The Central Electricity Authority (CEA) has released updated guidance on the selection of Flue Gas Desulphurization (FGD) technology for thermal power plants, effective from November 1, 2024. This updated advice supersedes the earlier document on the same subject issued on February 7, 2020.
The CEA’s guidance is prompted by amendments to environmental regulations by the Ministry of Environment, Forest and Climate Change (MoEF&CC). These amendments introduced new norms for emissions from Thermal Power Plants (TPPs), including Sulfur Dioxide (SO2), Nitrogen Oxides (NOx), and Mercury, as well as regulations on specific water consumption.
The CEA document provides a brief review of these new MoEF&CC environmental rules, outlining the emission limits based on the date of installation of the power plant and specific water consumption requirements. It also includes information on stack height requirements post-FGD installation, as per a MoEF&CC amendment notification dated June 28th, 2018.
While various technologies exist for De-SOx treatment, the CEA emphasizes that several factors should be carefully considered before finalizing the FGD technology for a particular plant. These factors include:
- SO2 removal efficiency
- Unit size
- Balance plant life
- Geographical location of the Thermal Power Plant
- Production of secondary pollution (e.g., SPM, CO2)
- Byproduct handling/sale
- Water consumption
The CEA advises utilities to conduct their own techno-economic feasibility study and a “Life Cycle Cost Based Analysis” of available FGD technologies, taking into account the aforementioned parameters. The life cycle cost analysis should include factors such as:
- Average Plant Load Factor (PLF) of the unit
- Required efficiency of the FGD system
- Balance operating life
- Capital Expenditure (CAPEX) and Operating Expenditure (OPEX)
- Byproduct handling/sale
- Water consumption
The geographical location of the plant is highlighted as a critical factor in technology selection. For instance, plants located on the sea coast may find sea-based FGD technologies more suitable. The availability of reagents and their distance from the plant should also be considered.
Ultimately, the CEA stresses that the final technology selection needs to be evaluated on a case-by-case basis, considering the specific requirements of each thermal power plant. Factors such as coal quality, unit size, space availability, reagent availability and purity, byproduct disposal/sale, balance plant life, auxiliary power consumption, life cycle costing, water availability, FGD system efficiency, stack considerations, PLF, and tariff impact all play a role in this decision.
