Conversion of Glycerol to Hydrogen via a Steam Reforming Process over Nickel Catalysts

Abstract

A glut of inexpensive glycerol has resulted from expanding biodiesel production around the world. This glycerol could be used as a good renewable source to produce hydrogen fuel. Hydrogen production from glycerol via a steam reforming process over Ni/CeO2, Ni/MgO, and Ni/TiO2 catalysts was studied. The catalysts were characterized by using X-ray diffraction, thermogravimetric analysis, BET surface area analysis, metal dispersion, active surface area analysis, and hydrogen temperature programmed reduction. Ni/CeO2 had the highest surface area (67.0 m2/g) followed by Ni/TiO2 (64.9 m2/g) and Ni/MgO (50.2 m2/g). Also, Ni/CeO2 showed the highest metal dispersion (6.14%) compared to Ni/MgO (0.38%) and Ni/TiO2 (0.29%). Effects of reaction temperatures, feed flow rates (FFRs), and water/glycerol molar ratios (WGMRs) on hydrogen selectivity and glycerol conversion were analyzed. Ni/CeO2 was found to be the best performing catalyst compared to Ni/MgO and Ni/TiO2 under the experimental conditions investigated. Ni/CeO2 gave the maximum hydrogen selectivity of 74.7% at a WGMR of 12:1, temperature of 600 °C, and FFR of 0.5 mL/min compared to Ni/MgO (38.6%) and Ni/TiO2 (28.3%) under similar conditions.

Hydrogen production by sorption-enhanced steam reforming of glycerol

“…Reforming reactions are generally highly endothermic, and a catalyst is often required to accelerate the reactions and favour hydrogen production in the reforming process (Adhikari, et al, 2008). The catalytic steam reforming of glycerol for hydrogen production involves complex reactions but these can be summarised by the mechanism outlined as follows.…”

Hydrogen via steam reforming of liquid biofeedstock

“…Thus efforts on utilization of this abundant and cheap resource for the production of hydrogen or synthesis gas have been increasingly appearing in the literature [42]. Several investigations on thermodynamic and catalytic investigations on the steam reforming of glycerol (SRG) have been reported [43][44][45][46][47][48][49][50]. Table 2 lists the outcomes of various investigations in terms of hydrogen yield, selectivity and molar composition in the SRG.…”

“…Adhikari et al [47] investigated the effect of catalyst support in SRG with S/G between 6 to 12 and the temperature range 823-923 K with varying feed flow from 0.15 to 0.45 ml/min. They reported Ni/CeO 2 as the best catalyst in SRG as compared to Ni/MgO and Ni/TiO 2 .…”

Utilization of Crude Glycerin for Synthetic Gas Production and Potential Electricity Generation

“…They recommended that the syngas could be used as a fuel for fuel cells. Additionally, Adhikari et al [6] found that the maximum hydrogen yield was obtained at 650°C with MgO as a supported catalyst. Valliyappan [7] found that the maximum hydrogen production of 68.4% was produced from glycerol gasification using Ni/Al 2 O 3 catalyst at a temperature of 800° C and steam to glycerol ratio of 25:75.…”