Last week Morielle I. Lotan asked me what my take is on carbon-neutral synthetic fuels. This post is my answer.
Before we start, let’s first explain what synthetic fuels are.
All the fossil fuels that are dug out of the ground have one thing in common: They are molecular chemical compounds made of hydrogen and carbon. When these compounds are combusted, oxygen atoms rip up the molecules and react with their components. The hydrogen atoms react with oxygen to form water and carbon atoms to form CO2, releasing an awful of energy in the process. Production of synthetic fuels uses chemical engineering to reverse that process: Taking water and CO2 and reacting them in proper conditions to form fuel molecules. Suppose the CO2 feedstock for the synthetic fuel comes from the atmosphere. In that case, when this synthetic fuel is combusted, there is no net contribution of atmospheric CO2 even if the generated CO2 is released. Synthetic fuels can be a solution for hard-to-abate sectors like aviation, which cannot use renewable electricity.
Like many climate-related ideas, I think using synthetic fuels is essential to the long-term vision of a carbon-neutral world. However, in the short term, it can be detrimental to the goal of climate change mitigation.
Why is that?
Producing synthetic fuels involves capturing or removing CO2 and then reacting it with water to form the fuel molecules. As an inversion of combustion, the last step requires lots of energy. This energy must be clean for synthetic fuel production to make sense. In a future where most or all of the energy grid is decarbonized, converting CO2 to fuels with excess energy makes sense. However, as long as renewable energy is a limiting resource, it is better to use clean energy to displace fossil fuels than to produce synthetic ones.
I think investments in this technology should focus on lab-scale R&D and piloting. That way, synthetic fuels will be produced effectively when renewable energy is truly abundant. However, till then, I believe that the opportunity cost of investing in utility-scale synthetic fuel factories is too high.
climatechange #energy #cleanenergy #renewableenergy #syntheticfuels #hardtodecarbonize #carbonneutral #carbonremoval #carboncapture
