Technology development at the Process Development Unit (PDU) in Waltz Mill, PA, has shown that the pressurized, ash-agglomerating fluidized-bed coal gasification process developed by KRW Energy Systems Inc. is an economically attractive coal conversion technology. Long duration testing has demonstrated high carbon conversion, and extensive environmental characterization of PDU effluents has shown that all PDU wastes can be economically and safely disposed. This fluidized-bed technology has been evaluated in the PDU, having a nominal air-blown feed rate of 15 tons per day, and in a full scale cold model to provide the necessary design models and scaleup design correlations. The KRW technology serves as the foundation for the current DOE development contract which focuses on hot gas cleanup and combined cycle generation and provides for the development of two complementary and novel hot gas cleanup technologies: in-bed desulfurization and external desulfurization. The DOE Morgantown Energy Technology Center (METC) pioneered the development of the external desulfurization process which is now being scaled for demonstration at the PDU. External hot gas cleanup design work is underway at KRW as discussed in Section 3.0. Testing at the PDU continued with completion of mechanistic test TP-035-5 in December 1984, which commissioned a two-stage L-valve fines recycle configuration with a tertiary non-recycle cyclone downstream. An assessment on the design basis for a multiple-jet configuration in the KRW cold flow scaleup facility (CFSF) and large-scale commercial units was completed and is presented herein. 67 refs., 32 figs., 14 tabs.