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What are the benefits of pyrolysis versus steam methane reforming (SMR)? My immediate thought would be that you leave energy on the table, and that storage at s

What are the benefits of pyrolysis versus steam methane reforming (SMR)? My immediate thought would be that you leave energy on the table, and that storage at scale is harder when the end result is graphite. Moreover, SMR is proven technology at very large scale.

azernik 7y ago
One advantage is that it produces high-purity graphite, which is a moderately expensive commodity, used for electronics manufacturing (especially power components in batteries), structural carbon composites, and machine lubricants. The percentage of carbon captured is also damn near 100% - quite a bit better than gaseous carbon capture techniques I've heard of. You do leave quite a lot of energy on the table (losing somewhere between 30% and 50%), so this is a technology that is only economically viable with high emissions pricing. But that seems like the way Europe is going anyway. And yes, SMR is the proven and clearly superior technology right now; I'd call this TRL 4/5 right now. But with another decade of development?
- semi-extrinsic 7y ago
  Aha, so it's targeting "CCU". Then OK, I can maybe see there is a point initially, but not at anything near the scale we need. Global graphite production from mining is at 1 megatonne/year, while synthetic is a few hundred kilotonnes/year. We need CCS to operate at tens of gigatonnes per year, that's four orders of magnitude beyond all the graphite the world needs. This is the problem with anything CCU - there just aren't viable options with consumption at the gigatonne scale.
  - azernik 7y ago
    I'd imagine extra graphite is pretty easy to store, though?
    - ed312 7y ago
      We could put it down in empty mine shafts... or build entire mountain tops out of it!
    - semi-extrinsic 7y ago
      At the gigatonne scale, nothing is easy to store. Fill the entire Hoover dam with graphite, and you've stored 6 gigatonnes. We need to store tens of gigatonnes per year for a hundred years.

azernik 7y ago

One advantage is that it produces high-purity graphite, which is a moderately expensive commodity, used for electronics manufacturing (especially power components in batteries), structural carbon composites, and machine lubricants. The percentage of carbon captured is also damn near 100% - quite a bit better than gaseous carbon capture techniques I've heard of. You do leave quite a lot of energy on the table (losing somewhere between 30% and 50%), so this is a technology that is only economically viable with high emissions pricing. But that seems like the way Europe is going anyway. And yes, SMR is the proven and clearly superior technology right now; I'd call this TRL 4/5 right now. But with another decade of development?

semi-extrinsic 7y ago
Aha, so it's targeting "CCU". Then OK, I can maybe see there is a point initially, but not at anything near the scale we need. Global graphite production from mining is at 1 megatonne/year, while synthetic is a few hundred kilotonnes/year. We need CCS to operate at tens of gigatonnes per year, that's four orders of magnitude beyond all the graphite the world needs. This is the problem with anything CCU - there just aren't viable options with consumption at the gigatonne scale.
- azernik 7y ago
  I'd imagine extra graphite is pretty easy to store, though?
  - ed312 7y ago
    We could put it down in empty mine shafts... or build entire mountain tops out of it!
  - semi-extrinsic 7y ago
    At the gigatonne scale, nothing is easy to store. Fill the entire Hoover dam with graphite, and you've stored 6 gigatonnes. We need to store tens of gigatonnes per year for a hundred years.