Affiliation:
1. Unidade de Bioenergia e Biorrefinarias, LNEG—Laboratório Nacional de Energia e Geologia, Estrada do Paço do Lumiar, 22, 1649-038 Lisboa, Portugal
2. LEAF—Linking Landscape, Environment, Agriculture and Food Research Center, Associated Laboratory TERRA, Instituto Superior de Agronomia, Universidade de Lisboa, Tapada da Ajuda, 1349-017 Lisboa, Portugal
Abstract
This work proposes a valorization route for spent coffee grounds (SCG), a widespread lignocellulosic residue, encompassing the production of: biomethane, lignin, and oligosaccharides as value-added products obtained simultaneously during a mild alkaline (NaOH) pretreatment. The studied operational variables were the reaction time (60–240 min), temperature (25–75 °C), and the NaOH concentration (0–2.5 M). The severity factor suitably describes the global process kinetics, with higher severities (log Mo = 5.5) yielding high product yields, 18.02% and 13.25% (on dry SCG basis) for lignin and oligosaccharides (XGMOS), respectively. Solid yield is negatively impacted by all studied variables (at the 95% confidence level). Conversely, XGMOS yield is positively influenced both by time and catalyst concentration, whereas lignin yield is only (positively) influenced by catalyst concentration. Optimal balance between product formation and potential operational costs is putatively achieved when using 0.625 M NaOH, at 50 °C for 60 min. The mild alkaline pretreated biomass (MAP-SCG) was compared to untreated SCG for biomethane production by anaerobic co-digestion with pig slurry (PS), using a ratio of biomass/PS = 1/3 (volatile solids (VS) basis). The proposed valorization route enabled the sequential production of 6.25 kg lignin, 6.36 kg oligosaccharides, and 138.05 kg biomethane per 100 kg of non-extracted SCG (and 287.60 kg pig slurry), in an integrated process that is technically feasible and promotes the circular bioeconomy.
Funder
BRISK II
Biomass and Bioenergy Research Infrastructure
Operational Programme for Competitiveness and Internationalization
Lisbon Portugal Regional Operational Programme
North Portugal Regional Operational Programme
FCT—Fundação para a Ciência e a Tecnologia, I.P.
Subject
Energy (miscellaneous),Energy Engineering and Power Technology,Renewable Energy, Sustainability and the Environment,Electrical and Electronic Engineering,Control and Optimization,Engineering (miscellaneous),Building and Construction
Reference49 articles.
1. Biodiesel, biogas and fermentable sugars production from spent coffee grounds: A cascade biorefinery approach;Battista;Bioresour. Technol.,2021
2. Teixeira, R.A., Bueno, B.A., Borges, R.M., and Bringhenti, J.R. (2021). Biochemical methane potential of spent coffee grounds via co-digestion with food waste. Bioenerg. Res., 1–12.
3. The circular bioeconomy: Its elements and role in European bioeconomy clusters;Stegmann;Resour Conserv Recycl X,2020
4. Towards the sustainable and circular bioeconomy: Insights on spent coffee grounds valorization;Gebreeyessus;Sci. Total Environ.,2022
5. Biotechnological conversion of spent coffee grounds into polyhydroxyalkanoates and carotenoids;Obruca;New Biotechnol.,2015
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