Water treatment facilities from a U.S. company have been installed in a major Taiwanese refinery and in two mainland Chinese oil fields.
Chinese Petroleum Corp. recently installed a wastewater treatment plant at its Kaohsiung, Taiwan, refinery. The treatment plant was needed because of expansion of the refinery's naphtha-cracking facilities at the 446,500-b/d refinery, the largest refinery, in terms of crude charging capacity, in the Asia/Pacific region.
The system, designed and supplied by Serck Baker Inc., Huntington Beach, Calif., was designed for a total wastewater flow rate of 10,000 cu m/hr (1,833 gpm).
Inlet wastewater streams come from a new ethylene unit and existing processing units. Treating requirements are summarized in the accompanying table.
To minimize odors escaping from the plant, the entire plant had to be covered and treated for odor.
One unique constraint on the installation was limited space, complicated by two nearby relief flares. The proximity of the flare stacks required that the wastewater treatment equipment be equipped with heat shields.
The complete water treatment system includes:
- Two inclined-plate separators that remove preliminary coarse oil and solids, complete with pumps, instruments, and controls.
- Side-by-side rectangular dissolved air flotation (DAF) units that conserve space and further reduce oil and particulates, with recycle systems and flash and flocculent tanks.
- Dual activated sludge systems in concrete basins, with corrosion-resistant stainless steel, deep-bed draft tubes, followed by degassing basins, clarifiers, chemical feed systems, instrumentation, and controls.
- An odor-control system with chemical-feed systems, stack instrumentation, and controls.
- Double digesters that provide the final dewatering step, in concrete basins with deep-bed draft tube design, instrumentation, controls, and dewatering feed pumps.
Serck Baker water treatment systems have also gone into two oil field applications in the People's Republic of China.
A 30,000 b/d produced water and well-wash treatment system has been installed in the Zhongyuan oil field (see photo).
Water quality acceptable for injection into the field's low-permeability zone is achieved by flowing the produced water through a corrugated plate and an inducedgas flotation unit. Well wash water containing considerable oil and solids is treated in a dissolved-gas flotation unit. Dual media filters downstream of the flotation units remove fine particles and any residual oil.
Final polishing cartridge filters are located at both the central processing system and at the injection wellhead.
Serck Baker manufactured and assembled the unit at its Huntington Beach facility for shipment in modules to China.
The complete system was designed by its in-house engineers.
A filtration system has been installed in the Shengli oil field.
Of the water, 80% comes directly from the Yangtse River, a main transportation artery linking remote areas of southern China.
The balance of the water to be treated is produced water from wells in the Shengli oil field. Inlet conditions and design effluent standards were defined as:
Inlet Outlet
Oil, ppm 10 2
TSS, ppm < 20 1
Oxygen, ppb 500 50
- Three dual media filters, each 96-in. in diameter, processing 5,200 cu m/day combined water flow.
- Central cartridge filters polishing the media filter effluent to meet 0.5 m particle retention.
- A dozen wellhead cartridge filters, each capable of flowing 200 cu m/day with elements, eliminating particulates as small as 1 m.
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