Among the many "colors" of hydrogen -- blue, green, grey, brown, turquoise, pink, red -- it seems we now have yet another one to add to our lexicon: "gold" hydrogen. Startup Cemvita Factory, with offices in Houston, Texas and Westminster, Colorado, has staked a claim to that color for hydrogen produced by a new process they have been working on. The hydrogen is produced in-situ within depleted oilfields after injection of a proprietary brew on water, nutrients, and engineered microbes. The microbes feed on the residual oil, producing a mix of hydrogen and CO2.
I came across this announcement of a field pilot demonstration published in Green Car Congress. Cemvita Factory believes they will be able to produce hydrogen for around $1.00 per kg. That would be a compelling price, if they can pull it off. At this point, I'd have to say that's a rather big IF. However I can't rule it out. What they're trying to do is theoretically possible. The recovery wells -- which are just the old oil and gas wells of the depleted field -- will produce a mix of hydrogen and CO2, undoubtedly along with traces of methane and light hydrocarbons. The hydrogen would need to be separated, but that's a fairly simple and well-proven process. My reservations about the process have more to do with whether in-situ microbial digestion of residual oil can produce hydrogen at a high enough rate to be commercially viable.
Guess we'll have to wait and see.