We commercialized a methane capture technology in ten years - here's how

Recent advances in abatement of methane and sulfur hexafluoride non-CO2 greenhouse gases under dual-carbon target

With the clarification of the CO2 abatement targets and pathways, the management and control of non-CO2 greenhouse gases (GHGs) have been widely emphasized. As the potent GHGs restricted by the Kyoto Protocol, methane (CH4) and sulfur hexafluoride (SF6) emissions contribute to a significant and increasing share of the total global GHG emissions, resulting in a continuous impact on the environment. Hence, the abatement of CH4 and SF6, the potent GHGs, is a matter of urgency. This paper focuses on recent advances in abatement of lean CH4 and SF6 waste gas. Firstly, a systematic review of abatement technologies for lean CH4 is presented, and two methods, namely, pressure swing adsorption and catalytic combustion, are emphasized. Additionally, the current status of four mainstream methods such as adsorption separation, thermal (catalytic) degradation, photocatalytic degradation, and non-thermal plasma degradation, as well as emerging technologies for SF6 abatement are summarized, and the inherent shortcomings and industrialization potentials of each technology are analyzed from multiple perspectives. This review demonstrates that, under dual-carbon target, existing abatement technologies are inadequate to meet the complex and diverse demands of the power and coal industries. There are many drawbacks for lean CH4 abatement technologies such as high investment in utilization devices, low processing capacity, high operating cost and requirement of high CH4 concentration. Degradation technologies for SF6 waste gas also suffer from low energy efficiency, high investment in catalytic degradation devices, and secondary pollution of degradation products. Based on this, two large-scale processing schemes with high feasibility are proposed. Finally, the current research hotspots, challenges, and future directions are put forward. This review aims to contribute some new perspectives to the abatement efforts of non-CO2 GHGs, so that the dual-carbon target can be realized as soon as possible.

Regulating adsorption performance of zeolites by pre-activation in electric fields

While multiple external stimuli (e.g., temperature, light, pressure) have been reported to regulate gas adsorption, limited studies have been conducted on controlling molecular admission in nanopores through the application of electric fields (E-field). Here we show gas adsorption capacity and selectivity in zeolite molecular sieves can be regulated by an external E-field. Through E-field pre-activation during degassing, several zeolites exhibited enhanced CO2 adsorption and decreased CH4 and N2 adsorptions, improving the CO2/CH4 and CO2/N2 separation selectivity by at least 25%. The enhanced separation performance of the zeolites pre-activated by E-field was maintained in multiple adsorption/desorption cycles. Powder X-ray diffraction analysis and ab initio computational studies revealed that the cation relocation and framework expansion induced by the E-field accounted for the changes in gas adsorption capacities. These findings demonstrate a regulation approach to sharpen the molecular sieving capability by E-fields and open new avenues for carbon capture and molecular separations.