This point has been clearly shown in a recent review of published studies. Food waste is generated at various stages, including agriculture, retail, restaurants, and households, with households contributing a significant portion.
Roozbeh Feiz noted that while Sweden has made strides in reducing food waste, much of the waste still ends up in incineration instead of biogas plants. He highlighted that source separation—separating food waste at the point of generation—is key to improving the efficiency of biogas production.
"Households are the largest contributor," he noted, underscoring the importance of tackling waste at its source.
He explained the biogas process, which includes source separation, collection, pretreatment, and anaerobic digestion.
"Once food waste is separated and collected properly, we can maximize the energy recovery"
Roozbeh Feiz emphasized the importance of collection system in this process, especially in peri-urban and rural areas where it is more energy intensive and costly to collect the waste.
To measure and improve the system, Roozbeh Feiz introduced Key Performance Indicators (KPIs). These KPIs track metrics like energy balance, nutrient recovery, and carbon footprint, helping to improve biogas production from a lifecycle perspective and in such a way that they include source-separation rate and collection efficiency. These KPIs allow fair comparison of different production systems.
"KPIs allow us to track improvements in the system while highlighting areas that need further development," said Roozbeh Feiz.
Roozbeh Feiz concluded by discussing the global potential of biogas. He explained that, despite some variation, biogas is one of the most efficient methods for managing food waste and recovering energy. The system’s effectiveness depends on improvements in waste collection, source separation, and nutrient recovery.
