16-03-2012

Siemens delivers yet another wet air oxidation system to Sinopec

Siemens Industry Automation Division is providing another Zimpro wet air oxidation (WAO) system to treat wastewater at Sinopec Yangzi Petrochemical Co., Ltd.'s facility, near the Yangzi River in Jiangsu Province, People's Republic of China. The most recent of seven Zimpro WAO systems installed at Sinopec facilities will be used to treat sulfidic spent caustic wastewater streams generated in the production of petrochemicals. The WAO system is designed to eliminate odorous sulfide pollutants and generate a biodegradable effluent that can be discharged to conventional biological wastewater treatment. Using the Siemens technology will help make petrochemical production more environmentally friendly. The Yangzi system will treat approximately 4 m3/hr (17.6 gpm) of wastewater. The system is anticipated to be operational by the end of 2012.

Wet oxidation is the oxidation of soluble or suspended components in an aqueous environment using oxygen as the oxidizing agent. When air is used as the source of oxygen, the process is referred to as wet air oxidation (WAO). The process will oxidize odorous reduced sulfur species such as sulfides and mercaptides. The system will also break down complex organic contaminants, such as phenols, to either carbon dioxide and water, or biodegradable organics.

The Yangzi facility includes both a refinery and a petrochemical plant where fuels and ethylene are produced. This Sinopec project marks the ninth Zimpro WAO system installed by Siemens Water Technologies in China for spent caustic treatment.

Sinopec Yangzi Petrochemical Company Limited is a wholly-owned subsidiary under China Petroleum & Chemical Corporation. The company is mainly engaged in refining crude oil as well as in producing and marketing hydrocarbon derivatives. At present, the company operates more than 60 sets of large-scale petrochemical units and produces more than 9 million t/a products, covering over 60 varieties in five categories, i.e. polyolefin plastics, polyester feedstock, basic organic chemical raw materials, product oil, and synthetic rubber.