燃烧和反应

Flow Properties of Entrained Flow Gasifier Fine Slag and Network Structure of its Molten Slag

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  • 1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China

网络出版日期: 2023-10-24

基金资助

This work was financially supported by Class A Strategic Pilot Science and Technology Project, Chinese Academy of Sciences (Grant No. XDA21040602), the National Natural Science Foundation of China (Grant No. U1810127) and the Youth Innovation Promotion Association, Chinese Academy of Science (Grant No. Y201932).

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Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2023

Flow Properties of Entrained Flow Gasifier Fine Slag and Network Structure of its Molten Slag

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  • 1. Institute of Engineering Thermophysics, Chinese Academy of Sciences, Beijing 100190, China
    2. University of Chinese Academy of Sciences, Beijing 100049, China

Online published: 2023-10-24

Supported by

This work was financially supported by Class A Strategic Pilot Science and Technology Project, Chinese Academy of Sciences (Grant No. XDA21040602), the National Natural Science Foundation of China (Grant No. U1810127) and the Youth Innovation Promotion Association, Chinese Academy of Science (Grant No. Y201932).

Copyright

Science Press, Institute of Engineering Thermophysics, CAS and Springer-Verlag GmbH Germany, part of Springer Nature 2023

摘要

现代煤化工产业是煤炭清洁利用的重要途径。在我国,煤化工产业规模每年以25%-30%的复合增长率快速增长,其促进了能源生产和消费升级并维护了国民经济健康发展。煤气化作为煤化工产业链的龙头技术,是煤化工发展的关键过程之一。煤气化细渣是煤经过气流床气化的副产物,其中的残碳虽然具有潜在的利用价值,但是其挥发分含量低,且灰分会包裹残碳,对残碳的进一步利用造成挑战。此外,残碳的存在也会阻碍灰分的进一步资源化利用,所以,完成煤气化灰渣的炭灰分离是实现其资源化利用的第一步。中国科学院工程热物理研究所提出采用流化熔融技术来实现煤气化细渣的炭灰分离,先对煤气化细渣进行流态化改性以改善残碳的燃烧性能,然后再将改性产物燃烧脱碳,燃烧释放的热量将灰分熔融转变为液态的熔体,熔体先以液态的形式排出炉膛外在对其水淬冷却从而获得高玻璃相含量的熔渣。在流化熔融工艺处置煤气化细渣过程中,煤气化细渣的熔融特性直接关系到系统运行温度的选择,熔融之后熔体冷却过程中黏度随温度的变化则关系到系统能否顺利液态排渣。因此,了解煤气化细渣的熔融特性和黏温特性是实现煤气化细渣流化熔融的基础。此外,明确熔渣的基本特性,根据其特性制备合适的高值化利用,才能实现煤气化细渣的资源利用最大化。本文选取了三种典型的煤气化细渣,通过热机械分析仪(TMA)、高温旋转粘度仪和FactSage对煤气化细渣的流动特性,包括熔融特性和黏温特性进行了研究。然后在水平管式炉上将煤气化细渣熔融以获取熔渣,利用X射线衍射(XRD)、X射线光电子能谱(XPS)和傅里叶变换红外光谱(FTIR)检测手段及数据拟合分析手段,研究了熔渣中的硅铝酸盐网络结构和熔渣的网络聚合度。

本文引用格式

ZHOU Li, REN Qiangqiang, YANG Guiyun, XU Jing, LI Wei . Flow Properties of Entrained Flow Gasifier Fine Slag and Network Structure of its Molten Slag[J]. 热科学学报, 2023 , 32(5) : 1878 -1888 . DOI: 10.1007/s11630-023-1874-z

Abstract

The entrained flow gasification has been identified as the most promising gasification technology. Serious environmental pollution and waste of land resources are caused by the increasing amount of storage and production of coal gasification slag. The aim of this work is to explore the feasibility of high-temperature combustion and melting technology for treating coal gasification fine slag and determine the important parameters of system operation. The flow properties and molten slag structure characteristics of three fine slags from different entrained flow gasifiers were studied. Depending on the melting mechanism of melt-dissolution, the melting time of fine slags is short. Three fine slags all produce glassy slags, which is conducive to slag discharge. The degree of polymerization of silicate melt is proportionate to the amount of SiO2 in the slag. A part of Al3+ exist in the form of [AlO4]5– because of the effect of CaO and Na2O, as the network former. Finally, the degree of polymerization of the three type molten slag was calculated by considering the role of Si and Al in molten slag and the property of each one.

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