The SINOPEC Shanghai Research Institute of Petrochemical Technology (SRIPT) has successfully developed a technology for clean production of ethyl benzene using the catalyst for alkylation of benzene in gaseous phase.

In the existing process for manufacturing ethyl benzene via alkylation of benzene with ethylene in gaseous phase,it is necessary to carry out a one-step exchange with ammonium ions to remove sodium ions from the zeolite,leading to the formation of large amount of ammonianitrogen rich wastewater, which would increase the pressure on environmental protection and wastewater treatment cost. In September 2018 the feasibility of the said clean production technology developed by SRIPT had been verified with success in an enlarged commercial scale,which had brought on stream all pieces of equipment in the process flow scheme designated for clean production of ethyl benzene. It took one and a half years to carry out the feasibility study on this project, which spanned the stages beginning from the laboratory scale and terminated at the commercial scale tests. The technical team has made great strides in the sodium-free synthesis of microcrystalline ZSM-5 zeolite with the zeolite grain size in the b-axis equating to 50 nm-100 nm, while reducing the consumption of the template by over 70% without using the ammonium exchange stage, which can reduce 60 tons of ammonia wastewater on one ton of catalyst produced thereby.

Hereby, this technology can effectively reduce the waste emissions in compliance with China's targets on construction of a resource-saving society to provide a solid technical support to the safe and sustainable production of catalysts.