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(Charm Co-founder here) Certainly - you're effectively describing biochar (https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar) which hi

(Charm Co-founder here) Certainly - you're effectively describing biochar (https://en.wikipedia.org/wiki/Biochar https://en.wikipedia.org/wiki/Biochar) which historically has been used as both an energy source and a soil amendment. Using it as a sequestration method has gained some attention recently, though I have reservations. For one, biochar is typically produced in small, low-efficiency reactors without proper emissions control (though this is solvable). The bigger issue is the high energy content of biochar (~30MJ/kg). Simply burying all of this energy isn't economical - it makes much more sense to store carbon in its oxidized state, and sell the energy that's released in the process (in various forms - we're starting with Hydrogen).

marvindanig 8y ago
Did you try blowing air through the mass from bottom up? It can help loosen the grass chips, reduce moisture and prevent agglomeration and is useful as long as the air flux doesn't prevent the grass from funneling down.
- chimere 8y ago
  Certainly we considered it. The problem is that on this prototype system we were operating with a sealed hopper. Thus any gas injected into the hopper would travel through the system and dilute our output gas stream. Also any oxygen in the injected gas would result in combustion rather than gasification.
  - marvindanig 8y ago
    The inside of the funnel can be lined with a tube punchered uniformly and use pneumatic nitrogen piped from above and outside of the sealed hopper? I’m getting these weird ideas in my head.
    - marvindanig 8y ago
      punctured^
jacknews 8y ago
Thanks for the reply, yes I am aware of biochar but wasn't sure grass was a suitable source. The latest research seems to show that done properly, biochar can improve crop yields substantially, so that could be a way to pay for the process, but the other aspect is that it can be produced in a very low-tech manner, which is almost certainly the situation in many or most parts of the world. How are you planning 'geological carbon dioxide sequestration'? I'm not sure of the chemistry/process, but is burning the charcoal completely actually necessary to produce hydrogen? It seems not, to me. The cynical view of course is that you will omit the costly sequestration step, which makes this just another biofuel endeavor, with the attendant pros, and, mainly (IMHO), cons...

marvindanig 8y ago

Did you try blowing air through the mass from bottom up? It can help loosen the grass chips, reduce moisture and prevent agglomeration and is useful as long as the air flux doesn't prevent the grass from funneling down.

chimere 8y ago
Certainly we considered it. The problem is that on this prototype system we were operating with a sealed hopper. Thus any gas injected into the hopper would travel through the system and dilute our output gas stream. Also any oxygen in the injected gas would result in combustion rather than gasification.
- marvindanig 8y ago
  The inside of the funnel can be lined with a tube punchered uniformly and use pneumatic nitrogen piped from above and outside of the sealed hopper? I’m getting these weird ideas in my head.
  - marvindanig 8y ago
    punctured^

jacknews 8y ago

Thanks for the reply, yes I am aware of biochar but wasn't sure grass was a suitable source. The latest research seems to show that done properly, biochar can improve crop yields substantially, so that could be a way to pay for the process, but the other aspect is that it can be produced in a very low-tech manner, which is almost certainly the situation in many or most parts of the world. How are you planning 'geological carbon dioxide sequestration'? I'm not sure of the chemistry/process, but is burning the charcoal completely actually necessary to produce hydrogen? It seems not, to me. The cynical view of course is that you will omit the costly sequestration step, which makes this just another biofuel endeavor, with the attendant pros, and, mainly (IMHO), cons...