Assessment of Environmental Control Technologies for Koppers-Totzek, Winkler, and Texaco Coal Gasification Systems

摘要

The US Department of Energy, Division of Environmental Control Technology, supports the Assistant Secretary for Environment in discharging responsibilities for environmental control aspects of technology in use and development. The coal gasification technologies employed by Winkler, Koppers-Totzek (K-T) and Texaco are described. Evaluation of the status of these technologies for control of major environmental pollutants indicates that a minimum risk to the environment is involved. The complete gasification process involves coal storage, coal preparation, gasification, gas cooling, particulate removal, acid gas cleanup, shift conversion, oxygen manufacture, cleanup of waste water and makeup water, and utility operation. The status of each of these technologies with respect to environmental acceptability is discussed. Very little is known about the behavior of trace elements in the K-T, Texaco and Winkler gasification systems. Airborne emissions of trace elements can occur from the utility boiler, and from wind entrainment of discharged residue and stored coal. Ash components are discharged from the gasification processes with gasifier residues and gas-cleanup sludges and residues. The trace element composition of coal is geochemically similar to the makeup of the earth's crust and includes almost all of the elements of the periodic table. The potential hazard from emissions of trace elements is mainly from long-term, low-level exposures to increased atmospheric pollution levels. Discharges from the K-T, Texaco and Winkler processes can be expected to have very minor contributions to atmospheric pollution levels of trace elements. Table 1 summarizes the status of technology and data needs for the different processing steps. The different process areas and their potential for intrusion of the environment are discussed. (ERA citation 04:055989)