Hydro-Pyrolysis and Catalytic Upgrading of Biomass and Its Hydroxy Residue Fast Pyrolysis Vapors

Abstract

Fast pyrolysis of Miscanthus, its hydrolysis residue and lignin were carried with a pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) followed by online vapor catalytic upgrading with sulfated ZrO2, sulfated TiO2 and sulfated 60 wt.% ZrO2-TiO2. The most evident influence of the catalyst on the vapor phase composition was observed for aromatic hydrocarbons, light phenols and heavy phenols. A larger amount of light phenols was detected, especially when 60 wt.% ZrO2-TiO2 was present. Thus, a lower average molecular weight and lower viscosity of bio-oil could be obtained with this catalyst. Pyrolysis was also performed at different pressures of hydrogen. The pressure of H2 has a great effect on the overall yield and the composition of biomass vapors. The peak area percentages of both aromatic hydrocarbons and cyclo-alkanes are enhanced with the increasing of H2 pressure. The overall yields are higher with the addition of either H2 or sulfated catalysts. This is beneficial as phenols are valuable chemicals, thus, increasing the value of bio-oil. The results show that the hydrolysis residue has the potential to become a resource for phenol production.

Chromatographic analysis of bio-oil formed in fast pyrolysis of lignocellulosic biomass

“…Subsequently, an analysis of the particular substances within the most interesting subgroups takes place. Liu et al [26] in their work devoted to hydro-pyrolysis of biomass discussed the effect of reaction conditions, presence of catalyst and type of feedstock on the content of phenolic compounds (including phenol and its derivatives, such as: 2-methyl-phenol, 4-methyl-phenol, 2-methoxy-phenol, 2-methoxy-4-methyl-phenol, 2-methoxy-4-vinyl-phenol and 2,6-dimethoxyphenol), aromatic hydrocarbons (benzene, toluene, p-xylene and 1-ethyl-methyl-benzene), cyclo-alkanes (i.e. cyclohexane, methyl-cyclohexane, 1,2-dimethyl-cyclohexane, ethyl-cyclohexane and propylcyclohexane), furans (2,3-dihydrobenzofuran, furfural, 2-ethyl-5-methyl-furan, furan and 2-methyl-furan) and alcohols (butanol and pentanol) ( Table 3).…”

Thermocatalytic Hydrodeoxygenation and Depolymerization of Waste Lignin to Oxygenates and Biofuels in a Continuous Flow Reactor at Atmospheric Pressure

“…They obtained a mixture of over 20 compounds including acetic acid, phenols, aromatics hydrocarbons, and cycloalkanes, at 46% lignin conversion. 18 Recently, we reported the catalytic effect of NiMoS 2 /C nanocatalysts synthesized using a microemulsion technique to thermocatalytically cleave C−C and C−O bonds in model compounds and kraft lignin in an autoclave at 300 °C and 50 bar H 2 , where 88.5% of the lignin was converted in 3 h at 75.5% yield of liquids with a 20% monomers yield. 19 Because of its excellent performance in the liquid phase, we chose this catalyst to test in the gas phase.…”

“…The vapor derived from the fast pyrolysis of lignin was passed over sulfated TiO 2 , ZrO 2 , and their mixtures. They obtained a mixture of over 20 compounds including acetic acid, phenols, aromatics hydrocarbons, and cycloalkanes, at 46% lignin conversion …”