Foghorn

Turning Seawater Into Fuel

Burning fossil fuels accounts for nearly 97% of transportation-related greenhouse gases.  Inspired by a scientific paper, the Foghorn team started collaborating with researchers at Palo Alto Research Center (PARC) to develop an end-to-end prototype and see if it was possible to reduce those emissions by making “seawater fuel.” The idea was to take seawater, which naturally absorbs CO₂ from the atmosphere, use electrolysis to extract the CO₂, then combine it with hydrogen in a prototype reactor to create methanol—a liquid fuel which could be used as liquid fuel.

Cost Challenges

After months of development, the team successfully produced methanol. But creating the fuel wasn't the hard part—creating it at a reasonable cost was. Early theoretical models suggested that it would be possible to make seawater fuel for somewhere between $5 and $10 per gasoline gallon equivalent (GGE). So, the team set a cost target of $8 per GGE and outlined a plan to reduce the cost to $5 per GGE within five years. This way, seawater fuel would be cost-competitive enough to give them a foothold in markets where gas is expensive, like Nordic countries.

However, as the team’s investigation continued, some barriers to meeting these targets became apparent. First, producing enough fuel would require a significant amount of seawater—an incredibly expensive process. The second challenge was finding a cheap source of hydrogen, a key ingredient. After investigating a number of hydrogen creation processes, they came across a technique called solid oxide electrolysis, which separates water into hydrogen and oxygen using electricity. Unfortunately, after meeting with numerous experts, the team learned that generating a reliable and cheap source of hydrogen would take more than five years of research and require substantial capital investment.