Peiwen Jiang

From lignin to cycloparaffins and aromatics: Directional synthesis of jet and diesel fuel range biofuels using biomass

The continual growth in commercial aviation fuels and more strict environmental legislations have led to immense interest in developing green aviation fuels from biomass. This paper demonstrated a controllable transformation of lignin into jet and diesel fuel range hydrocarbons, involving directional production of C8-C15 aromatics by the catalytic depolymerization of lignin into C6-C8 low carbon aromatic monomers coupled with the alkylation of aromatics, and the directional production of C8-C15 cycloparaffins by the hydrogenation of aromatics. The key step, the production of the desired C8-C15 aromatics with the selectivity up to 94.3%, was achieved by the low temperature alkylation reactions of the lignin-derived monomers using ionic liquid. The synthetic biofuels basically met the main technical requirements of conventional jet fuels. The transformation potentially provides a useful way for the development of cycloparaffinic and aromatic components in jet fuels using renewable lignocellulose biomass.

Production of aromatics through current-enhanced catalytic conversion of bio-oil tar.

Biomass conversion into benzene, toluene and xylenes (BTX) can provide basic feedstocks for the petrochemical industry, which also serve as the most important aromatic platform molecules for development of high-end chemicals. Present work explored a new route for transformation of bio-oil tar into BTX through current-enhanced catalytic conversion (CECC), involving the synergistic effect between the zeolite catalyst and current to promote the deoxygenation and cracking reactions. The proposed transformation shows an excellent BTX aromatics selectivity of 92.9 C-mol% with 25.1 wt.% yield at 400 °C over usual HZSM-5 catalyst. The study of the model compounds revealed that the groups such as methoxy, hydroxyl and methyl in aromatics can be effectively removed in the CECC process. Present transformation potentially provides an important approach for production of the key petrochemicals of BTX and the overall use of bio-oil tar derived from bio-oil or biomass.

Directional synthesis of ethylbenzene through catalytic transformation of lignin

Transformation of lignin to ethylbenzene can provide an important bulk raw material for the petrochemical industry. This work explored the production of ethylbenzene from lignin through the directional catalytic depolymerization of lignin into the aromatic monomers followed by the selective alkylation of the aromatic monomers. For the first step, the aromatics selectivity of benzene derived from the catalytic depolymerization of lignin reached about 90.2 C-mol% over the composite catalyst of Re-Y/HZSM-5 (25). For the alkylation of the aromatic monomers in the second step, the highest selectivity of ethylbenzene was about 72.3 C-mol% over the HZSM-5 (25) catalyst. The reaction pathway for the transformation of lignin to ethylbenzene was also addressed. Present transformation potentially provides a useful approach for the production of the basic petrochemical material and development of high-end chemicals utilizing lignin as the abundant natural aromatic resource.

Effect of Surfactant-Induced Modifications on CuCoMn Catalysts for Higher Alcohol Synthesis

A series of surfactant-modified CuCoMn-based catalysts were prepared for higher alcohol synthesis from biomass-based syngas. Three typical surfactants, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and pluronic P123 triblock copolymer (EO20PO70EO20), were employed. Compared to surfactant-free CuCoMn catalyst, CO conversion increased from 17.4% to 29.7% over SDS-modified CuCoMn catalyst, and the selectivity of higher alcohols increased from 22.0% to 41.2% over CTAB-modified catalyst. Besides, the proportions of higher alcohols in total alcohols increased over all surfactant-modified catalysts. The catalysts were characterized by N2 adsorption/desorption, XRD, XPS and IR analysis. The results showed that several more favorable features rendered the CTAB-modified CuCoMn catalyst to be suitable for higher alcohol production, such as the larger pore size, better crystallinity of CuCoMnO4 spinel, moderate surface atomic distribution and lower valence of metallic ions. In addition, it was v...

Conversion of Bio-syngas to Liquid Hydrocarbon over CuCoMn-Zeolite Bifunctional Catalysts

A series of bifunctional catalysts composed of a component for higher alcohol synthesis (CuCoMn oxides, CCM) and an acidic zeolite (SAPO-34, ZSM-5, Y, MCM-41) were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage process. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5>CCM-SAPO-34>CCM-Y>CCM-MCM-41. CCM-ZSM-5 (20wt%, Si/Al=100) prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion (76%) and yield of liquid products (30%). The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher specific surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites in...