Abstract: The chemical, material, and heat equilibrium of ethylbenzene synthesis through alkylation of dilute ethylene with benzene via catalysis and a gas phase-liquid phase exchange method was analyzed and calculated. The isothermal temperature increase is 175.6 ℃ under the conditions of 1 mol/h ethylene, 4 mol/h N2, 3 mol/h benzene, 185 ℃, and 2.0 MPa. The calculation values of temperature increase, ethylene conversion, and ethylbenzene selectivity are in agreement with the experimental results. In the upper section of the reactor, after the heat exchange of fresh benzene of 35 ℃ with the out gas mixture of 202.6 ℃ from the reaction section, the equilibrium temperature of the system is 185.9 ℃, which is 0.9 ℃ higher than the reaction temperature. However, in the bottom section of the reactor, when dilute ethylene of 35 ℃ mixes with the liquid products of 202.6 ℃, the equilibrium temperature is only 153.5 ℃. This is because dilute ethylene needs a lot of heat energy to make the products from the liquid phase to the gas phase. Only when the dilute ethylene temperature is increased to 523 ℃ or 91.5 kJ heat energy is added, the equilibrium temperature can reach 185 ℃.

Key words: benzene, ethylene, alkylation, ethylbenzene, phase exchange, equilibrium calculation