(376bt) Techno-Economic Analysis of Deep Eutectic Solvent Based so2-CO2 Co-Capture Process for Flue Gas

Over the last few decades, coal-fired power plants emission system has been upgraded in comply with baghouse, selective catalytic reducer (SCR), and flue gas desulphurization (FGD) unit to remove fine particulates (PM 2.5), NO_x, and SO₂, respectively. Each individual unit increase the parasitic loads (or, decrease overall efficiencies) of the coal-fired power plant. In fact, state-of-the-art wet limestone based FGD unit from CH2M reduces the overall coal-fired power plant efficiency around 2.0-2.5% depends of the throughput of the power plant. Another eminent technology is carbon capture and storage (CCS) to reduce the greenhouse gas emission from the coal-fired power plant. Unfortunately, this additional technology will further reduce the efficiency (~28% from ~34%) from the current practice. As a result, the power plant will have to consume more coal to deliver the current electricity demand. Therefore, a common solvent, which is not harmful to the environment but capture SO₂ and CO₂ simultaneously, is of great need to sustain the clean electricity production from coal-fired power plant.

Deep eutectic solvents (DES) are environmentally friendly and relatively less expansive solvent than ionic liquids and amine-based solvents. DESs are eutectic mixtures of salts or complexing agents with a certain stoichiometric ratio. Wide range of metal salts, metal oxides, and hydrogen-bond donors (HBD) can be the salts or complexing agents to form DES. Despite being a relatively newer technology, the wide applications of DES including CO₂ adsorption makes it very attractive separation technologies. However, the applicability of DES in CO₂-SO₂ co-sequestration has never been explored before.

In this project, experimentally and computationally determined parameters were evaluated and were incorporated into a full-scale techno-economic analysis for flue gas treatment. This evaluation includes several different solvents with sensitivity analysis and comparison to an NETL baseline capture process for a 550 MW coal fired power plant.