Valorization of food waste into hydroxymethylfurfural: Dual role of metal ions in successive conversion steps

Iris K.M. Yu, Daniel C.W. Tsang, Alex C.K. Yip, Season S. Chen, Yong Sik Ok, Chi Sun Poon

Research output: Journal article publicationJournal articleAcademic researchpeer-review

73 Citations (Scopus)


The results showed that using cooked rice and bread crust as surrogates of starch-rich food waste, yields of 8.1–9.5% HMF and 44.2–64.8% glucose were achieved over SnCl4catalyst. Protons released from metal hydrolysis and acidic by-products rendered Brønsted acidity to catalyze fructose dehydration and hydrolysis of glycosidic bond. Lewis acid site of metals could facilitate both fructose dehydration and glucose isomerization via promoting the rate-limiting internal hydride shift, with the catalytic activity determined by its electronegativity, electron configuration, and charge density. Lewis acid site of a higher valence also enhanced hydrolysis of polysaccharide. However, the metals also catalyzed undesirable polymerization possibly by polarizing the carbonyl groups of sugars and derivatives, which should be minimized by process optimization.
Original languageEnglish
Pages (from-to)338-347
Number of pages10
JournalBioresource Technology
Publication statusPublished - 1 Nov 2016


  • Biomass conversion
  • Bread/rice
  • Homogeneous catalysis
  • Lewis acid
  • Metal chloride

ASJC Scopus subject areas

  • Bioengineering
  • Environmental Engineering
  • Renewable Energy, Sustainability and the Environment
  • Waste Management and Disposal

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