Upgrading fast pyrolysis liquids: Blends of biodiesel and pyrolysis oil

• Published in: Fuel (Guildford) Vol. 109; pp. 417 - 426
• Main Authors: Alcala, A., Bridgwater, A.V.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2013; Elsevier
• Subjects: Alcohols; Applied sciences; Bio-oil; Bioalcohol; Biodiesel; Bioliquid; Blend; Blends; combustion; Energy; Energy. Thermal use of fuels; Engines; esterification; esters; ethanol; Ethyl alcohol; Exact sciences and technology; Fuels; isopropyl alcohol; Liquids; Polymer blends; Pyrolysis; Russia; Stability; temperature; vegetable oil; Vegetables; Eurasia; Russian Federation; Russia; Bioalcohol; Blend; Biodiesel; Bio-oil; Bioliquid; Diesel fuel; Alcohol; Biofuel; Combustion; Vegetable oil; Ester; Additive; Liquid fuel; Upgrading; Low temperature; Pyrolysis; Stability; Ethanol; Hydrocarbon; Propanol; Esterification; Project; Renewable energy; Butanol; Performance
• ISSN: 0016-2361; 1873-7153
• DOI: 10.1016/j.fuel.2013.02.058

► Homogenous blends of bio-oil/biodiesel were prepared with the use of alcohol. ► The blends were subject to visual and analytical tests, including adapting the empirical stability test used for bio-oil. ► Three phase charts were built for each alcohol used, showing both a homogenous and a phase separated area. Fast pyrolysis liquid or bio-oil has been used in engines with limited success. It requires a pilot fuel and/or an additive for successful combustion and there are problems with materials and liquid properties. It is immiscible with all conventional hydrocarbon fuels. Biodiesel, a product of esterification of vegetable oil with an alcohol, is widely used as a renewable liquid fuel as an additive to diesel at up to 20%. There are however limits to its use in conventional engines due to poor low temperature performance and variability in quality from a variety of vegetable oil qualities and variety of esterification processes. Within the European Project Bioliquids-CHP – a joint project between the European Commission and Russia – a study was undertaken to develop small scale CHP units based on engines and microturbines fuelled with bioliquids from fast pyrolysis and methyl esters of vegetable oil. Blends of bio-oil and biodiesel were evaluated and tested to overcome some of the disadvantages of using either fuel by itself. An alcohol was used as the co-solvent in the form of ethanol, 1-butanol or 2-propanol. Visual inspection of the blend homogeneity after 48h was used as an indicator of the product stability and the results were plotted in a three phase chart for each alcohol used. An accelerated stability test was performed on selected samples in order to predict its long term stability. We concluded that the type and quantity of alcohol is critical for the blend formation and stability. Using 1-butanol gave the widest selection of stable blends, followed by blends with 2-propanol and finally ethanol, thus 1-butanol blends accepted the largest proportion of bio-oil in the mixture.