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wrote:
wrote:
Lime sets by reacting with CO2 in the air, and is manufactured by
reversing this reaction using heat. The chemical cycle of lime is thus
CO2 neutral.

What's the "chemical cycle" of cement?

What about the production cycle? How much CO2 is released in processing
and transporting v. cement?

MBQ

I don't think the lime cycle is quite carbon neutral - as (fossil fuel
derived) heat is put into the kiln. However the CO2 driven off in the
kiln should be exactly balanced by that absorbed on the mortar taking
its final set. The fossil fuel footprint of transportation is probably
equal for cement and lime. I think the larger culprit is using large
amounts of concrete in construction - quick,convenient, relatively
cheap - and a lot of energy consumed in its manufacture/delivery.