CCS, Carbon Capture and Storage: Two Processes for the Future of Carbon Emissions?

What is Carbon Capture and Storage (CCS)? Also known as carbon capture sequestration, carbon capture and storage is one highly sought after technology to combat climate change. The two ways it can work: 1) pre-combustion or 2) post-combustion (Riso National Lab, 2007).

In pre-combustion CCS: carbon fuels like fossil fuels (coal and oil) and cleaner fuels (biomass, yard trimmings, compost, municipal solid waste) are "de-carbonized" by gasification or reforming. Gasification in a nutshell is the process of exposing the fuel to large amounts of oxygen or steam with the end product a fuel called syngas (mixture of carbon monoxide and hydrogen). A creative way to describe gasification is to use a cake, but consider that cake is unhealthy and full of sugar and preservatives. You still figure you can gain some energy out of it although it will harm your internal system, your body. The gasification process is similar to taking that cake and baking it while blasting it with oxygen and steam to produce an energy drink.

In post-combustion carbon capture & storage: fossil fuels are burned and then the resulting gas byproduct is filtered out using special absorbable materials. The carbon is then stored preventing additional emissions into the atmosphere. If the CO2 is coming from a large source such as a power plant, then it is transported by pipeline or tanker to either the sea floor bed or an underground location (oil wells, coal mines, saline aquifers). Oil mines and coal mines have the added benefit that CCS provides a way to flush out more fuel, like a rubber ducky toy rising out of a bathtub because it's been filled with water.

Is Carbon Capture and Storage technology proven? Conceptually, CCS strategies sound great: the strategy to retrofit current coal plants so after burning fossil fuels, they do not emit carbon emissions. Unfortunately, the technology is considered to be too infantile to help reduce global emissions and combat climate change in a timely manner.

Are there currently commercial CCS plants up and running? There are many proposed projects and pilots, but currently there are only three locations deemed to have reached commercial scale: 1) Sleipner; 2) In Salah; and 3) Weyburn (Page, Williamson & Mason, 2009). A total combined effort of these three sites stores 3-4 Megatons of CO2 a year, not nearly enough to put a dent into the 8000 Megatons of CO2 emitted into the atmosphere every year (IPCC, 2005). Little hope comes in the prediction that by 2030 the capacity of carbon storage would be an abysmal 500 Megatons a year (IPCC, 2007) because by then the rate of CO2 emissions may have more than doubled to 16000 Megatons a year (based on a geometric rate of carbon emissions). The final question to ask: is CCS the solution? The truth is that carbon capture and storage (CCS) is only a minor part of a larger global energy strategy that the world has yet to create.

photo credit: PD-USGOV