Two-phase systems for lignin recovery from deep eutectic solvents

• Grant number: 23/11739-9
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: December 12, 2023
• End date: March 11, 2024
• Field of knowledge: Engineering - Chemical Engineering - Chemical Technology
• Principal Investigator: Mariana Conceição da Costa
• Grantee: Larissa Kiyomi Tsukamoto
• Supervisor: João Manuel da Costa e Araújo Pereira Coutinho
• Host Institution: Faculdade de Engenharia Química (FEQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: Universidade de Aveiro (UA), Portugal
• Associated to the scholarship: 23/03569-6 - Two-phase systems for the recovery of lignin from deep eutectic solvents, BP.IC

Abstract

Lignocellulosic biomass is a promising alternative to fossil fuels as it is a cheap and abundantly available raw material. In this scenario, the concept of biorefineries emerges, aiming at the fractionation of biomass into its major components (cellulose, hemicellulose, and lignin), followed by their subsequent conversion into high-value bioproducts. Among these, lignin is the least sensitive fraction to chemical changes and generally has a lower degree of commercialization compared to other biomass fractions due to its high heterogeneity which is a reflex of its complex chemical structure and polydisperse molecular distribution. In this context, alternative methods to traditional ones, such as the use of deep eutectic solvents (DESs), have been identified as promising, as they produce a more homogeneous lignin with greater commercial interest. However, after its extraction and fractionation with DESs, a separation step must be carried out, which can be achieved through a biphasic system composed of water and an organic cosolvent. In this project, the feasibility of biphasic systems composed of water and esters will be evaluated for separating lignin from DESs consisting of choline chloride and ethylene glycol/1,4- butanediol. The characterization of the recovered lignin from both the top and bottom phases of the mentioned systems will also be performed to assess the alterations undergone during fractionation. Characterization will be conducted using spectroscopic techniques such as Phosphorus-31 Nuclear Magnetic Resonance (NMR), which provides information about the amount of hydroxyl groups present in the macromolecule, and Gel Permeation Chromatography (GPC). For this purpose, an exchange with the research group led by Professor João Coutinho at the University of Aveiro will be necessary. (AU)