Re:Nuclear is back on the table for a green future
by Manuel_D on Thursday June 16, 2022 @01:35AM
(#31762737)
Why are you all of a suddenly replying to a super-deep thread? Is pfdietz your alt? Regardless if you're asking about the technical shortcomings of ammonia and cryogenic air storage I'm happy the enlighten:
Ammonia storage would first require a source of hydrogen. Currently almost all hydrogen is produced through steam reformation which releases carbon dioxide. So this has to be replaced with electrolysis, which is more energy intensive and has issues with corrosion of electrodes. Then there's the issue of heating up this hydrogen and nitrogen to ~400C and compressing it to fix the nitrogen into ammonia. Currently this is done through combustion of fossil fuels. That too needs to be replaced with an electric source. All these changes drastically increases the cost of producing ammonia over existing processes.
Cryogenic storage is essentially producing liquid nitrogen by refrigerating air, and then hearing the nitrogen to create a pressure gradient to drive a heat engine. Cooling the air is a huge energy sink, and releasing the energy often has to be coupled with a heat source in order transition the liquid nitrogen to a gas. It's actually using the heat gradient of the ambient air and the liquid nitrogen to drive the heat engine, and that ambient air often doesn't have the required energy density to produce more than a few dozen megawatts. Existing prototypes often scavenge waste heat from a fossil fuel power plant. But again, not an option if you plan to eliminate fossil fuels.
Ammonia storage would first require a source of hydrogen. Currently almost all hydrogen is produced through steam reformation which releases carbon dioxide. So this has to be replaced with electrolysis, which is more energy intensive and has issues with corrosion of electrodes. Then there's the issue of heating up this hydrogen and nitrogen to ~400C and compressing it to fix the nitrogen into ammonia. Currently this is done through combustion of fossil fuels. That too needs to be replaced with an electric source. All these changes drastically increases the cost of producing ammonia over existing processes.
Cryogenic storage is essentially producing liquid nitrogen by refrigerating air, and then hearing the nitrogen to create a pressure gradient to drive a heat engine. Cooling the air is a huge energy sink, and releasing the energy often has to be coupled with a heat source in order transition the liquid nitrogen to a gas. It's actually using the heat gradient of the ambient air and the liquid nitrogen to drive the heat engine, and that ambient air often doesn't have the required energy density to produce more than a few dozen megawatts. Existing prototypes often scavenge waste heat from a fossil fuel power plant. But again, not an option if you plan to eliminate fossil fuels.