Upcycling Yard and Food Wastes into New Resources: Hydrochar for Supporting HKUST Greening
Upcycling Yard and Food Wastes into New Resources: Hydrochar for Supporting HKUST Greening
A sustainable way to deal with food and yard wastes by converting them into hydrochar, which is a high quality resource that can be used as a soil amendment agent for carbon sequestration, improving soil quality, plant health and ecological restoration.
What is the problem this project is trying to address?
Hong Kong is facing with the challenge to manage many tonnes of yard and food waste produced every day. Following the local government’s strategy: ‘a Food Waste & Yard Waste Plan for Hong Kong 2014-2022’, the major strategies currently adopted to deal with both food and yard wastes are natural degradation, anaerobic digestion and aerobic composting. Although these approaches have been widely used globally, they share the following major problems:
(i) creation of odours (hence lead to environmental pollution);
(ii) long start-up time (since the biochemical reactions involved are slow);
(iii) demand large land space (which is a major constraint in the case of the very crowded Hong Kong), and
(iv) requiring professional experts to operate.
How does this project support our sustainable smart campus as a living lab vision?
Through this project, we will increase the value of yard and food wastes which are otherwise landfilled (i.e. economic and environmental benefits), by transforming them into a resource that could improve the ecosystem functions and potentially the quality of life (societal benefit). This idea thus potentially supports economic and societal developments and environmental protection, which are the three pillars that constitute sustainability.
This project applies state-of-the-art technology (i.e., hydrothermal carbonization, HTC) to smartly upcycle low-value wastes into a higher value, yet less energy-intensive and more environmentally-friendly - hydrochar, compared to biochar.