Modification of CaSO4 oxygen carrier by Zhundong coal ash in chemical looping gasification and its mechanism

doi:10.16085/j.issn.1000-6613.2022-2010

Chemical Industry and Engineering Progress ›› 2023, Vol. 42 ›› Issue (9): 4628-4635.DOI: 10.16085/j.issn.1000-6613.2022-2010

• Energy processes and technology • Previous Articles Next Articles

Modification of CaSO₄ oxygen carrier by Zhundong coal ash in chemical looping gasification and its mechanism

ZHU Jie¹^,²(), JIN Jing¹^,²(), DING Zhenghao¹^,², YANG Huipan¹^,², HOU Fengxiao³

^1.School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
^2.Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, Shanghai 200093, China
^3.School of Energy and Power Engineering, North University of China, Taiyuan 030051, Shanxi, China

Received:2022-10-27 Revised:2022-11-18 Online:2023-09-28 Published:2023-09-15
Contact: JIN Jing

化学链气化中准东煤灰对CaSO₄载氧体改性及其作用机理

朱杰¹^,²(), 金晶¹^,²(), 丁正浩¹^,², 杨会盼¹^,², 侯封校³

^1.上海理工大学能源与动力工程学院，上海200093
^2.上海市动力工程多相流与传热重点实验室，上海200093
^3.中北大学能源与动力工程学院，山西太原030051

通讯作者: 金晶
作者简介:朱杰（1997—），男，硕士研究生，研究方向为化学链气化。E-mail：2579936484@qq.com。
基金资助:
国家自然科学基金(51976129);山西省基础研究计划(202103021223197);上海市科委项目(23010503500)

Abstract

Abstract:

Using CaSO₄ as the oxygen carrier, the CaSO₄-Ash composite oxygen carrier modified by Jiangjunmiao coal ash was prepared by mechanical mixing method. With the TG-MS device, the chemical looping gasification reaction characteristics of composite oxygen carrier CaSO₄-Ash and Jiangjunmiao coal were investigated, and the action mechanism of Jiangjunmiao coal ash-modified CaSO₄ oxygen carrier was studied. The results showed that Jiangjunmiao coal ash had a certain modification effect on CaSO₄ oxygen carrier. At 900℃, the CaSO₄-Ash composite oxygen carrier showed good reactivity and stability compared with the pure CaSO₄ oxygen carrier. The amount of CO produced by the chemical chain gasification of the CaSO₄-Ash composite oxygen carrier increased significantly, and the yield also more stable. X-ray diffraction (XRD) analysis showed that there were a small amount of Ca₂Fe₂O₅ and Fe₂O₃ in the CaSO₄-Ash composite oxygen carrier, which were attached to the surface of CaSO₄ and promoted the effect of CaSO₄ lattice oxygen migration as an intermediary for the transport of CaSO₄ lattice oxygen. The lattice constant and lattice volume of pure CaSO₄ oxygen carrier and modified CaSO₄ oxygen carrier were calculated by Jade software, and combined with Raman and Electron Paramagnetic Resonance (EPR) characterization, the mechanism for Na⁺ to modify CaSO₄ oxygen carrier in coal ash was proved. Through Scanning Electron Microscope (SEM) test, it was found that the surface pore structure of the modified CaSO₄ oxygen carrier was clearer.

Key words: chemical looping gasification, CaSO₄ oxygen carrier, Zhundong coal, coal ash modification

摘要：

以CaSO₄为载氧体，采用机械混合法制备了将军庙煤灰修饰的CaSO₄-Ash复合载氧体。借助TG-MS考察复合载氧体CaSO₄-Ash与将军庙煤的化学链气化反应特性，并对将军庙煤灰改性CaSO₄载氧体的作用机理进行了研究。结果表明：将军庙煤灰对CaSO₄载氧体有一定的改性作用。900℃时，与纯CaSO₄载氧体相比，CaSO₄-Ash复合载氧体表现出良好的反应活性和稳定性，CaSO₄-Ash复合载氧体化学链气化产生的CO量明显增多，产率也更加稳定。X射线衍射分析表明，CaSO₄-Ash复合载氧体中存在少量的Ca₂Fe₂O₅和Fe₂O₃，它们附着在CaSO₄表面，作为CaSO₄晶格氧传输的中介，起到促进CaSO₄晶格氧迁移的效果。通过Jade软件计算纯CaSO₄载氧体和改性后的CaSO₄载氧体的晶格常数和晶格体积，并结合拉曼光谱和电子顺磁共振光谱表征，证明了煤灰中Na⁺改性CaSO₄载氧体的机理。通过扫描电子显微镜测试，发现改性后的CaSO₄载氧体表面孔径结构更加清晰。

关键词: 化学链气化, CaSO₄载氧体, 准东煤, 煤灰改性

CLC Number:

TK16

ZHU Jie, JIN Jing, DING Zhenghao, YANG Huipan, HOU Fengxiao. Modification of CaSO₄ oxygen carrier by Zhundong coal ash in chemical looping gasification and its mechanism[J]. Chemical Industry and Engineering Progress, 2023, 42(9): 4628-4635.

朱杰, 金晶, 丁正浩, 杨会盼, 侯封校. 化学链气化中准东煤灰对CaSO₄载氧体改性及其作用机理[J]. 化工进展, 2023, 42(9): 4628-4635.

Figures/Tables 11

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工业分析/%				元素分析/%					放热量 /kJ·kg^-1
M	A	V	FC	C	H	O	N	S	放热量 /kJ·kg^-1
5.64	5.09	27.24	62.03	63.78	4.42	19.21	1.00	0.87	30517

工业分析/%				元素分析/%					放热量 /kJ·kg^-1
M	A	V	FC	C	H	O	N	S	放热量 /kJ·kg^-1
5.64	5.09	27.24	62.03	63.78	4.42	19.21	1.00	0.87	30517

煤种	成分质量分数
煤种	Na₂O	K₂O	CaO	Fe₂O₃	MgO	Al₂O₃	SiO₂	SO₃
准东将军庙煤	8.9	0.25	15.8	17.9	5.3	6.1	7.68	30.7

煤种	成分质量分数
煤种	Na₂O	K₂O	CaO	Fe₂O₃	MgO	Al₂O₃	SiO₂	SO₃
准东将军庙煤	8.9	0.25	15.8	17.9	5.3	6.1	7.68	30.7

样品	a/Å	b/Å	c/Å	V/Å
纯CaSO₄	6.998	6.992	6.238	305.29
改性后CaSO₄	6.984	6.967	6.229	303.13