Integrated Design of Biorefineries Based on Spent Coffee Grounds

The circular economy concept applied to the management of spent coffee grounds (SCG) is an opportunity to obtain a portfolio of high added-value products and reducing the environmental impact while increasing the profitability and reducing the energy consumption of the soluble coffee production process. A systematic analysis of the alternatives is performed to unveil integration opportunities and find synergies aiming at the optimal set of processes and products. In this work, five products, dry natural extract, dry natural pigment for the textile industry, biogas, digestate, and electrical energy, through three different processes are considered. The use of SCG to produce biodiesel is discarded after prescreening. A systematic techno-economic analysis of all processes is carried out, and two processes were found economically promising, the production of power and the production of natural extract and pigment. The production of natural pigment and natural extract is the most profitable process, with a profit 40 times larger than the production of electrical energy. The operation and investment costs are 4.59 MM(sic)/year and 13.97 MM(sic), respectively. Therefore, it is possible to achieve economic benefit from the treatment of this waste.

Automated summary

By applying the circular economy concept to the management of spent coffee grounds, it is possible to obtain high added-value products, reduce environmental impact, increase profitability, and lower energy consumption. Through systematic analysis and techno-economic evaluation, production of natural extract and pigment was found to be the most profitable process.