Defence Chencong Ruan: "Development of Catalytic Strategies and Process Technologies for the Valorization of Lignocellulose-derived Carbohydrates to Furanic Aldehydes in Choline Chloride-based Green Solvent Systems"

Promotors: 1^st promotor: Prof. Jun Yue, 2^nd promotor: Prof. Erik Heeres

Abstract: Biorefinery, emerging as a replacement to petroleum-based refinery, aims to manufacture biobased products from biomass feedstocks and follows the principles of sustainability and greenness. Furanic platform chemicals, e.g., 5-hydroxymethylfurfural (HMF) and furfural, play a crucial role within the biorefinery, because they are versatile to produce to a variety of value-added chemicals, biofuels and functional materials. In this thesis, attention was focused on developing efficient solvent systems and catalytic strategies for their synthesis from the corresponding hexose or pentose. The environmentally friendly deep eutectic solvents (DESs) and water-quaternary ammonium salts system (WQAS) were applied to facilitate the dehydration of pentose or hexose to the corresponding furanic aldehyde. In chapter 1, the state-of-the-art in using DESs and WQAS for carbohydrate valorization was reviewed as the introduction of the thesis. In chapters 2-5, research works regarding furfural and HMF synthesis in DES or WQAS systems under the homogeneous catalysis strategy were performed for the purpose to achieve high yields and develop green/sustainable/economic production process, coupling with the application of process intensification technologies such as reaction-extraction technology in biphasic solvent system and microreactor technology to suppress the HMF/furfural-involved side reactions. In addition, the tool of kinetic modeling was applied to give deep insights to the kinetic behavior, conversion pathway and reaction mechanism for the synthesis of furanic aldehyde. Future works about further enhancing the conversion efficiency (via designing solvent system or catalytic strategy) and developing efficient purification technologies of furanic aldehydes (especially HMF) are required.

Dissertation