CHEMICAL ENGINEERING TRANSACTIONS VOL. 80, 2020 A publication of The Italian Association of Chemical Engineering Online at www.cetjournal.it Guest Editors: Eliseo Maria Ranzi, Rubens Maciel Filho Copyright © 2020, AIDIC Servizi S.r.l. ISBN 978-88-95608-78-5; ISSN 2283-9216 Upgrading Technique of Sugarcane Bagasse Bio-Oil Heavy Fraction for Stability Improvement Lais W. Simões*, Nahieh T. Miranda, Rubens Maciel Filho, Maria Regina Wolf Maciel Laboratory of Optimization, Design, and Advanced Control (LOPCA)/Laboratory of Development of Separation Processes (LDPS), School of Chemical Engineering, University of Campinas, Av. Albert Einstein 500, Campinas, 13083-852, Brazil. laiswanderley@hotmail.com Energetic efficiency of sugarcane mills in Brazil has been increasing in the past decades, generating a surplus of bagasse. Even though bagasse has a low energy density, it has been used as fuel in boilers. Pyrolysis, a thermochemical process, produces bio-oil and biochar, being an alternative to increasing the energy density of biomass. In this context, bio-oil, when compared to bagasse, is more versatile in terms of use, storage, and transport. However, this biofuel is typically a viscous, acid, and thermally unstable liquid, which is harmful to engines and boilers. Furthermore, polymerization of bio-oil occurs during aging, which increases viscosity, average molar mass, and water content. In order to avoid these problems, upgrading techniques can be used. These techniques are usually applied to the whole oil. Nonetheless, the upgrading may be more effective if the bio-oil is fractioned and each fraction is processed separately. This study assessed the upgrade of the heavy fraction of bio-oil (HBO) through solvent addition. Initially, two different concentrations (10 wt. % and 15 wt. %) of methanol, ethanol, and acetone were added into HBO. The mixtures were submitted to an accelerating aging process: storage for 24 h at 80 °C. Physical properties including viscosity, pH, and water content were measured before and after storage. According to the properties analyzed, all blends met the appropriate specifications of ASTM D7544 (2017) for fast pyrolysis bio-oil. The results also indicated that all solvents had a significant effect on HBO properties, whereas their addition reduced its viscosity, improving stability. The blended HBO with 15 wt. % methanol achieved the lowest viscosity and aging rate. Therefore, in this case, methanol was more efficient than ethanol or acetone. 1. Introduction Sugarcane bagasse is a fibrous material from milling and juice extraction. It is predominantly composed of 20 wt. % lignin, 25 wt. % hemicellulose, and 42 wt. % cellulose (Kim; Day, 2011). This residual biomass is very popular in Brazil due to its current agribusiness scenario, being the largest sugarcane producer since 1980 (FAOSTAT, 2019). In this way, the bagasse supply can be considered as stable and constant, which is advantageous for raising interest in this biomass conversion into biofuels and added-value products (Loh et al., 2013). Conventionally, the bagasse is used as solid fuel through direct combustion in industrial boilers to energy cogeneration (Evans et al., 2010), but it may not be a better way of utilization because of its low energy density. Then, this biomass transformation into high-density fuels through pyrolysis is a suitable alternative (Dhyani; Bhaskar, 2017). Fast pyrolysis results in liquid and solid renewable fuels: bio-oil and biochar, respectively (Chong et al. 2017). Bio-oil can substitute fossil fuels such as heavy oil in stationary applications, but it depends on its quality and properties. This biofuel has a high viscosity, water content, acidity, and instability, which may cause combustion problems and equipment corrosiveness; so, these characteristics need to be considered on system design (Oasmaa et al., 2015). In order to avoid issues related to bio-oil high water content, it can be fractionated in two phases: an aqueous hydrophilic light fraction (carbohydrate-derived) and a non-aqueous hydrophobic heavy fraction (lignin- derived) (Guo et al., 2010). The heavy fraction is more feasible replacing oil fuel in boilers and furnaces than light fraction due to its lower water content and higher pH and heating value. Nevertheless, this fraction DOI: 10.3303/CET2080009 Paper Received: 18 November 2019; Revised: 2 February 2020; Accepted: 19 April 2020 Please cite this article as: Simoes L.W., Miranda N.T., Maciel Filho R., Wolf Maciel M.R., 2020, Upgrading Technique of Sugarcane Bagasse Bio-oil Heavy Fraction for Stability Improvement, Chemical Engineering Transactions, 80, 49-54 DOI:10.3303/CET2080009 49