Abstract
The coffee industry is raising environmental concerns around the world due to the high energy consumption and waste produced from processing coffee beans. The highest energy consumption is the roasting stage, which utilizes thermal energy from burning fossil fuels to heat the air to a temperature of around 220 °C. This hot stream is usually vented to the atmosphere. Additionally, the process produces a by-product known as ‘silverskin’, which is commonly discarded to landfills or gets incinerated by most industries as a waste. This by-product has the potential to be exploited for the generation of high value-added products, due to its high content in antioxidant compounds. In this study, energy-saving solutions related to hot stream recycling and the valorization of silverskin by-product were evaluated in the context of sustainability and circular economy. The proposed solutions of the present work include the installation of a heat pump for the pre-roasting of the coffee beans, resulting in a reduction in usage of fossil fuels and the incorporation of innovative extraction techniques for the recovery of valuable compounds, such as phenolics and flavonoids. Moreover, an economic analysis of the proposed solutions was carried out with the aim of evaluating the economic feasibility and sustainability of this specific investment project. Finally, scale-up experiments were performed to evaluate the impact of the proposed methodologies in a conventional coffee production line.
