Combined methane reforming by carbon dioxide and steam in ...zhaogroup.ust.hk/~mezhao/pdf/365-1.pdf · Combined methane reforming by carbon dioxide and steam in proton conducting
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
ww.sciencedirect.com
i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 4 4 ( 2 0 1 9 ) 1 5 3 1 3e1 5 3 2 1
Available online at w
ScienceDirect
journal homepage: www.elsevier .com/locate/he
Combined methane reforming by carbon dioxideand steam in proton conducting solid oxide fuelcells for syngas/power co-generation
Bin Chen a,b, Haoran Xu b, Yuan Zhang b,c, Feifei Dong d, Peng Tan b,Tianshou Zhao e,*, Meng Ni b,**
a Institute of Deep Earth Sciences and Green Energy, Shenzhen University, Shenzhen, 518060, Chinab Building Energy Research Group, Department of Building and Real Estate, The Hong Kong Polytechnic University,
Hung Hom, Kowloon, Hong Kong, Chinac State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech
University, No. 5 Xin Mofan Road, Nanjing 210009, PR Chinad College of Light Industry and Chemical Engineering, Guangdong University of Technology, Guangzhou, 510006,
Chinae Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong
Fig. 7 e The conversion ratios of CH4 and CO2, and current
density at different fuel flow rates at 0.7 V with 20% H2O
assisting.
i n t e rn a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 4 4 ( 2 0 1 9 ) 1 5 3 1 3e1 5 3 2 115320
relieve the starvation of H2 in the SOFC, thus lowering down
overpotentials.
Sensitivity of fuel flow rate
The sensitivity of fuel flow rate is investigated in this section.
The measured conversion ratios of CH4 and CO2 at three
different flow rates: 50, 100 and 200 SCCM according to Case
S3. It can be seen from Fig. 7 that the increase of anode flow
can simply increase the current density, but the conversion
ratios of CH4 and CO2 are both reduced. This can be explained
by the insufficient catalyst loading for DRM and MSR at the
current dimension of SOFC. Therefore, the excessive fuelling
of CH4 and CO2 inevitably dilutes the H2 and CO produced.
Conclusions
In this work, the effects of H2O assisting on CH4 reforming and
SOFC performance are investigated. It shows that H2O
assisting is beneficial to the syngas and power co-generation
in an HeSOFC by a 2D axisymmetric numerical model. It'sfound that 20% H2O assisting can improve CH4 conversion
from 0.830 to 0.898 and the current density from 2832 Am�2 to
3064 A m�2 at 0.7 V that corresponds to a power generation
improvement of 8.4%. The analysis of species distribution and
chemical reforming rates from the modelling work attributes
the improvement mainly to the synergies of combining dry
methane reforming and methane steam reforming. Sensi-
tivity studies of operating conditions, including H2O fraction,
operating voltage and fuel flow rate, are carried out. It is found
that 1) the produced syngas composition is greatly influenced
by the amount of H2O used for assisting. Specifically, the
higher fraction of H2O leads to the higher H2:CO ratio in the
syngas, as well as the higher current density; 2) the assisting
of H2O can effectively reduce the concentration overpotential
at a relative low voltage (<0.6 V) by relieving the H2 starvation;
3) the conversion ratio of CH4 and CO2 is restricted by the
reforming capacity of anode, which can be measured by
catalyst loading mass vs. inlet fuel flow rate. Therefore, the
dilution issue of H2 by the inlet flue (CH4/CO2/H2O) in such a
non-H2 fuelled proton SOFC system is more critical when
increasing the flow rate.
Acknowledgements
This research is supported by a grant under the Theme-based
Scheme (project number: T23-601/17-R) from Research Grant
Council, University Grants Committee, Hong Kong.
r e f e r e n c e s
[1] Wu Y, Liao Y, Liu G, Ma X. Syngas production by chemicallooping gasification of biomass with steam and CaO additive.Int J Hydrogen Energy 2018;43:19375e83.
[2] Toledo TM, Araus SK, Vasconcelo AD. Syngas productionfrom coal in presence of steam using filtration combustion.Int J Hydrogen Energy 2015;40:6340e5.
[3] Huang Q, Wang J, Qiu K, Pan Z, Wang S. Catalytic pyrolysis ofpetroleum sludge for production of hydrogen-enrichedsyngas. Int J Hydrogen Energy 2015;40:16077e85.
[4] Zhang G, Liu J, Xu Y, Sun Y. A review of CH4eCO2 reformingto synthesis gas over Ni-based catalysts in recent years(2010e2017). Int J Hydrogen Energy 2018;43:15030e54.
[5] Hegarty MES, O'Connor AM, Ross JRH. Syngas productionfrom natural gas using ZrO2-supported metals. Catal Today1998;42:225e32.
[6] Kathe M, Empfield A, Sandvik P, Fryer C, Zhang Y, Blair E,et al. Utilization of CO2 as a partial substitute for methanefeedstock in chemical looping methaneesteam redoxprocesses for syngas production. Energy Environ Sci2017;10:1345e9.
[7] Ni M. Modeling of SOFC running on partially pre-reformedgas mixture. Int J Hydrogen Energy 2012;37(2):1731e45.
[8] Hanna J, Lee WY, Shi Y, Ghoniem AF. Fundamentals ofelectro-and thermochemistry in the anode of solid-oxide fuelcells with hydrocarbon and syngas fuels. Prog EnergyCombust Sci 2014;40:74e111.
[9] Ni M. Modeling and parametric simulations of solid oxidefuel cells with methane carbon dioxide reforming. EnergyConvers Manag 2013;70:116e29.
[10] Sameshima S, Furukawa N, Hirata Y, Shimonosono T. Cellperformance of SOFC using CH4eCO2 mixed gases. Ceram Int2014;40:6279e84.
[11] Mishina T, Miya K, Kikuchi R, Sugawara T, Takagaki A,Oyama ST. Ni-SDC based cermets for direct dry reforming ofmethane on SOFC anode. ECS Trans 2017;78:1161e7.
[12] Wan T, Zhu A, Guo Y, Wang C, Huang S, Chen H, et al. Co-generation of electricity and syngas on proton-conductingsolid oxide fuel cell with a perovskite layer as a precursor of ahighly efficient reforming catalyst. J Power Sources2017;348:9e15.
[13] Hua B, Yan N, Li M, Zhang Y, Sun Y, Li J, et al. Novel layeredsolid oxide fuel cells with multiple-twinned Ni0.8Co0.2
nanoparticles: the key to thermally independent CO2
utilization and power-chemical cogeneration. EnergyEnviron Sci 2016;9:207e15.
[14] Chen B, Xu H, Sun Q, Zhang H, Tan P, Cai W, et al. Syngas/power cogeneration from proton conducting solid oxide fuelcells assisted by dry methane reforming: a thermal-electrochemical modelling study. Energy Convers Manag2018;167:37e44.
[15] Gangadharan P, Kanchi KC, Lou HH. Chemical engineeringresearch and design evaluation of the economic and
i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n en e r g y 4 4 ( 2 0 1 9 ) 1 5 3 1 3e1 5 3 2 1 15321
environmental impact of combining dry reforming withsteam reforming of methane. Chem Eng Res Des2012;90:1956e68.
[16] Finnerty CM, Coe NJ, Cunningham RH, Ormerod RM. Carbonformation on and deactivation of nickel-based/zirconiaanodes in solid oxide fuel cells running on methane. CatalToday 1998;46:137e45.
[17] Li Y, Wang Y, Zhang X, Mi Z. Thermodynamic analysis ofautothermal steam and CO2 reforming of methane. Int JHydrogen Energy 2008;33:2507e14.
[18] Samuel P. GTL technology-Challenges and opportunities incatalysis. Bull Catal Soc India 2003;2:82e99.
[19] Zhao J, Xu X, Zhou W, Blakey I, Liu S, Zhu Z. Proton-conducting La-doped ceria-based internal reforming layerfor direct methane solid oxide fuel cells. ACS Appl MaterInterfaces 2017;9:33758e65.
[20] Hua B, Li M, Pu J, Chi B, Jian L. BaZr0.1Ce0.7Y0.1Yb0.1O3�d
enhanced coking-free on-cell reforming for direct-methanesolid oxide fuel cells. J Mater Chem A 2014;2:12576e82.
[21] Chen B, Xu H, Zhang H, Tan P, Cai W, Ni M. A novel design ofsolid oxide electrolyser integrated with magnesium hydridebed for hydrogen generation and storageeA dynamicsimulation study. Appl Energy 2017;200:260e72.
[22] Chen B, Xu H, Chen L, Li Y, Xia C, Ni M. Modelling of one-stepmethanation process combining SOECs and Fischer-Tropsch-like reactor. J Electrochem Soc 2016;163:F3001e8.
[23] Ni M, Leung MKH, Leung DYC. Electrochemical modeling ofhydrogen production by proton-conducting solid oxidesteam electrolyzer. Int J Hydrogen Energy 2008;33:4040e7.
[24] He F, Song D, Peng R, Meng G, Yang S. Electrode performanceand analysis of reversible solid oxide fuel cells with protonconducting electrolyte of BaCe0.5Zr0.3Y0.2O3�d. J PowerSources 2010;195:3359e64.
[25] Chen B, Xu H, Ni M. Modelling of SOEC-FT reactor: pressureeffects on methanation process. Appl Energy2017;185:814e24.
[26] Ni M. 2D thermal modelling of a solid oxide electrolyzer cell(SOEC) for syngas production by H2O/CO2 co-electrolysis. IntJ Hydrogen Energy 2012;37(8):6389e99.
[27] Abashar MEE. Coupling of steam and dry reforming ofmethane in catalytic fluidized bed membrane reactors. Int JHydrogen Energy 2004;29:799e808.
[28] Djinovi�c P, Osojnik �crnivec IG, Erjavec B, Pintar A. Influenceof active metal loading and oxygen mobility on coke-free dryreforming of Ni-Co bimetallic catalysts. Appl Catal B Environ2012;125:259e70.
[29] Haberman BA, Young JB. Three-dimensional simulation ofchemically reacting gas flows in the porous support structureof an integrated-planar solid oxide fuel cell. Int J Heat MassTransf 2004;47:3617e29.