(35a) Single-Pot Hydrocarbon Production from Aqueous Phase Pyrolysis Oil Oxygenates Using Multifunctional Red Mud-Supported Nickel Catalysts

Catalytic pyrolysis of lignocellulosic biomass generates four main products; organic phase liquid, aqueous phase liquid, syngas, and bio-char. The water-soluble low molecular weight oxygenates such as acetic acid, acetone, furfural, butanone, guaiacol, phenol etc. are usually found in the aqueous phase pyrolysis oil. These compounds are not suitable for conventional hydrocarbon fuel application, and are a major source of carbon loss in the net pyrolysis-hydrodeoxygenation process. A new heterogeneous red mud-supported Ni catalyst (Ni/RM) has been developed. Herein we investigated the hydroprocessing of aqueous phase pinyon-juniper catalytic pyrolysis oil (APPJCPO) using the new Ni/RM catalyst. Surprisingly, the system produced liquid hydrocarbons in a single-stage process. The hydrocarbon mixture consisted of aliphatics, aromatics, and alkylated aromatic hydrocarbons as well as small amounts of oxygenates. Extensive model compound experimentation revealed that the catalyst simultaneously catalyzed ketonization, hydrodeoxygenation, and a new class of reaction which was called “carbonyl alkylation”. These model compound studies were carried out under two main classifications of “furfural reactions” and “guaiacol reactions” to produce C₆ to C₁₅ hydrocarbons in a one-pot synthesis. The RM support catalyzed ketonization of carboxylic acids. The Ni metal catalyzed partial reduction of furfural to furan and 2-methylfuran; as well as guaiacol to anisole. These intermediates underwent “carbonyl alkylation” with aldehydes and ketones on the RM and produced diverse types of liquid hydrocarbons.