I just did a quick search on impact of biochar on corn yield and the research seems mixed, at best. It seems to have the most impact on poor soil, but little impact on yield in good soil (e.g., the corn belt). A public benefit may be reduction of nitrate leaching—-so applied at scale that could help the Gulf. Water retention can be improved, too; it’d be interesting to see whether there’s impact on yield in drought years.
So ideally one of your systems would be at the local elevator to make stover dropoff/biochar pickup easy? And then maybe someday combines would have a baler on them? And the biochar could go in a manure spreader for application?
Is there waste heat/syngas coming off the pyrolysis (beyond what's needed for sustaining it)? If so, have you looked into applying that to grain drying?