Life Cycle Analysis of Food Waste Valorization in Laboratory-Scale

Abstract

Among the different alternatives for the production of biofuels, food waste could be a favorable bioenergy source. Using food waste as a feedstock has the potential to meet the expectations of the second generation of biofuels, in terms of environmental savings and revenue-generation, and which, along with other valuable co-products, can contribute to biorefinery profits. This study aimed to investigate the early stages of life-cycle assessment (LCA) for restaurant food waste processed into bioethanol, biomethane, and oil, split over different scenarios. Based on a life cycle inventory analysis, the environmental impacts were assessed using an IMPACT 2002+ methodology. The characterized impacts were then normalized against the average impacts, and the normalized results were weighted and aggregated to provide single score LCA results. The overall findings showed that electricity consumption and condensates included VFAs, as well as enzymes, yeast, and n-hexane, were the main contributors to the environmental burdens in all impact categories. Considering the sensitivity analysis, the results demonstrated that the enzyme dosage loading in the hydrolysis process and n-hexane utilization in the fat extraction process can change the environmental performance, along with the process efficiency. This study can provide an approach to foresee environmental hotspots in the very early developmental stages of food waste valorization into biofuels, and for highlighting drawbacks connected to the implementation of conversion processes at pilot and industrial scales.

Bioprocessing of Waste for Renewable Chemicals and Fuels to Promote Bioeconomy

“…Biorefinery enables us to identify sources such as lignocellulosic crops, which are grown specially to function as feedstocks. Carbohydrates and lignin, triglycerides, and mixed organic residues are the three classes of biomass feedstocks, while the main products of a biorefinery are broadly categorized into two-material products and energy products [3,143]. Materials and energy are the output of biorefinery, apart from multiple other low-value products.…”

A Life Cycle Assessment of Methane Slip in Biogas Upgrading Based on Permeable Membrane Technology with Variable Methane Concentration in Raw Biogas

“…An LCA of biomethane production can also help to determine the environmental benefits and potential trade-offs of biomethane compared to other energy systems. Several recent studies have conducted LCA of biomethane production from different organic waste substrates, such as bread waste, food waste and sewage sludge, and compared the performance of different biomethane production pathways, such as biogas upgrading to bioethanol and biomethane [14,[37][38][39][40], and even direct use of biogas and biomethane as a fuel [41]. These studies have considered the environmental benefits and trade-offs of biomethane production, such as reduced GHGs, improved waste management, and reduced dependence on fossil fuels, as well as the environmental impacts of biomethane production, such as energy use, nutrient losses, and emissions to air, water, and soil.…”