Carbon capture and storage (CCS) has emerged as a promising means of lowering CO2 emissions from fossil fuel combustion. However, concerns about the possibility of harmful CO2 leakage are contributing to slow widespread adoption of the technology. Research to date has failed to identify a cheap and effective means of unambiguously identifying leakage of CO2 injected, or a viable means of identifying ownership of it. This means that in the event of a leak from a storage site that multiple operators have injected into, it is impossible to determine whose CO2 is leaking. The on-going debate regarding leakage and how to detect it has been frequently documented in the popular press and scientific publications. This has contributed to public confusion and fear, particularly close to proposed storage sites, causing the cancellation of several large storage projects such as that at Barendrecht in the Netherlands. One means to reduce public fears over CCS is to demonstrate a simple method which is able to reliably detect the leakage of CO2 from a storage site and determine the ownership of that CO2. Measurements of noble gases (helium, neon, argon, krypton and xenon) and the ratios of light and heavy stable isotopes of carbon and oxygen in natural CO2 fields have shown how CO2 is naturally stored over millions of years. Noble gases have also proved to be effective at identifying the natural leakage of CO2 above a CO2 reservoir in Arizona and an oil field in Wyoming and in ruling out the alleged leakage of CO2 from the Weyburn storage site in Canada. Recent research has shown amounts of krypton are enhanced relative to those of argon and helium in CO2 captured from a nitrate fertiliser plant in Brazil. This enrichment is due to the greater solubility of the heavier noble gases, so they are more readily dissolved into the solvent used for capture. This fingerprint has been shown to act as an effective means of tracking CO2 injected into Brazilian and USA oil fields to increase oil production. Similar enrichments in heavy noble gases, along with high helium concentrations are well documented in coals, coal-bed methane and in organic rich oil and gas source rocks. As noble gases are unreactive, these enrichments will not be affected by burning the gas or coal in a power station and hence will be passed onto the flue gases. Samples of CO2 obtained from an oxyfuel pilot CO2 capture plant at Lacq in France which contain helium and krypton enrichments well above atmospheric values confirm this. Despite identification of these distinctive fingerprints, no study has yet investigated if there is a correlation between them and different CO2 capture technologies or the fossil fuel being burnt. We propose to measure the carbon and oxygen stable isotope and noble gas fingerprint in captured CO2 from post, pre and oxyfuel pilot capture plants. We will find out if unique fingerprints arise from the capture technology used or fuel being burnt. We will determine if these fingerprints are distinctive enough to track the CO2 once it is injected underground without the need of adding expense artificial tracers. We will investigate if they are sufficient to distinguish ownership of multiple CO2 streams injected into the same storage site and if they can provide an early warning of unplanned CO2 movement out of the storage site. Grant number: EP/K036033/1.
This presentation on the UKCCSRC Call 1 project, Chemical Looping for low-cost Oxygen Production, was presented at the Cranfield Biannual, 22.04.15. Grant number: UKCCSRC-C1-39.
This project contributes significantly to the de-risking of a technology which has a significantly lower efficiency penalty than post-combustion capture using Monoethanolamine (MEA) scrubbing. The work here specifically targets two industrial sectors where MEA scrubbing is at a significant disadvantage (only ~ 30 % of the low-grade heat required for MEA scrubbing is present in a cement plant, for example ), and in both cases the spent CaO is valuable as an input to the process itself (either as the main feedstock for cement clinker production, or as a flux in iron production). The project builds on several current projects at both Imperial College and Cranfield University and offers excellent value for money because of these synergies. Grant number: UKCCSRC-C2-209.
This presentation on the EPSRC project, CONTAIN, was presented at the Cranfield Biannual, 21.04.15. Grant number: EP/K036025/1.
This poster on the UKCCSRC Call 2 project Process-Performance Indexed Design of Ionic Liquids for Carbon Capture was presented at the CSLF Call project poster reception, London, 27.06.16. Grant number: UKCCSRC-C2-199. The elevated cost of carbon capture and storage (CCS) is currently hindering its implementation at large scale. We aim to design a 'perfect' solvent for the capture of carbon dioxide (CO2). The design of the solvent is based on process performance indexes.
Aqueous amine scrubbing was originally developed for natural gas treatment and is currently considered to be the current best available technology for post-combustion capture (PCC) of CO2 from both pulverised fuel (PF) and natural gas combined cycle (NGCC) power plants. A major issue is the severe thermo-oxidative degradation of alkanomaine solvents that occurs in PCC compared to natural gas processing, with the problem being compounded by the presence of acid gases that lead to the formation of heat stable salts (HSS). The accumulation of degradation products is known to reduce CO2 capture efficiency and cause excessive foaming and fouling and unacceptably high corrosion rates. Current measures to compensate for degradation involves purging spent solvent solution for reclaimation, makeup with fresh amine and the addition of anti-foam and oxidation/corrosion inhibitors. Reclaimer technologies based on distillation, ion-exchange and elecrodialysis have been developed to deal primarily with HSS where distillation has the advantage of removing both the HSS and their anions (i.e. formate and acetate). However, these technologies do not deal with the majority of the other degradation products, particularly those arising from thermal and oxidative degradation. Further, it has generally recognised that MEA forms high boiling polymeric material where N-(2-hydroxyethyl)-ethylenediamine (HEEDA), in particular, may continue to degrade in the presence of CO2 to form longer substituted ethlyenediamines. This proposal has been prompted by our extremely promising preliminary results that the thermal and oxidative degradation of an amine polymer (polyethyleneimine) can largely be reversed using both hydrogenation and hydrothermal (hydrous) treatments. We used non-catalytic hydropyrolysis and hydrous pyrolysis treatments at temperatures below 250oC which were clearly effective in reducing oxygen functionalities without causing any degradation of the polymer chain. The challenge is to partially reduce degraded amines to hydroxyamines and also, for polymeric forms, to induce some hydrogenolysis to reduce chain lengths. Hydrous pyrolysis has the potential advantage of not directly requiring hydrogen with water being the hydrogen source. Judicious choice of catalysts provides selectivity for hydrogenation and hydrogenolysis and research on amine degradation in natural gas sweetening has shown degradation products, such as N,N-bis(2-hydroxy-ethyl)piperazine and N,N,N-tris(2-hydroxyethyl)ethylenediamine, can be converted back to hydroxyamines by a hydrotreating reactions . Directly targeting a high research priority identified by the RAPID Handbook, the proposed research aims to investigate novel reductive approaches for rejuvenating spent amine solutions from PCC plants, namely selective catalytic hydrotreatments at modest temperatures and H2 pressures and hydrous pyrolysis (hydrothermal conversion). The specific objectives are: 1.To apply the hydrogenation/ hydropyrolysis and hydrothermal treatments to individual compounds, including 1-(2-hydroxyethyl)-2-imidazolidone (HEIA), HEEDA, .N-(2-hydroxyethyl)acetamide and N-methylformamide 2.Based on the model compound results, to conduct experiments on actual fractions from degraded amine solvents, notably the residues from distillation containing HSS and the compounds targeted above; and 3.To use the results to define the overall benefits hydrogenation, hydropyrolysis and hydrothermal treatments in solvent rejuvenation and a basis for planning the subsequent research needed to take forward these new treatments, in terms of identifying how these treatments can best be conducted continuously. Grant number: UKCCSRC-C2-189.
This presentation on the UKCCSRC Call 1 project, UK Bio-CCS CAP, was presented at the Cranfield Biannual, 22.04.15. Grant number: UKCCSRC-C1-38.
The data consists of a spreadsheet containing gas column height, CO2 content and estimated retained buoyancy pressures for Southern North Sea gas fields, based on published information. The data were obtained from published field records and papers on behalf of the 'Fault seal controls on CO2 storage capacity in aquifers' project funded by the UKCCS Research Centre, grant number UKCCSRC-C1-14.
This presentation on the UKCCSRC Call 2 project Performance of Flow Meters with Dense Phase CO2 and CCS Recovery Streams was presented at the UKCCSRC Edinburgh Biannual Meeting, 15.09.2016. Grant number: UKCCSRC-C2-201.
It is crucial that the engineered seals of boreholes in the vicinity of a deep storage facility remain effective for considerable timescales if the long-term geological containment of stored CO2 is to be effective. These timescales extend beyond those achievable by laboratory experiments or industrial experience. Study of the carbonation of natural Ca silicate hydrate (CSH) phases provides a useful insight into the alteration processes and evolution of cement phases over long-timescales more comparable with those considered in performance assessments. Samples from two such natural analogues in Northern Ireland have been compared with samples from laboratory experiments on the carbonation of Portland cement. Samples showed similar carbonation reaction processes even though the natural and experimental samples underwent carbonation under very different conditions and timescales. These included conversion of the CSH phases to CaCO3 and SiO2, and the formation of a well-defined reaction front. In laboratory experiments the reaction front is associated with localised Ca migration, localised matrix porosity increase, and localised shrinkage of the cement matrix with concomitant cracking. Behind the reaction front is a zone of CaCO3 precipitation that partly seals porosity. A broader and more porous/permeable reaction zone was created in the laboratory experiments compared to the natural samples, and it is possible that short-term experiments might not fully replicate slower, longer-term processes. That the natural samples had only undergone limited carbonation, even though they had been exposed to atmospheric CO2 or dissolved View the MathML sourceHCO3- in groundwater for several thousands of years, may indicate that the limited amounts of carbonate mineral formation may have protected the CSH phases from further reaction. doi:10.1016/j.apgeochem.2012.09.007. http://www.sciencedirect.com/science/article/pii/S0883292712002594.