Nutrient cycling in biomass gassification

I’m new to this stuff, but one of the things I was hearing about the digester/reactor method is that the sludge left over retains pretty much all of the nutrients and could be used as fertilizer. What happens to the nutrients or minerals in the gasification process. I assume nitrogen might be escaping but idk. Probably someone more knowledgeable than me out there.

The gas will be mainly CH4, CO2, H2S. Means that everything else is the effluent: PKN, Minerals, etc.