Exploring Spent Coffee Grounds Energy Potential in the Brazilian Scenario

Abstract

Coffee stands out worldwide for being widely traded and consumed. However, this consumption generates a large amount of spent coffee grounds (SCGs) that are typically arbitrarily discarded. This biomass has a high heating value and molecular composition that allows for it to be a raw material for generating heat and energy. The search for renewable energy sources should consider the potential of SCGs. Thus, the objective of this study was to estimate the energy potential of SCGs in Brazil. The methodology consisted of searching for data to represent the generation of SCGs in the country and estimate its energy potential. It was found that the amount of SCGs available for power generation through direct combustion was approximately one thousand tons, and the power generation potential was 6.83 TWh/year in Brazil. This energy is sufficient to meet, for example, the total annual demand for public lighting in the country's Southeast. These results are the first steps towards evaluating the potential use of SCGs as an energy source and its environmental benefits. Additionally, this study explored limitations and barriers, providing valuable information for developing routes for using this energy residue and incentives for public policies.

Enhancing the Fuel Properties of Spent Coffee Grounds through Hydrothermal Carbonization: Output Prediction and Post-Treatment Approaches

“…Spent coffee grounds (SCGs), one of the major by-products from the production of coffee drinks and other products, are produced in similar quantities, though very decentrally, in locations ranging from home kitchens and coffee shops to instant coffee and drink producers. After brewing or extracting for coffee beverages, SCGs contain a high water content of 50-60 wt%, a relatively high calorific value of 19-22 MJ/kg, and a carbon content of 47.0-60.0 wt% [2][3][4][5]. The carbon content includes celluloses, hemicelluloses, lignins, lipids, minerals, and protein, together with phenolic compounds, caffeine, and chlorogenic acids, in addition to nutrients such as calcium, magnesium, potassium, sodium, iron, zinc, manganese, and copper [6][7][8].…”