CO2 Capture from Medium Scale Combustion Installations

Publication Overview

The study assesses the costs and performance of medium-scale CO2 capture technologies The focus is on CO2 capture from medium-scale power generation systems, from medium-scale systems for industrial heat production and from medium-scale combined heat and power systems. Other industrial processes which produce CO2, such as cement, metallurgical and petrochemical processes are not considered in this study With respect to the size, we focus on novel technologies which will become available on the longer term, because it is expected that CO2 is only likely to be captured from medium-scale sources when most large-scale capture opportunities have been exhausted. An exception is the MEA scrubbing technology which is currently used in industrial applications at a scale of 50 to 400 kt per year. The study only considers new systems and does not consider retrofit systems.

Publication Summary

Medium scale combustion installations (1-100MWth) account for substantial emissions of CO2, of the order of 15-20% of total global emissions. There is therefore considerable technical potential for CO2 capture. Natural gas fired boilers are the most significant medium scale combustion installations in the EU and USA but coal fired boilers are most significant in China.

Plants for capture of CO2 from medium scale natural gas-fired boilers using amine scrubbing are already commercially available, for example for supply of CO2 to the food and drinks industries.

Various alternative CO2 capture technologies may be suitable for medium scale installations.

The costs of CO2 capture depend strongly on local conditions, including the size of the installation, the operating load factor and the ability to make use of any low grade heat that is rejected by the capture process. Installations which are only operated seasonally or for peak load duties will have relatively high costs of avoiding CO2 emissions.

A boiler combined with membrane oxygen production offers the prospect of a significantly lower cost of capture than post combustion amine scrubbing for a medium scale installation. However, development of such a system presents considerable challenges and research, development and demonstration is needed.

The cost of capture and storage of CO2 from medium scale installations depends on the proximity of other CO2 sources, to give economies of scale in CO2 pipeline systems. IEA GHG will shortly publish another study which assesses the feasibility and costs of collecting CO2 from medium scale installations.

The economic feasibility of capturing CO2 from medium scale installations will depend on the carbon price, which will depend on the extent to which global emissions of CO2 need to be reduced and the costs of alternative ways of reducing emissions. Further work in this area is needed.