TRAP-OXIDIZER TECHNOLOGY FOR LIGHT-DUTY DIESEL VEHICLES: STATUS, PROSPECTS, AND CURRENT ISSUES

Current U.S. Environmental regulations will limit particulate emissions by light duty diesel automobiles and trucks to 0.2 and 0.26 grams per mile respectively, beginning in 1987. Barring some breakthrough, attainment of these emissions levels will require the use of trap-oxidizers on all but the smallest vehicles. This paper reviews the present state of the art in trap-oxidizer technology and examines the requirements which a trap-oxidizer system would have to meet in order to be installed and marketed in production vehicles. The tasks remaining to be accomplished in the development of commercially feasible trap-oxidizer systems are briefly discussed. It is concluded that trap technology is quite advanced, with at least two apparently feasible types of particulate traps now available. The remaining tasks in developing a commercial trap-oxidizer system involve the development of improved trap regeneration systems and the development of automatic controls for the regeneration process. Three promising trap/regeneration system combinations are identified and discussed in detail.