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Ag tubular membrane reactor for methane dry reforming: a reactive method for CO2 consumption
Desalination 200 (2006) 684–685
A Pd/Ag tubular membrane reactor for methane dry reforming: a reactive method for CO2 consumption L. Paturzo, F. Gallucci, A. Basile* Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, Via P. Bucci, Cubo 17/C, 87030 Rende (CS), Italy Tel. +39 0984 492013; Fax +39 0984 402103; email: [email protected] Received 18 October 2005; accepted 2 March 2006
Abstract This paper focuses on methane reaction with carbon dioxide to perform the dry reforming reaction in the temperature range 350–450° C during time. It is well known that CO2 in the atmosphere is the main cause of the greenhouse effect world-wide: several strategies are proposed for its consumption, for example pumping into subsoil (exhaust oil reservoirs) or into sea background. In this work, we propose CO2 consumption via chemical reaction with methane. In particular, the reaction of dry reforming of methane to produce syngas was carried out first in a traditional reactor, and subsequently in a membrane one. A porous Pd/Ag tubular membrane has been used for this purpose. Both reactors have been compared in terms of experimental results regarding methane and carbon dioxide conversions, and carbon monoxide and hydrogen selectivities. The experimental results achieved have also been compared with what we found in the literature.
1. Conclusions In this work, the methane dry reforming reaction for producing syngas has been studied in a porous Pd/Ag (25 wt.% of Ag) membrane reactor. For what concerns gas permeation, the Pd/Ag membrane showed H2/N2 selectivity lower than the Knudsen one. At 450° C, the maximum selectivity (pure gases) of the Pd/Ag *Corresponding author.
membrane is about 3.2 at Dp = 4000 Pa, while it is about 2.5 at 350° C and Dp = 2000 Pa. According to the literature, CO2 conversion is always higher than CH4 conversion, since CO2 is involved as reactant in several reactions. Moreover, according to the endothermicity of the reaction system, both CH4 and CO2 conversion increases with increasing temperature, as well as H2 and CO selectivity. In fact, the maximum CO2 conversion is 20.6% for MR at 450° C, versus the corresponding value of 14% achieved
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2006.03.469
L. Paturzo et al. / Desalination 200 (2006) 684–685
with TR. While, the maximum CH4 conversion is 17.41% for TR at 450° C, versus the corresponding value of 8.4% achieved with MR. A direct comparison between MR and TR in terms of CH4 and CO2 conversion demonstrates that, by choosing one reactor instead of the other, a different parameter could be maximised: CH4 conversion by choosing TR, CO2 conversion by choosing MR. So, in this case, the choice of the reactor type could depend on the goal of the reaction system. A similar consideration can be done by comparing MR and TR in terms of H2 and CO selectivity (average values): again, the
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goal of maximizing CH4 conversion leads to maximize H2 production (TR), while the goal of maximizing CO2 conversion leads to maximize CO production (MR). These considerations are valid for experimental conditions adopted in this work. With regard to carbon deposition during 100 min of reaction time, MR gives an increasing trend with the temperature. Generally, these considerations make the membrane reactor a very interesting device for the methane dry reforming reaction, mainly if the goal of the process is to maximize the CO2 conversion.
A Pd/Ag tubular membrane reactor for methane dry reforming: a reactive method for CO2 consumption L. Paturzo, F. Gallucci, A. Basile* Institute on Membrane Technology, ITM-CNR, c/o University of Calabria, Via P. Bucci, Cubo 17/C, 87030 Rende (CS), Italy Tel. +39 0984 492013; Fax +39 0984 402103; email: [email protected] Received 18 October 2005; accepted 2 March 2006
Abstract This paper focuses on methane reaction with carbon dioxide to perform the dry reforming reaction in the temperature range 350–450° C during time. It is well known that CO2 in the atmosphere is the main cause of the greenhouse effect world-wide: several strategies are proposed for its consumption, for example pumping into subsoil (exhaust oil reservoirs) or into sea background. In this work, we propose CO2 consumption via chemical reaction with methane. In particular, the reaction of dry reforming of methane to produce syngas was carried out first in a traditional reactor, and subsequently in a membrane one. A porous Pd/Ag tubular membrane has been used for this purpose. Both reactors have been compared in terms of experimental results regarding methane and carbon dioxide conversions, and carbon monoxide and hydrogen selectivities. The experimental results achieved have also been compared with what we found in the literature.
1. Conclusions In this work, the methane dry reforming reaction for producing syngas has been studied in a porous Pd/Ag (25 wt.% of Ag) membrane reactor. For what concerns gas permeation, the Pd/Ag membrane showed H2/N2 selectivity lower than the Knudsen one. At 450° C, the maximum selectivity (pure gases) of the Pd/Ag *Corresponding author.
membrane is about 3.2 at Dp = 4000 Pa, while it is about 2.5 at 350° C and Dp = 2000 Pa. According to the literature, CO2 conversion is always higher than CH4 conversion, since CO2 is involved as reactant in several reactions. Moreover, according to the endothermicity of the reaction system, both CH4 and CO2 conversion increases with increasing temperature, as well as H2 and CO selectivity. In fact, the maximum CO2 conversion is 20.6% for MR at 450° C, versus the corresponding value of 14% achieved
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.desal.2006.03.469
L. Paturzo et al. / Desalination 200 (2006) 684–685
with TR. While, the maximum CH4 conversion is 17.41% for TR at 450° C, versus the corresponding value of 8.4% achieved with MR. A direct comparison between MR and TR in terms of CH4 and CO2 conversion demonstrates that, by choosing one reactor instead of the other, a different parameter could be maximised: CH4 conversion by choosing TR, CO2 conversion by choosing MR. So, in this case, the choice of the reactor type could depend on the goal of the reaction system. A similar consideration can be done by comparing MR and TR in terms of H2 and CO selectivity (average values): again, the
685
goal of maximizing CH4 conversion leads to maximize H2 production (TR), while the goal of maximizing CO2 conversion leads to maximize CO production (MR). These considerations are valid for experimental conditions adopted in this work. With regard to carbon deposition during 100 min of reaction time, MR gives an increasing trend with the temperature. Generally, these considerations make the membrane reactor a very interesting device for the methane dry reforming reaction, mainly if the goal of the process is to maximize the CO2 conversion.