Tailored solar field and solvent storage for direct solvent regeneration: A novel approach to solarise carbon capture technology

Abstract

For effective greenhouse gas (GHG) emission reduction, solvent-based post-combustion carbon capture (PCC) is the most recognized remedy option worldwide. Due to the very high thermal energy demand of this technology and the potential impact on the power production, solar-assisted PCC (SPCC) was proposed to offset part of this energy penalty. However this option is far from commercialization readiness, because of the solar intermittence and the costly thermal energy storage (TES).This paper promotes a dynamic carbon capture using innovative solar collector field (SCF). By eliminating the complex and costly stripper/s from the conventional PCC, we propose regenerating the solvent directly in the SCF and proportionally to the solar thermal energy gain. We also propose an underground solvent storage system instead of TES to buffer in-between the dynamic solvent regeneration via SCF and the steady-state absorption process in the absorber/s. For capturing 1.5 million tonneCO2/y from a 660 MWe coal-fired power plant in three representative locations in Australia, it is found that the equivalent annual cost of desorption is quite reasonable, particularly at higher solar multiples (SM). For SM = 1.5, the levelized cost of desorption is the lowest in Townsville ($ 12.34 per tonneCO2), followed by Sydney ($16.31 per tonneCO2), while Melbourne would need larger SCF (SM = 2.0) to lower the levelized cost of desorption ($ 22.52 per tonneCO2). These costs are calculated irrespective of the credits gained from steam preservation for power production and the resulted positive impact on the overall life cycle analysis. Noting the trajectory trend of GHG reduction cost, this novel approach in solarising carbon capture may bring SPCC to the competitive advantage in short/mid-term.