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Production of hydrogen by plasma-reforming of methanol
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
Available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/he
Technical Communication
Production of hydrogen by plasma-reforming of methanol Ya-Fen Wang a,*, Yen-Sheng You a, Cheng-Hsien Tsai b, Lin-Chi Wang c a
Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chung-Li 320, Taiwan Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan c Department of Chemical and Materials Engineering, Cheng Shiu University, Kaohsiung 833, Taiwan b
article info
abstract
Article history:
The reforming of methanol is usually carried out by a catalytic process. In this study,
Received 25 April 2010
a single-stage, non-catalytic, methanol pyrolysis and reforming, process for producing
Received in revised form
mainly hydrogen using an atmospheric-pressure microwave plasma reactor is demon-
21 June 2010
strated. When the applied power was elevated from 800 to 1400 W, the selectivity of H2
Accepted 26 June 2010
increased from 77.5% to 85.8% at inlet molar fraction of MeOH ¼ 3.3%. The selectivities of
Available online 31 July 2010
carbon-containing byproducts were in the order: CO > carbon black > C2H2 > CH4 > CO2 w C2H4. In addition, a higher conversion of methanol with a higher selectivity of H2
Keywords:
was achieved at a higher applied power. While a low required energy consumption of H2
Pyrolysis
(13.2 eV/molecule-H2) was obtained at a low applied power (800 W) and a higher inlet
Hydrogen
concentration of methanol (5.0%).
Methanol
ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Discharge Energy conversion
1.
Introduction
Hydrogen is a promising option for the energy supply of fuel cells. The production of hydrogen from the conversion of methanol (CH3OH, MeOH) is usually carried out through a catalytic steam reforming reaction, oxidative steam reforming reaction, or decomposition processes [1e3]. Traditionally, methanol conversion is based on the utilization of active catalysts, including Cu-, Pt-, and Pd-based catalysts at 200e300 C [4e9]. However, the lifetime of catalysts, catalytic activity and stability all still need to be improved. Therefore, non-catalytic plasma technology operated at room temperature has been developed to alleviate the shortcomings of catalytic conversion. Hydrogen production from Ar-purged methanol has been performed using DC or AC corona discharge. The results showed that a high conversion
of methanol can be achieved at high water content, energy density, or residence time, a low methanol feed concentration, and using AC discharge [10,11]. The decomposition of methanol into hydrogen using dielectric-barrier discharge has also been performed, and the maximum conversion of CH3OH/Ar to H2 was 80%, with the major byproducts of CO and CO2 for the conditions without and with water, respectively [12]. However, the previous methods were operated at a low total flow rate with Ar as the carrier gas. MW plasma, commonly used in microwave ovens, diamond deposits, and IC manufacturing, has the advantages of easy operation, an electrodeless reactor, high plasma density, and high electron mean energy. Consequently, a single-stage, non-catalytic, methanol plasma pyrolysis and reforming process to produce mainly hydrogen using an atmosphericpressure microwave plasma reactor is demonstrated in this
* Corresponding author. Tel.: þ886 3 265 4912; fax: þ886 3 265 4949. E-mail address: [email protected] (Y.-F. Wang). 0360-3199/$ e see front matter ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2010.06.104
9638
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
study. The selectivities of H2 and H-containing compounds, the conversion of methanol, and the required energy consumption are all examined.
2.
Experimental section
The continuous microwave plasma system (Fig. 1) [13,14] was assembled with a commercially available magnetron (National Electronics YJ-1600, 2.45 GHz) with a maximum stationary power of 5 kW. A quartz tube (2.9-cm-i.d.) intersected the waveguide (ASTEX WR340), while the resonator was placed perpendicular to it. The products were identified and quantified using a gas chromatograph (Varian, GC3800, column type: SUPELCO 13821) equipped with a thermal conductivity detector for identifying H2, CH4, C2H2, C2H4, and C2H6. An on-line Fourier transform infrared spectrometer (Nicolet, Avator 370) was used to identify CO and CO2 and to check the accuracy of GC analysis (except for H2). Methanol was quantified with a quadrupole mass-spectrometer (Extorr, XT200). The experimental conditions were as follows: the inlet molar fraction of MeOH was 3.3% or 5.0% with N2 as the balance gas and the system pressure was set at atmosphericpressure; the applied MW power was set at 800e1400 W; the temperature of the feed was set at room temperature; and the total flow rate was fixed at 12.4 slpm (standard liter/min). By estimation, the reaction time was in the range of 0.05 s for passing the resonant cavity (at a typical temperature of 1500 K) and 0.22 s for passing the plasma zone (at 873 K).
1200 W, and was in the range of 97.0e99.8% (Fig. 2). Because the feeding position of methanol was at the upstream of the cavity resonator, the methanol molecules passed through the major discharge zone resulting in the rapid dissociation of methanol. Moreover, a low inlet concentration of MeOH did not significantly quench the electron concentration in the cavity resonator. The conversion of methanol decreased slightly at a higher applied power (1400 W). This was because more fine carbon powders were formed during the pyrolysis of methanol, and these attached to the wall of the cavity resonator and absorbed microwave energy, resulting in a decrease in the energy applied to the electrons [15]. Energetic electrons are generated in MW discharge. A large amount of free radicals and active species are then produced via the electron impaction dissociation reaction, penning dissociation reaction, or moleculeeradical reactions, with the fragments of methanol reforming as stable, small molecule weight compounds. The results show that the species of byproducts produced by the pyrolysis of MeOH are similar for various applied powers or inlet molar fraction of MeOH. In addition, H2 was the predominant H-containing compound, while CO and nano carbon black particles were the major C-containing species. The minor and trace byproducts were CH4, C2H2, C2H4, and CO2. However, toxic HCN was not found.
3.2. Selectivity of hydrogen and byproducts and required energy consumption of H2 The selectivity of H2 was calculated using the following equation:
3.
Results and discussion Selectivity of H2 ¼ ½H2 =ð½H2 þ ½C2 H2 þ 2½C2 H4 þ 0:5½HCN
The conversion of methanol is defined as (CH3OH consumed)/ (CH3OH fed to the reactor) * 100%.
3.1. Conversion of methanol and identification of byproducts The results show that the conversion of MeOH was slightly elevated by increasing the applied power from 800 W to
Fig. 1 e Schematic of the atmospheric-pressure microwave plasma system.
þ ½H2 OÞ 100% When the applied power was elevated from 800 W to 1400 W, Fig. 3 shows that the selectivity of H2 increased slightly from 77.5% to 85.8% at inlet molar fraction of MeOH ¼ 3.3%, and from 73.6% to 82.2% at inlet molar fraction of MeOH ¼ 5.0%. A slight elevation of H2 selectivity was found, and this might be due to the dissociation of more CH3 radicals from the decomposition
Fig. 2 e Conversion of methanol for various applied powers at inlet molar fraction of MeOH [ 3.3% or 5.0%.
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
9639
molecule-H2) or at inlet molar fraction of MeOH ¼ 5.0% and 1400 W (21.0 eV/molecule-H2). This value is lower than that achieved by using AC corona discharge to convert Ar/saturated methanol mixtures (65.8 eV/molecule-H2) [11], but higher than that obtained from liquid methanol in water using corona discharge (only 8.23 eV/molecule-H2) [10].
4.
Fig. 3 e Selectivity of hydrogen for various applied powers at inlet molar fraction of MeOH [ 3.3% or 5.0%.
of MeOH, producing more H atoms, and thus then more H2, resulting in reduced yields of CH4, C2H2, and C2H4. The selectivity of H-containing trace byproducts, CH4, C2H4, and C2H4, decreased from 1.74% to 0.39%, 0.84% to 0.28%, and 0.40% to 0.05%, respectively, when the power was elevated from 800 to 1400 W at inlet molar fraction of MeOH ¼ 3.3% (Fig. 4). The selectivity of the carbon-containing components was in the order: CO > carbon black > C2H2 > CH4 > CO2 w C2H4. At inlet molar fraction of MeOH ¼ 3.3%, and when the power was elevated from 800 to 1400 W, the C atom selectivity of CO increased from 62.6% to 67.4% with a selectivity of carbon black in the range of 28.9e31.6%. The amount of carbon powders was estimated using the mass balance of C atoms, because it could not be measured directly. For hydrogen production, the required energy consumption of H2 is defined as the ratio of electrical power to the hydrogen throughput of the product gas. A lower energy consumption of H2 was achieved at a lower applied power (800 W) with a higher inlet molar fraction of MeOH (5.0%), being 13.2 eV/molecule-H2. This was also lower than that at inlet molar fraction of MeOH ¼ 3.3% and 800 W (19.9 eV/
Fig. 4 e Selectivity of CH4, C2H2, and C2H4 for various applied powers at inlet molar fraction of MeOH [ 3.3%.
Conclusions
In this study, hydrogen-rich gas was the most abundant product from the pyrolysis of methanol in an atmospheric-pressure microwave discharge environment. The results show that a high conversion of methanol (>97.0%) was achieved at a high applied power and a low inlet molar fraction of MeOH. A high selectivity of H2 (85.5%) was also found at a high applied power. Carbon-containing compounds produced included major CO and nano carbon black powders, and minor CH4, C2H2, C2H4, and CO2. A 13.2 eV/molecule-H2 required energy consumption of H2 was obtained at 800 W and inlet molar fraction of MeOH ¼ 5.0%. A higher inlet molar fraction of MeOH or larger flow rate should be tested in future work for the possible further reduction of the required energy consumption of H2.
references
[1] Ma L, Gong B, Tran T, Wainwright MS. Cr2O3 promoted skeletal Cu catalysts for the reactions of methanol steam reforming and water gas shift. Catal Today 2000;63:499e505. [2] Geissler K, Newson E, Vogel F, Truong TB, Hottinger P, Wokaun A. Autothermal methanol reforming for hydrogen production in fuel cell applications. Phys Chem Chem Phys 2001;3:289e93. [3] Boccuzzi F, Chiorino A, Manzoli M. FTIR study of methanol decomposition on gold catalyst for fuel cells. J Power Sources 2003;118:304e10. [4] de Wild PJ, Verhaak MJFM. Catalytic production of hydrogen from methanol. Catal Today 2000;60:2e10. [5] Lindstorm B, Pettersson LJ. Stream reforming of methanol over copper-based monoliths: the effects of zirconia doping. J Power Sources 2002;106:264e73. [6] Lindstrom B, Agrell J, Pettersson LJ. Combined methanol reforming for hydrogen generaion over monolithic catalysts. Chem Eng J 2003;93:91e101. [7] Itoh N, Kaneko Y, Igarashi A. Efficient hydrogen production via methanol steam reforming by preventing backpermeation of hydrogen in a palladium membrane reactor. Ind Eng Chem Res 2002;41:4702e6. [8] Brown JC, Gulari E. Hydrogen production from methanol decomposition over Pt/Al2O3 and ceria promoted Pt/Al2O3 catalysts. Catal Commun 2004;5:431e6. [9] Cubeiro ML, Fierro JLG. Partial oxidation of methanol over supported palladium catalysts. Appl Catal A Gen 1998;168: 307e22. [10] Liu XZ, Liu CJ, Eliasson B. Hydrogen production from methanol using corona discharges. Chinese Chem Lett 2003;14:631e3. [11] Li HQ, Zou JJ, Zhang YP, Liu CJ. Novel plasma methanol decomposition to hydrogen using corona discharges. Chem Lett 2004;33:744e5. [12] Tanabe S, Matsuguma H, Okitsu K, Matsumoto H. Generation of hydrogen from methanol in a dielectric-barrier dischargeplasma system. Chem Lett; 2000:1116e7.
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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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
[13] Tsai CH, Chen KT. Production of hydrogen and nano carbon powders from direct plasmalysis of methane. Int J Hydrogen Energ 2009;34:833e8. [14] Wang YF, Tsai CH, Chang WY, Kuo YM. Methane steam reforming for producing hydrogen in an atmospheric-
pressure microwave plasma reactor. Int J Hydrogen Energ 2010;35:135e40. [15] Le H, Lobban LL, Mallinson RG. Some temperature effects on stability and carbon formation in low temperature ac plasma conversion of methane. Catal Today 2004;89:15e20.
Available at www.sciencedirect.com
journal homepage: www.elsevier.com/locate/he
Technical Communication
Production of hydrogen by plasma-reforming of methanol Ya-Fen Wang a,*, Yen-Sheng You a, Cheng-Hsien Tsai b, Lin-Chi Wang c a
Department of Bioenvironmental Engineering, Chung Yuan Christian University, Chung-Li 320, Taiwan Department of Chemical and Materials Engineering, National Kaohsiung University of Applied Sciences, Kaohsiung 807, Taiwan c Department of Chemical and Materials Engineering, Cheng Shiu University, Kaohsiung 833, Taiwan b
article info
abstract
Article history:
The reforming of methanol is usually carried out by a catalytic process. In this study,
Received 25 April 2010
a single-stage, non-catalytic, methanol pyrolysis and reforming, process for producing
Received in revised form
mainly hydrogen using an atmospheric-pressure microwave plasma reactor is demon-
21 June 2010
strated. When the applied power was elevated from 800 to 1400 W, the selectivity of H2
Accepted 26 June 2010
increased from 77.5% to 85.8% at inlet molar fraction of MeOH ¼ 3.3%. The selectivities of
Available online 31 July 2010
carbon-containing byproducts were in the order: CO > carbon black > C2H2 > CH4 > CO2 w C2H4. In addition, a higher conversion of methanol with a higher selectivity of H2
Keywords:
was achieved at a higher applied power. While a low required energy consumption of H2
Pyrolysis
(13.2 eV/molecule-H2) was obtained at a low applied power (800 W) and a higher inlet
Hydrogen
concentration of methanol (5.0%).
Methanol
ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
Discharge Energy conversion
1.
Introduction
Hydrogen is a promising option for the energy supply of fuel cells. The production of hydrogen from the conversion of methanol (CH3OH, MeOH) is usually carried out through a catalytic steam reforming reaction, oxidative steam reforming reaction, or decomposition processes [1e3]. Traditionally, methanol conversion is based on the utilization of active catalysts, including Cu-, Pt-, and Pd-based catalysts at 200e300 C [4e9]. However, the lifetime of catalysts, catalytic activity and stability all still need to be improved. Therefore, non-catalytic plasma technology operated at room temperature has been developed to alleviate the shortcomings of catalytic conversion. Hydrogen production from Ar-purged methanol has been performed using DC or AC corona discharge. The results showed that a high conversion
of methanol can be achieved at high water content, energy density, or residence time, a low methanol feed concentration, and using AC discharge [10,11]. The decomposition of methanol into hydrogen using dielectric-barrier discharge has also been performed, and the maximum conversion of CH3OH/Ar to H2 was 80%, with the major byproducts of CO and CO2 for the conditions without and with water, respectively [12]. However, the previous methods were operated at a low total flow rate with Ar as the carrier gas. MW plasma, commonly used in microwave ovens, diamond deposits, and IC manufacturing, has the advantages of easy operation, an electrodeless reactor, high plasma density, and high electron mean energy. Consequently, a single-stage, non-catalytic, methanol plasma pyrolysis and reforming process to produce mainly hydrogen using an atmosphericpressure microwave plasma reactor is demonstrated in this
* Corresponding author. Tel.: þ886 3 265 4912; fax: þ886 3 265 4949. E-mail address: [email protected] (Y.-F. Wang). 0360-3199/$ e see front matter ª 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.ijhydene.2010.06.104
9638
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
study. The selectivities of H2 and H-containing compounds, the conversion of methanol, and the required energy consumption are all examined.
2.
Experimental section
The continuous microwave plasma system (Fig. 1) [13,14] was assembled with a commercially available magnetron (National Electronics YJ-1600, 2.45 GHz) with a maximum stationary power of 5 kW. A quartz tube (2.9-cm-i.d.) intersected the waveguide (ASTEX WR340), while the resonator was placed perpendicular to it. The products were identified and quantified using a gas chromatograph (Varian, GC3800, column type: SUPELCO 13821) equipped with a thermal conductivity detector for identifying H2, CH4, C2H2, C2H4, and C2H6. An on-line Fourier transform infrared spectrometer (Nicolet, Avator 370) was used to identify CO and CO2 and to check the accuracy of GC analysis (except for H2). Methanol was quantified with a quadrupole mass-spectrometer (Extorr, XT200). The experimental conditions were as follows: the inlet molar fraction of MeOH was 3.3% or 5.0% with N2 as the balance gas and the system pressure was set at atmosphericpressure; the applied MW power was set at 800e1400 W; the temperature of the feed was set at room temperature; and the total flow rate was fixed at 12.4 slpm (standard liter/min). By estimation, the reaction time was in the range of 0.05 s for passing the resonant cavity (at a typical temperature of 1500 K) and 0.22 s for passing the plasma zone (at 873 K).
1200 W, and was in the range of 97.0e99.8% (Fig. 2). Because the feeding position of methanol was at the upstream of the cavity resonator, the methanol molecules passed through the major discharge zone resulting in the rapid dissociation of methanol. Moreover, a low inlet concentration of MeOH did not significantly quench the electron concentration in the cavity resonator. The conversion of methanol decreased slightly at a higher applied power (1400 W). This was because more fine carbon powders were formed during the pyrolysis of methanol, and these attached to the wall of the cavity resonator and absorbed microwave energy, resulting in a decrease in the energy applied to the electrons [15]. Energetic electrons are generated in MW discharge. A large amount of free radicals and active species are then produced via the electron impaction dissociation reaction, penning dissociation reaction, or moleculeeradical reactions, with the fragments of methanol reforming as stable, small molecule weight compounds. The results show that the species of byproducts produced by the pyrolysis of MeOH are similar for various applied powers or inlet molar fraction of MeOH. In addition, H2 was the predominant H-containing compound, while CO and nano carbon black particles were the major C-containing species. The minor and trace byproducts were CH4, C2H2, C2H4, and CO2. However, toxic HCN was not found.
3.2. Selectivity of hydrogen and byproducts and required energy consumption of H2 The selectivity of H2 was calculated using the following equation:
3.
Results and discussion Selectivity of H2 ¼ ½H2 =ð½H2 þ ½C2 H2 þ 2½C2 H4 þ 0:5½HCN
The conversion of methanol is defined as (CH3OH consumed)/ (CH3OH fed to the reactor) * 100%.
3.1. Conversion of methanol and identification of byproducts The results show that the conversion of MeOH was slightly elevated by increasing the applied power from 800 W to
Fig. 1 e Schematic of the atmospheric-pressure microwave plasma system.
þ ½H2 OÞ 100% When the applied power was elevated from 800 W to 1400 W, Fig. 3 shows that the selectivity of H2 increased slightly from 77.5% to 85.8% at inlet molar fraction of MeOH ¼ 3.3%, and from 73.6% to 82.2% at inlet molar fraction of MeOH ¼ 5.0%. A slight elevation of H2 selectivity was found, and this might be due to the dissociation of more CH3 radicals from the decomposition
Fig. 2 e Conversion of methanol for various applied powers at inlet molar fraction of MeOH [ 3.3% or 5.0%.
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
9639
molecule-H2) or at inlet molar fraction of MeOH ¼ 5.0% and 1400 W (21.0 eV/molecule-H2). This value is lower than that achieved by using AC corona discharge to convert Ar/saturated methanol mixtures (65.8 eV/molecule-H2) [11], but higher than that obtained from liquid methanol in water using corona discharge (only 8.23 eV/molecule-H2) [10].
4.
Fig. 3 e Selectivity of hydrogen for various applied powers at inlet molar fraction of MeOH [ 3.3% or 5.0%.
of MeOH, producing more H atoms, and thus then more H2, resulting in reduced yields of CH4, C2H2, and C2H4. The selectivity of H-containing trace byproducts, CH4, C2H4, and C2H4, decreased from 1.74% to 0.39%, 0.84% to 0.28%, and 0.40% to 0.05%, respectively, when the power was elevated from 800 to 1400 W at inlet molar fraction of MeOH ¼ 3.3% (Fig. 4). The selectivity of the carbon-containing components was in the order: CO > carbon black > C2H2 > CH4 > CO2 w C2H4. At inlet molar fraction of MeOH ¼ 3.3%, and when the power was elevated from 800 to 1400 W, the C atom selectivity of CO increased from 62.6% to 67.4% with a selectivity of carbon black in the range of 28.9e31.6%. The amount of carbon powders was estimated using the mass balance of C atoms, because it could not be measured directly. For hydrogen production, the required energy consumption of H2 is defined as the ratio of electrical power to the hydrogen throughput of the product gas. A lower energy consumption of H2 was achieved at a lower applied power (800 W) with a higher inlet molar fraction of MeOH (5.0%), being 13.2 eV/molecule-H2. This was also lower than that at inlet molar fraction of MeOH ¼ 3.3% and 800 W (19.9 eV/
Fig. 4 e Selectivity of CH4, C2H2, and C2H4 for various applied powers at inlet molar fraction of MeOH [ 3.3%.
Conclusions
In this study, hydrogen-rich gas was the most abundant product from the pyrolysis of methanol in an atmospheric-pressure microwave discharge environment. The results show that a high conversion of methanol (>97.0%) was achieved at a high applied power and a low inlet molar fraction of MeOH. A high selectivity of H2 (85.5%) was also found at a high applied power. Carbon-containing compounds produced included major CO and nano carbon black powders, and minor CH4, C2H2, C2H4, and CO2. A 13.2 eV/molecule-H2 required energy consumption of H2 was obtained at 800 W and inlet molar fraction of MeOH ¼ 5.0%. A higher inlet molar fraction of MeOH or larger flow rate should be tested in future work for the possible further reduction of the required energy consumption of H2.
references
[1] Ma L, Gong B, Tran T, Wainwright MS. Cr2O3 promoted skeletal Cu catalysts for the reactions of methanol steam reforming and water gas shift. Catal Today 2000;63:499e505. [2] Geissler K, Newson E, Vogel F, Truong TB, Hottinger P, Wokaun A. Autothermal methanol reforming for hydrogen production in fuel cell applications. Phys Chem Chem Phys 2001;3:289e93. [3] Boccuzzi F, Chiorino A, Manzoli M. FTIR study of methanol decomposition on gold catalyst for fuel cells. J Power Sources 2003;118:304e10. [4] de Wild PJ, Verhaak MJFM. Catalytic production of hydrogen from methanol. Catal Today 2000;60:2e10. [5] Lindstorm B, Pettersson LJ. Stream reforming of methanol over copper-based monoliths: the effects of zirconia doping. J Power Sources 2002;106:264e73. [6] Lindstrom B, Agrell J, Pettersson LJ. Combined methanol reforming for hydrogen generaion over monolithic catalysts. Chem Eng J 2003;93:91e101. [7] Itoh N, Kaneko Y, Igarashi A. Efficient hydrogen production via methanol steam reforming by preventing backpermeation of hydrogen in a palladium membrane reactor. Ind Eng Chem Res 2002;41:4702e6. [8] Brown JC, Gulari E. Hydrogen production from methanol decomposition over Pt/Al2O3 and ceria promoted Pt/Al2O3 catalysts. Catal Commun 2004;5:431e6. [9] Cubeiro ML, Fierro JLG. Partial oxidation of methanol over supported palladium catalysts. Appl Catal A Gen 1998;168: 307e22. [10] Liu XZ, Liu CJ, Eliasson B. Hydrogen production from methanol using corona discharges. Chinese Chem Lett 2003;14:631e3. [11] Li HQ, Zou JJ, Zhang YP, Liu CJ. Novel plasma methanol decomposition to hydrogen using corona discharges. Chem Lett 2004;33:744e5. [12] Tanabe S, Matsuguma H, Okitsu K, Matsumoto H. Generation of hydrogen from methanol in a dielectric-barrier dischargeplasma system. Chem Lett; 2000:1116e7.
9640
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 e n e r g y 3 5 ( 2 0 1 0 ) 9 6 3 7 e9 6 4 0
[13] Tsai CH, Chen KT. Production of hydrogen and nano carbon powders from direct plasmalysis of methane. Int J Hydrogen Energ 2009;34:833e8. [14] Wang YF, Tsai CH, Chang WY, Kuo YM. Methane steam reforming for producing hydrogen in an atmospheric-
pressure microwave plasma reactor. Int J Hydrogen Energ 2010;35:135e40. [15] Le H, Lobban LL, Mallinson RG. Some temperature effects on stability and carbon formation in low temperature ac plasma conversion of methane. Catal Today 2004;89:15e20.