Author: Yu, Ka Ming
Title: Valorisation of carbohydrate-rich food waste for synthesis of hydroxymethylfurfural (HMF)
Degree: Ph.D.
Year: 2018
Subject: Hong Kong Polytechnic University -- Dissertations
Food waste -- Recycling
Catalysis
Pages: xix, 233 pages : color illustrations
Abstract: Food waste that amounts to over one billion tonnes per year globally is a potential renewable feedstock for biorefinery. This thesis focuses on the development of high-throughput catalytic systems to produce value-added chemicals, such as hydroxymethylfurfural (HMF), from various selected food waste that is rich in starch, cellulose, or sugars. Different homogeneous catalysts and solvents are scrutinised to pursue an efficient conversion system. The findings highlight that the derived Brønsted acidity and intrinsic Lewis acidity of metals (e.g., Sn(IV) and Al(III)) are critical for HMF selectivity, by maneuvering the kinetics of desirable tandem reactions and undesirable side reactions. These acidities depend on the electrochemical properties of metal ions, e.g., electronegativity and charge density. Adding a co-catalyst (e.g., maleic acid) to the metal-based catalytic systems is demonstrated to be a feasible means to control conversion rate and selectivity. In addition, solvents are evidenced to play an important role beyond serving as a reaction medium. Production of HMF in a binary mixture of water and acetone or acetonitrile (i.e., acetone/H₂O and acetonitrile/H₂O, respectively) is substantially faster than that in dimethyl sulfoxide/H₂O and tetrahydrofuran/H₂O. Replacing the industrial co-solvents by greener alternatives, e.g., propylene carbonate and γ-valerolactone, can further accelerate the conversion, in which HMF of 20-25 mol% can be produced from bread waste within 20 min under microwave heating at 120°C. The solvent medium interacts with the substrates and catalysts, altering their reactivity during catalysis. These research efforts elucidate the roles of different parameters, advise the design of high-performance solid catalyst for recycling purpose, and demonstrate a good potential of food waste valorisation for synthesis of value-added chemicals in real-life applications.
Access: open access

Files in This Item:
File Description SizeFormat 
991022168749103411.pdfFor All Users6.88 MBAdobe PDFView/Open


Copyright Undertaking

As a bona fide Library user, I declare that:

  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.

By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.

Show full item record

Please use this identifier to cite or link to this item: https://theses.lib.polyu.edu.hk/handle/200/9747