Community Research and Development Information Service - CORDIS

Abstract

"The main objective of the project was to develop an innovative, highly efficient reverse flow molten slag gasifier for combined heat and power production in a capacity range of 0.5 - 2.5 MWel. The new gasifier should be able to convert relatively wet and ash-rich biomass.

Main results

A membrane separation technology has been selected for air oxygen enrichment, for which the maximum oxygen content is limited to about 40 vol%. Based on a techno-economic evaluation of the complete process it was concluded that oxygen enrichment does not improve the overall system performance and it results in higher investment and operating costs.

The novel gasifier was designed and tested at lab-scale (2 kg biomass per hour) and mini-plant scale (20 kg biomass per hour). Succesful operation of the novel gasifier was demonstrated. Producer gas from the gasifier contained only minor amounts of tar and heating values up to 7 MJ/Nm3 could be measured. During the project the operability of the system was significantly improved, although some constructional problems persist with respect to gas sealing.

An economic process model has been developed including performance and economic costs functions for the major unit operations in the process including the dryer, reverse-flow gasifier, oxygen enrichment unit and prime mover. A major conclusion was that a system with the novel gasifier - in comparison with one with a conventional gasifier - shows an increased overall efficiency for all levels of air oxygen enrichment. However, cost of electricity is only superior to a conventional gasifier system if unenriched air is used, due mostly to the cost and energy requirement of the enrichment unit.

Before the new gasifier can be demonstrated on a (semi) commercial scale additional development activities are required."

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Record Number: 1501 / Last updated on: 2000-09-14
Category: PROJ