Application of Cement Clinker as Ni-Catalyst Support for Glycerol Dry Reforming

Abstract

The increase in biodiesel production inevitably yield plethora of glycerol. Therefore, glycerol has been touted as the most promising source for bio-syngas (mixture of H2 and CO) production. Significantly, coking on nickel-based catalysts has been identified as a major deactivation factor in reforming technology. Indeed, coke-resistant catalyst development is essential to enhance syngas production. The current work develops cement clinker (comprised of 62.0% calcium oxide)-supported nickel catalyst (with metal loadings of 5, 10, 15 and 20 wt%) for glycerol dry reforming (CO2). Physicochemical characterization of the catalysts was performed using XRD, XRF, BET, TGA and FESEM-EDS techniques. Subsequently, reaction studies were conducted in a 7-mm ID fixed-bed stainless steel reactor at 1023 K with various CO2 partial pressures at constant weight-hourly space velocity (WHSV) of 7.2×104 ml gcat -1 h -1 . Gas compositions were determined using Agilent 3000 micro-gas chromatography (GC) and Lancom III gas analyzer. Results obtained showed an increment of BET surface area up to 32-fold with Ni loading which was corroborated by FESEM images. Syngas (H2 and CO) ratios of less than 2 were being produced at 1023 K. A closer scrutiny to the transient profile revealed that the presence of CO2 higher or lower than CGR 1:1 promotes the Boudouard reaction.

Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts

“…For Ni/CaO, there are peaks that presence before 227 °C. This shows that the water vapour from the catalyst is eliminate [13]. Peak that formed around 300 to 400 °C respectively for all Ni/CaO catalysts shows the transformation of Ni3(NO3)2.6H2O into NiO [13,34] which in line with XRD result as shown in Figure 2.…”

“…( 2) where d is the crystallite size, K is the shape factor, λ is the X-ray radiation (λ=0.154 nm), β is the full-width at half maximum (FWHM) and θ is half of diffraction angle [12][13].…”

“…(1) Prior works has been done on the glycerol dry reforming, concentrating on the thermodynamic analysis and effect on different types of support and promoters over Nickel (Ni) based catalyst [1,[13][14]. Wang and co workers [15] has performed the thermodynamic analysis using Gibbs free energy method and found that the maximum quantities of syngas can be reached at atmospheric pressure where the temperature is set at 1000 K. Lee et al [13] reported on the use of cement clinker as support for the Ni based where the reaction temperature was held at 1023 K. In the experiment, the CO2 to glycerol ratio (CGR) was manipulated with the pressure of CO2. The result shows that higher pressure of CO2 and CGR will favor the side reaction (i.e.…”

“…The primary drawback of Ni related to coke formation and sintering of Ni particles where it cause the catalyst to rapidly deactivate due to losses of surface area [8,20]. Previous research found that introduction of an alkaline earth oxide (MgO and CaO) and rare earth oxides (La2O3 and CeO) would help to inhibit the formation of coke [5,13,19]. Magnesium Oxide (MgO), Aluminium oxide (Al2O3), Titanium dioxide (TiO2), cement clinker, Zirconium oxide (ZrO2) and Calcium oxide (CaO) are the example of supports that has been explored in the glycerol reforming process.…”

Characterization of Ag-promoted Ni/SiO2 Catalysts for Syngas Production via Carbon Dioxide (CO2) Dry Reforming of Glycerol

“…At 1023 K reaction temperature, hydrogen-to-carbon dioxide ratio is less than 2.0 which is suitable for FischerTropsch synthesis. Unfortunately, side reactions like methanation and hydrogenation of carbon dioxide affected the production of syngas [4].…”