Silver catalysts for the ethylene epoxidation process

Ethylene oxides (EO) and ethylene glycols (EG) are the crucial derivatives of ethane, and the silver catalysts play key roles in industrial production of ethylene oxides and ethylene glycols. Up to 2016, the production capacity of producing ethylene glycol and ethylene oxide by the ethylene direct oxidation process has reached to 7,000,000 MTA of EO equivalents at home, then the the demand of silver catalysts at domestic market has reached over 1350 tons per year. According to the different technical process of numerous EO/EG units, the silver catalysts are classified into three types, namely high selectivity silver catalyst, middle selectivity silver catalyst and high efficiency silver catalyst. The new-built EO/EG units usually tend to adopt the high selectivity silver catalyst.

The high selectivity silver catalysts, namely YS-8810 and YS-9010, developed by BRICI, the selectivity of which has reached over 90%, have applied several rounds successfully in various EO/EG units, and were individually awarded the second prize of SINOPEC Science-Technology Progress Award in 2013 and the first prize of SINOPEC Technological Invention Award in 2015.

The middle selectivity silver catalyst, YS-8520, which has applied successfully in several foreign and domestic EO/EG units, and is mainly used in the early EO/EG units, the decarbonization systems of which have be revamped, and gained the second prize of SINOPEC Science-Technology Progress Award in 2011 and the first prize of CPCIF Science-Technology Progress Award in 2012 respectively.

The newly developed high efficiency silver catalyst, YS-8830, is particularly suitable for the reactors where the concentrations of carbon dioxide in feed gas and space-time yield are higher. The comprehensive performances of three types silver catalysts above have reached the international leading level.

The successful industrial application of silver catalysts, YS-8810 and YS-8520, made the average unit price of foreign silver catalysts reduce by 45%, indeed, lowered procurement costs tens of millions of dollars for enterprise every year.

Till now, YS series of silver catalysts have applied 54 rounds in 14 sets foreign and domestic EO/EG units.

Fig. 1 Accumulative sales of YS series silver catalysts

Fig. 2 Golden Award of Chinese Patent

Fig. 3 ‘The research, development and industrial application of newly developed middle selectivity silver catalyst’ gained the first prize of CPCIF Science-Technology Progress Award

Fig. 4 ‘The industrial development and application of YS-8810 silver catalyst’ gained the second prize of SINOPEC Science-Technology Progress Award

Fig. 5 ‘Technology for the epoxidation of ethylene over high selectivity silver catalysts’ gained the first prize of SINOPEC Technological Invention Award

Fig. 6 YS-8810 silver catalyst was applied in a domestic EO/EG unit

Fig. 7 YS-8520 silver catalyst was applied in a domestic EO/EG unit