Design of Bio-Oil Solvents using Multi-Stage Computer-Aided Molecular Design Tools

Abstract

Abstract Direct application of fast-pyrolysis bio-oil as biofuel is limited due to its undesirable attributes like low heating value, high viscosity, and storage instability. Solvent addition is a simple and practical method in upgrading pyrolysis bio-oil. In this work, a computeraided molecular design (CAMD) tool was developed to generate the molecular structure of the solvent with desirable properties. Molecular signature descriptors were employed to represent property prediction models that comprise different classes of topological indices. Because of the differences in the structural details involved in different property prediction models, signatures of different heights were needed in formulating the design problem. However, the complexity of a CAMD problem increases with the height of signatures, due to the combinatorial nature of higher-order signatures. Thus, a multi-stage framework was developed by introducing a novel set of consistency rules that restrict the number of higher-order signatures. With the developed consistency rules, only relevant and consistent signatures were generated to keep the CAMD problem in a manageable size. Phase stability analysis was conducted after solvent candidates were identified to evaluate the stability and miscibility of the solvent-oil blend. As a result, a feasible solvent that fulfils the target properties with low environmental impact was identified.