Spent Coffee Grounds (SCG) Valorization: Applications and Management Practices in the Stavanger Region

Master's thesis in Environmental engineeringThe environmental impact of food waste has been growing in interest among various environmental organizations as well as communities in the last decade. Coffee has been one of the largest consumed drinks worldwide that result in copious quantities of spent coffee ground (SCG) generated as a by-product. SCG has much nutritional value and energy that is normally not captured when dumped into a landfill in addition to the detrimental environmental impact due to the release of Methane. Therefore, valorization of SCG help create new sustainable products and reduce the environmental footprint. The waste recycling approach to producing high-value products also promotes a circular economy. This study is focused on understanding the SCG generation potential in the Stavanger region of Norway. Various data related to SCG generation, consumption, and recycling effort have been collected from different coffee shops as well as restaurants in the region. There is a SCG potential of about 54 – 75 tonnes/year in the Stavanger region from various coffee shops and restaurants, whereas the total potential is in the range of 600 – 2000 tonnes/year. The study compares a few key valorization routes such as industrial composting, fuel pallets, and oyster mushroom production for their technical and economic feasibility. The economic analysis is performed based on a very conservative amount of 37.5 tonnes/year SCG that is assumed to be available for free. Composting and fuel pallets are not profitable whereas oyster mushroom can be profitable with reduced raw materials cost. The future work should extend the data collection to the other regions of Norway as well as various sources of SCG generations to get a more accurate estimate and therefore, look for industrial-scale recycling options such as biodiesel and the respective economic feasibility