Re:Decrement carbon: Stripe's negative emissions commitment
by semi-extrinsic on Friday August 16, 2019 @07:21AM
(#20714023)
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.
Re:Decrement carbon: Stripe's negative emissions commitment
by azernik on Friday August 16, 2019 @07:41AM
(#20714131)
I'd imagine extra graphite is pretty easy to store, though?
Re:Decrement carbon: Stripe's negative emissions commitment
by semi-extrinsic on Friday August 16, 2019 @04:00PM
(#20719122)
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.
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?