Power-to-gas to energy systems are of increasing interest for low carbon fuels production and as a low-cost grid-balancing solution for renewables penetration. However, such gas generation systems are typically focused on hydrogen production, which has compatibility issues with the existing natural gas pipeline infrastructures. This study presents a power-to-synthetic natural gas (SNG) plant design and a techno-economic analysis of its performance for producing SNG by reacting renewably generated hydrogen from low-temperature electrolysis with captured carbon dioxide. The study presents a “bulk” methanation process that is unique due to the high concentration of carbon oxides and hydrogen. Carbon dioxide, as the only carbon feedstock, has much different reaction characteristics than carbon monoxide. Thermodynamic and kinetic considerations of the methanation reaction are explored to design a system of multistaged reactors for the conversion of hydrogen and carbon dioxide to SNG. Heat recuperation from the methanation reaction is accomplished using organic Rankine cycle (ORC) units to generate electricity. The product SNG has a Wobbe index of 47.5 MJ/m3 and the overall plant efficiency (H2/CO2 to SNG) is shown to be 78.1% LHV (83.2% HHV). The nominal production cost for SNG is estimated at 132 $/MWh (38.8 $/MMBTU) with 3 $/kg hydrogen and a 65% capacity factor. At U.S. DOE target hydrogen production costs (2.2 $/kg), SNG cost is estimated to be as low as 97.6 $/MWh (28.6 $/MMBtu or 1.46 $/kgSNG).
Production of Synthetic Natural Gas From Carbon Dioxide and Renewably Generated Hydrogen: A Techno-Economic Analysis of a Power-to-Gas Strategy
Contributed by the Advanced Energy Systems Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received May 22, 2018; final manuscript received August 14, 2018; published online September 26, 2018. Assoc. Editor: Luis Serra.
- Views Icon Views
- Share Icon Share
- Cite Icon Cite
- Search Site
Becker, W. L., Penev, M., and Braun, R. J. (September 26, 2018). "Production of Synthetic Natural Gas From Carbon Dioxide and Renewably Generated Hydrogen: A Techno-Economic Analysis of a Power-to-Gas Strategy." ASME. J. Energy Resour. Technol. February 2019; 141(2): 021901. https://doi.org/10.1115/1.4041381
Download citation file:
- Ris (Zotero)
- Reference Manager