Catalytic Upgrading of Fast Pyrolysis Bio-oil Using Zeolites

Abstract: Fast pyrolysis bio-oil is considered as a possible source for production of liquid bio-fuels and bio-chemicals enabling the necessary transition to a renewable energy system. In this Master’s thesis work the upgrading of fast pyrolysis bio-oils with Fluid Catalytic Cracking (FCC) conversion process at industrially relevant conditions is studied using Fluid Catalytic Cracking Micro Activity Test (FCC MAT) unit at RISE ETC in Piteå, Sweden. The study is focused on evaluating the process in terms of production of value-added products including petrochemical materials, such as propylene and benzene, toluene, xylene (BTX), and petroleum range liquid biofuels. The evaluation of the process was based on the upgraded products yield and quality characterized by the chemical composition of collected liquid and gas samples with regards to several influencing factors including origin of the bio-oil, addition of ZSM-5 zeolite to the commercial catalyst and FCC operation parameters, such as reaction temperature, catalyst to oil (CTO) ratio and ZSM5 zeolite catalysts acidity. Several analytical methods were applied for characterization of both feedstock and products, including GC MS analysis and determination of the boiling range distribution of the liquid products by simulated distillation. The results of this work showed that the process of upgrading pure pyrolysis bio-oil was challenging and required further studies to develop a practical operating process. While the process of co-feeding of the pyrolysis bio-oil with commercial FCC fossil feedstock was determined as feasible at industrially relevant conditions. Catalytic conversion of co-fed pyrolysis bio-oil at the ratio of 20/80 resulted similar petrochemical products to commercial fossil feedstock with full deoxygenation of pyrolysis bio-oil. Moreover, the results showed that high catalytic reaction activity conditions with high reaction temperature along with the use of ZSM-5 zeolite were favored for maximizing the BTX and gasoline range products.