Environmental Impact Assessment of GHG Emissions Generated by Coal Life Cycle and Solutions for Reducing CO<sub>2</sub>

Abstract

The objective of this paper consists of evaluating the coal life cycle and proposing technical solutions for reducing GHG emissions. After applying the life cycle assessment on the coal life cycle, it was noticed that the power engineering stage has a bigger environmental impact on different indicator impacts. In order to reduce the GHG emissions the CO 2 chemical absorption process was integrated in the power plant based on the circulating fluidized bed combustion technology. Two cases were analyzed: super-critical and ultra-supra-critical parameters. For each case the environmental indicators (global warming potential, abiotic depletion potential, human toxicity potential, photochemical potential, acidification potential, eutrophisation potential) were evaluated in order to estimate the environmental effects on the coal life cycle with CO 2 capture process. After the integration of the CO 2 capture post-combustion process into the power plant, the GHG emissions decreased from 450,760 CO 2 equiv. tons to 75,937 CO 2 equiv. tons for super-critical parameters and from 438122 CO 2 equiv. tons to 73245 CO 2 equiv. tons for ultra-supra-critical parameters respectively. In order to increase the absorption capacity of the MEA solvent the SO 2 emissions were reduced from flue gases and consequently the acidification potential was reduced too in both cases. On the contrary, the amount of fuel increased in order to maintain the functional unit as a result of the efficiency penalty of the CO 2 capture integration in the power plant.