Chitin: sustainable valorization into nitrogen-rich chemical products
| PhD ceremony: | Ms T. (Ting) Wang |
| When: | June 20, 2025 |
| Start: | 12:45 |
| Supervisors: | prof. dr. P.J. (Peter) Deuss, prof. dr. ir. H.J. (Hero Jan) Heeres |
| Where: | Academy building RUG / Student Information & Administration |
| Faculty: | Science and Engineering |
Chitin, an abundant biopolymer in crustacean waste, presents a valuable renewable source of carbon and fixed nitrogen. Its efficient utilization holds great promise for developing sustainable biorefineries and reducing dependence on fossil-based chemicals and the energy-intensive Haber-Bosch process. In her thesis, Ting Wang explores chitin conversion technologies to expand the chemical space for nitrogen-rich bio-based chemicals through chemocatalysis, pyrolysis, and mechanochemical methods.
Wang provides an overview of chitin’s structure, extraction methods, and valorization potential and delves into five transformation strategies: pyrolysis, deacetylation to chitosan, depolymerization into COSs and NAG, conversion into platform molecules (e.g., furans, amines), and synthesis of benzenoid aromatics.
Wang then focuses on synthesizing chitin-derived amido furans and their reactivity in Diels-Alder reactions. Reactivity and endo/exo selectivity varied with functional groups, supported by DFT calculations and kinetic modeling, offering insights into structure-reactivity relationships.
Wang also investigates CoOx@Co-NC catalysts in hydrogenating chitin-derived aldehydes into their corresponding alcohols. The presence of oxidized cobalt species, particularly CoOOH and Co3O4 contributes to the high activity and selectivity. Additionally, the enzymatic polymerization of BHMF mixtures allowed tunable bio-polyester synthesis.
Finally, Wang examines the thermal decomposition of pretreated chitin. Ball-milling and acid pretreatment lower decomposition temperatures and alter product profiles. Catalysts (CaO, Al₂O₃, H-ZSM5) direct selectivity: CaO preserves nitrogenous compounds, Al₂O₃ enhances levoglucosenone, and H-ZSM-5 favors aromatics (BTX) while suppressing nitrogen byproducts. Overall, this work advances understanding of chitin valorization pathways and supports its integration into sustainable chemical production systems.