Some of the companies that do upgrading include Vertimass, Gevo, Swedish Biofuels, for example, and there are some methods that are not under patent protection

Some of the companies that do upgrading include Vertimass, Gevo, Swedish Biofuels, for example, and there are some methods that are not under patent protection that anyone can use. Basically a catalyst that dehydrates the alcohols and oligomerizes them into longer carbon chains. No other products than a combustible fuel.