Study On The Energy-Saving Technology In Chloroethylene Process

The existing oxychlorination producing chloroethylene process consumes substantial amount of energy.It is of great significance to study the energy-saving problem by optimizing the energy using scheme of chloroethylene production process.Focusing on the subject and according to the real situation of a certain chloroethylene plant,the energy saving technology of the chloroethylene production process was studied in this paper.Based on the mathematical simulation,the energy consumption of each section was analyzed comparatively.The results showed that the energy consumption was demonstrated mainly by the coolers and reboilers of the distillation column.So we can adopt the heat integration between distillation columns or columns and process.The author suggested two energy-saving schemes,they were the situation of didn't chang the parameters of the process (scheme one)and chang the parameters (scheme two).In scheme one,use reaction heat instead of the heat demanded by reboilers of distillation column and use it to preheat the feed of distillation column;use bottom matieral of cooling distillation column DA401 to heat the reboiler of packed distillation column in purify section.The whole process needed to increase a heat exchanger.The calculation results showed that this scheme could save 4582,000 yuan every year..In scheme two,chang the parameter of the process by reducing the reflution ratio of distillation column DA502 and increase the pressure of distillation column DA303.By increasing the pressure of distillation column,we have abtained the high-quality heat utility.It can heat the reboilers of distillation column DA302,DA301, DA304 and DA501.This scheme could save 25660,000 yuan every year.Use pinch technology to check scheme one and two.The result showed that scheme one accorded with the pinch rules.Though it had more energy-saving possibility, because of the temperature on heat streams was too low and cold streams was too high, it didn't allow more saving.The result also showed that scheme two had pinch violated.Though this scheme consumedly used of the residual heat, the existing the heat exchangers across the pinch and the cooler above the pinch,energy consuming increased.Energy optimization by using pinch technology on scheme two abtained the scheme three.Based on the scheme two,adequately use the high-quality heat of DA303 to heat the reboilers of distillation column DA302,DA301 and DA501.At the same time, use the residual high-quality heat to partial preheat the feed of cracking.Scheme three have to increase one heat exchanger based on scheme two.The calculation results showed that this scheme could save 26619,000 yuan every year.Compared these three schemes,scheme three was the final scheme of energy saving.