Electronic Thesis and Dissertation Repository


Master of Engineering Science


Chemical and Biochemical Engineering


Chunbao (Charles) Xu, Sohrab Rohani


Catalytic hydrodeoxygenation (HDO) is considered to be the most promising route to upgrade pyrolysis oil to liquid transportation fuels. The objective of this research was to explore inexpensive supported metal oxides/metal phosphide catalysts for the upgrading of pyrolysis oil into advanced drop-in hydrocarbon liquid fuels by HDO.

The first stage of this thesis project investigates a series of molybdenum oxides/phosphide catalysts on different supports that were prepared in-house, such as Al2O3, activated carbon (AC), MgAl2O4 and Mg6Al2(CO3)(OH)16. The HDO activity of these catalysts were investigated using a 100 mL bench-scale reactor operating at 300 °C with an initial hydrogen pressure of 50 bar for 3 h. The catalytic efficiency were compared with a commercially available Ru/C catalyst, and the most active catalyst was selected, i.e., MoP/AC. Two other transition metal phosphides Nickel and Cobalt were also prepared in the same manner using AC support, and their catalytic activities for HDO of pyrolysis oil were compared. The activities of the three catalysts were found to be in the order of NiP/AC > CoP/AC > MoP/AC.

The second stage of the project aimed to optimize the addition of phosphorous. A series of supported nickel and cobalt phosphide catalysts with different metal/ phosphorous (M/P) ratios (mol/mol) were prepared and their catalytic activities studied for HDO of pyrolysis oil. Addition of phosphorous to the both Nikel and Cobalt at certain M/P ratios greatly influenced H2 consumption, oil yield, the degree of deoxygenation and HHV values of the upgraded bio-oils. The fresh/spent catalysts were characterized by BET, XPS, TEM and XRD, and the upgraded bio-oils were characterized using Karl Fischer titration, GPC, elemental analysis and GC/MS.