Environmental impact of the food waste utilization instead of raw material: the potential and limitations

Description

With the global urban development, economies are expanding, and the amount of generated waste is increasing. A recent report by the United Nations Environment Programme shows that in 2019, a significant amount, i.e. 931 million tons, of food (from households, retail and food service industry) is wasted worldwide, thus leaving valuable resource without proper treatment and causing serious environmental problems. In recent decades, there have been increasing attempts to reduce the amount of food being wasted and landfilled. The main principle of the circular economy is that at the end of its life waste must be reintroduced into an industrial process as material or energy inflow complying with hygiene and safety requirements. It is often considered that using waste as a raw material is better for the environment than using virgin material. This study aims to assess what are the potentials and limitations of using waste material instead of raw material.
Life Cycle Assessment (LCA) is the most common approach to evaluate the environmental impact of product and production process. In this study, we performed LCA for sophorolipids (bio-based surfactant) production process that uses waste cooking oil (WCO) as a substrate and compared the same process with using raw cooking oil (RCO) as a substrate to evaluate the difference of environmental impact for both processes.
The overall sophorolipids production chain is the same for the WCO- and RCO-based processes and can be divided into three main stages – raw material selection, production process itself, and product application opportunities. Each of these stages has strengths and weaknesses of using waste material as a substrate.
At the resource selection stage, the biggest advantage of using the waste material is resource conservation that would otherwise be used to produce RCO and avoided transportation.
Usage of waste material may cause problems in the production stage. Our previous studies show that WCO often contains some food and salt residues, that can have a negative impact on the production process and final product application. Therefore, it is necessary to consider and implement the pretreatment stage. Adding a pretreatment method to the production process would increase the environmental impact, regarding the mechanical or chemical method is selected. In our study, WCO is used to obtain sophorolipids using fermentation, therefore a risk exists that salt residues can damage reactor mechanisms and reduce the lifetime of the equipment. Hence, at the production stage, life cycle environmental impacts are caused by the selected pretreatment option, resource (energy and chemicals) consumption, and wear of equipment.
The substrate used for production may limit product application options. Even pretreated WCOs can contain some residues, and it can still limit the range of applications, excluding products with constant, standardized chemical compositions as personal care products, cosmetics, food, and pharmaceuticals. Other less-demanding applications like soil improvement, bioremediation, and mineral resource extraction may still be considered as viable application options for WCO-derived sophorolipids. While the selection of the resource may have an impact on product quality and application opportunities, waste as a resource relieves the load imposed on the raw material.

Period	12 Oct 2022 → 14 Oct 2022
Event title	13th International Conference on Life Cycle Assessment of Food
Event type	Conference
Conference number	13
Location	Lima, PeruShow on map
Degree of Recognition	International