Samarium Promoted Ni/Al2O3 Catalysts for Syngas Production from Glycerol Pyrolysis

Abstract

The current paper reports on the kinetics of glycerol reforming over the alumina-supported Ni catalyst that was promoted with rare earth elements. The catalysts were synthesized via wet impregnation method with formulations of 3 wt% Sm-20 wt% Ni/77 wt% Al2O3. The characterizations of all the assynthesized catalysts were carried out, viz. BET specific surface area measurements, thermogravimetri analysis for temperature-programmed calcination studies, FESEM for surface imaging, XRD to obtain diffraction patterns, XRF for elemental analysis, etc.. Reaction studies were performed in a stainless steel fixed bed reactor with reaction temperatures set at 973, 1023 and 1073 K employing weight hourly space velocity (WHSV) of 4.5×10 4 mL g -1 h -1 . Agilent GC with TCD capillary column was used to analyze gas compositions. Results gathered showed that the BET specific surface area was 2.09 m 2 .g -1 for the unpromoted Ni catalyst while for the promoted catalysts, was 2.68 m 2 .g -1 . Significantly, the BET results were supported by the FESEM images which showed promoted catalysts exhibit smaller particle size compared to the unpromoted catalyst. It can be deduced that the promoter can increase metal dispersion on alumina support, hence decreasing the size of particles. The TGA analysis consistently showed four peaks which represent water removal at temperature 373-463 K, followed by decomposition of nickel nitrate to produce nickel oxide. From reaction results for Sm promotion showed glycerol conversion, XG of 27% which was 7% higher than unpromoted catalyst. The syngas productions were produced from glycerol decomposition and created H2:CO product ratio which always lower than 2.0. The H2:CO product ratio of 3 wt% Sm promoted Ni/Al2O3 catalyst was 1.70 at reaction temperature of 973 K and glycerol partial pressure of 18 kPa and suitable enough for Fischer-Tropsch synthesis.

Evaluation of Hydrogen Yield Evolution in Gaseous Fraction and Biochar Structure Resulting from Walnut Shells Pyrolysis

“…Thermocatalytic biomass conversion includes pyrolysis, gasification and reforming processes while the biological route refers to the fermentative process [13][14][15][16]. These conversion processes produce gases such as, H 2 , CO 2 , CO, CH 4 and also light gaseous hydrocarbon.…”

“…The mixture of H 2 and CO, known as syngas, could be used as an intermediate for the obtaining of gasoline by Fischer-Tropsch synthesis [15,16]. Although, research has been focused on how the different conversion processes could be improved to increase the productivity, there is also high attention on the environmental impact of using the different technical routes for hydrogen-rich syngas production [14,17]. There are extensive review studies on hydrogen production by CH 4 conversion, agricultural residues by fermentation process [18], photochemical conversion of hydrogen sulfide and thermochemical biomass conversion [19][20][21].…”

A Mini-Review on Hydrogen-Rich Syngas Production by Thermo-Catalytic and Bioconversion of Biomass and Its Environmental Implications

“…Two of the most prominent means of converting biomass is thermo-catalytic and bio-chemical pathways (Damartzis and Zabaniotou, 2011;Tyagi et al, 2014). Thermo-catalytic routes include processes such as gasification, reforming, pyrolysis while the biochemical route involve the fermentative process (Parthasarathy and Narayanan, 2014;Shahirah et al, 2016;Kaiwen et al, 2017;Yamakawa et al, 2018). The product of the various technical pathways produces gases such as, H 2 , CO, CO 2 , CH 4 , and light gaseous hydrocarbon.…”

Use of bio-glycerol for the production of synthesis gas by chemical looping reforming

“…However, the use of a renewable fuel as glycerol for syngas and H 2 production have clear environmental benefits [4]. This can be carried out by using several technologies: steam reforming [5,6], autothermal partial oxidation [7], dry reforming [8], aqueous phase reforming [9,10], anaerobic fermentation [11], pyrolysis [12] and gasification [13]. Assuming future increase in H 2 demand, as an energetic vector or for industrial use, it would be desirable to delocalize the H 2 production [4].…”