Innovative Electrolyzer Paves Way For Sustainable Propane Production

[Meredith Poor + 898]

A rhetorical question: why would the average farmer or homeowner want to capture CO2 from air in their 'backyard'?

If an answer to that was to 'make methane', then the issue turns out to be that methane is difficult to process once it is generated. This is particularly the case when it is necessary to compress the gas and stored it under pressure.

Propane, in comparison, is 'all over the place': anywhere from backyard grills to cook stoves to water heaters to furnaces to pickup trucks to tour buses. The Kwh equivalent of gasoline is 32Kwh per gallon, propane is 27Kwh per gallon, or about .85 of gasoline. Someone driving 40 miles per day in a 30 mile per gallon car would burn 1.3 gallons of gas or 1.6 gallons of propane.

This suggests that consumers now have an incentive to set up direct air capture equipment in their yards, particularly if their yards are multiple acres. From there, the rest is pretty easy.

Generating 1.6 gallons of propane would require 40Kwh of electricity at 100% faradaic efficiency. At 91% efficiency, 44 Kwh would be required to make 1.6 gallons. 44Kwh / 5 hours per day of solar power generation would be 8.8 (rounded to 9) Kw of panels. At 25% power conversion efficiency, this would be 36 square meters or roughly 400 square feet of panels. The cost of the panels by themselves (at 20 cents per watt) would be $1800. This would have to be added to the cost of DAC equipment and whatever provides water to the system, as well as the electrolyzer, compressor, and storage tank.

[turbguy + 1,553]

Clever, but not practical for the vast majority.

I do not want any rotating equipment to deal with.

[Ron Wagner + 714]

Farmers use a lot of propane to dry their crops, warm their buildings etc. It seems like a great idea to me. It could also be used for subsistence farmers. Another simple answer is to use manure and other biomass in an anaerobic process to create methane which can be filtered and used as fuel. Unfortunately This process is not used as much as it should be. 

https://docs.google.com/document/d/1N-TLMeHsKYBCirxS0vbqMGHpU2SmyLuCc7bqp8eYXVM/edit

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