Energy cost of heat activating serpentinites for CO2 storage by mineralisation

Abstract

In this contribution, we present fuel cost estimates based on a practical heat activation strategy for serpentinites, for large-scale mineralisation of CO2 in New South Wales, Australia. We have found the serpentinites from the Great Serpentinite Belt in New South Wales to be particularly suitable for heat activation, as opposed to the partly serpentinised ultramafic minerals of the Coolac Serpentinite Belt. The activation strategy comprises prograde heating to produce an active material with 20% OHres and the recovery of ∼80% of the sensible heat from the dehydroxylated mineral. The strategy also involves direct combustion of natural gas to supply an energy input of at least 574MJ (tSerpentinite)−1, to minimise secondary CO2 emissions generated from the thermal activation of serpentinite. A CO2 penalty of about 7% yields 0.93 net tonne of available active serpentine per tonne of serpentinite feedstock. The cost for serpentinite heat activation for this practical heating strategy amounts to A$ 1.25 per tonne of available active serpentine.