vonwolfhausen's comments

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

I've been enjoying this thread. I have a company that does this (Eion). We are recruiting for a data engineer role to implement the algorithms for quantifying carbon removal, if these questions are interesting to you. Touches on nearly every aspect in this thread.

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

Can be <5 years if it is super fine (~25um) or >20 years if it is coarse (minus 3/8" fines).

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

Dust is never good, but olivine specifically was introduced as a foundry sand specifically because it doesn't cause silicosis (vs quartz).

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

Indeed, the largest active olivine quarry is in Norway, it's all hydro!

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

It depends on the feedstock, and how far you truck it (last mile) but in general this is one of the most bang-for-the-buck CDR approaches, with yields of 5-10x CO2 removed vs CO2 required.

vonwolfhausen | 2 years ago | on: Adding crushed rock to farmland pulls carbon out of the air

Olivine comes from Norway, which uses hydro power. The energy in extracting and crushing is around 4kg CO2/ton. Pulverizing is around 30-50kgCO2/ton rock. Majority of transport is on water (ocean, river), which is low emissions. In the end, for every ton of rock around 850kg of CO2 are removed.

For basalt, it's around 200kg net, so the supply chains have to be shorter.

I checked my math with the DOE's experts, and it checks out.