Critical Analysis of Coal Life Cycle Using the Life Cycle Assessment

Coal has the largest share of utility power generation in the Romania, accounting for approximately 40% of all utility-produced electricity. Therefore, understanding the environmental implications of producing electricity from coal is an important component of any plan to reduce total emissions and resource consumption. Three systems were examined: a) a plant that represents the average emissions and efficiency of currently operating coal-fired power plants in the Romania; b) a new coal-fired power plant that meets the New Source Performance Standards (NSPS); c) a highly advanced coal-fired power plant utilizing a low emission boiler system (LEBS). The results are then used to evaluate the environmental impacts of the process so that efforts can be focused on mitigating possible effects. Each system analyzed consists of coal mining, transportation, and electricity generation. In keeping with the cradle-to-grave concept of LCA, upstream processes required for the operation of these three subsystems were also included in this study. As expected, because coal combustion results in the production of CO(2) from carbon that was previously sequestered underground, CO(2) accounts for the vast majority (98%-99% by weight) of the total air emissions from each system examined. The rate of production is 1,022 g/kWh, 941 g/kWh, and 741 g/kWh for the Average, NSPS, and LEBS systems, respectively. Two other climate change gases, methane and nitrous oxide, are also emitted from the system. Although the global warming potential (GWP) of these gases is much higher than that of CO(2), they are emitted in much smaller quantities and therefore do not significantly change the GWP of the overall systems. Apart from the CO(2) produced during coal combustion, operations related to flue gas clean-up produce more CO(2) than any other upstream process. Limestone production, transportation, and use account for 59% and 62% of the non-coal CO(2) emissions in the Average and NSPS systems. These amounts are greater than twice the CO(2) emissions related to transportation of the coal. In the LEBS system, operations associated with the production and use of natural gas to regenerate the CuO sorbent is responsible for 35% of the total non-coal CO(2) emissions. Coal transportation, in this system, produces nearly 40% of the non-coal CO(2).