Renewable natural gas value chain based on cryogenic carbon capture, utilization and storage, and power-to-gas for a net-zero CO2 economy

This study introduces an integrated renewable natural gas value chain utilizing cryogenic carbon capture, utilization, and storage along with power-to-gas technologies to promote a closed carbon cycle and achieve net-zero CO2 emissions. This study aims to optimize energy efficiency and minimize life-cycle greenhouse gas emissions by evaluating diverse configurations of renewable natural gas through case studies and comparing them with conventional fossil natural gas systems. These configurations employ advancements in cryogenic energy utilization that significantly decrease energy consumption throughout the lifecycle of renewable natural gas, particularly in the carbon capture and renewable natural gas liquefaction processes. The findings indicate that the integrated value chain of renewable natural gas can reduce energy waste by up to 25.87 % and potentially lower life-cycle greenhouse emissions by up to 91.42 % compared to fossil natural gas. Technoeconomic analyses revealed that the renewable natural gas value chain is cost-competitive with fossil natural gas in 2020, with potential for further competitiveness by 2050 owing to decreasing renewable energy costs and increasing investments of power-to-gas. The proposed renewable natural gas system could drastically reduce greenhouse emissions and operational expenses, making renewable natural gas a viable and competitive alternative to traditional fossil natural gas.