Experimental investigation on separation and energy-efficiency performance of temperature swing adsorption system for CO2 capture

Can Charge-Modulated Metal-Organic Frameworks Achieve High-Performance CO2 Capture and Separation over H2 , N2 , and CH4 ?

CO₂ capture and separation by using charge-modulated adsorbent materials is a promising strategy to reduce CO₂ emissions. Herein, three TM-HAB (TM=Co, Ni, and Cu; HAB=hexa-aminobenzene) metal-organic frameworks (MOFs) were evaluated as charge-modulated CO₂ capture and separation materials by using density functional theory and grand canonical Monte Carlo simulations. The results showed that each TM-HAB presented a high electrical conductivity and structural stability when injecting charges. The CO₂ adsorption energy increased from 0.211 to 2.091 eV on Co-HAB, 0.262 to 2.119 eV on Ni-HAB, and 0.904 to 2.803 eV on Cu-HAB, respectively, with the increase in charge state from 0.0 to 3.0 e^- . Co-HAB and Ni-HAB were better charge-modulated CO₂ capture materials with less structure deformation based on energy decomposition analyses. The kinetic process demonstrated that considerably low energy consumptions of 0.911 and 1.589 GJ ton^-1 CO₂ were observed for a complete adsorption-desorption cycle on Co-HAB and Ni-HAB. All charged MOFs, especially Co-HAB and Ni-HAB, exhibited higher CO₂ adsorption energies and adsorption capacities than those of H₂ , N₂ , and CH₄ , thereby exhibiting high CO₂ selectivities. Interaction analysis confirmed that the injecting charges had a more pronounced enhancement in the coulombic interactions between CO₂ and MOFs. The results of this work highlight Co-HAB and Ni-HAB as promising charge-modulated CO₂ capture and separation materials with controllable CO₂ capture, high selectivity, and low energy consumption.

Synthesis and Characterization of Aminosilane Grafted Cellulose Nanocrystal Modified Formaldehyde-Free Decorative Paper and its CO2 Adsorption Capacity

As one of the main consumables of interior decoration and furniture, decorative paper can be seen everywhere in the indoor space. However, because of its high content of formaldehyde, it has a certain threat to people’s health. Therefore, it is necessary to develop and study new formaldehyde-free decorative paper to meet the market demand. In this work, we have obtained formaldehyde-free decorative paper with high CO₂ adsorption capacity. Here, cellulose nanocrystals (CNC) were prepared by hydrolyzing microcrystalline cellulose with sulfuric acid. The N-(2-aminoethyl) (3-amino-propyl) methyldimethoxysilane (AEAPMDS) was grafted onto the CNCs by liquid phase hydrothermal treatment, and the aqueous solution was substituted by tert-butanol to obtain aminated CNCs (AEAPMDS-CNCs). The as-prepared AEAPMDS-CNCs were applied to formaldehyde-free decorative paper by the spin-coating method. The effects of various parameters on the properties of synthetic materials were systematically studied, and the optimum reaction conditions were revealed. Moreover, the surface bond strength and abrasion resistance of modified formaldehyde-free decorative paper were investigated. The experimental results showed that AEAPMDS grafted successfully without destroying the basic morphology of the CNCs. The formaldehyde-free decorative paper coated with AEAPMDS-CNCs had high CO₂ adsorption capacity and exhibited excellent performance of veneer to plywood. Therefore, laminating the prepared formaldehyde-free decorative paper onto indoor furniture can achieve the purpose of capturing indoor CO₂ and have a highly potential use for the indoor decoration.

Intrinsic Thermal Desorption in a 3D Printed Multifunctional Composite CO2 Sorbent with Embedded Heating Capability

Efficient removal of CO₂ from enclosed environments is a significant challenge, particularly in human space flight where strict restrictions on mass and volume are present. To address this issue, this study describes the use of a multimaterial, layer-by-layer, additive manufacturing technique to directly print a structured multifunctional composite for CO₂ sorption with embedded, intrinsic, heating capability to facilitate thermal desorption, removing the need for an external heat source from the system. This multifunctional composite is coprinted from an ink formulation based on zeolite 13X, and an electrically conductive sorbent ink formulation, which includes metal particles blended with the zeolite. The composites are characterized using analytical and imaging tools and then tested for CO₂ adsorption/desorption. The resistivity of the conductive sorbent is <2 mΩ m, providing a temperature increase up to 200 °C under 7 V applied bias, which is sufficient to trigger CO₂ desorption. The CO₂ adsorption capability of the conductive zeolite ink appears to be unaffected by the presence of the conductive particles, meaning a large fraction of the total mass of the structured composite device is functional.