A preliminary analysis of increase in water use with carbon capture and storage for Indian coal-fired power plants

Coal shall continue to be the mainstay of Indian energy sector. Nevertheless, if greater decarbonization is desired owing to more stringent climate regulations, CO₂ capture and storage may be an important technology. This work focuses on identifying the impact of carbon capture techniques on the water usage of Indian coal-fired power plants. The paper also compares two cooling systems i.e. wet cooling towers and air cooled condensers in their implications on plant performance parameters. To date, various studies have been conducted discussing the effect of CCS technologies in terms of cost and energy requirements in Indian context. However, with stringent water consumption regulations, there is a need for analysing the water-stress caused due to these technologies. This paper uses the Integrated Environmental Control Model (IECM v9.2.1), developed at the Carnegie Mellon University, USA, to carry out a probabilistic modelling to gain insight into the water-energy nexus for CO₂ capture systems in India. It is found that, in terms of cost, energy usage and water consumption, the suitability of amine based capture type is maximum. Membrane based capture technique is the most cost intensive whereas ammonia based capture is the most water intensive technology. With inclusion of cooling systems to post-combustion CO₂ capture systems methods, it is noted that wet cooling towers perform better than air cooled condensers. But, in a highly water-stressed scenario, air cooled condensers will be preferable due to minimum water consumption. The paper also conducts a sensitivity analysis on the parameters that affect the choice of CO₂ capture system and cooling systems such as fuel type, steam cycle heat rate and unit components of cooling systems.