4th Bioenergy Studies Symposium, Ankara, Turkey, 26 - 27 May 2022
Although, fossil fuels are the primary sources used in energy production, their negative effects on the environment and rapid depletion of reserves necessitated production of alternative and clean energy sources. Biomass energy, in the general sense, is accepted as a clean alternative fuel type due to its lower SO2 and NOx emissions and negligible ash content compared to conventional fuels. However, direct utilization of bio-oil in motor vehicles is not possible for the time being due to its low calorific value, high oxygen content and high acidity related corrosiveness. The reduction of bio-oil’s high oxygen content is addressed with present study by zeolite cracking reaction leading to bio-fuel production with high selectivity. Literature survey revealed bio zeolites as the most commonly used catalysts in the production of biofuel from bio-oil. HZSM-5 became prominent with its microporous structure, high surface area and high surface acidity containing both Lewis and Bronsted acid sites in its structure. Recent studies investigating reaction performance of HZSM-5 catalyst at 350 and 400 oC and at 70/30 and 50/50 ethanol/reactant molar ratios revealed the increase of biofuel selectivity with increasing reaction temperature. Besides, higher ethanol content in the feed stream was shown to enhance bio-fuel selectivity. However, higher ethanol content lead to the increase of coke formation as a by-product. Based on literature survey optimum reaction conditions were determined as 400oC and 70/30 ethanol/reactant molar ratio. Reaction experiments conducted under these conditions revealed high amount of bio-fuel with decreased oxygen content.