Processamento de matéria-prima lignocelulósica utilizando líquidos iônicos para aplicação em biorrefinaria

Author(s)

Felipe Augusto Ferrari

• Document type: Doctoral Thesis
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Engenharia de Alimentos
• Defense date: 2021-04-22

Examining board members

Marcus Bruno Soares Forte; Patricia Osseweijer; Jason Patrick Hallet; Solange Inês Mussatto; Adriano Pinto Mariano

• Advisor: Marcus Bruno Soares Forte

Abstract

The use of Lignocellulosic residues (LC), such as conventional food crop remains, for Bioenergy and Biorefinery applications is an attractive way to increase feedstock availability without the investment in additional land area, and The biomolecules produced from LC has a potentially better greenhouse gases emissions balance. Sugarcane is one of the most economically successful lignocellulosic sources. Although rich in carbohydrates, LC’s sugars are not readily converted, consequently, it must betreated. Such process is called pretreatment (PT) and is considered the most important step to obtain an efficient conversion of LC’s constituents. Ionic liquids (ILs) have emerged as an alternative technology for biomass pretreatment. The objective of this work was to use ionic liquids (ILs) for LC pretreatment in a Biorefinery concept addressing the overall question "Are protic ionic liquids viable alternatives for biomass pretreatment in large scale Biorefineries, and which are the key parameters involved?". In Chapter 2 a good enzymatic digestibility efficiency was obtained using the mixture of [Mea][Ac]/[Mea][Hex] at 13 % (w/w) solids loading and water content in the reaction medium. Under mild temperature conditions, the [Mea][Ac]/[Mea][Hex] mixture increased delignification compared with pure ILs. The effects of variables were assessed and the process scaled up from a 50 mL static flask to a 1 L impelled reactor. The most significant variables were found to be temperature, solid loading and water content. Enzymatic hydrolysis of residual solids after pretreatment of SW for 3 h at 15% (w/w) solids loading and 20% (w/w) water content in the liquid phase resulted in 98% cellulose digestibility under non-optimized conditions. In Chapter 3 the recycle of [Mea][Ac] [Mea][Hex] were explored. ILs were efficiently recycled whether pure or mixed, without mass loss by the freezing concentration process. The freezing point of the aqueous solutions were determined and the water activities were satisfactory calculated from the water freezing point depression. The FC can be operated in continuous mode without waste generation and removing water as pure as desired. The mass and energy balance within the hole Biorefinery were assessed in Chapter 4. Results showed that the solid loading and IL dilution have a direct effect for the reduction of steam consumption. Temperature also had a direct influence in the steam consumption. Apart from product selling price, IL recycle is the dominant factor on economic and environmental impacts. Most of the process’s parameters analyzed in this work had a significant impact on ethanol’s environmental impact profile. The IL-based pretreatment feasibility was shown to be dependent on conditions that minimize the IL make-up. In the Appendices the study of the physicochemical properties of [Mea][Ac] and [Mea][Hex], and their mixture in water was conducted. Density data was fitted to a polynomial for density predictions as function of temperature and IL concentration. The viscosities of the binary systems (IL+water) were studied considering 6 different models. Conductivity, water activity and surface tension data were consolidated and the influence of both anionsevaluated. The mixture of ILs showed to be an interesting strategy to fine-tune system’s properties (AU)

• FAPESP's process: 19/19976-4 - Lignocellulosic biomass processing using ionic liquids for biorefinery application
• Grantee: Felipe Augusto Ferrari
• Support Opportunities: Scholarships in Brazil - Doctorate