COMPARISON OF CHEMICAL SOLVENTS FOR MITIGATING CO2 EMISSIONS FROM COAL-FIRED POWER-PLANTS

There is a growing concern about the effect of greenhouse gases on glo bal warming. Among the many greenhouse gases, CO2 produced from burnin g fossil fuels is a major contributor due to the huge volumes emitted into the atmosphere. According to the estimates of the Intergovernment al Panel on Climate Change (IPCC), a worldwide reduction in the emissi on of greenhouse gases by more than 60% is necessary to avert signific ant global climate changes. This paper examines the key issues involve d in greenhouse gas emissions from coal-fired power plants. At the pre sent time, absorption by chemical solvents appears to be the best opti on for the separation of CO2 from low pressure flue gas streams. The c osts of separation and disposal of CO2 from existing coal fired, air b lown boilers are estimated to increase the cost of electricity by abou t 75%. Therefore, there is a need to optimize the selection of process ing solvents and operating parameters to minimize the cost of separati on. Increasing the inlet flue gas pressure did not improve mass transf er rates sufficiently to compensate for the higher compression costs. The effects of other process variables were also examined. In this wor k, we have examined the cost effectiveness of six ethanolamine-based s olvents. Overall, monoethanolamine (MEA) was found to be the best solv ent.