Thermodynamic analyses of adsorption-enhanced steam reforming of glycerol for hydrogen production

Thermodynamic analysis of Glycerol Steam Reforming for hydrogen production with in situ hydrogen and carbon dioxide separation

“…The value of depends on the values of the global removal fractions of CO2 ( 2 ) and H2 ( 2 ) specified (higher values of imply higher values of ). It is worth mentioning that a similar methodology has been used in previous works [1,3].…”

“…methanation) leads to a decrease in hydrogen production. Theoretical studies on new reactor configurations that combine GSR and carbon dioxide [1,2] or hydrogen [3] selective removal (reaction products in eq. (1)) have allowed to conclude that such intensified processes permit to enhance the hydrogen production and decrease the production of both methane and carbon monoxide by-products by shifting the thermodynamic equilibrium.…”

Steam reforming of crude glycerol with in situ CO2 sorption

“…The latter showed that the crude glycerol exhibited four phases of decomposition with increasing temperature at a rate of 5 K min -1 , which were attributed to the evaporation of water and evaporation/decomposition of methanol below 150 °C, then, mainly thermal decomposition of glycerol up to 230 °C, followed by decomposition products of fatty acid methyl esters and other impurities up to 435 °C and finally tarry residues to up to 850 °C. A detailed study of temperature, pressure, steam to glycerol ratio, fractional CO 2 sorption and N 2 dilution effects on the thermodynamic equilibrium of steam reforming of pure glycerol with CO 2 sorption was also conducted as part of this project and the results are presented in Chen et al, (2009). The most favourable conditions for sorption enhanced steam reforming of pure glycerol were found to be 800-850 K (527-577 °C), 1 bar, and steam to carbon ratio of 3.…”

Glycerol, the Co-Product of Biodiesel: One Key for the Future Bio-Refinery

“…Rossi et al [2009] reported the increase of hydrogen production by increasing water:glycerol feed ratio or temperature. Chen et al [2009] analyzed the adsorption-enhanced steam reforming of glycerol, stating that the use of a CO 2 adsorbent enhanced from 6 to 7 moles of hydrogen produced per mole of glycerol, while the most favorable temperature for steam reforming in the presence of a CO 2 adsorbent was 800-850 K, being about 100 K lower than that for reforming without CO 2 adsorption. Dou et al [2010] evaluated the steam reforming of both pure glycerol and crude by-product of a biodiesel production plant at atmospheric pressure, with and without in situ CO 2 sorption, between 400 and 700ºC; both crude glycerol and steam conversions and the hydrogen purity reached 100, 11, and 68%, respectively at 600ºC.…”

“…At water:glycerol molar ratios lower than 3:1, the insufficient steam supply favored the methane decomposition forming solid carbon, decreasing the hydrogen production, and also causing catalyst deactivation [Rossi et al, 2009]. By considering thermodynamic analyses of adsorption-enhanced steam reforming of glycerol, Chen et al [2009] analyzed the effects of reaction parameters on the carbon formation, concluding the use of a CO 2 adsorbent can suppress the carbon-formation reaction and substantially reduce the lower limit of the water:glycerol feed ratio. Slinn et al [2008] reported a minimal degradation of a platinum-alumina catalyst after several days of continuous operating under the optimum conditions for glycerol reforming, only 0.4% of feed was deposited.…”