Transitioning to cleaner energy: A policy-driven economic analysis of SCR and SNCR for NOx control in India's coal-fired thermal power plants

This research analyses the costs and effectiveness of Selective Catalytic Reduction (SCR) and Selective Non-Catalytic Reduction (SNCR) technologies for controlling NO x emissions from coal-fired Thermal Power Plants (TPPs) in India. Cost and effectiveness analysis focuses on Total Capital Investment (TCI), Direct Annual Cost (DAC), and Total Annual Cost (TAC) under various scenarios of moderate (35 %) and high NO x control (80 %), both for retrofitting and integrated installations. SNCR technology proved more cost-effective for moderate NO x control than SCR, requiring lower capital and operational costs. For higher NO x control, SCR remains the only viable option. Excluding 20 years or more old power plants, TPPs of 177 GW capacity were considered (both existing and proposed TPPs) and the total costs were: TCI US$ 2.4billion, DAC US$ 0.7billion, and TAC US$0.9 billion. In terms of TAC effectiveness, SNCR controls 1125 g NO x /US$ (for moderate control in a capacity of 128 GW), while SCR controls 830 g NO x /US$ (for high control in a capacity of 49 GW). The net present value of the investment over 30 years is US$23.4 billion. The uncontrolled NO x emissions of 2329 kilotons/year can be reduced to 1014 kilotons/year (about 56 % control) through optimum selection of technology. The study provides valuable insights for policymakers and investors, highlighting the economic and environmental benefits of adopting cost-effective ways for NO x control. • SNCR more cost-effective for moderate (35 %) and SCR for high (80 %) NO x control. • Cost for moderate control (in 128 GW) and higher control (in 49 GW): US$2.4 billion TCI and US$0.9 billion TAC. • TAC: SNCR 1125 gram NO x /US$ and for SCR 830 NO x gram/US$. • Net present value of SCR and SNCR over 30 years: US$23.4 billion. • Likely NO x reduction from 2329 kilotons/year to 1014 kilotons/year.