To dream or not to dream in Havana: multi-criteria decision-making for material and energy recovery from municipal solid wastes.

Currently, solid waste management strategies in Havana are outdated.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/tMSW. The AHP results showed that environmental criteria had the highest priority, resulting in ~63% and ~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.

Municipal solid waste management scenarios for Attica and their greenhouse gas emission impact.

Disposal of municipal solid waste in sanitary landfills is still the main waste management method in the Attica region, as in most regions of Greece. Nevertheless, diversion from landfilling is being promoted by regional plans, in which the perspectives of new waste treatment technologies are being evaluated. The present study aimed to assess the greenhouse gas (GHG) emissions impact of different municipal solid waste treatment technologies currently under assessment in the new regional plan for Attica. These technologies are mechanical-biological treatment, mass-burn incineration and mechanical treatment and have been assessed in the context of different scenarios. The present study utilized existing methodologies and emission factors for the quantification of GHG emissions from the waste management process and found that all technologies under assessment could provide GHG emission savings. However, the performance and ranking of these technologies is strongly dependent on the existence of end markets for the waste-derived fuels produced by the mechanical-biological treatment processes. In the absence of these markets the disposal of these fuels would be necessary and thus significant GHG savings would be lost.