From Factory to Supply Chain: Reducing Environmental Impacts of Confectionery Manufacturing using Heat Integration and Life Cycle Assessment

摘要

Global consumption for confectionery products are growing and is exerting enormous pressures on confectionery supply chains across the world to efficiently utilise natural resources towards becoming environmentally sustainable. However, there are a disparate range of studies investigating the environmental impacts of confectionery products, and more importantly how to improve environmental sustainability performance. In this thesis, the aim was to improve knowledge of opportunities for reducing environmental impact in confectionery manufacturing -- from factory to supply chain -- by developing methodological tools based on heat integration and Life Cycle Assessment (LCA). A range of novel methodologies were developed to advance heat integration and LCA knowledge, including (1) a heat integration framework combining direct and indirect heat exchange from zonal to multiple zones, possibly incorporating heat pump technology to enhance low grade heat recovery; (2) methodologies for systematically improving Life Cycle Inventory (LCI) data based on the role of multinational companies and for conducting effective LCA for confectionery products; and (3) a methodology to assess and quantify the environmental life cycle impacts of multi-product food factories. These methodologies have been applied at a multi-product confectionery factory, which has revealed significant findings: (1) combining direct and indirect heat integration from zonal to multiple zones can reduce factory energy by 4.04--6.05%, (2) heat pump technology can reduce factory energy by up to 29.2% but imposes design complexity and long economic paybacks up to 6.62 years, (3) fine bakery ware products on average was found to have the highest aggregated environmental life cycle impacts (higher than chocolate products by 7.1%, milk-based products by 18%, and sugar by 51.9%), and (4) combined improvement strategies of 50% energy reduction with 100% renewable energy, zero food waste to landfill (inc. 50% food waste reduction), and raw material changes to lower impacts can potentially reduce: Global Warming Potential by 65.82%, water depletion by 43.02%, abiotic depletion potential by 20.66%, land use by 17.45% and ecosystem quality by 7.24%. Overall, this research has culminated in several contributions to knowledge which substantially increases understanding of how to improve the environmental sustainability of confectionery manufacturing across the product, factory and supply chain level. The research will serve as a guide for future improvements, research and policies of confectionery manufacturers, supply chain actors, policy makers, and research institutes.