China now is the largest natural gas importer in the world, with the dependency on foreign countries has reached to 45.3%.On the other hand, China has a huge amount of natural gas resources in the South China Sea to be developed, but most of them are CO2-rich gas which contains 15%~80% CO2 located in the deep sea. How to develop these valuable offshore gas resources economically, efficiently, sustainably and environmental friendly, without causing greenhouse gas emission, has always been one of the biggest challenges in the offshore petroleum industry.
Power-to-Hydrogen (PTH) from offshore renewables and CO2 methanation are expected to provide a new technical solution for the utilization of offshore CO2-rich gas. This method can improve the composition of CH4 to meet the requirements of economic pipeline transportation, and even the requirements of liquefaction to LNG.
However, this technology is still under development. Regardless of the technology itself, the bottleneck exists in the balance between the costs of hydrogen and natural gas production and the economy condition for the whole life cycle of gas field development. But this technology still has the potential to provide a new solution for the development of CO2-rich natural gas resources. It is preliminary estimated that when the costs of offshore power are less than ¥0.3 / kWh, the project can be commercialized.