Reactive and non-reactive solvents as bio-oil blends: a computer-aided molecular design approach

Abstract

This paper presents a systematic framework of computer-aided molecular design (CAMD), to design solvents that can improve the critical properties of bio-oil. CAMD tools have been used in this work to improve the key properties of bio-oil such as heating value, water content, viscosity, acidity and stability in storage. The design of both non-reactive and reactive solvents has been covered in this work. In both cases, the main objective was to design solvents that form the bio-oil solvent blend with minimum solvent content. In order to model the bio-oil, five major components in the bio-oil are used and the solvent design problem focussed on designing this surrogate solvent. Mixing rules have been employed to estimate the properties of various bio-oil solvent blends. The main objective is to compute the minimum amount of solvent needed by identifying the optimal combination of functional groups for the solvent molecules. The improvement in properties had been tracked using group contribution models. This work also presents a framework to design solvents that improve bio-oil properties by undergoing chemical reactions with the bio-oil components. In order to ensure the homogeneity after solvent addition, miscibility test between solvent and bio-oil is conducted using appropriate thermodynamic models. Based on the results, the use of mixtures of alkene and alcohol is more recommended as the optimal blend solvents since the mass fraction and viscosity could be balanced to meet the final heating value target and viscosity constraints of the blends.