Quantification of olive pomace availability for biogas production by using a GIS‐based model

Abstract

AbstractRecently, to obtain biogas from biomass, an innovative system based on both sustainable intensification of crop rotation and use of by‐products was developed. This system derives from BIOGASDONERIGHT concept, which was put forward with the aim of making more sustainable biogas production. Among the by‐products that could be considered for the anaerobic digestion within this new concept, olive pomace (OP) has been the object of research studies aimed at evaluating its possible reuse for energy purpose in terms of economic sustainability. This possibility is of relevant importance to reduce the environmental burden caused by disposal processes of the residues of olive oil industries. However, to the authors’ knowledge, the amount of processed olives in olive‐producing areas, as well as the correct planning of OP use for energy purposes, has not yet been the object of research activities. Therefore, the aim of this research study was to compute the availability of OP, the main waste from the olive oil industry to be disposed of, by following a methodology which included a geographic information system (GIS) based model that allowed the computation of indicators suitable to describe OP potential production within geographical areas. In the first phase of the study, the spatial distribution of the olive‐producing areas in Sicily, a geographical area of the Mediterranean Basin highly representative of olive oil production, was analyzed. Then, a GIS‐based model, previously defined and applied to evaluate the amount of citrus pulp production, was applied to this case study to estimate OP potential production by the computation of a suitable index. The model required information about olive oil industries, which was gathered by performing specific surveys, and included the computation of indicators regarding olive‐producing areas, the amount of olive oil produced, and the amount of OP obtained. In the second phase of this study, the quantification of OP that can be available for biogas production was carried out at a provincial level in an area described by the highest potential of OP production. The total amount of OP available for biogas production corresponded theoretically to 1.9 million Nm3 biogas. This result proved that OP has a high potential to be converted into a resource for renewable energy production, such as biogas. Therefore, it constituted a potential solution to issues related to the environmental burden of OP disposal. Furthermore, the GIS‐based model applied in this case study, by giving the potential production of OP, could contribute to build an information base aimed at improving the sustainability of biogas sector. In this context, by considering the availability and distribution of other agricultural biomasses, the results of this study could be useful for applications in geographical areas where biogas sector is still developing. In fact, the obtained results could help identifying the best location of new biogas plants in terms of optimization of the logistics of biomasses supply. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd