高炉煤气源头脱硫催化反应过程的介尺度调控机制及工业应用

The “desulfurization at source” of blast furnace gas can solve the problems of traditional desulfurization process such as the complexity of “multi-unit desulfurization”, the large amount of solid waste and the difficulty to meet the ultra-low sulfur emission standard of iron and steel industry. This project innovatively puts forward the idea of “desulfurization at source” for blast furnace gas with structured base center on hydrotalcite (LDHs) for catalytic carbonyl sulfur hydrolysis, and hydrotalcite derived Cu sulfides (LDO) for H2S removal, focusing on solving the mesoscale problems of gas-solid interface on the catalysts and the packed pore structure in the reactor. The competitive adsorption mechanism of COS and H2O on LDHs and the matching mechanism of sulfide reduction catalytic cycle on Cu- LDO are elucidated, and the coordination mechanism of fluid flow and external diffusion in the catalyst bed is revealed. Microkinetics models, which include the mesoscale structure of the gas-solid interface, and particle resolved computational fluid dynamics reactor models, which include the mesoscale structure of the packed pores, are developed. A reaction-diffusion model is developed for the catalyst pellets to bridge the two levels of mesoscale. An efficient desulfurization catalytic reactor of 100 cubic meters in size is to be developed, and a new set of desulfurization technology is established and will be applied in an iron and steel company with a production capacity of two million tons/year.

高炉煤气“源头脱硫”可解决传统“多单元脱硫”工艺复杂、固废多、难以达到钢铁行业超低排放标准等难题，其工业应用关键在于高效催化反应过程的开发。本项目创新性提出水滑石（LDHs）结构化碱中心催化羰基硫（COS）水解串联水滑石衍生含Cu氧化物（Cu/LDO）硫化-还原催化循环的高炉煤气“源头脱硫”思路，重点解决气-固界面和异形催化剂堆积空隙结构两个层次介尺度问题。阐明COS与H2O在LDHs上的竞争吸附机制和H2S在Cu/LDO上的硫化-还原催化循环匹配机制，揭示异形催化剂堆积空隙结构对流动-扩散-反应过程的影响规律；建立包含气-固界面和异形催化剂堆积空隙介尺度结构的微观动力学和颗粒分辨计算流体力学反应器模型，发展气-固界面和异形催化剂堆积空隙结构两个层次介尺度之间关联的理论与方法。设计开发高效脱硫催化反应器，形成高炉煤气前脱硫成套新技术，率先在200万吨/年钢铁企业实现百立方级反应器工业应用。

项目针对高炉煤气传统“多单元脱硫”工艺复杂、固废多、难以达到钢铁行业超低排放标准等难题，创新性提出水滑石（LDHs）结构化碱中心催化羰基硫（COS）水解串联Cu氧化物硫化-还原催化循环的高炉煤气“源头脱硫”思路，重点研究气-固界面和异形催化剂堆积空隙结构两个层次介尺度问题。创制了表界面结构可调的高效COS水解LDHs等催化材料，研究了气-固界面COS、H2O的吸附-活化态、分布及其演变规律，理解了COS水解反应介尺度机制及其对反应定向性的调控；精准调控了金属氧化物催化剂表面结构，研究了H2S和CO与CuOx的气-固界面吸附-活化态、分布及其演变规律，探究了CuOx上硫化-还原催化循环反应中表界面介尺度结构的形成机理以及硫化-还原催化循环的竞争调和机制；建立了可以准确描述固定床反应器中催化剂颗粒堆积结构的计算流体力学模型及从活性位到催化剂颗粒再到固定床反应器的跨尺度数学模型，利用该模型优化了催化剂的孔结构和颗粒外形；发展了催化剂放大制备技术，建成了年产千吨级脱硫催化剂剂生产线，完成了500 m3脱硫催化剂生产，建成了COS水解串联H2S脱除硫化-还原催化循环“源头脱硫”新技术的百立方级工业反应装置，实现了在年产230万吨级钢铁企业中的重大工业应用。