Life cycle assessment of the valorization of rice straw for energy purposes. Rice production in Cuba
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.