Effect of zeolites and nanopowder metal oxides on the distribution of chiral anhydrosugars evolved from pyrolysis of cellulose: An analytical study

b s t r a c tCatalytic pyrolysis is a promising way to improve bio-oil product quality. In this study, metal salts were directly impregnated in biomass to generate in situ catalysts and investigate their impact on pyrolysis products. Seven metals -Ce, Mn, Fe, Co, Ni, Cu and Zn -were selected and impregnated in eucalyptus using nitrate salts. A fixed-bed reactor, pre-heated at 500• C and inerted with N 2 flow, was used for pyrolysis. Both gas and bio-oil compositions were analysed, paying particular attention to the production of anhydrosugars. The anhydrosugar yields were found to be strongly influenced by the presence of metal salt catalysts. In particular, both Zn and Co salts yielded more anhydrosugars in comparison with catalyst-free sample. Moreover, LAC (1-hydroxy-(1R)-3,6-dioxabicyclo[3.2.1]octan-2-one) was produced in higher amounts than levoglucosan which is commonly produced without any catalyst. Metals were found to remain in all chars and tended to form metal-based nanoparticles (e.g. Cu 0 , Ni 0 , ZnO) able to act as in situ catalysts during the pyrolysis process. It seems that those metal nanoparticles are closely related to LAC production. In parallel to metal cations, nitrates were also suspected to play a significant role during pyrolysis. The suspected impact of anions on levoglucosenone production is discussed. Concerning gas yields, the impregnated nitrate salts were found to strongly affect CO 2 production.

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“…Levoglucosan, LAC, DGP and levoglucosenone are the most classically reported anhydrosugars [36][37][38] (Fig. 4).…”

Section: Catalytic Effects Of Metal Salts On Bio-oil Compositionsmentioning

confidence: 97%

Catalytic effect of metal nitrate salts during pyrolysis of impregnated biomass

Eibner

Broust

Blin

et al. 2015

Journal of Analytical and Applied Pyrolysis

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“…The catalytic pyrolysis of cellulose was reported by Fabbri et al [36] using zeolites and nanopowder metal oxides. Zeolite catalysts were found to reduce the overall yields of anhydrosugars with respect to pure cellulose while all nanopowder oxides but silicon oxide provided higher yields.…”

Section: Comparison Of This Study To Previous Studies Of Biomass-derimentioning

confidence: 99%

“…Zeolite catalysts were found to reduce the overall yields of anhydrosugars with respect to pure cellulose while all nanopowder oxides but silicon oxide provided higher yields. Fabbri et al [36] carried out catalytic pyrolysis experiments using a similar pyroprobe system employed in this work. To date, few other workers have utilized the pyroprobe system in order to screen potential catalyst materials for the pyrolysis of biomass.…”

Section: Comparison Of This Study To Previous Studies Of Biomass-derimentioning

confidence: 99%

“…Predominately, solid acid catalysts (e.g., ZSM-5) have been used for the conversion of biomass to oils using pyrolysis. Only, Nokkosmaki et al [16] and Fabbri et al [36] applied basic oxides in catalytic pyrolysis, ZnO and MgO, respectively. Base catalytic activity has been shown to lead to much higher conversions compared to acid catalysts in other biofuel reactions, such as aldol condensation and transesterification [5].…”

Section: Comparison Of This Study To Previous Studies Of Biomass-derimentioning

confidence: 99%

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Aromatic Production from Catalytic Fast Pyrolysis of Biomass-Derived Feedstocks

et al. 2009

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The conversion of biomass compounds to aromatics by thermal decomposition in the presence of catalysts was investigated using a pyroprobe analytical pyrolyzer. The first step in this process is the thermal decomposition of the biomass to smaller oxygenates that then enter the catalysts pores where they are converted to CO, CO 2 , water, coke and volatile aromatics. The desired reaction is the conversion of biomass into aromatics, CO 2 and water with the undesired products being coke and water. Both the reaction conditions and catalyst properties are critical in maximizing the desired product selectivity. High heating rates and high catalyst to feed ratio favor aromatic production over coke formation. Aromatics with carbon yields in excess of 30 molar carbon% were obtained from glucose, xylitol, cellobiose, and cellulose with ZSM-5 (Si/Al = 60) at the optimal reactor conditions. The aromatic yield for all the products was similar suggesting that all of these biomass-derived oxygenates go through a common intermediate. At lower catalyst to feed ratios volatile oxygenates are formed including furan type compounds, acetic acid and hydroxyacetaldehyde. The product selectivity is dependent on both the size of the catalyst pores and the nature of the active sites. Five catalysts were tested including ZSM-5, silicalite, beta, Y-zeolite and silica-alumina. ZSM-5 had the highest aromatic yields (30% carbon yield) and the least amount of coke.

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“…According to some previous studies, fast pyrolysis of cellulose mixed with nanopowder aluminium titanate at 350 °C obtained the LGO and LAC as the major products, with the yields reaching 22 wt% and 8.6 wt%, respectively. When the pyrolysis temperature was increased to 500 °C, the LAC was formed as the only predominant product with high purity, but its yield was decreased to 6.2 wt% (the LGO yield was decreased to 0.77 wt%) (Fabbri et , 2007a;Fabbri et al, 2007b;Torri et al, 2009b). As been indicated above, the utilization of solid catalysts will provide a convenient way for the catalyst recycles.…”

Section: -Hydroxy-36-dioxabicyclo[321]octan-2-onementioning

confidence: 97%