Environmental hazards from coal conversion plants

Pollution from coal gasification processes

Nature

The commercial coal conversion plants place a great strain on limited water supplies. Water is required for both cooling purposes and for process water. Discharged water can contain suspended and dissolved solids and may be acidic. Air pollutants arising from coal handling are dust, fine coal dusta, sulphur oxides and nitrogen oxides.

Incidence

About 89 per cent of electricity generation in the Africa region is from coal, mostly produced in South Africa where it accounted for 97 per cent of total electricity generation in 1994 (Sivertsen and others 1995). As South African coal contains about 1 per cent sulphur, the country emits more sulphur dioxide than any other in the SADC region and is ranked as the 15th largest emitter of greenhouse gases in the world (USAID 1997). During 1990-91, South Africa contributed 66 per cent of all sulphur emissions in the SADC region, whereas Lesotho, Swaziland and Mozambique jointly contributed only 0.9 per cent (Sivertsen and others 1995). As this dependence on coal-based thermal power will persist for years, sulphur dioxide pollution will remain a problem unless measures are taken to reduce the levels of sulphur in coal or provide incentives for developing alternative energy sources such as hydropower, wind, geothermal and solar.

Claim

Coal-fired power stations account for less than 7 percent of national nitrous oxide emissions of several European countries (equivalent to less than 1 percent of the carbon dioxide emitted by these power plants), hence do not appear to be the significant source of nitrous dioxide once believed. However, fluidized bed combustion systems emit much more nitrous oxide than conventional systems.