 2009,the feedstock of ethylene plant's cracking furnaces would use more and more gaseous hydrocarbon at Dushanzi Petrochemical Company.The feed loading of cracking furnaces has exceeded the scope of original design.And it found that propylene rectification tower(55)has some big problems,which it has high loss rate of propylene and high energy consumption of ethylene plant.It makes propylene distillation column under a non-economic operation in a steady state.The thesis has investigated the feed distribution project based on the Dushanzi Petrochemical Company's ethylene cracking furnace in recent five years.It combined with the on-line analytical letters.Research has analyzed the effect of variable cases of feedstock al ocation scheme to feed composition of propylene distillation columns.It established the mathematical model of Dushanzi Petrochemical Company ethylene plant's propylene distillation columns 10-C-5501 A/B by simulation software of Aspen plus and the equations of PENG-ROB,SRK and RK-SOVAE were calculated.Its results found that the calculation results of PENG-ROB equation's simulation are in good agreement with results of design and the error is controlled within a reasonable range.The composition of product can meet the separation requirements.O n the basis of this model,it analyzed the operation effect of propylene distillation column on composition of feed,feed load,bottoms rate,reflux rate,reflux temperature,the concentration of reflux propylene and so on.In the cases of different reflux propylene,it created the optimal operating conditions in the feed composition of 5%~11% propane and feed load of 38000 kg·h-1~41000 kg·h-1.It maintained propylene loss rate of 7.5%.Also,the paper analyzed the effect of feed composition,feed load,reflux rate,the operating pressure on plate temperature of propylene distillation column by Aspen model.It identified 160 and 180 plate to sensitive plate in stripping section.It put forward reasonable suggestions to propylene distillation column in variable cases.