WASTE GASIFICATION – WHAT ARE DATA NEEDS?

摘要

The EPA’s proposed exclusion of hazardous oil-bearing petroleum refinery secondary materials from the definition of solid waste (and thereby from RCRA hazardous waste regulations) if they are gasified can provide common-sense regulatory relief and increase energy recovery and minimize wastes. The proposed exclusion is intended to “put resource conservation and recovery” back into Resource Conservation and Recovery Act (RCRA) by providing regulatory relief to enable more energy conservation and recovery, and waste minimization. The EPA has also suggested that the exclusion may be extended to various other hazardous secondary materials. Limited evaluations suggest that refinery secondary material gasification according to the conditions of the exclusion is more protective of human health and the environment than coking. However, comparisons between traditional incineration and coal gasification are not sufficient to support a broader exclusion to other secondary materials. Available data from waste gasification systems show that air emissions can be equal to or lower than the HWC MACT standards, but some areas that deserve some more data gathering include (a) transportation, handling, and storage without RCRA regulations prior to treatment, (b) destruction of hazardous organic compounds under reducing conditions, ? amounts of metals and other inorganic constituents in candidate secondary materials, and partitioning and control of those constituents during gasification, and (d) levels of hazardous air pollutants in syngas, and whether those levels would be restricted by quality requirements of the syngas end uses or by applicable emission limits (for example, for gas turbines) so that protection of human health and the environment is ensured. Compliance to the Comparable/Syngas Fuel Exclusion does not ensure protection of human health and the environment equivalent to compliance to the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Fortunately, limited syngas composition data and calculations show that waste gasifier syngas can have impurity levels far below the limits of the Comparable/Syngas Fuel Exclusion.