COAL UTILIZATION PROCESSES AND THEIR APPLICATION TO WASTE RECYCLING AND BIOMASS CONVERSION

This paper presents a survey of advanced coal conversion processes, an d a discussion of the potential of coal upgrading processes for organi c waste and biomass. Several qualitative similarities can be found bet ween these classes of material as both are mixtures of organic and min eral components, both contain elements that form hazardous effluents a nd both have a tendency to swelling and coking during pyrolysis. Howev er, considerable differences exist with respect to the molecular struc ture of the organic fractions. Accordant differences were found in the yields and properties of the respective pyrolysis products and their dependence on temperature and pressure. The gasification behaviour of chars from the various materials was as expected. An analysis of the h ydrogenation behaviour based on knowledge gained from the hydrogenatio n of coal showed that biomass is of minor interest as a feedstock beca use of its high oxygen content. Two examples for commercial applicatio n in Germany are given: the use of an industrial hydrogenation plant f or the conversion of organic waste, and the recycling of plastics wast e by pyrolysis.