The high energy consumption of CO2-loaded solvent regeneration is the biggest impediment for the real application of the amine-based CO2 capture process. To lower the energy requirement, three Fe promoted SO4 2–/ZrO2 supported on MCM-41 (SZMF) catalysts with different iron oxide content (5%, 10%, and 15%) were synthesized and applied for the rich monoethanolamine solution regeneration process at 98 °C. Results reveal that the use of SZMF hugely enhanced the CO2 desorption performances (i.e., desorption factor) by 260–388% and reduced the heat duty by about 28–40%, which is better than most of the reported catalysts for this purpose. The eminent catalytic activities of SZMF are related to their enhanced ratio of Brønsted to Lewis acid sites, weak acid sites, basic sites, and high dispersed Fe3+ species. Meanwhile, the addition of SZMF for CO2 desorption shows a promotional effect on its CO2 absorption performance, and SZMF presents an excellent cyclic stability. A possible mechanism is suggested for the SZMF catalyzed CO2 desorption process. Results of this work may provide direction for future research and rational design of more efficient catalysts for this potential catalyst-aided CO2 desorption technology.

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In this work, industrial grade sepiolite (IG-SEP) was premodified with hydrochloric acid, and then premodified sepiolite (SEP) was impregnated with triethylenetetramine (TETA) to create a novel TETA functionalized SEP adsorbent. The effects of TETA loading and adsorption temperature on CO2 adsorption capacity, as well as the CO2 adsorption isotherm and cyclic regenerability were investigated. Results show that, when SEP was optimized at 30 wt % TETA (SEP-TETA-30%), the adsorbent attained a CO2 adsorption capacity as high as 1.93 mmol/g at 50 °C with fast adsorption kinetics and good regenerability. The Freundlich model was best able to fit the experimental adsorption isotherm, and the isosteric heat of adsorption at high CO2 coverage was 28 kJ/mol. The presence of moisture in simulated gas has a positive effect on the adsorption capacity, with less harm to adsorption stability. The adsorbent samples were further characterized by N2 adsorption/desorption, scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The increased surface area and pore volume of the SEP allow for effective immobilization of TETA within its channels. A kinetic study demonstrated that the experimental adsorption data for SEP-TETA-30% were well fitted by the pseudo-second-order model. More importantly, an index of cost efficiency was proposed to evaluate the practicability and competitiveness of amine-impregnated adsorbents. The cost efficiency of SEP-TETA-30% adsorbent was estimated as 0.19 mol CO2/$, which was higher than reported adsorbents, suggesting that the TETA functionalized SEP (SEP-TETA-30%) composite is a promising adsorbent for cyclic postcombustion CO2 capture processes.

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The synthesis and utilization of bimetallic catalysts for the hydrogenation of dimethyl terephthalate (DMT) to dimethyl cyclohexanedicarboxylates (DMCD) is described in this Article. A variety of techniques, such as low temperature N 2 adsorption−desorption, transmission electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and H 2 temperature-programmed desorption were employed to characterize both the supports and the catalysts. The influence of various operational parameters, for example reaction temperature, pressure, and time, on the catalytic performance for the hydrogenation of DMT was systematically analyzed. Under optimized conditions, a DMT conversion of 80% along with DMCD selectivity of 95% were achieved. Furthermore, efforts were also made to probe the catalyst stability. The enhanced catalytic performance of optimized Ru−Ni/CNT catalysts can be attributed to the tight immobilization of the metal particles on the carbon nanotubes and the unique properties of the nitric acid-treated carbon nanotubes.