Carbon capture storage CCS, is a process consisting of the separation of CO2 from industrial and energy-related sources, transport to a storage location and long-term isolation from the atmosphere. The widespread application of CCS (also known as Geosequestration or Marine Sequestration ) will depend on how quickly the technology matures, costs, diffusion and transfer of the technology to developing countries and their capacity to apply the technology, along with regulatory aspects, environmental issues and management of public perception
Why Do We Need CCS?
Coal is currently the dominant fuel in the power sector, accounting for around 40% of electricity generated globally, with hydro power accounting for 17.5%, natural gas for 17.3%, nuclear for 16.8%, oil for 9%, and non-hydro renewables for 1.6%. Coal is projected to remain the dominant fuel for power generation in 2020 (perhaps reducing to 36%). Given that dirty energy sources are around for some time to come, it is important to find ways to significantly capture and cut CO2 emissions from these sources.
Carbon Capture Storage CCS Applications
Capture of CO2 can be applied to large fossil fuel or biomass energy facilities, major CO2-emitting industries, natural gas production, synthetic fuel plants and fossil fuel-based hydrogen production plants. The CO2 would then be compressed and transported for storage underground in deep saline aquifers, depleted oil and gas reservoirs, coal seams or natural underground pore spaces.
Stages of Carbon Capture Storage CCS
There are three pretty distinct stages in carbon capture and storage, or geosequestration:
(1) Capture and separation – this involves the separation of the carbon dioxide from other gases such as flue gas emissions from a power station or gases produced from a petroleum production well. Separation is necessary to ensure that only carbon dioxide is sequestered and not other products or gases;
(2) Transportation – this involves moving large volumes of carbon dioxide from the collection source to a site where the carbon dioxide can be injected and stored underground. Transportation could be by way of pipeline, rail, road or ship; and
(3) Injection and storage – this involves the injection of the carbon dioxide into deep underground storage Reservoirs and ongoing management and monitoring of the storage site.
Will it Stay Underground?
Only certain geologic formations are considered suitable for carbon dioxide storage. In general, CO2 can be stored in a layer of permeable rock that has a layer of impermeable rock above it. Permeable rock has pores through which fluids can flow and gather. Fluids cannot pass through impermeable rock, and so the top layer traps CO2 that is injected into the permeable formation. Such sites are the same type of formation that have trapped crude oil and natural gas over millions of years, and provides a natural precedent for long-term CO2 storage.
Gabriela von Goerne, the Climate and Energy Campaigner from Greenpeace in Germany, says “Carbon Capture Storage CCS might be an option in the future when all the questions have been answered and problems ironed out but there is an urgent need for immediate action. That action should be the massive and widespread deployment of available renewable energy and energy efficiency technologies combined with energy conservation.”
I think Gabriela is right, we certainly don’t want to write carbon capture and storage off, but we need to take urgent action right now and focus squarely on developing and deploying renewable energy.