| Cumene is an important organic chemical raw materials and chemical intermediate products, whose main purpose is to produce phenol and acetone. Nowadays, cumene synthesis technology has become a mature technology.Alkylating reaction of benzene with propylene is an important link in cumene synthesis process. Yanshan Petrochemical Plant used the fixed bed reactor with multistage bed layer, the Feeding method of propylene is subsection and discharge the heat from material outer loop. This process has a lot of shortcomings, for example producding more reaction by-products and more difficult to reduce energy consumption, catalytic role cannot give full play.The article proposed a new process for synthesis of cumene. the new process used the structured catalyst named YSBH instead of the granular catalyst for traditional process, and replaced the fixed bed reactor with bubble point reactor. Using Aspen Plus software to simulate the bubble point reactor and benzene tower and to optimize the process conditions, and to simulate the mass balance and heat balance of the whole system. The influence of feed condition of bubble point reactor on the net duty and the composition of main components was discussed. Finally, the new process was proved feasible.We designed a new modification scheme for cumene unit based on the simulation results, and determine the operating conditions for new technology ultimately:the absolute pressure of the top of reactor should be controlled at 0.5 MPa; The inlet temperature of benzene is controlled at 40 C and the inlet temperature of propene is controlled at 18 C; circulating fluid temperature is controlled at 165 C; the circulation ratio is controlled at 2.3-2.5; the operating temperature of alkylation reactor is controlled at 140-170 C; the operating pressure of alkylation reactor is controlled at 0.2-0.45Mpa; the operating temperature of benzene tower should be controlled at 95.3-201.3 C; the operating pressure of benzene tower should be controlled at 0.1-0.18 MPa. The ratio of benzene to olefin of feed should be controlled within 2.5-3.0; propylene space velocity is 0.4-0.5h-1. The mass reflex ratio is 8.5; the mass ratio of Top distillate and the feed is 0.47.According to the reform plan, the phenol device of Yanshan Petrochemical Plant which Yield is 16 million tons per year used structured catalyst and bubble point reaction. The device is running so far, and all targets have reached the design requirements. The calibration results of new process of bubble point show that:(1) Producing per ton of cumene need to consume 653.891kg benzene and 351.905kg propylene using bubble structured process in phenol plant. The consumption of benzene and propylene was 654.7kg and 352.5kg respectively to produce per ton cumene before the transformation of old process.(2) The energy consumption of bubble structured process used of Yanshan Petrochemical Plant was 73.695 kg oil to produce per ton of cumene, but The energy consumption before the transformation of old process was 96.280 kilograms of standard oil. It showed that the new process could save energy by 23.46% compared to old process. It has reached the design goals.(3) The purity of cumene was 99.8969% according to the calibration results which was lower than the 99.97% of old process. |
