Optimization and economic evaluation of carbon dioxide BOG Re-liquefaction process considering storage pressure and nitrogen impurity

The increasing demand for carbon capture and storage (CCS) has heightened the need for liquefied carbon dioxide (LCO 2 ) carriers, which require re-liquefaction systems to manage boil-off gas (BOG) generated during transportation. This study proposed new two-stage separation re-liquefaction processes with mixed refrigerants for CO 2 BOG containing nitrogen impurity. The proposed processes were evaluated and compared with conventional processes based on annual CO 2 emissions under different storage pressure conditions of 6.5 bar and 15 bar. The results demonstrated that the proposed processes reduced annual CO 2 emissions by up to 71.6 % and 35.6 % at the storage pressure of 6.5 bar and 15 bar, respectively. Furthermore, the economic feasibility was assessed by considering annual CO 2 emissions and annual transported CO 2 amount under both pressure conditions. The results indicated that t…