Cryogenic CO2 capture in natural gas

Increasing world energy demand and pricing trends have encouraged oil and gas companies to look at developing contaminated natural gas fields previously deemed uneconomic. At the same time, world wide perceptions on climate change are pressuring energy companies to adopt global best practices to reduce carbon emissions. Developing currently unviable contaminated natural gas fields requires developing new technologies for high CO2 gas treatment. Current technologies available in the market for natural gas treating may not be ideally suitable for treating highly contaminated natural gas where CO2 geo-sequestration is required. Use of physical and chemical absorption solvents have been the most popular method for treating natural gas with high CO2, and to a lesser extent, membranes and adsorption methods. These technologies remove CO2 at near ambient pressures thus requiring substantial amount of compression to levels needed for geo-sequestration. Cryogenic CO2 removal methods can capture CO2 in a liquid form thus making it relatively easy to pump underground for storage or send for enhanced oil recovery. This new cryogenic CO2 removal method has been researched and tested in a demonstration plant and is soon to be implemented in commercial field applications. This paper intends to share recent field experience and test results from Cool Energy’s CryoCell® demonstration plant in Western Australia. The CryoCell® process was developed by Cool Energy Ltd and tested in collaboration with other industrial partners including Shell Global Solutions. This presentation will also discuss and compare existing CO2 treatment technologies for developing high CO2 natural gas fields requiring CO2 geo-sequestration with the CryoCell® CO2 capture process. Basic economic comparisons between the CryoCell® process and an amine based process including CO2 geo-sequestration will be presented.