熔融金属法甲烷裂解制氢和碳材料研究进展

doi:10.16085/j.issn.1000-6613.2022-0902

摘要/Abstract

摘要：

熔融金属法甲烷裂解技术作为近年来新兴的制氢技术，有效地解决了传统甲烷热裂解或催化裂解高能耗、低转化率以及催化剂失活等问题，避免了甲烷蒸汽重整制氢工艺高碳排放。在制氢的同时还能生产出具有附加值的碳产品，因而受到各方广泛关注。本文总结了熔融金属法甲烷裂解技术研究进展，并围绕工艺流程、反应机理、熔融介质的选择以及反应器设计等方面展开，给出了液相介质是否起催化作用的两类甲烷裂解反应机理，并详细阐述了熔融介质选择原则、发展趋势以及不同类型熔融介质的优缺点。再者，技术经济性以及温室气体减排量也在文中详细体现，进一步论证了该工艺的可行性和潜在效益。此外，文中还给出了未来技术发展趋势和建议，指出调控碳材料形貌，使之向高附加值碳材料转变应是未来重点发展方向之一。

关键词: 熔融金属, 熔融盐, 甲烷, 热解, 氢, 碳产品

Abstract:

Molten metal methane pyrolysis is an emerging hydrogen production technology in recent years. Compared with conventional methane pyrolysis and catalytic pyrolysis, it effectively overcomes the problems of high energy consumption, low conversion and catalyst deactivation, and also avoids the high carbon emission as in steam methane reforming technology. The ability to produce value-added solid carbon products along with hydrogen has attracted extensive attention. This article summarizes the latest research and development of methane pyrolysis based on molten metal technology, focusing on the process flow, reaction mechanism, selection of molten medium and rector design etc. We also propose two types of potential reaction mechanisms for elucidating whether the liquid medium plays a catalytic role in methane pyrolysis. Moreover, the selection principle, trends in the development, benefits and drawbacks of different types of molten media are comprehensively elaborated. And the technical economy and greenhouse gas emission reduction also have been discussed, which further demonstrates the feasibility and potential benefits of the process. Finally, suggestions for future technological improvements are presented, and we points out morphology regulation of carbon materials to facilitate transformation into high-value-added products should inevitably become one of the key development directions in the future.

Key words: molten metal, molten salt, methane, pyrolysis, hydrogen, solid carbon products

中图分类号:

TE09

何阳东, 常宏岗, 王丹, 陈昌介, 李雅欣. 熔融金属法甲烷裂解制氢和碳材料研究进展[J]. 化工进展, 2023, 42(3): 1270-1280.

HE Yangdong, CHANG Honggang, WANG Dan, CHEN Changjie, LI Yaxin. Development of methane pyrolysis based on molten metal technology for coproduction of hydrogen and solid carbon products[J]. Chemical Industry and Engineering Progress, 2023, 42(3): 1270-1280.

图/表 12

参考文献 43

1	ABÁNADES A, RUBBIA C, SALMIERI D. Thermal cracking of methane into Hydrogen for a CO₂-free utilization of natural gas[J]. International Journal of Hydrogen Energy, 2013, 38(20): 8491-8496.
2	HE Yangdong, ZHU Lin, FAN Junming, et al. Life cycle assessment of CO₂ emission reduction potential of carbon capture and utilization for liquid fuel and power cogeneration[J]. Fuel Processing Technology, 2021, 221: 106924.
3	HE Yangdong, ZHU Lin, LI Luling, et al. Hydrogen and power cogeneration based on chemical looping combustion: is it capable of reducing carbon emissions and the cost of production?[J]. Energy & Fuels, 2020, 34(3): 3501-3512.
4	NOH Y G, LEE Y J, KIM J, et al. Enhanced efficiency in CO₂-free hydrogen production from methane in a molten liquid alloy bubble column reactor with zirconia beads[J]. Chemical Engineering Journal, 2022, 428: 131095.
5	ABÁNADES A, RUIZ E, FERRUELO E M, et al. Experimental analysis of direct thermal methane cracking[J]. International Journal of Hydrogen Energy, 2011, 36(20): 12877-12886.
6	SERBAN M, LEWIS M A, MARSHALL C L, et al. Hydrogen production by direct contact pyrolysis of natural gas[J]. Energy & Fuels, 2003, 17(3): 705-713.
7	AO Dongyi, TANG Yongliang, XU Xiaofeng, et al. Highly conductive PDMS composite mechanically enhanced with 3D-graphene network for high-performance EMI shielding application[J]. Nanomaterials (Basel, Switzerland), 2020, 10(4): 768.
8	GEIßLER T, ABÁNADES A, HEINZEL A,et al. Hydrogen production via methane pyrolysis in a liquid metal bubble column reactor with a packed bed[J]. Chemical Engineering Journal, 2016, 299: 192-200.
9	CHEN C J, BACK M H, BACK R A. The thermal decomposition of methane. Ⅱ. Secondary reactions, autocatalysis and carbon formation; non-Arrhenius behaviour in the reaction of CH₃ with ethane[J]. Canadian Journal of Chemistry, 1976, 54(20): 3175-3184.
10	CHEN C J, BACK M H, BACK R A. Mechanism of the thermal decomposition of methane[J]. ACS Symposium Series, 1976(32): 1-16.
11	ROSCOE J M, THOMPSON M J. Thermal decomposition of methane: Autocatalysis[J]. International Journal of Chemical Kinetics, 1985, 17(9): 967-990.
12	KHAN M S, CRYNES B L. Survey of recent methane pyrolysis literature[J]. Industrial & Engineering Chemistry, 1970, 62(10): 54-59.
13	KEVORKIAN V, HEATH C E, BOUDART M. The decomposition of methane in shock waves[J]. The Journal of Physical Chemistry, 1960, 64(8): 964-968.
14	KOZLOV G I, KNORRE V G. Single-pulse shock tube studies on the kinetics of the thermal decomposition of methane[J]. Combustion and Flame, 1962, 6: 253-263.
15	CHEN Q Q, LUA A C. Kinetic reaction and deactivation studies on thermocatalytic decomposition of methane by electroless nickel plating catalyst[J]. Chemical Engineering Journal, 2020, 389: 124366.
16	WANG Jiaofei, LI Xiaoming, ZHOU Yang, et al. Mechanism of methane decomposition with hydrogen addition over activated carbon via in-situ pyrolysis-electron impact ionization time-of-flight mass spectrometry[J]. Fuel, 2020, 263: 116734.
17	YADAV M D, DASGUPTA K, PATWARDHAN A W, et al. Kinetic study of single-walled carbon nanotube synthesis by thermocatalytic decomposition of methane using floating catalyst chemical vapour deposition[J]. Chemical Engineering Science, 2019, 196: 91-103.
18	WANG K, LI W S, ZHOU X P. Hydrogen generation by direct decomposition of hydrocarbons over molten magnesium[J]. Journal of Molecular Catalysis A: Chemical, 2008, 283(1/2): 153-157.
19	ZHOU Lu, ENAKONDA L R, HARB M, et al. Fe catalysts for methane decomposition to produce hydrogen and carbon nano materials[J]. Applied Catalysis B: Environmental, 2017, 208: 44-59.
20	PLEVAN M, GEIßLER T, ABÁNADES A, et al. Thermal cracking of methane in a liquid metal bubble column reactor: Experiments and kinetic analysis[J]. International Journal of Hydrogen Energy, 2015, 40(25): 8020-8033.
21	TANG Yongliang, PENG Peng, WANG Shuangyue, et al. Continuous production of graphite nanosheets by bubbling chemical vapor deposition using molten copper[J]. Chemistry of Materials, 2017, 29(19): 8404-8411.
22	ZENG J R, TARAZKAR M, PENNEBAKER T, et al. Catalytic methane pyrolysis with liquid and vapor phase tellurium[J]. ACS Catalysis, 2020, 10(15): 8223-8230.
23	PÉREZ B J L, MEDRANO JIMÉNEZ J A, BHARDWAJ R, et al. Methane pyrolysis in a molten gallium bubble column reactor for sustainable hydrogen production: Proof of concept & techno-economic assessment[J]. International Journal of Hydrogen Energy, 2020, 46(7): 4917-4935.
24	UPHAM D C, AGARWAL V, KHECHFE A, et al. Catalytic molten metals for the direct conversion of methane to hydrogen and separable carbon[J]. Science, 2017, 358(6365): 917-921.
25	PALMER C, BUNYAN E, GELINAS J, et al. CO₂-Free hydrogen production by catalytic pyrolysis of hydrocarbon feedstocks in molten Ni-Bi[J]. Energy & Fuels, 2020, 34(12): 16073-16080.
26	敖东羿. 多层高品质石墨烯的大量制备及其应用研究[D]. 成都: 电子科技大学, 2020.
	AO Dongyi. Study on massive production of multilayer high-quality graphene and its applications[D]. Chengdu: University of Electronic Science and Technology of China, 2020.
27	PALMER C, TARAZKAR M, KRISTOFFERSEN H H, et al. Methane pyrolysis with a molten Cu-Bi alloy catalyst[J]. ACS Catalysis, 2019, 9(9): 8337-8345.
28	RIEDEWALD F, SOUSA-GALLAGHER M. Novel waste printed circuit board recycling process with molten salt[J]. Methods X, 2015, 2: 100-106.
29	RAHIMI N, KANG D, GELINAS J, et al. Solid carbon production and recovery from high temperature methane pyrolysis in bubble columns containing molten metals and molten salts[J]. Carbon, 2019, 151: 181-191.
30	WICHTERLE K. Breakup of gas bubbles rising in molten metals[J]. Steel Research International, 2010, 81(5): 356-361.
31	KANG D, RAHIMI N, GORDON M J, et al. Catalytic methane pyrolysis in molten MnCl₂-KCl[J]. Applied Catalysis B: Environmental, 2019, 254: 659-666.
32	KANG D, PALMER C, MANNINI D, et al. Catalytic methane pyrolysis in molten alkali chloride salts containing iron[J]. ACS Catalysis, 2020, 10(13): 7032-7042.
33	PARKINSON B, PATZSCHKE C F, NIKOLIS D, et al. Methane pyrolysis in monovalent alkali halide salts: Kinetics and pyrolytic carbon properties[J]. International Journal of Hydrogen Energy, 2021, 46(9): 6225-6238.
34	PARKINSON B, TABATABAEI M, UPHAM D C, et al. Hydrogen production using methane: Techno-economics of decarbonizing fuels and chemicals[J]. International Journal of Hydrogen Energy, 2018, 43(5): 2540-2555.
35	芶富均, 陈建军, 叶宗标, 等. 一种催化辅助甲烷裂解制氢的设备: CN113213423A[P]. 2021-08-06.
	GOU Fujun, CHEN Jianjun, YE Zongbiao,et al. Catalysis-assisted methane cracking hydrogen production equipment: CN113213423A[P]. 2021-08-06.
36	KUDINOV I V, PIMENOV A A, KRYUKOV Y A, et al. A theoretical and experimental study on hydrodynamics, heat exchange and diffusion during methane pyrolysis in a layer of molten tin[J]. International Journal of Hydrogen Energy, 2021, 46(17): 10183-10190.
37	PARKINSON B, MATTHEWS J W, MCCONNAUGHY T B, et al. Techno-economic analysis of methane pyrolysis in molten metals: Decarbonizing natural gas[J]. Chemical Engineering & Technology, 2017, 40(6): 1022-1030.
38	TIMMERBERG S, KALTSCHMITT M, FINKBEINER M. Hydrogen and hydrogen-derived fuels through methane decomposition of natural gas-GHG emissions and costs[J]. Energy Conversion and Management: X, 2020, 7: 100043.
39	ABÁNADES A, RATHNAM R K, GEIßLER T, et al. Development of methane decarbonisation based on liquid metal technology for CO₂-free production of hydrogen[J]. International Journal of Hydrogen Energy, 2016, 41(19): 8159-8167.
40	STEINBERG M. Fossil fuel decarbonization technology for mitigating global warming[J]. International Journal of Hydrogen Energy, 1999, 24(8): 771-777.
41	RODAT S, ABÁNADS S, FLAMANT G. Co-production of hydrogen and carbon black from solar thermal methane splitting in a tubular reactor prototype[J]. Solar Energy, 2011, 85(4): 645-652.
42	DUFOUR J, GÁLVEZ J L, SERRANO D P, et al. Life cycle assessment of hydrogen production by methane decomposition using carbonaceous catalysts[J]. International Journal of Hydrogen Energy, 2010, 35(3): 1205-1212.
43	POSTELS S, ABÁNADES A, VON DER ASSEN N, et al. Life cycle assessment of hydrogen production by thermal cracking of methane based on liquid-metal technology[J]. International Journal of Hydrogen Energy, 2016, 41(48): 23204-23212.

熔融介质	装载高度/mm	纯化方式^①	C/%	Ni/%	Bi/%	Na/%	K/%	Br/%
NiBi	350	—	17.36	12.98	69.66	—	—	—
NiBi	350	真空加热	51.82	1.84	46.34	—	—	—
NiBi	350	酸洗	58.81	4.09	37.10	—	—	—
NiBi/KBr	110/110	水洗+真空加热	85.63	0.82	1.10	—	3.73	8.72
NiBi/KBr	240/110	水洗	85.68	0.22	0.66	—	4.38	9.06
NiBi/KBr	240/110	水洗+真空加热	98.22	0.23	0.32	—	0.36	0.87
NiBi/KBr	110/240	水洗	74.19	0.06	0.42	—	8.07	17.26
NiBi/KBr	110/240	水洗+真空加热	88.47	0.10	0.00	—	3.60	7.83
NiBi/KBr	110/240	水洗+酸洗	84.63	0	0.00	—	4.98	10.39
NiBi/NaBr	110/240	水洗	95.06	0.18	0.56	1.06	—	3.14
NiBi/NaBr	110/240	水洗+真空加热	97.40	0.18	0.00	0.59	—	1.83
NiBi/NaBr	110/240	水洗+酸洗	97.34	0	0.00	1.15	—	1.51

熔融介质	装载高度/mm	纯化方式^①	C/%	Ni/%	Bi/%	Na/%	K/%	Br/%
NiBi	350	—	17.36	12.98	69.66	—	—	—
NiBi	350	真空加热	51.82	1.84	46.34	—	—	—
NiBi	350	酸洗	58.81	4.09	37.10	—	—	—
NiBi/KBr	110/110	水洗+真空加热	85.63	0.82	1.10	—	3.73	8.72
NiBi/KBr	240/110	水洗	85.68	0.22	0.66	—	4.38	9.06
NiBi/KBr	240/110	水洗+真空加热	98.22	0.23	0.32	—	0.36	0.87
NiBi/KBr	110/240	水洗	74.19	0.06	0.42	—	8.07	17.26
NiBi/KBr	110/240	水洗+真空加热	88.47	0.10	0.00	—	3.60	7.83
NiBi/KBr	110/240	水洗+酸洗	84.63	0	0.00	—	4.98	10.39
NiBi/NaBr	110/240	水洗	95.06	0.18	0.56	1.06	—	3.14
NiBi/NaBr	110/240	水洗+真空加热	97.40	0.18	0.00	0.59	—	1.83
NiBi/NaBr	110/240	水洗+酸洗	97.34	0	0.00	1.15	—	1.51

成本	SMR	质子交换膜电解水	熔融金属法
总装置成本/10⁶USD	42	495.8	40.8
总投资成本/10⁶USD	252.1	829.1	349.7
运行成本/10⁶USD·a^-1	94.5	582.4	122
原料成本/10⁶USD·a^-1	63.2	543.8	92.8
净电输出/MW_e	12.6^①	—	5.4^①
1kg H₂的碳排放/kg	9.3	0	2.5
氢气售价（IRR=10%）/USD·kg^-1	1.26	7.13^②	1.39^③
与SMR工艺IRR收益为10%相等时，碳税价格/USD·t^-1	—	585	18

成本	SMR	质子交换膜电解水	熔融金属法
总装置成本/10⁶USD	42	495.8	40.8
总投资成本/10⁶USD	252.1	829.1	349.7
运行成本/10⁶USD·a^-1	94.5	582.4	122
原料成本/10⁶USD·a^-1	63.2	543.8	92.8
净电输出/MW_e	12.6^①	—	5.4^①
1kg H₂的碳排放/kg	9.3	0	2.5
氢气售价（IRR=10%）/USD·kg^-1	1.26	7.13^②	1.39^③
与SMR工艺IRR收益为10%相等时，碳税价格/USD·t^-1	—	585	18

CO₂捕集条件	SMR		熔融金属法（碳供能）		熔融金属法（氢供能）	熔融金属法（天然气供能）		熔融金属法（电供能）
CO₂捕集条件	—	MDEA脱碳	—	MEA脱碳	熔融金属法（氢供能）	—	MEA脱碳	熔融金属法（电供能）
反应温度/℃	890	890	1200	1200	1200	1200	1200	1200
反应压力/MPa	3.2	3.2	1	1	1	1	1	1
NG流率/kg·s^-1	2.62	2.81	3.86	3.86	7.31	5.33	5.33	3.86
H₂流率/kg·s^-1	0.75	0.75	0.75	0.75	0.75	0.75	0.75	0.75
1mol CH₄的H₂产率/mol	2.49	2.48	1.65	1.63	0.93	1.25	1.23	1.71
1kg H₂的CO₂排放量/kg	9.18	1.57	5.26	0.45	1.46	6.16	0.56	1.01
CO₂减排率/%	—	83	43	95	84	33	94	89