Search

Abstract: Desulfurization of JP-5 jet fuel (1172ppmw S) was investigated by π-complexation adsorption with AgNO3 supported on mesoporous silica SBA-15 and MCM-41. The average pore sizes of AgNO3/SBA-15 and AgNO3/MCM-41 were 48.8 and 19.1Å, respectively. The results of JP-5 desulfurization showed that significant sulfur breakthrough occurred at ∼10.0 and ∼15.0mL/g by AgNO3/SBA-15 and AgNO3/MCM-41, respectively, at a space velocity of 1.25h−1. The spent AgNO3/MCM-41 was regenerated by a simple process (heating in air at 200°C) and ∼50% of the sulfur capacity was recovered after the first cycle. Molecular orbital calculations show that Cu+ (as that in CuY zeolite) formed stronger π-complexation bonding with the thiophenic compounds than Ag+ (in AgNO3), as evidenced by experimental heats of adsorption. However, pore diffusion limitation of the large sulfur molecules (alkylated benzothiophenes) became an important factor for desulfurization of high sulfur jet fuels such that the AgNO3-supported mesoporous sorbents yielded substantially better results than Cu(I)Y, although Cu(I)Y was better for a model fuel that contained only small sulfur molecules. Among all sorbents that have been investigated, the AgNO3/MCM-41 sorbent showed the best desulfurization performance for high sulfur jet fuels. [Copyright &y& Elsevier]

Abstract: A new bridge-building technique was used for facilitating H spillover on metal doped adsorbents for hydrogen storage at room temperature. By preadsorbing of CH4 on Pt/AX-21 (superactivated carbon), the adsorbed amount of hydrogen increased by ∼100% at 1 atm and 25 °C, attributed to the adsorbed CH4 serving as bridges for spillover. We conclude that the Benson–Boudart method can provide a good assessment for the dispersion of metals supported on Al2O3 (and zeolites). For carbon and SiO2 supports, even with pure H2, spillover leads to overestimates of dispersion, and any small amounts of gaseous impurities could lead to much greater overestimates. [Copyright &y& Elsevier]

Desulfurization of a JP-5 light fraction (841ppmw S) for fuel cell applications was achieved by -complexation adsorption with CuCl and supported on the MCM-41 and SBA-15 mesoporous materials. CuCl/MCM-41, , CuCl/SBA-15 and sorbents were prepared with spontaneous monolayer dispersion of metal halides onto surfaces of supports. These sorbents were characterized with XRD, physical adsorption and CO chemisorption. The results showed that the mesoporous structures remained in the supported sorbents. Desulfurization of JP-5 light fraction with these sorbents was investigated at room temperature. showed by far the highest capacity of selective sulfur adsorption among all known sorbents, and the significant breakthrough occurred at about 50.0ml/g for desulfurization of JP-5 light fraction. The total sulfur content of JP-5 light fraction can be reduced from 841ppmw S to below 50.0ppmw S. The spent was regenerated by purge with benzene at 70°C, and the regenerated was tested again for the desulfurization. The results showed that about 44% and 48% of the sulfur capacity were recovered at breakthrough and saturation, respectively. [Copyright &y& Elsevier]

Shale gas reservoir is comprised of highly heterogeneous porosity systems including hydraulic/secondary fractures, inorganic and organic matrix. Multiple non-Darcy flow mechanisms in the shale matrix further bring challenges for modeling. In this paper, we developed a framework combining a multi-physics compositional simulator with Multi-Porosity Modeling preprocessor for gas storage and transport in shale. A Triple-Porosity Model is used to characterize the three porosity systems in shale gas reservoirs. In the fracture porosity the heterogeneous impact of secondary fractures distribution on matrix-to-fracture fluid transfer is revealed by shape factor distribution. They are upscaled with superior accuracy from a detailed Discrete Fracture Network Model (DFN) sector model, where orthogonal hydraulic fractures are explicitly discretized. With the occurrence of nano-pores in shale matrix, the interaction between pore-wall and gas molecules is considered via Knudsen diffusion and gas slippage. Gas adsorption on the pore-wall of organic matrix is modeled by extended Langmuir isotherm. The inter-porosity and intra-porosity connectivities in the Triple-Porosity Model are flexibly controlled by arbitrary connections. Our results show that gas production in the Triple-Porosity Model with shape factor upscaled from DFN exhibits different production performance from models with uniform shape factor distribution. The deviations are caused by the dominance of different regions at different production periods. Connection topology in the shale gas reservoir is also comprehensively assessed. We demonstrate that the intra-porosity connections in the inorganic and organic matrix have negligible impact on the global gas flux, while the inter-porosity connections have different levels of importance for the gas production. Moreover, different combinations of flow and storage mechanisms are investigated. We show that Langmuir desorption maintains reservoir pressure, but gas slippage and Knudsen diffusion accelerate the pressure drop. Both mechanisms contribute to improve the gas production and the consideration of them simultaneously improve gas production most. [ABSTRACT FROM AUTHOR]