Power to fuel using electrolysis and CO2 capture

Conversion of renewable electricity to synthetic fuel using electrolysis to produce at H2 and CO, which is furtherused to form liquid or gaseous fuel, called “power to fuel” or “power2fuel” has got a lot of attention recently.This is because synthetic fuels (synfuels) in the form CO2 neutral “green” hydrocarbon fuels seem particularlybenign to replace the fossil fuels, and electrolysis seems to be a feasible step in production of green fuels.

In particular, synthetic hydrocarbon based fuel will be necessary for the heavy transportation vehicles such as airplanes, ships, and trucks. More than 65 % of the cost of H2 produced by electrolysis originates from electricity cost. How much more depends on the actual electricity price and depends further on efficiency, investment cost and lifetime of electrolyzer.

Investment costs are inversely proportional the current density at a given cell voltage, to lifetimeand directly proportional to materials cost.The solid oxide electrolyser cell has probably the biggest potential for a low cost electrolysis system, but thereare issues of performance and lifetime that must be solved before it will become an affordable technology.

Other electrolyzer cells, alkaline electrolyte and polymer electrolyte electrolyzer cells are also under development. The technical status will be described and necessary further work will be discussed. Sources and techniques for capture of the necessary CO2 will be presented briefly in order to explain how toget enough concentrated CO2 for large scale fuel production.