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Effective separation methods must be developed before bio-oils become a source of chemical products or liquid fuels by further upgrading. Phase separation is one effective pathway to realize an initial isolation of bio-oils. When aqueous salt solutions are added, phase separation of the pyrolysis bio-oil can occur to form two different phases: the upper layer with high contents of water, acetic acid, and water-soluble compounds and the bottom layers with low water content and high lignin pyrolysis compounds [Song, Q.-H.; Nie, J.-Q.; Ren, M.-G.; Guo, Q.-X.Effective phase separation of biomass pyrolysis oils by adding aqueous salt solutions. Energy Fuels 2009, 23 (6), 3307−3312]. In this paper, the salt-induced phase separation of bio-oils with 20 kinds of salt solutions was investigated. On the basis of the dependence of the mass ratio of the bio-oil bottom layer to the whole bio-oil sample upon the salt solution concentrations, it has been demonstrated that the phase separation derives from a normal ionic...

A highly selective decomposition of formic acid in aqueous medium was achieved with immobilized catalysts. In the gas product of all of the experiments, only hydrogen and carbon dioxide were detected. The activity of different immobilized catalysts for the decomposition of formic acid was checked, and the highest turnover frequency (TOF) was observed using Pd–S–SiO2. Moreover, we have found that the addition of sulfates could significantly promote the activities of mercapto-functionalized catalysts by 30–70%, which is attractive for practical applications.

O-Methylation of phenols has been studied as an important organic reaction, and its products, aryl methyl ethers, are valuable intermediates in fine chemicals. The phenolic component is one of the factors leading to the thermal instability of biomass pyrolysis oils. O-Methylation of phenols is helpful to improve the stability of bio-oil. Using dimethyl carbonate (DMC) as a methylation reagent, model O-methylations of three phenols (phenol, guaiacol, and eugenol) have been investigated in an ionic liquid, 1-butyl-3-methylimidazolium chloride ([bmim]Cl), in the presence of water and carboxylic acid, separately. In [bmim]Cl at 130 °C, both hydrolysis of DMC and esterification of acetic acid with DMC would occur and compete with the O-methylation of phenol and decrease the yield of the methylation. However, the esterification of carboxylic acids is helpful for bio-oil upgrading. Under the same reaction conditions, the methylation was performed for a phenolic bio-oil, which is the ether extractive from the bot...