Siliceous Cementation of Chlorite-Coated Grains in the Permian Sandstone Gas Reservoirs,Ordos Basin

Objective It has long been controversial that whether authigenic chlorite coatings in sandstone reservoirs can prevent precipitation of siliceous cements. It is commonly believed that chlorite coatings （also called chlorite films, chlorite linings, or chlorite rims） may prevent quartz overgrowth, and thus help the preservation of original pores in sandstone reservoirs. Recently, however, this assumption has been challenged by reservoir geologists. This dispute cannot be solved by mere analysis of thin sections, nor by chemical equations and diagenesis analysis. The main objective of the present contribution is to shed light on this problem on the basis of sandstone samples from the Permian Shanxi and Shihezi Formations in the eastern part of the Sulige gas field, Ordos Basin in central China.

Experimental Investigation on the Performance of[APMIm][NTf_(2)]for Capturing CO_(2)from Flue Gas of the Cement Kiln Tail

Facing the global warming trend,humanity has been paying more and more attention to the Carbon Capture,Utilization and Storage.Large amounts of CO_(2)is emitted with burning fossil fuel as well as by some special industrial processes like the decomposition of calcium carbonate in a cement plant.The cement industry contributes about 7%of the total worldwide CO_(2)emissions and the CO_(2)concentration of flue gas of the cement kiln tail even exceeds 30%.Ionic liquid is considered to be an effective and potential material to capture CO_(2).In order to investigate the performance of ionic liquids for capturing CO_(2)from flue gas of the cement kiln tail,an experiment system was established and an ionic liquid,[APMIm][NTf_(2)](1-aminopropyl-3-imidazolium bis(trifluoromethylsulfonyl)imine),was tested using pure CO_(2)and simulated gas.The results showed that both physical and chemical absorption play roles while physical absorption dominates in the absorption process.Both the absorption capacity and rate decrease with raising the operating temperature.In the experiment with pure CO_(2),the absorption capacity is 0.296molCO_(2)⋅molIL−1 at 30℃ and 0.067molCO_(2)⋅molIL−1 at 70℃.Meanwhile,the ionic liquid can be regenerated for recycling without obvious changes of the absorption capacity.When the ionic liquid is used for flue gas of the cement kiln tail rather than pure CO_(2),a sharp decrease of the absorption capacity and rate was observed obviously.The absorption capacity at 30℃ dropped even to 0.038molCO_(2)⋅mol_(IL)^(−1),12.8%of that for pure CO_(2).Additionally,a natural desorption of CO_(2)from the ionic liquid was observed and affected the experimental results of the absorption capacity and the absorption-desorption rate to some extent.

Gas separation using porous cement membrane

Gas separation is a key issue in various industrial fields. Hydrogen has the potential for application in clean fuel technologies. Therefore, the separation and purification of hydrogen is an important research subject. CO2 capture and storage have important roles in ＂green chemistry＂. As an effective clean technology, gas separation using inorganic membranes has attracted much attention in the last several decades. Membrane processes have many applications in the field of gas separation. Cement is one type of inorganic material, with the advantages of a lower cost and a longer lifespan. An experimental setup has been created and improved to measure twenty different cement membranes. The purpose of this work was to investigate the influence of gas molecule properties on the material transport and to explore the influence of operating conditions and membrane composition on separation efficiency. The influences of the above parameters are determined, the best conditions and membrane type are found, it is shown that cementitious material has the ability to separate gas mixtures, and the gas transport mechanism is studied.