Coal-derived synthetic natural gas as an alternative energy carrier for application to produce power --- comparison of integrated vs. non-integrated processes

Abstract

This work addresses clean utilization of coal through thermo-chemical processes (i.e., gasification & methanation) that convert solid carbonaceous feedstock to gaseous fuel for power generation, which features potential advantages for environmental benignity and energy security. It would be beneficial to convert coal to synthetic natural gas (SNG) that can feed the combined cycle units in the regions like Taiwan where natural gas (NG) is imported, which would help stabilize the price of electricity and alleviate the energy security concern. The objective of this study is to investigate the performance as well as the pros and cons between integrated and non-integrated SNG plants. The characteristics of power and chemical plants differs in various aspects, thus the concept of non-integrated approach to produce SNG and power offers better system resilience, availability and market flexibility at the expense of reduced efficiency. Fuel switch strategy would be one of the key pillars for the pathway toward Net-Zero Emissions (NZE) by 2050. Alternative energy carriers (AECs), generally synthesized from conversion of other energy sources, may provide solutions to decarbonization and low-emission environment. In summary, the thermo-chemical conversion processes studied in the present work address the core issues in clean and efficient utilization of carbonaceous resources.