A life cycle assessment of coal-fired thermal power plants with post-combustion control techniques: an India scenario

Abstract

In recent years, there has been a focus on clean power generation, and it is critical to assess the environmental impact of novel technologies used in pollution control in power generation. The study uses life cycle assessment (LCA) to assess the environmental impacts of coal-fired thermal power plants with different emission control techniques in an Indian scenario. As there are no such studies available in the Indian context, this work might provide a holistic view of the impacts of energy generation. A supercritical coal-fired plant with a capacity of 660 MW is considered in this study. The system boundary included coal extraction, transportation, power plant operation, and transmission losses of electricity with a functional unit of 1 kWh. It was observed that there was an energy penalty due to the power consumed in emission control devices, but the maximum energy penalty was due to the power used in the carbon capture system. The LCA is done from "cradle to gate", with impact indicators at the mid-point evaluated using the RECIPE (H) 2016 LCIA method. LCA results showed that power plant operation is the most significant contributor to environmental impact. Initially, in cases 1 and 2, climate change (CC) potential was a major impact category, but CC potential was reduced with carbon capture and storage, 0.27 kg CO₂ eq. in case 3 with ESP, FGD, SCR, and carbon capture and storage (CCS) and 0.263 kg CO₂ eq. in case 4 with ESP and CCS. But there was a considerable increase in the majority of the impact categories in case 4. Freshwater consumption potential increased from 3.98 E-03 m³ in base case 1 to 4.98 E-03 m³ in case 3 due to the amount of water used in chemical production during CCS, as CC potential is a major concern in power generation, However, compared to case 1, the potential for climate change increased in case 2, whilst in case 4, the potential for climate change is lower but has resulted in an increase in the majority of impact categories. Case 3 shows an optimal approach to reducing CO₂ emissions compared to other cases. The combination of ESP, FGD, SCR, and CCS is favourable for cleaner energy generation.

Keywords: CCS; Coal; ESP; FGD; Life cycle assessment; SCR; Thermal power plant.