*Article* **Computer-Aided Framework for the Design of Optimal Bio-Oil/Solvent Blend with Economic Considerations**

**Jia Wen Chong 1, Lik Yin Ng 2, Omar Anas Aboagwa 1, Suchithra Thangalazhy-Gopakumar 1, Kasturi Muthoosamy <sup>3</sup> and Nishanth G. Chemmangattuvalappil 1,\***


**Citation:** Jia Wen Chong, Lik Yin Ng, Omar Anas Aboagwa, Suchithra Thangalazhy-Gopakumar, Kasturi Muthoosamy and Nishanth G. Chemmangattuvalappil Computer-Aided Framework for the Design of Optimal Bio-Oil/Solvent Blend with Economic Considerations. *Processes* **2021**, *9*, 2159. https:// doi.org/10.3390/pr9122159

Academic Editor: Gade Pandu Rangaiah

Received: 29 October 2021 Accepted: 26 November 2021 Published: 29 November 2021

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**Abstract:** A major obstacle in utilising pyrolysis bio-oil as biofuel is its relatively low heating value, high viscosity, and non-homogeneity. Solvent addition is a simple yet practical approach in upgrading pyrolysis bio-oil. However, most solvents are often manufactured as specialty chemicals, and thus, this leads to a high production cost of solvents. It is crucial for the designed solvent-oil blend to achieve both fuel functionality and economic targets to be competitive with the conventional diesel fuel. Hence, the objective of this work is to generate feasible solvent candidates by solving this multi-objective optimisation (MOO) problem via a computer-aided molecular design (CAMD) approach. Initially, an optimisation model was developed to identify potential solvents that satisfied the predefined targeted properties. Next, a MOO model was developed via a fuzzy optimisation approach to identify the trade-off between profitability and heating value of the solvent-oil blend. A pricing model was employed to estimate the profitability of the solvent-oil blend. The production of bio-oil in a pyrolysis plant was used to illustrate the applicability of the pricing model. Lastly, phase stability analysis was conducted to ensure the stability and miscibility of the solvent-oil blend. With the developed framework, a promising and cost-effective solvent-oil blend can be generated while displaying optimal biofuel properties.

**Keywords:** pyrolysis bio-oil; CAMD; solvent design; fuzzy multi-objective optimisation; cost optimisation
