Mineral Dissolution/Precipitation During CO2 Injection into Coal Reservoir: A Laboratory Study

AbstractCO2 Supercritical Fluid Extraction (SFE) has been performed on Kushiro coal. The results showed there were slightly changes in major metal oxide due to mineral dissolution/precipitation during CO2 injection. To predict mineral dissolution/precipitation in the field scale and for long geologic period of time, numerical simulations using GMG-GEM simulator were carried out. The numerical simulation was only focused on the calcite that showed to dissolve in the near injection well area (higher pressure) as well as to precipitate at some distance from the injection well when injection of CO2 was stopped

NUMERICAL MODELLING AND SIMULATION OF CO2 –ENHANCED COAL-BED METHANE RECOVERY (CO2-ECBMR): THE EFFECT OF COAL SWELLING ON GAS PRODUCTION PERFORMANCE

This presents study investigate the effect of swelling on gas production performances at coal reservoirs during CO2-ECBMR processes. The stressdependent permeability-models to express effect of coal matrix shrinkage/swelling using Palmer and Mansoori (P&M) and Shi and Durucan (S&D) models were constructed based on present experimental results for typical coal reservoirs with the distance of 400 to 800 m between injection and production wells. By applying the P&M and S&D models, the numerical simulation results showed that CH4 production rate was decreasing and peak production time was delayed due to effect of stress and permeability changes caused by coal matrix swelling. The total CH4 production ratio of swelling effect/no-swelling was simulated as 0.18 to 0.95 for permeability 1 to 100 mD, respectively. It has been cleared that swelling affects gas production at permeability 1 to 15 mD, however, it can be negligible at permeability over 15 mD

Economical Considerations on CCS System for Geological Uncertainty and Injection Failure

In this study, an operation research on the performances of Tomakomai CCS project has been carried out for investigating the permeability uncertainty and the failures on CO2 operation and transportation. Firstly, economical effects of estimation error in aquifer permeability were investigated by using a reservoir block modeling based on numerical simulation results on CO2 injection rate. Secondary, economic loss resulted from failure of CO2 injection was evaluated by assuming periodical injection halts. It is clear that CO2 buffers, such as sphere gas tanks, should be installed to store CO2 on the CCS process which can temporarily store CO2 after it is captured when a trouble on transportation or injection processes occurs. Without a buffer, releasing the captured CO2 to the atmosphere due to system failure or trouble in injection will add to capture costs, or will result in carbon tax or opportunity loss on CCS. The larger size of CO2 buffer volume can potentially withstand against long-term trouble, however the larger buffer volume needs larger cost for initial construction and maintenance. The study also present the optimum CO2 buffer volume based on economical evaluations for a commercial CCS model based on several simulations performed with and without CO2 buffer in the system. Keywords: CCS; Uncertainty; Economic Evaluations; Permeability; CO2 Buffer JEL Classifications: Q35; Q41; Q5

Total Synthesis and Structural Revision of Cyclotetrapeptide Asperterrestide A

The structural revision of cyclotetrapeptide asperterrestide A has been achieved based on total synthesis and molecular modeling. For these studies, (2R,3S)-MePhe­(3-OH) and (2S,3S)-MePhe­(3-OH) suitably protected for peptide synthesis were prepared via a stereoselective reduction of a ketone precursor derived from L- or d-serine, using L-selectride or DIBAL-H. The synthesis of the proposed structure of asperterrestide A (1a) was accomplished by solution-phase synthesis of a linear precursor followed by macrolactamization. The NMR spectra of our synthetic 1a were not identical to those reported for the natural compound. Molecular modeling studies suggested that the correct structure 1b was the one in which the stereochemistry at the α-positions of the Ala and MePhe­(3-OH) residues is the opposite to that of the proposed structure. This was confirmed by the total synthesis of 1b and its subsequent structural characterization

Isorhamnetin Promotes 53BP1 Recruitment through the Enhancement of ATM Phosphorylation and Protects Mice from Radiation Gastrointestinal Syndrome

Flavonoids are a subclass of polyphenols which are attractive, due to possessing various physiological activities, including a radioprotective effect. Tumor suppressor p53 is a primary regulator in the radiation response and is involved in the pathogenesis of radiation injuries. In this study, we revealed that isorhamnetin inhibited radiation cell death, and investigated its action mechanism focusing on DNA damage response. Although isorhamnetin moderated p53 activity, it promoted phosphorylation of ataxia telangiectasia mutated (ATM) and enhanced 53BP1 recruitment in irradiated cells. The radioprotective effect of isorhamnetin was not observed in the presence of ATM inhibitor, indicating that its protective effect was dependent on ATM. Furthermore, isorhamnetin-treated mice survived gastrointestinal death caused by a lethal dose of abdominal irradiation. These findings suggested that isorhamnetin enhances the ATM-dependent DNA repair process, which is presumably associated with the suppressive effect against GI syndrome