Extractive distillation to produce anhydrous bioethanol with choline chloride with urea (1:2) as a solvent: a comparative evaluation of the equilibrium and the rate-based models

Author(s)

Fontana, Michelli ^[1] ; Marchesan, Andressa Neves ^[1] ; Filho, Rubens Maciel ^[1] ; Maciel, Maria Regina Wolf ^[1]

Affiliation

^[1] Univ Campinas UNICAMP, Sch Chem Engn, Dept Proc & Prod Dev, Av Albert Einstein 500, BR-13083852 Campinas, SP - Brazil

• Document type: Journal article
• Source: CHEMICAL ENGINEERING AND PROCESSING; v. 168, NOV 2021.
• Web of Science Citations: 0

Abstract

The purification of bioethanol to achieve anhydrous purity standards requires separation processes other than conventional distillation, such as extractive distillation. Different solvents have been studied to find alternatives to ethylene glycol, which is widely used in this application. In this study, the aim is to find the column configuration that offers the minimum total annual cost (TAC), considering a more realistic modeling than the equilibrium stage approach for the extractive distillation with ChCl:Urea (1:2) under atmospheric pressure. This evaluation uses the rate-based modeling in the Aspen Plus (R) simulator. The equilibrium stage model results show that, for the same number of distillation stages and solvent flow rate, ChCl:Urea (1:2) offers from 27 to 43 % lower energy requirement for the extractive distillation process than ethylene glycol. In addition, for the same number of distillation stages it is required lower solvent amount of ChCl:Urea (1:2) in comparison with ethylene glycol. Considering the configurations of each mole flow evaluated of ChCl:Urea (1:2), on average, the rate-based simulation required columns with 62 % more stages and 8.4 % higher TAC than the equilibrium simulation. These results demonstrate the importance of considering mass and heat transfer effects to model the real process. (AU)

• FAPESP's process: 19/24071-0 - Comparative evaluation of processes for obtaining 1st and 2nd generation hydrated and anhydro bioethanol using models of non-equilibrium stages
• Grantee: Michelli Fontana
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 15/20630-4 - Biorefinery development integrated to a bioethanol sugar cane plant with zero CO2 emission: routes to convert renewable resources to bio-products and bio-electricity
• Grantee: Rubens Maciel Filho
• Support Opportunities: Research Projects - Thematic Grants