They don't say how much rock they added to each field, but note that the 0.15 tons of CO2 they remove is only 300 lbs. A gallon of gasoline emits 20 lbs of CO2 when burnt.
So, if they use more than 15 gallons of gasoline to mine, crush, transport and spread the rock over 2.47 acres, then this process emits more CO2 than it captures.
I think they'd need to use electric high-tonnage dump trucks and electric tractors to make this process actually capture carbon. Electric tractors are stating to become available, but I don't know of any high-tonnage electric truck manufacturers.
So, if they use more than 15 gallons of gasoline to mine, crush, transport and spread the rock over 2.47 acres, then this process emits more CO2 than it captures.
I think they'd need to use electric high-tonnage dump trucks and electric tractors to make this process actually capture carbon. Electric tractors are stating to become available, but I don't know of any high-tonnage electric truck manufacturers.