Review of contemporary ethylbenzene production technologies

Objectives . Ethylbenzene is an important intermediate for styrene production. Most of the ethylbenzene synthesized worldwide is used to produce styrene, with smaller amounts used as a solvent or for the production of other chemicals. This article reviews contemporary technologies for the production of ethylbenzene.  Results . The liquid-phase method of ethylbenzene production using zeolite-containing catalysts for alkylation and transalkylation exhibits the highest efficiency and simplicity. In comparison with liquid-phase alkylation catalysts, e.g., aluminum chloride, zeolitecontaining catalysts demonstrate high activity, selectivity, stability, and resistance to impurities. In addition, they are non-corrosive, environmentally friendly, regenerable, and have a prolonged cycle length between regenerations. More than half of the ethylbenzene synthesized globally is produced by the Badger EBMax process using a catalyst based on zeolite of the MWW family (MCM-22). This technology enables a low benzene to ethylene ratio (from 2.5 to 4), which reduces the benzene circulation rate, increases efficiency, and reduces the column throughput for benzene extraction. The main part of contemporary research in the field of benzene alkylation with ethylene into ethylbenzene is associated with the creation and use of zeolite-containing catalysts, which are solid porous systems containing an active component and a binder. The active component is USY, beta, mordenite, ZSM-5, ZSM-11, ZSM-12, ZSM-23, ZSM-35, ZSM-48, MCM-22, and MCM-49 zeolites. Among the preferred alkylation catalysts are Beta zeolite or zeolite of the MCM-22 family. The binder is Al2O3, SiO2, or amorphous aluminosilicate. Current research also focuses on methods for creating zeolite materials with an increased mesoporous surface area by treating the initial zeolite precursor using various technologies, including combinations of acid treatment and surfactant treatment followed by alkaline solution treatment. Contemporary developments in the field of domestic alkylation and transalkylation catalysts for ethylbenzene production are presented. Conclusions . The production of ethylbenzene and the further development of technologies for obtaining catalysts for its synthesis are highly promising and important directions in Russia. The technology of liquid-phase alkylation in the presence of contemporary highly active zeolite-containing catalysts offers significant advantages.