Ethanol steam reforming reaction

The thermodynamic analysis of loannides [193] on SRE in a solid polymer fuel cell indicated that the ethanol steam reforming reaction needs to be carried out in two steps a high-temperature endothermic step (steam reforming), in which ethanol is converted to a gaseous mixtures of H2, CO, CO2, CH4 and unreacted H2O, and a subsequent, low-temperature step (WGSR) in which CO reacts with water to form H2 and CO2. 

Llorca, J., Homs, N., and Ramirez de la Piscina, P. In situ DRIFT-mass spectrometry study of the ethanol steam-reforming reaction over carbonyl-derived Co/ZnO catalysts. Journal of Catalysis,... 

Basile, A., Pinacci, P., lulianelli, A. et al. (2011) Ethanol steam reforming reaction in a porous stainless steel supported palladium membrane reactor. International Journal of Hydrogen Energy, 36,2029-2037. 

Seelam P K, Liguori S, lulianeUi A, Pinacci P, Drago F, Calabrb V, Huuhtanen M, Keiski R, Piemonte V, Tosti S, De Falco M and Basile A (2012), Hydrogen production from bio-ethanol steam reforming reaction in a Pd/PSS membrane reactor , Catal Today, 193,42-48. 

The main thermodynamic properties of the methanol and ethanol steam reforming reactions are plotted in Fig. 18.3 for comparison. Both are endothermic. However, they are spontaneous, due to large entropy changes associated with the dissociation of the alcohols. Spontaneous methanol dissociation is obtained at a lower temperature (AG < 0 at - 325 K) compared to ethanol (AG < 0 at 475 K), which requires practical dissociation temperatures of 600 K. It is therefore possible to incorporate a palladium permeation membrane into a methanol steam reformer (in such cases, both processes are operating at the same temperature) whereas for ethanol, reforming and extraction of hydrogen are usually performed in two separate... 

Figure 6.3 Number of publications of Ethanol steam reforming reaction in conventional reactors throughout the years.

Database, www.scopus.com, searching keywords ethanol steam reforming reaction and conventional reactor . 

Yun, S., Lim, H., Oyama, S. T. (2012). Experimental and kinetic studies of the ethanol steam reforming reaction equipped with ultrathin Pd and Pd—Cu membranes for improved conversion and hydrogen yield. Journal of Membrane Science., 409-410, 222—231. 

Figure 8.8 Schematic representation of the catalytic hollow fiber MMR for hydrogen production using ethanol steam reforming reaction.

Percentage distribution of the catalysts used for carrying out the ethanol steam reforming reaction in traditional reactors. 

Ethanol steam reforming reaction conversion versus reaction temperature. 

Ethanol can be derived from biomass by means of acidic/enzymatic hydrolysis or also by thermochemical conversion and subsequent enzymatic ethanol formation. Likewise for methanol, hydrogen can be produced from ethanol with the ease of storage/transportation and an additional advantage of its nontoxicity. Apart from thermodynamic studies on hydrogen from ethanol steam reforming,117-119 catalytic reaction studies were also performed on this reaction using Ni-Cu-Cr catalysts,120 Ni-Cu-K alumina-supported catalysts,121 Cu-Zn alumina-supported catalysts,122,123 Ca-Zn alumina-supported catalysts,122 and Ni-Cu silica-supported catalysts.123... 

Ethanol and methane steam reforming reactions were studied assuming that the exit composition of the ethanol reformer depends on the steam reforming of methane. The competition for the same active site for ethanol and methane reforming maximizes the H2 and C02 production and minimizes the CO formation Catalysts were prepared by incipient wet impregnation. 20 wt% Ni supported on ZnO exhibited better performance compared to that supported on La203, MgO and A1203... 

Recently, Comas et al.219 performed the thermodynamic analysis of the SRE reaction in the presence of CaO as a C02 sorbent. The equilibrium calculations indicate that the presence of CaO in the ethanol steam reforming reactor enhances the H2 yield while reducing the CO concentrations in the outlet of the reformer. Furthermore, the temperature range at which maximum H2 yield could be obtained also shifts from above 700 °C for the conventional steam reforming reaction without CaO to below 700 °C, typically around 500 °C in the presence of CaO. It appears that the presence of CaO along with ethanol reforming catalyst shift the WGS equilibrium in the forward direction and converts more CO into C02 that will be simultaneously removed by CaO by adsorption. 

These systems were tested in several catalytic reactions, giving promising results for methane rich combustion and ethanol steam reforming (BaRhxZr(i. x)03), and for methane lean combustion (BaPdxZr(i x)03). 

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