12 research outputs found

    Catalytic Depolymerization of Organosolv Lignin in a Novel Water/Oil Emulsion Reactor: Lignin as the Self-Surfactant

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    A novel and efficient water/oil emulsion reactor for organosolv lignin depolymerization is presented using an ionic liquid catalyst based on the self-surfactivity of lignin. The physicalchemical properties of the emulsion reactor and lignin were intensively studied using optical photo, dynamic light scattering, surface tension measurement, and hydrophilelipophile balance value determination. The results show that the emulsion reactor demonstrates a more significant process intensification effect on lignin depolymerization, with more than 29.60 mg g(-1) desired phenolic compounds obtained, which is about 3.3 times higher than that from a reactor without emulsification. Another advantage of this water/oil emulsion reactor is that both the organic solvent (n-butanol) and the ionic liquid catalyst can be recycled easily, as the depletion of lignin surfactant at the end of depolymerization can result in the phase partition and the enrichment of final products in the oil phase automatically

    Oxidation of organosolv lignin in a novel surfactant-free microemulsion reactor

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    Lignin is considered as a promising substitute for fossil resources, but its efficient conversion remains a huge challenge due to the structural complexity and immiscibility with typical solvents. Herein, a series of surfactant-free microemulsion reactors comprised of n-octane, water and n-propanol were designed and their corresponding phase behaviors alongside their ability to intensify oxidative depolymerization of lignin were explored. Experimental results show that the phenolic monomer yield improves substantially (40-500 wt%) by comparison with processes performed in a single solvent. Detailed characterizations also suggest that the above intensification is rationalized by the solubilization effect of microemulsion system and directional aggregation of lignin at the microemulsion interface

    Jet fuel range hydrocarbon production from propanal: Mechanistic insights into active site requirement of a dual-bed catalyst

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    Utilization of sustainable biomass to produce jet fuel range hydrocarbons is imperatively needed to mitigate CO2 emissions and to liberate the over-reliance on fossil resources. Using propanal as the feedstock, an excellent jet fuel range hydrocarbon yield (81.7%), high conversion (ca. 100%), and purity (85%) were achieved over a novel dual-bed Cu/SiO2–TiO2||Ni/ZSM-5 catalyst at low temperature and pressure in only one reactor. The intrinsic active site requirement was further investigated by multitechniques including density functional theory calculation, quantitative CO2/NH3-temperature-programmed desorption/diffuse reflectance infrared Fourier-transform spectroscopy, high-resolution transmission electron microscopy, and thermogravimetric analysis–mass spectrometry. Results showed that for the upstream bed catalyst (Cu/SiO2–TiO2), the Ti–O site pair and Ti Lewis acid site were crucial for enolate formation, carbon-chain growth, and ring closure reactions, which can be altered by the calcination temperature. The synergy between the site strength and number led to a volcanic relationship between acidity/basicity and the intermediate yield. In addition, the downstream bed Ni/HZSM-5 catalyst promoted the hydrodeoxygenation reaction toward hydrocarbon formation
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