Browsing by Author "Lorenzo-Llanes, Junior"

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    Enhanced methane production from protein and lipid-rich wastewater using powdered oat husk-biochar
    (2024) Pages-Diaz, Jhosane; Vidal, Ivan; Huilinir, Cesar; Hernandez-Velez, Leslie; Lorenzo-Llanes, Junior
    BACKGROUNDDue to the lower degradation and the potential inhibitory compounds present in slaughterhouse wastewater (SW), its industrial applications are often limited to methane production. This study investigated the combined effect of conductive material such as oat husk-biochar at different concentrations (0, 5, 10, 15, 20, 25 g L-1) and particle sizes (i.e., Powder Biochar (PB) (0.05-0.08 mm) vs. Granular Biochar (GB) (0.8-1.0 mm)) in the methane production, biodegradability, kinetic parameters, methanogenic activity and digestate quality of SW, using a multilevel factorial design.RESULTSExperimental results showed that lower concentration (5, 10 g L-1) increased the methane yield up to 35% for PB and between 11 and 13% for GB compared to the control reactor. The total ammoniacal nitrogen concentrations in the digestate declined between 14% and 52% for all biochar dosages and particle sizes. PB improved the specific methanogenic activity of the biomass compared with GB, indicating that PB can support a well-balanced methanogenic community compared with GB inside the digester. The multiple response optimization process computed that 7.5 g L-1 of PB is optimal to increase the methane yield, the COD degradation efficiency and shorten the lag phase. On the other hand, doses higher than 15 g L-1 hinder methane generation.CONCLUSIONSPB supplementation has significant potential to improve the anaerobic degradation of SW. The improvement is attributed to the higher specific surface area, contributing to better support and microbial activity. (c) 2024 Society of Chemical Industry (SCI).
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    To dream or not to dream in Havana: multi-criteria decision-making for material and energy recovery from municipal solid wastes
    (2023) Alfonso-Cardero, Arael; Pages-Diaz, Jhosane; Kalogirou, Efstratios; Psomopoulos, Constantinos S.; Lorenzo-Llanes, Junior
    Currently, solid waste management strategies in Havana are outdated. This paper aimed to select the most suitable alternative for integrating material recovery facilities (MRF) with waste-to-energy technologies in the city of Havana, Cuba. Seven scenarios were considered: combustion, gasification, and hydrothermal carbonization (HTC) with and without carbon capture, and anaerobic digestion (AD). The selection was based on environmental, techno-economic, and social parameters using an analytic hierarchy process (AHP) as a multi-criteria decision-making tool (MCDM). The MCDM-AHP accounted for qualitative criteria (based on experts' judgments) and quantitative (based on Aspen Plus simulation models). From the MRF, 63% of the input recyclable materials were recovered, representing an energy saving of 256 kW-h/t(MSW). The AHP results showed that environmental criteria had the highest priority, resulting in similar to 63% and similar to 73% higher than social and techno-economic criteria, respectively. Likewise, from the techno-economic, environmental, and social sub-criteria analysis, investment risk, pollution, and work safety had the major concern compared with the other sub-criteria levels. Overall, MRF+AD was the most suitable scenario (21% preference) for treating Havana's municipal solid waste (MSW), followed by combustion and gasification with carbon capture, respectively. This study confirms that AD is a preference option for emerging economies like Cuba, mainly due to low environmental pollution, high social acceptance, and financial stability in the long term.