Project Supported by Higher Education Institutions, 2022 - Continues
Due to its refreshing properties, coffee is one of the most consumed and popular beverages globally. However, this industry generates huge amounts of organic wastes that are directly dumped into the landfills without a proper waste management. Spent coffee grounds (SCG) stands among the most generated wastes from this industry. Current research indicated that SCG have excellent characteristics and therefore it can be valorised to produce numerous types of biofuels and value-added products.
This proposal aims to valorise SCG through a proposed small-scale biorefinery to be developed at the alternative fuels research laboratory (AFRL) to generate green energy and value-added products. Upon collection, the wet SCG will be dried followed by the extraction of the lipids. The lipids, known as spent coffee grounds oil (SCGO) will be blended, in small percentages, with waste cooking oil (WCO) to reduce its extremely high acidity for biodiesel production. Biodiesel will be tested in a compression ignition (CI) diesel engine. The remain of SCG after oil extraction, known as defatted spent coffee grounds (DSCG) will be also valorised. Part of the DSCG will be anaerobically digested to produce biogas through mono- and co-digestion with glycerine which is a by-product of the transesterification process besides other organic wastes. Various pre-treatment, co-digestions and refining approaches will be applied to have a high quality and yield of bio-methane. DSCG will be also assessed to be used as a catalyst for the biodiesel production and for supercapacitor applications. Additionally, glycerine will be assessed as a catalyst for alkaline glycerol direct fuel cells (AGDFC).
The outcome of this project will, definitely, contribute to support the concept of integrated biorefineries. This also supports the gradual transformation into a circular bioeconomy in Turkey to achieve a partially self-sufficient demand of energy needs and production of value-added products.