Comment by magnuspaaske

There are people who use pyrolysis to turn left over biomass to biochar which can then be added to the soil and, depending on your energy use for other things, can turn the process carbon net negative. It is a roundabout way to sequester carbon though as you need to consider the opportunity cost of doing other things with the land (like leaving it for nature to take over and sequester carbon that way).

It's always worth being sceptical about some of these claims about processes magically being carbon net negative since cleaning up the atmosphere might not actually be what's paying the bills leading to inherent conflicts between selling a product (ethanol) and doing an environmental service. Switching to EVs will allow you to use much less land to fuel the cars with wind or solar energy and then the leftover land can be used for carbon sequestration and rewilding/biodiversity projects where that's the sole focus of the operation.