(197c) Green LNG from Green H2

In recent years, reducing CO2 emission has been the focus for addressing the concern over global warming and presumed related abnormal weather phenomena such as wildfire in California, US and Turkish, serious flooding in US, Europe and China, strong hurricanes, drought, and the melting of the permafrost of Alaska and Siberia and polar ice caps. The baseload LNG industry has already taken steps to reduce the CO2 emission by using high efficiency gas turbines instead of steam turbine systems, both for the liquefaction plant and for the power plant. Will these steps be enough to satisfy the ever-increasing social concerns, or will further reductions be required?

To respond to the social concern, green LNG concept has been presented at AIChE Spring 2022, following the ideas, new development are presented here:

• Methane, SNG, synthesis and SNG Liquefaction plant: renewable energy, i.e., wind power generation lead to hydrogen production by electrolysis. Methane is synthesized by Sabatier reaction with recycled CO2.
• To absorb the fluctuation of H2 generation from the electrolyzer according to the wind power fluctuation, the high pressure H2 storage is provided
• To pressurize the H2 to the storage, electrochemical isothermal compression cell is applied.
• Receiving Terminal and Power Generation: application of high efficiency combined cycle systems, CO2 recovery by amine process from gas turbine exhaust and CO2 is liquefied for transport.
• LCO2 Tanker: the CO2 is liquefied and recycled to SNG synthesis.

This concept would lead to higher power costs for the consumer as from15 to 50 cents per kWh, it may look costly, however it will solve the global warming issue completely, which has been started since industrial revolution at 18^th century in UK.