关键词: 催化裂化, 干气, 液相法, 乙苯, 加压吸收, 循环, 工业侧线

Abstract: Aiming at the problem of "four highs" (high reaction temperature, high benzene-olefin ratio, high energy consumption and high xylene content) in the process of FCC dry gas to ethylbenzene in refinery enterprises, an innovative liquid phase ethylbenzene production technology from FCC dry gas has been developed. By adopting key technical means such as "pressurized absorption at room temperature", "pressurized absorption liquid" and "circulation of reaction liquid", a major breakthrough in the technology of liquid phase synthesis of ethylbenzene from FCC dry gas has been successfully achieved.The industrial side-stream test showed that the ethylene content in the absorption tail gas was no more than 0.5%, the selectivity of ethylbenzene in the reaction products was no less than 88.5%, the selectivity of ethylation was no less than 99.5%, and the mass fraction of xylene was no more than 100μg/g under the conditions of absorption pressure of 2.2 MPa, reaction inlet temperature of 205℃, and molar ratio of fresh benzene to ethylene (abbreviated as benzene-ethylene ratio) of 3.5. Compared with the original gas phase technology, the process flow and the reactor structure are simple, the raw material benzene heating furnace is eliminated, the energy consumption is reduced by 51.0%, and the CO2 emission is reduced by 36%. The development of new technologies can meet the requirements of green low-carbon transformation, help to promote the high-quality development of enterprises, showing good industrial promotion value.

Key words: catalytic cracking, dry gas, liquid phase method, ethylbenzene, pressurized absorption, circulation, industrial side stream