Investigation of the carbon dioxide sorption capacity and structural deformation of coal

Due to increasing atmospheric CO2 concentrations causing the global energy and environmental crises, geological sequestration of carbon dioxide is now being actively considered as an attractive option to mitigate greenhouse gas emissions. One of the important strategies is to use deep unminable coal seams, for those generally contain significant quantities of coal bed methane that can be recovered by CO2 injection through enhanced coal bed natural gas production, as a method to safely store CO2. It has been well known that the adsorbing CO2 molecules introduce structural deformation, such as distortion, shrinkage, or swelling, of the adsorbent of coal organic matrix. The accurate investigations of CO2 sorption capacity as well as of adsorption behavior need to be performed under the conditions that coals deform. The U.S. Department of Energy-National Energy Technology Laboratory and Regional University Alliance are conducting carbon dioxide sorption isotherm experiments by using manometric analysis method for estimation of CO2 sorption capacity of various coal samples and are constructing a gravimetric apparatus which has a visual window cell. The gravimetric apparatus improves the accuracy of carbon dioxide sorption capacity and provides feasibility for the observation of structural deformation of coal sample while carbon dioxide molecules interact with coal organic matrix. The CO2 sorption isotherm measurements have been conducted for moist and dried samples of the Central Appalachian Basin (Russell County, VA) coal seam, received from the SECARB partnership, at the temperature of 55 C

Control of the Nano-Particle Weight Ratio in Stainless Steel Micro and Nano Powders by Radio Frequency Plasma Treatment

This study describes how to make stainless steel hybrid micro-nano-powders (a mixture of micro-powder and nano-powder) using an in situ one-step process via radio frequency (RF) thermal plasma treatment. Nano-particles attached to micro-powders were successfully prepared by RF thermal plasma treatment of stainless steel powder with an average size of 35 μm. The ratio of nano-powders is estimated with a two-dimensional fluid simulation that calculates the temperature profile influencing the rate of surface evaporation. The simulation is conducted to determine the variation of the input power and the distance from the plasma torch to the feeding nozzle. It was demonstrated experimentally that the nano-powder ratio in the micro-nano-powder mixture can be controlled by adjusting the feeding rate, plasma power, feeding position and quenching effect during plasma treatment. The ratio of nano-particles in the micro-nano-powder mixture was controlled in a range from 0.1 (wt. %) to 30.7 (wt. %)

Long-Term Comparison of Platinum Chromium Everolimus-Eluting Stent vs. Cobalt Chromium Zotarolimus-Eluting Stent-3-Year Outcomes From the HOST-ASSURE Randomized Clinical Trial -

Background: There are limited data on the long-term outcome of platinum chromium-based everolimus-eluting stents (PtCr-EES) vs. cobalt chromium-based zotarolimus-eluting stents (CoCr-ZES). Methods and Results: A total of 3,755 patients undergoing percutaneous coronary intervention (PCI) were randomized 2: 1 to PtCr-EES or CoCr-ZES, and 96.0% of patients completed the 3-year clinical follow-up. The primary outcome was target lesion failure (TLF), defined as a composite of cardiac death, target vessel-related myocardial infarction (MI), and clinically-driven target lesion revascularization (TLR). At 3 years, TLF occurred in 5.3% and in 5.4% of the PtCr-EES and CoCr-ZES groups, respectively (hazard ratio 0.978; 95% confidence interval 0.730-1.310, P=0.919). There were no significant differences in the individual components of TLF. Routine angiographic follow-up was performed in 38.9% of the total patients. In a landmark analysis of the subgroup that had follow-up angiography, the clinically-driven TLR rate of CoCr-ZES was significantly higher than PtCr-EES group during the angiography follow-up period (P=0.009). Overall definite and probable stent thrombosis rates were very low in both groups (0.5% vs. 0.6%, P=0.677). Conclusions: PtCr-EES and CoCr-ZES had similar and excellent long-term outcomes in both efficacy and safety after PCI in an all-comer population.Y