For example, MEA is recommended to approach the upper bound in both cases. On the other hand, two types of optimization differ on some operating conditions: single-objective optimization suggests some extreme conditions (approach either lower or upper bound of decision variables). In contrast, multi-objective optimization offers more moderate operating conditions. For example, single-objective optimization selects the lowest PL (corresponding to the best recovery for CO2 but also the highest energy consumption ) for the PSA system; also, MS is chosen as the main CO2 utilization pathway. By contrast, multi-objective optimization determines a relatively low value for PL and recommends to mix FT with MS in the utilization pathways. This is because the multi-objective optimization delivers more practical solutions, where GHG emissions reduction should be balanced with the economic aspects. Fuel-gas heating is partially substituted by low-carbon elec.