An approach to the simultaneous reclamation of carbon and sulfur resources from CO_2 and H_2S has been proposed and effectively implemented with the aid of catalysts. A brief thermodynamic study reveals the potential of direct reduction of CO_2 with H_2S(15:15 mol% balanced with N_2) for selective production of CO and elemental sulfur. The experiments carried out in a fixed-bed flow reactor over the temperature range of 400–800 °C give evidence of the importance of the employment of catalysts. Both the conversions of the reactants and the selectivities of the target products can be substantially promoted over most catalysts studied. Nevertheless, little difference appears among their catalytic performance. The results also prove that the presence of CO_2 can remarkably enhance H_2S conversion and the sulfur yield in comparison with H_2S direct decomposition. A longtime reaction test on Mg O catalyst manifests its superior durability at high temperature(700 °C) and huge gas hourly space velocity(100,000 h-1). Free radicals initiated by catalysts are supposed to dominate the reactions between CO_2 and H_2S.
采用幂函数型动力学模型,对十氢萘气相脱氢实验数据进行非线性最小二乘拟合,得到关于十氢萘反应级数为0.585,活化能为59.012 k J/mol的动力学方程。对同心套管式反应器中十氢萘气相脱氢和氢气催化燃烧的耦合反应进行了理论研究,分析并排除了脱氢反应催化剂颗粒内及气固相间传质及传热阻力影响,建立了一维拟均相稳态反应器模型,考察了进料空气氢气比例、脱氢侧和烧氢侧进口流量、并逆流方式对反应器性能的影响。最终设计出1.7 L的反应器单元,反应器理论产氢速率达7.69 mmol/s,可满足1 k W的燃料电池发电供氢需求。
