Análisis de la sostenibilidad de la producción de biodiésel en España frente a las importaciones de Argentina: Análisis del Ciclo de Vida, Análisis Input-Output y Proceso Analítico Jerárquico

Résumé

The bioenergy sector in the European Union has experienced strong growth in recent decades thanks to the promotion of a legislative framework that favours the use of biofuels over fossil fuels, with the main objective of reducing CO2 emissions and promoting environmentally beneficial alternatives. However, this is not the only goal that renewable energies must meet in order to be sustainable, as sustainable development consists of three pillars, seeking to achieve, in a balanced manner, economic development, social development and environmental protection. In Spain, biodiesel is the main biofuel. Its sales are six times higher than those of bioethanol and three times higher than those of hydrotreated vegetable oils (HVO), and its production is three times higher than both, so it deserves special attention as a biofuel. As in most countries in the world, in Spain the production of biofuels would not be profitable for its industry competing in the free market with conventional fuels. Therefore, its market must necessarily be regulated by means of public policies. In recent years, palm oil has been the main raw material used to produce biodiesel in Spain, but due to policy measures imposed by the EU its use will be reduced from 2023 onwards. Palm oil will most likely be replaced by soybean oil or rapeseed oil. In recent years, Argentina has been the main producer of biodiesel produced from soybean oil for consumption in Europe, and its imports have caused significant economic damage to the European biodiesel industry, which uses rapeseed oil as its main feedstock. However, the proportion of one or the other feedstock will continue depending on policy measures. Therefore, the design of policies should take into account the sustainability of each biodiesel production pathway to promote the most sustainable alternative. This PhD thesis analyses the sustainability of biodiesel produced from rapeseed oil and biodiesel produced from soybean oil for use as fuel in Spain for three alternative routes whose consumption is expected to increase in Spain to replace biodiesel produced from palm oil: A) Argentinean Soy Methyl Ester (ASME): soybean-based biodiesel produced entirely in Argentina and exported to Spain B) Spanish Soy Methyl Ester (SSME): soybean-based biodiesel produced in Spain (transesterification) using soybean oil imported from Argentina C) Spanish Rape Methyl Ester (SRME): rapeseed-based biodiesel produced entirely in Spain The Life Cycle Assessment (LCA) of these biodiesel alternatives showed that biodiesel produced with rapeseed oil in Spain (SRME) causes greater environmental impacts than biodiesel produced with soybean oil, either in Argentina or in Spain (ASME and SSME alternatives). Fertilization is the process that produces more environmental loads during the life cycle of biodiesel, so calculating a rational contribution of nutrients is a fundamental step to make a correct analysis of impacts. From the environmental point of view, soybean has a key advantage over rapeseed in terms of fertilization: approximately 50% of the N used by the soybean crop is supplied by biological fixation, which means that less nitrogenous mineral fertilizers are needed, reducing environmental impacts. From the economic and social point of view, the biodiesel produced with rapeseed oil in Spain (SRME) has greater benefits than biodiesel produced with soybean oil, either in Argentina or in Spain (ASME and SSME). In Spain, agroclimatic conditions are suitable for rapeseed and its rotation with cereal would bring great agronomic, economic and social benefits. However, its area has been very small so far compared to other EU countries, probably due to the massive poisoning in 1981 that caused more than 30,000 people affected. Finally, the sustainability assessment identified the SRME alternative (biodiesel based on rapeseed produced entirely in Spain) as the most sustainable biodiesel alternative for Spain. The alternative that proved to be most beneficial for the environment (ASME) was not the most sustainable, as the environmental benefits that can be provided by the SSME or ASME alternatives do not exceed the large economic and social benefits of the SRME alternative. For all the above reasons, the consumption of domestically produced biodiesel using rapeseed oil grown in Spain as raw material would generate positive economic and social impacts for the Spanish society that would justify political measures of differentiated support to the production of this biodiesel alternative. E