Abstract: In the first IGCC power plant in China, there are some problems in the operation process such as the water drainage process is not reasonable and the coal gasification and sulfur containing wastewater is difficult to deal with. In view of these problems, this study proposes the water gradient utilization and zero emission scheme. Through the systematic analysis and diagnosis of the current situation of IGCC power plant's water utilization and drainage, especially the operation of the wastewater treatment system, a detailed update plan is proposed. The main contents are as follows:(1) Low-salt waste-water and high-salt wastewater should be collected and reused separately; (2) The update schemes of domestic sewage, coal gasification wastewater, chemical desalted water, and terminal waste water treatment are proposed separately. Especially for the special gasification and sulfur containing wastewater of the IGCC power plant, a new treatment process is proposed. Through the upgrade of the above water gradient utilization and zero emission scheme, the zero emission of the whole plant wastewater can be realized, and the water intake for unit power generation is reduced from 1.51m³/(MW h) to 1.01m³/(MW h).

Key words: IGCC power plant, water grading use, ultra low emission, zero discharge, coal gasification and sulfur containing wastewater