气流床煤气化细渣结构、性质与其粒度分布关系研究  

Study on the relationship between structure,properties and size distribution of fine slag from entrained flow gasification

作　　者：吴昊东 邵丰华 吕鹏 白永辉 宋旭东 王焦飞 郭庆华 王学斌[3] 于广锁[1,2] WU Hao-dong;SHAO Feng-hua;LÜPeng;BAI Yong-hui;SONG Xu-dong;WANG Jiao-fei;GUO Qing-hua;WANG Xue-bin;YU Guang-suo(State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering,College of Chemistry and Chemical Engineering,College of Chemistry and Chemical Engineering Ningxia University,Yinchuan 750021,China;Institute of Clean Coal Technology,East China University of Science and Technology,Shanghai 200237,China;School of Energy and Power Engineering,Xi'an Jiao tong University,Xi'an 710049,China)

机构地区：[1]宁夏大学省部共建煤炭高效利用与绿色化工国家重点实验室,宁夏银川750021 [2]华东理工大学洁净煤技术研究所,上海200237 [3]西安交通大学能源与动力工程学院,陕西西安710049

出　　处：《燃料化学学报》2022年第5期513-522,共10页Journal of Fuel Chemistry and Technology

基　　金：宁夏回族自治区重点研发计划东西部合作项目(2021BEE03011)资助~~

摘　　要：气化过程中,不同粒度颗粒的受热破裂方式、挥发分脱除行为、焦-熔渣相互作用等具有显著差异,导致所产生的不同尺寸的煤气化细渣具有不同的结构特征和反应特性,通过研究气流床煤气化细渣结构、性质与其粒度分布的关系可为溯源气化炉内细渣形成机制及入炉煤粒度优化提供重要依据。为此,本研究选用宁夏宁东典型GSP煤气化工艺细渣为原料,通过烘干、破碎、筛分处理,获取了粒度分别为<0.125、0.125–0.250、>0.250 mm的三种样品,分别称为小、中、大粒级样品,借助氮气吸附-脱附法、XRD、Raman光谱、TGA等表征分析手段对其理化结构及燃烧活性进行了研究。结果表明,不同粒级气化细渣在组成、结构及反应活性方面有显著差异,三种粒级样品在渣中所占比例分别22%、46%、32%,均含有大量的球状颗粒与不规则颗粒。其中,中粒级气化细渣气化程度最小,残炭含量最高,达19%,石墨化程度最低,仅为30%,比表面积最大,达87.8 m2/g,在不同的升温速率下综合燃烧特性指数最优,大粒级气化细渣以上性质则与其完全相反。显然,气化较充分的煤粉趋向于形成大粒级的气化细渣,气化程度较低的煤粉更易形成中粒级气化细渣,这为煤气化过程的研究提供了一定的依据。中粒级气化细渣在细渣中含量最多,且气化程度低、含碳量高,比表面积和孔隙率大,所以仍具有一定潜在的利用价值,这也为气化细渣的处理与处置提供了思路。In the process of gasification for different size of coal particles,there are remarkable differences in the cracking mode,behavior of volatile removal and coke-slag interaction.These differences lead to the discrepancies in structural characteristics and reaction behavior for fine slag.Therefore,it is considered that the study on relationship between structure,properties and size distribution of fine slag from entrained flow gasification can provide vital guidance for analyzing the formation mechanism of fine slag and optimizing the size of coal particles for gasification.For this purpose,the fine slag from Ningdong typical GSP technology in Ningxia Province was selected as a raw material.After drying,crushing and sieving,three kinds of samples with size of<0.125,0.125–0.250 and>0.250 mm were prepared,and called small,medium and large size samples respectively.The nitrogen adsorption,XRD,Raman spectroscopy and TGA were applied to clarify the physicochemical structure and combustion reactivity of samples.It is found that there are huge differences in the composition,structure or reactivity of the samples in different size.Precisely,three types of samples account for 22%,46%,and 32%respectively.All the fine slag contains a large number of spherical particles and irregular particles.The sample with the middle size particles,which has the most content of residual carbon(19%)and the lowest graphitization degree(30%),shows the slightest gasification degree.It also presents the largest specific surface area(87.8 m2/g),and the optimal combustibility index regardless of the heating rate.While,the above properties of the sample with large size particles are completely opposite.Apparently,coal gasified sufficiently tends to form fine slag in large particle size,while coal gasified insufficiently is more likely to form slag in middle particle size.To some degree,all these findings can supply a certain basis to the study of gasification process.Meanwhile,the medium-sized fine slag with the most content in fine slag has low

关 键 词：气化 煤气化细渣 粒度分布 燃烧反应性 显微结构 

分 类 号：TQ536.4[化学工程—煤化学工程]