Evaluation of Eight Environmental Control Systems for Low-BTU Coal Gasification Plants

摘要

Based upon the results of this study and the peripheral information assimilated, the following conclusions can be made regarding environmental controls for the production of clean low-Btu gas from coal: (1) While commercial processes are available for the removal or destruction of many of the known contaminants likely to be present with the low-Btu gas, many of these processes have been proven in applications other than coal gasification (e.g., petroleum processes). The environmental control processes have not have proven for the removal of the particular contaminants from the complex product mixtures expected to be present in coal-derived gases or wastewater. (2) The estimated capital investment for the environmental control processes evaluated in this study varies from approx. 10 to approx. 32% of the total direct onsite plant cost for the battery-limits plant. (3) The increase in the calculated product price for the low-Btu gas due to providing the environmental control processes considered varies from $0.37 to $2.39 per million Btu. (4) No correlations between treatment costs, gasifier type and size, and the degrees to which contaminants are controlled are discernible because of the limited number of cases evaluated. (5) The production of environmentally safe low-Btu gas and waste effluents from such a gasification facility cannot be guaranteed because of reasons outlined in the report. (6) The design of the environmental control systems is complicated by lack of process performance data on coal-derived products and by the lack of contaminant loadings in the product gases and liquids. (7) The study was hampered by a lack of adequate process data. (ERA citation 05:014712)