Abstract Using solid waste carbide slag (CS) as a calcium precursor and silicon nitride (Si3N4) as a new inert dopant, a series of calcium oxide (CaO)-based adsorbents were prepared by a simple dry mixing method and high temperature CO2 cyclic adsorption property was tested in a thermogravimetric analyzer (TGA). A lot of matters were studied in this work like the effects of Si3N4 type, dopant content, pre-calcination conditions, CO2 concentration and long-term cycles on CO2 adsorption property. The phase composition, surface morphology and surface area of the adsorbents were characterized by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Nitrogen Physisorption analyses. The cyclic conversion experiments of three kinds of Si3N4 such as α-Si3N4, β-Si3N4 and the self-prepared Si3N4 by sol-gel method showed that the adsorbents doped with the self-prepared Si3N4 had a superior cyclic adsorption property (68.34 % after 10 cycles). The calcined CS (CCS) doped with 5 wt.% self-prepared Si3N4, pre-calcined at 850 °C for 4 h (CCS-Si3N4-5-4-850) exhibited a higher conversion (>70 % after 10 cycles, 57.09 % after 20 cycles). The incorporation of Si3N4 inhibited the sintering between the adsorbent particles, which is in favor of enhancing the cyclic adsorption durability. The adsorption kinetics showed that the activation energies of CCS-Si3N4-5-4-850 chemisorption and diffusion were estimated to be 68.17 kJ/mol and 102.34 kJ/mol, respectively, which are consistent with the actual adsorption process.

中文翻译：

---

掺杂氮化硅的煅烧电石渣循环捕集CO2的研究及动力学分析

摘要 以固体废电石渣（CS）为钙前驱体，氮化硅（Si3N4）为新型惰性掺杂剂，采用简单干混法和高温CO2循环吸附法制备了一系列氧化钙（CaO）基吸附剂。在热重分析仪 (TGA) 中测试性能。研究了Si3N4类型、掺杂剂含量、预煅烧条件、CO2浓度和长期循环对CO2吸附性能的影响等诸多问题。吸附剂的相组成、表面形态和表面积通过 X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和氮物理吸附分析进行表征。α-Si3N4等三种Si3N4的循环转化实验，β-Si3N4 和溶胶-凝胶法制备的Si3N4 表明掺杂自制备Si3N4 的吸附剂具有优异的循环吸附性能（10 次循环后达到68.34%）。掺杂 5 wt.% 自制备 Si3N4 的煅烧 CS (CCS)，在 850 °C 下预煅烧 4 小时（CCS-Si3N4-5-4-850）表现出更高的转化率（10 次循环后 >70%， 20 个循环后为 57.09 %）。Si3N4 的加入抑制了吸附剂颗粒之间的烧结，有利于提高循环吸附耐久性。吸附动力学表明CCS-Si3N4-5-4-850化学吸附和扩散的活化能分别为68.17 kJ/mol和102.34 kJ/mol，与实际吸附过程一致。掺杂 5 wt.% 自制备 Si3N4 的煅烧 CS (CCS)，在 850 °C 下预煅烧 4 小时（CCS-Si3N4-5-4-850）表现出更高的转化率（10 次循环后 >70%， 20 个循环后为 57.09 %）。Si3N4 的加入抑制了吸附剂颗粒之间的烧结，有利于提高循环吸附耐久性。吸附动力学表明，CCS-Si3N4-5-4-850化学吸附和扩散的活化能分别为68.17 kJ/mol和102.34 kJ/mol，与实际吸附过程一致。掺杂有 5 wt.% 自制备 Si3N4 的煅烧 CS (CCS)，在 850 °C 下预煅烧 4 小时（CCS-Si3N4-5-4-850）表现出更高的转化率（10 次循环后 >70%， 20 个循环后为 57.09 %）。Si3N4 的加入抑制了吸附剂颗粒之间的烧结，有利于提高循环吸附耐久性。吸附动力学表明，CCS-Si3N4-5-4-850化学吸附和扩散的活化能分别为68.17 kJ/mol和102.34 kJ/mol，与实际吸附过程一致。有利于提高循环吸附耐久性。吸附动力学表明，CCS-Si3N4-5-4-850化学吸附和扩散的活化能分别为68.17 kJ/mol和102.34 kJ/mol，与实际吸附过程一致。有利于提高循环吸附耐久性。吸附动力学表明，CCS-Si3N4-5-4-850化学吸附和扩散的活化能分别为68.17 kJ/mol和102.34 kJ/mol，与实际吸附过程一致。