Techno-economic and carbon footprint evaluation of anaerobic digestion plants treating agro-industrial and municipal wastes in North African countries

Mohammed El Ibrahimi; Ismail Khay; Anas El Maakoul; Mohamed Bakhouya

doi:10.1016/j.wasman.2022.09.019

Techno-economic and carbon footprint evaluation of anaerobic digestion plants treating agro-industrial and municipal wastes in North African countries

Waste Manag. 2022 Dec:154:84-95. doi: 10.1016/j.wasman.2022.09.019. Epub 2022 Oct 7.

Authors

Mohammed El Ibrahimi¹, Ismail Khay², Anas El Maakoul², Mohamed Bakhouya²

Affiliations

¹ International University of Rabat, College of Engineering and Architecture, LERMA Lab, 11100 Sala Al Jadida, Morocco. Electronic address: mohammed.elibrahimi@uir.ac.ma.
² International University of Rabat, College of Engineering and Architecture, LERMA Lab, 11100 Sala Al Jadida, Morocco.

PMID: 36215753
DOI: 10.1016/j.wasman.2022.09.019

Abstract

The agro-industrial activity, which is regarded as a pillar of the North-African economy, is responsible for generating considerable waste quantities. These byproducts can be treated through anaerobic digestion (AD), which offers various financial and ecological benefits over traditional waste disposal methods. However, the transition to this sustainable process is faced with several challenges due to the heterogeneity and seasonality of agro-industrial wastes. In this study, we proposed and evaluated three waste management strategies for treating agro-industrial wastes in large-scale AD plants conceived in specific North-African countries. These strategies involve co-digesting seasonal agro-industrial wastes, i.e., three-phase olive pomace (3POP), grape pomace, and orange peel, with the organic fraction of municipal solid waste (OFMSW) throughout the year (MS1); co-digesting the dominant agro-industrial waste (3POP) with OFMSW during the olive harvest season and mono-digesting OFMSW during the rest of the year (MS2); and co-digesting 3POP and OFMSW year-round by storing 3POP in cold storage facilities (MS3). The techno-economic findings show that the proposed AD plants would be profitable in Morocco and Algeria under both MS1 and MS2, with internal rate of return (IRR) values respectively reaching 10.8% and 18.4% under MS1 and 12.4% and 20.1% under MS2. In contrast, the conceived Tunisian plants would be financially feasible only if MS2 is adopted (IRR of 10.7%). Furthermore, the sensitivity analysis indicates that the economic performance of the proposed plants would mostly be affected by the biomethane selling price and capital cost. Additionally, the carbon footprint analysis suggests that the AD plants could, during their lifetime, reduce the CO₂-eq emissions by 411, 208, and 26 Mt (under respectively MS1, MS2, and MS3) compared to the currently used waste disposal practices in the North African region.

Keywords: Agro-industrial waste; Anaerobic digestion; Carbon footprint analysis; Economic evaluation; Municipal solid waste; Waste management.