CEST2025

According to Hong Kong Environmental Protection Department (HKEPD), approx. 1.2 million ton food waste (FW) and 80 kilo ton yard waste (YW), as two typical organic solid wastes, are generated annually in Hong Kong. In fact, both FW and YW are valuable renewable carbon resources or green alternatives to petroleum for energy and chemical production. However, the majority of these resources in Hong Kong are disposed of as wastes at landfills or by incineration, causing not only fast-depleted landfill spaces, but also secondary pollutions (leachate, CH4, GHG, NOx, and dioxins). Therefore, it is urgent to develop new technologies for the harmless, reduction, and resourceful treatment of organic wastes for bioenergy and high value-added bioproducts, in order to achieve the goal of zero landfill by 2035 & carbon neutrality by 2050 in the Hong Kong and support China’s initiative of promoting the construction of “waste-free cities”. Previous efforts in conversion of biomass or organic solid waste (OSW) often focused primarily on specific target bioproducts, but they often overlooked the potential of valorization of the byproducts generated during the biomass/OSW conversion process. In this talk, research projects including innovative biorefinery approach for conversion of food and yard waste residues into various value-added products such as biobased non-isocyanate polyurethane (NIPU) resin and sustainable aviation fuels (SAF) will be introduced to illustrate how science and engineering can be applied for organic waste valorisation. The second part of the talk will focus on food waste hydrolysis using commercial enzymes for the mixotrophic cultivation of microalga Euglena gracilis. The remaining solids after food waste hydrolysis were mixed with algae biomass as the feedstocks of the hydrothermal liquefaction process for biofuel production.