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Multi-criteria methods are highly attractive tools to address the inherent complexity of evaluating problems in various scientific areas. The combination of methods such as Delphi/AHP is emerging as a robust alternative to evaluate the sustainability of renewable energy sources. In this theoretical-descriptive research, the use of the Delphi method is proposed to select criteria and sub-criteria to obtain a high level of reliability, while the AHP method is used to establish an order of preference among the alternatives analyzed. This process requires the support of a committee of experts, whose role is to identify the various biomass alternatives that can be used in the sugar industry, considering aspects related to sustainability. The selected experts have identified energy, exergy, and emergetic indicators, in which economic, environmental, and social aspects are integrated. The multi-criteria analysis shows that the V1 variant was the most satisfactory in terms of biomass sustainability, representing 45% and 53% of the overall priorities in the evaluated case studies. In addition, the sensitivity analysis under an equal-weighted scenario for both study cases evidenced that variant V1 acquired the highest score (38.17%) among all alternatives. Variant V4 achieved the second highest score (31.79%), while alternative V2 achieved only 29.04%, respectively. The integration of Delphi/AHP methods emerges as a novel tool to assess sustainability in different industries of the energy sector.

Introducción: La protección ambiental se ha convertido en un factor importante en los indicadores de resultados de las industrias modernas debido a la creciente demanda de procesos de fabricación más sostenibles. Considerando el acelerado proceso de urbanización en Cuba, la industria de materiales de la construcción es de especial interés, destacándose, en este sector, la producción de áridos, la cual, además de la presión a la que se ve sometida, ha sufrido décadas de explotación. Objetivo: Analizar los potenciales impactos ambientales de diferentes esquemas de producción de áridos en Cuba, tomando como caso de estudio la fábrica El Canal ubicada en la provincia de Cienfuegos. Materiales y Métodos: Se usó el análisis emergético por su capacidad de evaluar la influencia de diferentes tipos de recursos en el sistema económico. Resultados y Discusión: El proceso de producción de la fábrica El Canal puede ser mejorado mediante diferentes cambios tecnológicos, siendo el más adecuado la introducción de plantas de hidrociclones en el proceso de clasificación, dado que mitiga impactos ambientales con una considerable menor inversión emergética. Conclusiones: Si bien el proceso de producción de áridos tiene un impacto económico moderado, este no es sostenible a largo plazo (ESI=0,0011) ya que incurre en marcados impactos ambientales debido al uso intensivo de recursos no renovables.

The present Cuban economic model focuses on renewable sources of energy production, according to sustainable development strategies for 2030. However, the strategies do not consider biogas (or methane) due to, among other reasons, a lack of knowledge of its actual potential. Following the methodology of the batch anaerobic digestion process, the studyshows the biomethane potential contained in the most critical agricultural solid wastes generated in Cuba, i.e., rice straw, cane straw, corn straw, bean straw, banana straw (leaves), coffee husk, and parchment coffee. Biochemical Methane Potential (BMP) was assayed by lab-scale (585 ml) batch reactors, using the pig manure anaerobic sludge as inoculum under mesophilic conditions (35 ± 2 °C). Physicochemical parameters (total volatile solids, pH, alkalinity, volatile fatty acid concentration, and alkalinity ratio) were determined for process stability, quantifying the biogas production daily. Subsequently, the BMP was calculated for all substrates. The results showed that corn straw (0.42 l CH4 per gram of volatile solids) contained the highest biomethane potential. Stability on all systems was obtained, demonstrating the viability of the inoculum used to start digesters that treat this waste. The total potential methane obtained was 1258 106 m3/year, which is enough to generate 3,750 GWh of power per year—equivalent to 18 % of the total annual electricity generation in the country.

Due to the need to evaluate the sustainability of the management of rice straw during rice production in Cuba, the objective of this work was to propose the analysis of four possible alternatives, for the valorization of rice straw for energy purposes in Cuba in two different scenarios, the Life Cycle Assessment (LCA) metodology was used. The "South of the Jíbaro" Grain Enterprise was evaluated as a case study. The environmental impacts generated from the intermediate impact categories and those associated with the three categories of final damages proposed by the methodology ReCiPe was evaluated. In addition, the behavior of the ecological footprint was evaluated. The climate change impact category expressed in kg CO2-Eq. The three alternatives 2, 3 and 4, where valorization of rice straw for energy purposes are considered, presented the better results. The alternative 4, where part of the biogas generated is used in the transportation of the different products has the least impact on climate change, with a difference from the currently used alternative 1, of 4.09923 e + 7 kg of CO2-Eq. In the particle formation impact category expressed in (kg PM10-Eq), alternatives 2 and 3 have the most unfavorable results with emissions of 3.46561 e + 5 kg PM10-Eq. This value is higher than the alternative 1 (the currently used), which is associated with the necessary increase of diesel consumption for the transfer of the different products in the process. However, in Alternative 4, the emissions are reduced in 1.86204e + 5 kg PM10-Eq when the biogas is used as a fuel source for the replacement of a part of the diesel used in transportation. In the categories of final damages, the three alternatives where it is proposed to valorize rice straw for energy purposes have advantages with respect to Alternative 1. Alternatives 2 and 3 have a score of 9.11450e + 5 less than Alternative 1; and Alternative 4 reaches a score of 3.033540e + 6 less than Alternative 1 and of 2.119390e + 6 points with respect to Alternatives 2 and 3, what makes Alternative 4 the one that damages the environment.

Por la necesidad de evaluar la sostenibilidad de la generación distribuida en Cuba, con este trabajo se persigue: evaluar el impacto ambiental y la eficiencia exergética de la generación distribuida en la Central Eléctrica de Fuel oí l Sancti Spíritus. Se aplicó la metodología de Análisis del ciclo de vida a dos variantes y un balance exergético al área de generación. En el motor es donde ocurre mayor transformación de la energía. En los gases de escape de la primera variante se pierde a la atmosfera 986,32 kW lo que representa un 34,80% de la energía total que entra al motor, y en la segunda 1168,57kW el 40,39%. De igual manera en la primera variante el aprovechamiento de la energía en la generación de electricidad es de 35,29% de la energía total del fuel oíl y en la segunda 34,56%, demostrándose que la primera variante es más eficiente energéticamente. El proceso de generación es el que mayor responsabilidad tiene sobre los impactos que genera la central y la categoría de impacto sobre las que más incide es el impacto sobre la salud humana. En el proceso de generación la eficiencia exergética del producto (1 MWh) en la primera variante es de 17,60% del total de exergíasuministrada y la segunda el 17,37%. La eficiencia exergética en la primera variante fuede 67,36% y en la segunda variante de 62,42%. En el aprovechamiento de los gases de escape fue de 10,91 % para la primera variante y 6,06 % para la segunda.