Performing Department
(N/A)
Non Technical Summary
The successful implementation of biorefineries is necessary to strengthen the U.S. bioeconomy and increase U.S. energy security. Lignin is the second most abundant biopolymer in nature after cellulose, making up roughly 25 to 40 wt% of forest biomasses. However, lignin is currently underutilized in biorefineries, which limits the commercialization of new forest biorefineries and affects the revenues of pulp and paper biorefineries in the United States. Since about 25 to 40 wt% of the woody biomass in most biorefineries is often left as a by-product (e.g., biochar or lignin), finding a sustainable solution is crucial for advancing new biorefinery technologies. Additionally, declining revenues in pulp and paper facilities could be mitigated by creating new revenue streams using kraft lignin to produce high-value composites. However, the use of lignin in the production of high value-added renewable composites is limited because its structure is complex, and it doesn't have the fibrous form needed for these products. This grant will help us to develop new and cost-effective methods to produce different types of lignin with adjustable properties (like size and structure) to enhance its application in the production of lignin containing cellulose nanofibrils (LCNF) composites.Recent advances in the use of cellulose nanofibrils (CNFs) to make sustainable polymer composites have demonstrated the potential to revolutionize the U.S. bioeconomy and Maine's forest bio-product industry. Since CNFs naturally attract water, they don't mix well with plastic-like materials that repel water. This challenge with the CNF can be overcome with the production of LCNF, which will improve the hydrophobicity of CNF while providing a market for lignin. Current research is focused on producing LCNF directly from partially delignified fibers containing residual lignin content. This approach would limit the amount of lignin to less than 1 wt% in the production of LCNF derived thermoplastic composites. As an alternative, we will produce LCNF from separated lignin (such as kraft lignin) and adjust its properties, along with the amount of lignin on the surface of CNF particles, to improve its compatibility with plastic materials. The successful formulation of LCNF-reinforced thermoplastic composites can yield enhanced mechanical and viscoelastic properties capable of reducing the U.S. dependence on the non-renewable petroleum feedstock to produce building and packaging materials and increasing the profitability of forest biorefineries.
Animal Health Component
0%
Research Effort Categories
Basic
100%
Applied
0%
Developmental
0%
Goals / Objectives
The overarching goal of this project is to produce lignin basedthermoplastic composites with enhanced properties. To accomplish this goal, the project team in collaboration with industrial partners will address four interrelated research objectives: 1) Develop a cost effective lignin fractionation process using deep eutectic solvent (DES)s and produce multiple lignin fractions with a tunable structural heterogeneity and polymer attributes; 2) Utilize lignin fractions to create LCNFs-reinforced thermoplastic composites, and demonstrate the enhanced mechanical and viscoelastic properties of these composites; 3) Establish the foundational correlations between the structural and polymer characteristics of lignin and the properties of LCNF derived composites; and 4) Perform techno-economic and life cycle assessment of the production of LCNF-reinforced thermoplastic composites to assess the economic viability and environmental sustainability. Our team's education plan involves developing 'bioeconomy course modules' based on research outcomes and integrating them into the chemical engineering curriculum, while also recruiting and training graduate and undergraduate students to support the development of a competent U.S. bioeconomy workforce. Our extension plan involves creating YouTube videos and newsletters based on the research findings.
Project Methods
New DES will be synthesized for the effective fractionation of lignin. The synthesized DES and lignin fractions will be characterized to using different analytical techniques to determine their physical and chemical attributes. After lignin fractionation, the DES will be recovered using a simple separation processfor effective reuse. The fractionated lignin will be mixed with CNF to produce LCNF, which will then be blended with polylactic acid (PLA) matrices at varying compositions. The mechanical and viscoelastic properties of LCNF-reinforced polymer composites will be evaluated following ASTM standards. The development of DES-based lignin fractionation technology and LCNF-reinforced polymer composites will be guided by techno-economicanalysis (Discounted cash flow analysis) and attributional life cycle assessment methods. A DES-based lignin fractionation module is being developed and will be integrated into the unit process lab at UMaine Orono. In this lab, students will have the opportunity to gain hands-on experience with advanced analytical instruments. Research internships will be offered to undergraduate and graduate students to provide training in bioeconomy. YouTube videos will be developed to increase public awareness of renewable composites. Finally, the research findings will be shared with industry stakeholders (bioenergy and bioproducts producers) in the bioeconomy through industry-specific conference presentations and newsletters.