If CO2 shall be captured from the flue gases of coal fired power stations for subsequent dumping, a viable technology should be available also for retrofitting existing conventional pulverized coal fired power stations.
The objectives are to study experimentally at pilot scale the concept of firing combustion plant with oxygen and recycled flue gas with regard to flame stability, gaseous emissions, heat transfer, fly ash properties, deposition and sulphur build-up and to undertake techno-economic assessment of processes to remove CO2 from flue gas based upon the findings of the experimental study.
Two process schemes were developed for flue gas treatment. One involved the recovery of pure CO2, the
second was a minimum treatment scheme. On technical, environmental and economic grounds the process which
used low purity oxygen and has minimum flue gas treatment was the best option. However, although this process
eliminated CO2 emissions completely, it reduced the efficiency by 8.5%, increased the total capital cost by 50%,
increased specific investment by 90% and increased the break-even electricity selling price by 55% compared
with a standard air-fired power plant.
The elimination of nitrogen from combustion processes by firing with oxygen and recycled flue gas results in a substantial reduction in the downstream processing required to subsequently remove the carbon dioxide produced. The project aims to provide experimental data with regard to the combustion process, gaseous emissions, ash properties, ash deposition and heat transfer so as to allow better technical assessment of retrofittable processes for the removal of carbon dioxide from the flue gas of coalfired furnaces.
The following tasks will be undertaken during the course of the project:
1. Modify the 150 kW Clean Coal Combustion Test Facility of Babcock Energy Limited to burn pulverized coal in an oxygen/recycled flue gas environment.
2. Undertake testing on the 150 kW facility under varying process conditions to establish the effects of flue gas recycle relative to conventional combustion.
3. Analyse the experimental data and assess its significance on equipment design.
4. Investigate the potential of sulphur build-up and problems that might be associated with this.
5. Undertake a techno-economic assessment of overall processes in the light of the new experimental data.
6. Model carbon dioxide capture and disposal options and examine the viability of using flue gas recycle as a means of reducing these emissions.
Funding SchemeCSC - Cost-sharing contracts