Comparison among different feeding behavior in a two-stage gasifier

摘要

Gasification, although still at its early stages as a large commercial industry, is claimed to represent the next evolution in the thermal processing of waste and particularly in the waste-to-energy (WTE) technology. However, before gasification will became competitive with the more conventional combustion processes it is necessary to develop gasifiers capable to produce a raw syngas sufficiently clean for power generation without the necessity of costly cleaning facilities. This objective was obtained by means of a two stage gasifier. Starting from some experimental data obtained with the developed gasifier in a lab-plant scale with various wastes, aim of this paper is to compare, on the basis of thermodynamic and kinetic considerations, the effect of different feeding wastes on the gasifying performance . The two main items, namely residual carbon in the ash and syngas composition at stage two, are taken into account to perform this comparison . According to the found kinetic law, residual carbon in the ash is characteristic of the short-time test normally performed in a bench scale reactor. As far as stage two concerns, the heat content of the outgoing syngas depends on the ultimate analysis of the used wastes in terms of carbon, hydrogen and oxygen.