(10d) Performance Evaluation of Biomass Co-Gasification with Coal

Biomass has great potential as a clean, renewable feedstock for generating electricity or producing biofuel. Biomass energy is expected to become increasingly important in the future to reduce CO2-emissions, improve local environment, and obtain security of supply. There are several ways to utilize the biomass energy: Combustion, Pyrolysis, Carbonization and Gasification. Combustion is the most common ways of converting solid biomass fuels to energy. Gasification characterized by excellent performance as well as high biomass feedstock flexibility is focused on by much efforts recently. Entrained flow gasification processes have already been developed and demonstrated on large-scale for coal. After pre-treating, biomass feedstock can take advantages of the coal-based technology. Biomass co-gasification with coal allows the reduction of fossil fuel consumption and the accompanying CO2-emmissions. Different entrained flow gasifiers are operated worldwide, but only few have experience with biomass.

The objective of this work is to evaluate the performance of biomass co-gasification with coal in an entrained flow gasifier with the oxygen as the agent. The research cases include the followings: (1) The slurry (coal+water) as a basic fuel is gasified and the composition of product gas and the thermal efficiency can be required and calculated by modeling and simulation with Gibbs reactor using Aspen Plus; (2) the biomass feedstock co-gasification with coal are straw, wood and sludge with moisture changing from 5% to 30%; (3) The biomass ratio in whole fuel feedstock changes from 5% to 20%. The pressure of the gasifier is 3,0Mpa and the temperature of gasifier remains at 1350°C, with the water adjusting.

The oxygen flow, the composition of product gas and the thermal efficiency change in different cases and the optimum conditions can be obtained. This work has important significance to development of biomass energy and can supply reference for co-gasification operation.

Acknowledgement:

This project is supported by the Cluster of Excellence ?Unifying Concepts in Catalysis? coordinated by the Berlin Institute of Technology and funded by the German Research Foundation.

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