Confinement-enhanced integrated CO2 capture and in-situ conversion from high-temperature flue gas to syngas over Ni-MgO/CaO hollow microsphere
JIA Zhonghao
SHAO Bin
XIE Zhicheng
HU Jun
Abstract：CO2 capture and in-situ conversion(iCCC)technology can play a crucial role in mitigating global climate change.When the iCCC technology is applied to the CO2 capture from the high-temperature flue gas,its thermo-energy can be directly converted CO2 into the syngas during CO2 conversion at the same fixed bed.The rational design of efficient dual functional materials(DFMs)is key to achieve high-efficiency iCCC processes.Here,we synthesized a series of xNi-MgO/CaO DFMs with varying Ni/Mg ratios by a hard template method using NaOH-activated porous carbon spheres.The structure of the hollow microsphere not only reduces the diffusion resistance during CO2 adsorption but also provides buffer space to accommodate the volume expansion of CaO/CaCO3 during the iCCC process.In addition,the NiO-MgO solid solution formed within the confined space of the hollow microspheres acts as a physical barrier,isolating the catalytic Ni0 particles and effectively preventing the sintering of Ni nanoparticle at high temperatures.By optimizing the Ni/Mg ratio,reaction temperature,and H2 concentration,the iCCC performance of the xNi-MgO/CaO DFMs were evaluated.Under the optimal reaction temperature of 650℃and H2 concentration of 10%,the 10Ni-MgO/CaO DFM exhibited a CO2 adsorption capacity of 10 mmol/g,a CO2 conversion efficiency above 94%with a 100%CO selectivity after 10 adsorption-conversion cycles.Kinetic studies further demonstrated that the confined space in the Ni-MgO/CaO DFM significantly enhances the reaction rates of iCCC to syngas.
Keywords：hollow microspheresconfined spacedual-functional materialsCO2 capture and in-situ conversionsyngas
Publication Date：2025-06-30
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 25-35 )