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.

In the previous work of this series, we reported a wide experimental and computational analysis of the properties of hydroxylammonium-based ionic liquids. This family of ionic liquids shows very favorable economical, technological, and environmental properties in comparison with other ionic liquid types. We report in this work a computational study, using quantum chemistry and molecular dynamics methods, to analyze the absorption of carbon dioxide by hydroxylammonium ionic liquids. The selected compounds were 2-hydroxyethyl-trimethylammonium L-(+)-lactate and tris(2-hydroxyethyl)methylammonium methylsulfate. The main objective of this work is to study and analyze CO(2) absorption from the molecular point of view, therefore contributing to the knowledge and advancement on the absorption ability of ionic liquids. The computational study would lead to a deeper knowledge of factors controlling CO(2) absorption for this ionic liquid family in comparison with available information for other relevant types. The results were analyzed considering the effects of absorbed gas on the ionic liquid structuring from a molecular level viewpoint, interionic interactions, diffusion of the involved compounds, and interaction of CO(2) with anions and cations. The reported results show a strong effect of the presence of hydroxyl groups in the involved cations and anions through the interaction with CO(2) molecules, along with the effects rising from the size of cations on the fluid structure.

Reliable speed of sound, c, values in CO 2 -rich mixtures and pure CO 2 are required for carbon capture and storage (CCS) technology but are difficult to determine, particularly at relatively high frequencies. We tested the suitability of methanol as doping agent to obtain accurate c values in CCS systems at 5 MHz. We measured c in seven CO 2 -rich, CO 2 +methanol mixtures between 263.15 and 323.15 K and up to 196.30 MPa, and we extrapolated the values to obtain c in pure CO 2 .Additionally, we measured c from 263.15 to 373.19 K and up to 190.10 MPa in two CO 2 -rich, CO 2 +SO 2 mixtures with the same SO 2 composition, which is of interest for CCS, with one mixture doped with methanol. We compared our results for pure CO 2 with the literature and the Span and Wagner equation of state (EoS). We validated the PC-SAFT EoS and the modeling with the REFPROP 9 software for the mixtures by comparing the predicted values with our experimental data under the studied conditions. We conclude that methanol is a suitable doping agent to measure c in pure CO 2 and CO 2 -rich mixtures. For the CO 2 +SO 2 mixtures, the effect of methanol on the experimental values is small and negligible for modeling. *Manuscript Click here to download Manuscript: Revised Manuscript.docx Click here to view linked References

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This paper discusses the influence of the noncondensable impurities CO and CH4 on Carbon Capture and Storage (CCS) technology. We calculated and drew conclusions about the impact of both impurities in the CO2 on selected transport, injection, and storage parameters (pipeline pressure drop, storage capacity, etc.), whose analysis is necessary for the safe construction and operation of CO2 pipelines and for the secure long-term geological storage of anthropogenic CO2. To calculate these parameters, it is necessary to acquire data on the volumetric properties and the vapor-liquid equilibrium of the fluid being subjected to CCS. In addition to literature data, we used new experimental data, which are presented here and were obtained for five mixtures of CO2+CO with compositions characteristic of the typical emissions of the E.U. and the U.S.A. Temperatures and pressures are based on relevant CO2 pipeline and geological storage site values. From our experimental results, Peng-Robinson, PC-SAFT, and GERG Equations of State for were validated CO2+CO under the conditions of CCS. We conclude that the concentration of both impurities strongly affects the studied parameters, with CO being the most influential and problematic. The overall result of these negative effects is an increase in the difficulties, risks, and overall costs of CCS.