It's quite obvious at a theoretical level but not easy in terms of figuring out the actual process. A lot of science like that.

Hopefully by producing a potentially profitable product, they’ll secure the funding to drive some carbon capture systems as well.

Adding other elements changes the taste,

This is not how chemistry works at all.

To start with, fatty acids also need Oxygen because of the COOH and OH group of the glycerin in fat. They are not hydrocarbons. You know what also is just made of Carbon, Oxygen and Hydrogen? Hundreds of thousands of molecules. All sugars and carbohydrates. If you allow for Nitrogen too, you could cover most molecules found in biological life.

None of this has any bearing on how difficult or complicated it is to synthesize these from more basic molecules like CO2 or H2.

this is a good https://www.nature.com/articles/s41893-023-01241-2 article on different ways this can be done

i learned the nazis made butter from coal!

Something I wondered with this, is that butter/margarine/similar need an emulsifier. They consist of basically 80% fat + 20% water, which would not normally mix, but then you add an emulsifier and they do.

There's lots of different emulsifiers. In butter, it's apparently mostly casein. My margarine lists lecithin and glyceride.

And well, looks like glyceride consists out of lots of H, C and O, so I'm guessing that's probably what they're using in this process...