基于高炉渣余热回收的生物质气化实验研究
发布时间：2018-07-18 15:57
【摘要】：高炉渣是钢铁生产过程的主要副产品,是一种多元金属熔体,具有大量显热并能促进焦油及甲烷等低分子碳氢化合物的催化转化。本研究提出采用干法离心粒化技术将液态炉渣制备成液-固过渡态的高温炉渣颗粒,作为生物质气化热载体,同时利用炉渣中多种金属矿物对大分子的解构、断键和分解的催化作用,提高气化反应的选择性,实现对炉渣显热的回收和转换,将低品位的液态炉渣余热转换成高品位的氢能。为此,在总结前期课题组研究工作基础上,围绕该工艺的构建,开展高炉渣热载体催化气化生物质的机理研究,提出了本研究主要内容:以干法离心粒化方法制备的高炉渣颗粒作为生物质催化气化制氢的热载体和催化剂,以移动床气化装置为实验平台,对高炉渣和生物质异质混合颗粒的在移动床气化炉内的运动状态和传热规律进行探讨,结果表明:异质颗粒在移动床反应器内的运动分为密相堆积流动和充分混合流动两个阶段;可采用球壳传热模型对颗粒间的传热过程进行描述,分别建立了平推流动阶段和充分混合流动阶段的传热计算方程;对高炉渣的催化性能进行评价,明确提高生物质燃气中氢气含量和产率的最佳工艺条件,结果表明:高炉渣在促进焦油分解和碳氢化合物重整方面表现出良好的催化性能,增加热载体炉渣颗粒温度,减小颗粒粒径能够减小炉渣表面积碳,降低气化产物中焦油产率和提升富氢气体品质,在最佳工况下(选用粒径小于2mm,温度为1200℃的高炉渣颗粒作为热载体),气化产物中焦油含量仅为2.52%,气体产率达到1.65Nm3/kg,富氢气体中H2含量可达53.22%;通过分析反应过程中各种原料、和主、副产品(焦油和灰分)成分及产量的数据建立质量平衡;以物料平衡计算为基础,结合能量守恒定律,对进出系统的物料的焓差或热力学能进行计算,推导出能量平衡关系。结果表明:研发的以高炉渣为热载体的生物质气化系统能源回收效率约为51.44%,能耗比约为1.86。
[Abstract]:Blast furnace slag is a kind of polymetallic melt which is the main by-product of iron and steel production. It has a lot of sensible heat and can promote the catalytic conversion of low molecular hydrocarbons such as tar and methane. In this paper, a dry centrifuge granulation technique is proposed to prepare liquid slag particles from liquid to solid transition state as heat carrier of biomass gasification, and to destruct macromolecules by using a variety of metal minerals in slag. The catalytic action of broken bond and decomposition can improve the selectivity of gasification reaction, realize the recovery and conversion of sensible heat of slag, and convert the waste heat of low-grade liquid slag into high-grade hydrogen energy. Therefore, on the basis of summarizing the previous research work, the mechanism of biomass gasification catalyzed by heat carrier of blast furnace slag was studied around the construction of the process. The main contents of this study are as follows: the blast furnace slag particles prepared by dry centrifugal granulation are used as the heat carrier and catalyst for hydrogen production from biomass catalytic gasification, and the moving bed gasification unit is used as the experimental platform. The moving state and heat transfer law of mixed particles of blast furnace slag and biomass in moving bed gasifier are discussed. The results show that the motion of heterogeneous particles in a moving bed reactor can be divided into two stages: dense stacking flow and fully mixed flow, and the spherical shell heat transfer model can be used to describe the heat transfer process between particles. The calculation equations of heat transfer in the phase of flat-push flow and the stage of full mixing flow were established, the catalytic performance of blast furnace slag was evaluated, and the optimum technological conditions for increasing hydrogen content and yield of biomass gas were determined. The results show that the blast furnace slag has good catalytic performance in promoting tar decomposition and hydrocarbon reforming. Increasing the particle temperature of heat carrier slag and reducing the particle size can reduce the carbon surface area of slag. Reducing the tar yield in gasification products and improving the quality of hydrogen rich body, Under the optimum conditions (using blast furnace slag particles with diameter less than 2mm and temperature of 1200 鈩，
本文编号：2132406
[Abstract]:Blast furnace slag is a kind of polymetallic melt which is the main by-product of iron and steel production. It has a lot of sensible heat and can promote the catalytic conversion of low molecular hydrocarbons such as tar and methane. In this paper, a dry centrifuge granulation technique is proposed to prepare liquid slag particles from liquid to solid transition state as heat carrier of biomass gasification, and to destruct macromolecules by using a variety of metal minerals in slag. The catalytic action of broken bond and decomposition can improve the selectivity of gasification reaction, realize the recovery and conversion of sensible heat of slag, and convert the waste heat of low-grade liquid slag into high-grade hydrogen energy. Therefore, on the basis of summarizing the previous research work, the mechanism of biomass gasification catalyzed by heat carrier of blast furnace slag was studied around the construction of the process. The main contents of this study are as follows: the blast furnace slag particles prepared by dry centrifugal granulation are used as the heat carrier and catalyst for hydrogen production from biomass catalytic gasification, and the moving bed gasification unit is used as the experimental platform. The moving state and heat transfer law of mixed particles of blast furnace slag and biomass in moving bed gasifier are discussed. The results show that the motion of heterogeneous particles in a moving bed reactor can be divided into two stages: dense stacking flow and fully mixed flow, and the spherical shell heat transfer model can be used to describe the heat transfer process between particles. The calculation equations of heat transfer in the phase of flat-push flow and the stage of full mixing flow were established, the catalytic performance of blast furnace slag was evaluated, and the optimum technological conditions for increasing hydrogen content and yield of biomass gas were determined. The results show that the blast furnace slag has good catalytic performance in promoting tar decomposition and hydrocarbon reforming. Increasing the particle temperature of heat carrier slag and reducing the particle size can reduce the carbon surface area of slag. Reducing the tar yield in gasification products and improving the quality of hydrogen rich body, Under the optimum conditions (using blast furnace slag particles with diameter less than 2mm and temperature of 1200 鈩，
本文编号：2132406
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