Das Projekt "Coal gasification - waste heat utilization - phase 2 stage 2 -" wird vom Umweltbundesamt gefördert und von Krupp Koppers durchgeführt. Objective: The aim of the project is the energetic optimisation of the PRENLO-process for the gasification of solid fuels under pressure by development and testing of a new waste heat boiler system. The engineering and construction of a PRENFLO-plant (Pressurized Entrained flow Coal Gasification) with a capacity of 48 t/d Coal throughput at design pressure (Contract LG/018/83/DE) and the execution of the subsequent test programme (Phase 2 of the project; LG/270/85/DE and the present contract, LG/354/87/DE) served to justify the technical and economic risks of commercializing the process on a large industrial scale and demonstrate the long-term availability of the system and of newly developed components. General Information: The PRENFLO process is based on the atmospheric Koppers-Totzek process. This new technology is characterized by high gasifier unit capacity, high thermal efficiency, independence of coal quality, high gas quality and low environmental impact. To demonstrate the PRENFLO process and to test as well as optimize the components of the system a 48 t/d PRENFLO plant was erected on the site of the technology centre of the Saarbergwerke AG in Forstenhausen (Saarland, Germany), project LG/018/83/DE. PRENFLO gasification operates according to the entrained flow principle. Coal dust with a grain size of smaller than100 m is conveyed under pressure, using nitrogen, to a reactor with a water-cooled refractory lining. The gasification agents oxygen and steam are added at the gasifier burners. The gasification of the coal dust, i.e. reactor with a water-cooled refractory lining. The gasification agents oxygen and steam are added at the gasifier burners. The gasification of the coal dust, i.e. the partial oxidation of the carbon to carbon monoxide, takes place in a flame reaction at temperatures of more than 2000 deg. C and a pressure of 24 to 30 bar, the coal substance being converted into CO, H2 and small amounts of CO2. The sulphur content in the coal is converted into H2S and to a limited extent COS, the chlorine into HCl. Coal ash flows as liquid slag out of the gasifier into a water bath and is discharged from there as granulated inert high-temperature slag. Some of the coal ash is removed from the reactor as fly ash together with the raw gas. The raw gas leaves the reactor from the top and is normally quenched with cole and cleaned recycle gas in order to solidify discharged liquid ash particles. The raw gas is further cooled in the waste heat boiler. High pressure steam generation is coupled with the cooling system of the reactor. The steam produced in both systems is passed to super heaters. The downstream raw gas cleaning system comprises a dry dedusting unit, Venturi scrubber, a high-pressure separator and a scrubbing water circulation system with a pressure filter for separation of filter cake and a stripper for waste water purification. In the present programme (LG/255/89/DE) the raw gas leaving the PRENFLO reactor is not