Carbon capture and storage

The process and technology of carbon capture and storage (CCS) from electric power, heavy oil operations, and other industry plant processes is still far from being commercially viable or available on a large scale for EOR, and will be fully realized only when significant technological challenges are overcome by multidisciplinary teams of scientists and engineers. CCS is being pursued by almost every industrialized nation across the globe and progress is being made between government and industry through collaborative projects such as the CO2 Capture Project (CCP).  From an oil industry perspective, most of the majors have ongoing CCS research projects with activities in the US, Canada, Australia, and the Norway for the purposes of EOR and reducing green house gas emissions. CCS can essentially be considered as three interconnecting processes:

• CO2 from the combustion of fossil (or other) fuel is captured efficiently in a form from which it can be readily released.
• CO2 is transported from where it is captured to where it ultimately will be stored.
• CO2 is stored permanently at specially selected sites and is continuously monitored for leakage.

There are typically three main capture technologies and four storage mechanisms. The capture methodologies include:

•  post-combustion scrubbing - This process is considered the first step towards large-scale capture where CO₂ is removed from exhaust gas after combustion. This technology can typically be retrofitted to existing equipment.
• pre-combustion decarbonization (hydrogen) – In this process natural gas is converted to hydrogen and CO₂ in a reformer. The CO₂ is compressed for storage and the hydrogen is mixed with air for combustion, emitting only nitrogen and water.
• oxyfuel - Oxygen is separated from air and then burned with hydrocarbons to produce an exhaust with a high concentration of CO₂ for storage.

CO2 storage mechanisms include:

• displacement mechanism for EOR
• storage in depleted oil and gas reservoirs
• displacement mechanism for methane in coal (coal-bed methane)
• storage in saline aquifers

In subsequent posts we will review the application of post and pre combustion along with the various CO2 storage scenarios and their application to heavy oil.

Kambiz.