Experimental study of onboard carbon capture pilot plant with a compact integrated stripper under variable parameters

Abstract

In this paper, a new compact onboard carbon capture system (COCCS) for ships was proposed. The system had a reboiler and stripper as a single unit, and the structure of built-in coils provided a method for the utilization of ship flue gas waste heat. A parametric study was conducted to improve the operational efficiency of the COCCS. Emphasis was placed on reducing the energy consumption by changing the parameters only, without increasing system construction costs. Therefore, a COCCS pilot plant was established to obtain the database for multi-parameter testing. The parameters were designed according to the actual gas emissions from the ship, where the flue gas input concentration was 4–10 %, and the liquid-to-gas ratio (L/G) was 2–6. The desorption pressure (1.1–2.1 bar) was adjusted to give a large improvement in the system performance with "a lossless gain characteristic". The experimental results showed that the highest capture efficiency of 88.6 %, the lowest regeneration heat of 3.97 MJ/kgCO₂, and the highest recycle capacity of 0.27 mol/mol were achieved under parameter optimization. The optimization of L/G showed the most significant improvement in the capture efficiency, which was enhanced by 15.06 %. The optimization of desorption pressure showed the most significant improvement in regeneration heat with a reduction of 44 %. This study provided support for parameter schemes for existing and future onboard carbon capture devices and highlighted the potential for parameter optimization to improve system performance without additional infrastructure investment.