Economics of CO₂ and Mixed Gas Geosequestration of Flue Gas Using Gas Separation Membranes

Abstract

Greenhouse gas emission sources generally produce mixed gases. Previous studies of CO2 capture and storage have typically examined only sequestration of pure CO2. This paper analyzes the cost of separating a gas mixture from a power station flue gas stream and injecting it into an offshore subsurface reservoir. The costs of separating and storing various gas mixtures were analyzed at two extremes. One extreme in which the entire flue gas stream containing both CO2 and N2 is stored. The other extreme in which as much CO2 is separated as is technically possible using gas membrane capture coupled with chemical absorption. The results indicate that for the gases investigated, using a gas membrane capture system, the lowest sequestration cost per tonne of CO2 avoided occurs when a mixed gas with a CO2 content of about 60% is sequestered. Lower costs and higher tonnages of CO2 avoided can be achieved using an amine based absorption capture system. At the lowest cost point, and for most of the range of cases studied, the cost of capture is significantly greater than the cost of storage. However, this depends on the source of the CO2, the distance between the source and the injection site, and the reservoir into which CO2 is injected.

Effect of storage capacity on CO2 pipeline optimisation

“…The techno-economic calculations are based on the Integrated Carbon Capture and Storage Economics Model (ICCSEM), developed by UNSW Australia for the CO2CRC. ICCSEM has been thoroughly validated and benchmarked, and has been found to be in good agreement with other published studies [6]. Further details about the assumptions used in this model are available elsewhere [7].…”

Assessment of postcombustion carbon capture technologies for power generation

“…The lack of moving parts, convenient startup/shut down, and simple process requirements make membranes very promising for future separation applications. Simple versus two-stage configurations were modelled by Ho et al [19] specifically for PCC of CO 2 from flue gas (Fig. 4).…”

“…4 Process configurations for modelling. Simple (A) and two stage (B) [19] plants therefore demonstrate PCC technology for GHG capture purposes. Most of the power station plants generate food grade CO 2 .…”

Membrane Process to Sequester Co2 From Power Plant Flue Gas

“…Currently, CO 2 capture with amine absorption seems to be the leading candidate technology  although membrane processes have been suggested. [5,6] The Achilles heel of previous membrane processes has been the enormous membrane area required for separation, because of the low partial pressure of carbon dioxide in flue gas. To address this problem, MTR has proposed a two-pronged strategy:…”