Influence of Methane in CO₂ Transport and Storage for CCS Technology

Abstract

CO(2) Capture and Storage (CCS) is a good strategy to mitigate levels of atmospheric greenhouse gases. The type and quantity of impurities influence the properties and behavior of the anthropogenic CO(2), and so must be considered in the design and operation of CCS technology facilities. Their study is necessary for CO(2) transport and storage, and to develop theoretical models for specific engineering applications to CCS technology. In this work we determined the influence of CH(4), an important impurity of anthropogenic CO(2), within different steps of CCS technology: transport, injection, and geological storage. For this, we obtained new pressure-density-temperature (PρT) and vapor-liquid equilibrium (VLE) experimental data for six CO(2) + CH(4) mixtures at compositions which represent emissions from the main sources in the European Union and United States. The P and T ranges studied are within those estimated for CO(2) pipelines and geological storage sites. From these data we evaluated the minimal pressures for transport, regarding the density and pipeline's capacity requirements, and values for the solubility parameter of the mixtures, a factor which governs the solubility of substances present in the reservoir before injection. We concluded that the presence of CH(4) reduces the storage capacity and increases the buoyancy of the CO(2) plume, which diminishes the efficiency of solubility and residual trapping of CO(2), and reduces the injectivity into geological formations.

A Critical Review of the Impacts of Leaking CO₂ Gas and Brine on Groundwater Quality

“…A variety of compositions may be present in the gas stream due to the presence of trace contaminants remaining after the CO2 capture process. Methane, for example, can be present as an impurity in the injection gas (Blanco et al, 2012;Mohd Amin et al, 2014). Methane can also be present as a native gas within the reservoir (Taggart, 2010;Oldenburg and Doughty, 2011;Hosseini et al, 2012), or could be produced through methanogenesis either in the reservoir or after CO2 enters the aquifer (Leu et al, 2011).…”

Evaluating impacts of CO2 and CH4 gas intrusion into an unconsolidated aquifer: fate of As and Cd

“…Future studies should investigate the effect of these greater concentrations of CH 4 in the gas mixture on pH. While 10% may be an overestimate of CH 4 present in CO 2 sequestration projects, Blanco et al (2012) stated that industrial emissions can reach CH 4 concentrations of >5%. The Eh measured in the columns with and without CH 4 were similar at the beginning of the experiments.…”

“…Blanco et al (2012) reported CH 4 levels as high as 6% in industrial emissions in Spain (generated by waste management); however, a study conducted by de Visser et al (2008), in agreement with the European Enhanced Capture (ENCAP) project, suggested a limit of 4% CH 4 in gas injection streams. CH 4 can also be present as a native gas prior to injection (Taggart, 2010;Oldenburg and Doughty, 2011;Hosseini et al, 2012).…”

“…In addition to CO 2 , CH 4 may be present in the deep subsurface reservoirs through co-injection with CO 2 (Blanco et al, 2012;Mohd Amin et al, 2014). Blanco et al (2012) reported CH 4 levels as high as 6% in industrial emissions in Spain (generated by waste management); however, a study conducted by de Visser et al (2008), in agreement with the European Enhanced Capture (ENCAP) project, suggested a limit of 4% CH 4 in gas injection streams.…”

“…The production of methane by methane-producing bacteria is also a source of CH 4 within storage reservoirs (Leu et al, 2011). Experimental data and modeling have shown that CH 4 causes an increase in gas plume size and is more buoyant than CO 2 (Blanco et al, 2012;Hosseini et al, 2012) and, according to modeling done by Taggart (2010), will form a leading CH 4 plume. It is therefore likely that the aquifer sediments would be exposed to a leaking stream of mixed gasses that in addition to CO 2 may also contain CH 4 .…”