Warrendale, Pa., August 28, 2006 -- A joint venture made up of the Fujian Petrochemical Co., Ltd., Exxon/Mobil and Saudi Aramco selected the Water Technologies division of the Siemens Group Industrial Solutions and Services (I&S) to provide equipment for treating ethylene spent caustic and wastewater. The four-part system, comprised of Zimpro® wet air oxidation, PACT® biological treatment, Zimpro® wet air regeneration and Hydro-Clear® sand filter systems, will help the joint venture meet stringent discharge and reuse regulations. Located in Quanzhou, Fujian Province, the Fujian Refining and Ethylene Joint Venture Project is the largest world-class Sino-foreign refining and petrochemicals project undertaken in China.
The Fujian Refining and Ethylene Joint Venture Project will expand the existing refinery at Fujian Petrochemical Co., Ltd. (FPCL) from 4 million tons-per-year to 12 million tons-per-year. The upgraded refinery will be designed to refine and process sour Arabian crude. In addition, the project will build new petrochemical facilities, including an 800,000 tons-per-year ethylene steam cracker, a 650,000 tons-per-year polyethylene unit, a 400,000 tons-per-year polypropylene unit and a 1 million tons-per-year aromatics unit. A 300,000 tons crude berth and associated utilities will also be built.
The Zimpro wet air oxidation system will help alleviate two problems frequently associated with ethylene spent caustic: disposal and odor. The technology destroys odorous sulfides and allows acid neutralization of the spent caustic. It also allows for discharge to biological treatment, in this case, a PACT system followed by sand filtration.
The new PACT system will treat combined refinery wastewaters high in TDS and ethylene plant wastewaters. Also to achieve reuse objectives and reduce COD, an activated sludge wastewater system already in use at the plant will be converted into a second PACT system. A new wet air regeneration system is being installed at the plant, which will treat spent carbon and biomass from both PACT systems. Both PACT systems also have effluent quality guarantees.
For tertiary treatment following the PACT systems, the Hydro-Clear sand filter uses a shallow, 10-inch bed of 0.45 mm sand and a pulsed bed to help achieve low effluent CODs. Effluent from the new wastewater treatment plant will contain <100 mg/L COD, and will be discharged to the ocean. A <30 mg/L effluent COD from the existing wastewater treatment plant will be reused for cooling tower makeup water.
"Zimpro wet air oxidation is state-of-the-art technology for treating ethylene spent caustic," says Claude Ellis, director of sales in Asia for Siemens Water Technologies. "And by providing the PACT and Hydro-Clear sand filter systems on the project as well, we are able to guarantee final effluent quality to the customer."