Deoxygenation of pyrolysis vapor from palm fruit cake over NiMo/γ-Al2O3 catalyst: Effect of CeO2, TiO2, and ZrO2 additives

Abstract

Deoxygenation of pyrolysis vapor from palm fruit cake by different catalysts was prior investigated by using Ni/γ-Al2O3, Mo/γ-Al2O3, and NiMo/γ-Al2O3 prepared by wet impregnation method. NiMo/γ-Al2O3 showing the highest degree of deoxygenation (%DOD) activity was subsequently mixed with metal oxides: CeO2, TiO2, and ZrO2. Effects of the catalysts on upgrading of pyrolysis vapor from palm fruit cake at 450°C under N2 atmosphere in a semi-batch process were investigated. The oil products were analyzed for CHNO elements by elemental analyzer, chemical compositions by a gas chromatograph coupled to a mass spectrometer (GC-MS), and higher heating values (HHV) by Dulong's equation. Catalysts have been characterized and discussed related to the product yields and properties. Acidity and acid strength of the catalyst mixture play an important role on the products. NiMo/γ-Al2O3 improved properties of the crude bio-oil by increasing organic phase yield, %DOD, and HHV. Addition of CeO2 to NiMo/γ-Al2O3 reduced phenol compound in the liquid products while addition of TiO2 to NiMo/γ-Al2O3 provided high aromatics and hydrocarbons comparable to those obtained from NiMo/γ-Al2O3/ZrO2. Addition of ZrO2 to NiMo/γ-Al2O3 exhibited the highest organic phase yield (%), %DOD (71%), and HHV (37 MJ/kg).