Production of upgraded bio-oils by biomass catalytic pyrolysis in an auger reactor using low cost materials

Increased charcoal yield and production of lighter oils from the slow pyrolysis of biomass

“…K, Ca) or adding generally basic 90 transition metal oxides (e.g. MgO) [16][17][18][19][20][21]. These are added to the pyrolysis reactor with the aim of cracking 91 heavy oils in the oil, reducing the amount of oxygenation present in the resulting oil, or changing the resulting 92 pyrolysis product mixture.…”

“…Gerçel [32] also showed findings 118 that agreed with Rutkowski [30] that sepiolite lowers the yield of charcoal, so it could be expected that the 119 effects using bentonite may translate to slow pyrolysis as well. Bentonite was looked at by Veses, et al [19], 120 who studied the effects of it at 450°C. This study provides evidence that with pinewood liquid yield is reduced 121 and tar cracking reactions are happening, but have not characterised the results over a temperature range or 122 catalyst concentration as they have done with sepiolite.…”

“…This will be done over a temperature range from 400-700°C and clay mineral 128 concentrations of up to 60%wt (compared to input biomass), a much greater range than presented in Veses, 129 et al [19]. Pinewood has been chosen for its abundance in European and American forests and its widely 130 studied nature.…”

“…show a reduction in oil yield, which causes an increase in charcoal and gas yield, although at 700°C there is 213 some water loss which could be due to favoured gas phase reactions utilising the water, under steam 214 reforming pathways [35]. Parallels with the 1:6 weight ratio (16.7 wt%) bentonite 450°C experiment by 215 Veses, et al [19] can be seen by interpolating between the 400 and 500°C experiments in this study, 216 indicating some agreement between the works. 217…”

“…Due to the nature of the clay mineral and findings from literature, it is 231 speculated that these results are showing catalytic cracking of the liquid into the charcoal and gas products, 232 which is expected to become more efficient at higher temperatures as gas phase cracking become more 233 dominant [19,35]. There may be some evidence in the data that low concentrations of clay experience some 234 inactivation due to blocking of active site by charcoal condensation on the clay surface, but further 235 experiments are required to determine the full extent of the clay's activity.…”