EU policy in recent years has been to promote the use of biocarburantes with the aim of reducing greenhouse gas emissions and the impact of transport on the environment, as well as looking for alternative supply solutions should fossil fuels one day become exhausted. One of the biocarburante substitutions for fossil fuels which till now has been developed more than any other on a world-wide scale is bioethanol. This alcohol can be used as alternative fuel and is already being added to EU petrol in the form of ETBE and also directly, whenever its content doesn´t exceed 5%. The Renewable Energy plan already approved in Spain and EU contemplate an increase in bioethanol production and its gradual incorporation in petrol during the period 2000-2010. An increase in the use of biocarburantes in the transport sector offers considerable environmental benefits, because it will not only contribute to reducing emissions of polluting gases and their hothouse effect in the atmosphere, but will also provide a source of renewable clean energy.
Starch from cereal seeds, along with sucrose from sugar cane or beet, offer the most accessible source of fermentable sugars for the obtention of bioethanol . The process of bioethanol production generally consists of different enzymatic stages, in which different enzymes, cellulases, glucanases, amylases are involved hydrolysing the sugars in cereal seed materials so that at a later stage, yeasts (generally Saccharomyces cerevisiae) can transform them into ethanol. The optimization of the process is essential to increase process yield and reduce unnecessary costs. On the other hand, there are carbohydrates in vegetables residues, with low costs, which can be considered as an alternative fot bioethanol production.
The main objective of the projects in course in the CIB is to produce the maximum quantity of bioethanol from the process by taking fuller advantage of the sugars in the raw materials: grains and cereal residuals. To carry out this study we propose: i) A study of the different commercial enzymatic complexes that are employed in bioethanol production, ii) Optimizing the dose of enzymes used industrially in bioethanol production, iii) Characterize the raw materials and their agricultural by-products, iv) Study fungal pretreatment of lignocellulose residues as an alternative to physico-chemical methods used at currently to pre-treated the lignocellulosic materials before enzymatic hydrolysis, v) Study the effect of funfal oxidoreductases (lacases and/or peroxidases) in lignin biodegradation, before the carbohydrate hydrolysis (pretreatment), to increase final yield of fermentable sugars and vi) Look for new fungal strains secreting high levels of cellulases and/or xylanases to reduce costs and increase bioethanol process yield.
The projects are been carried out in collaboration with “Abengoa Nuevas Tecnologías” (previously named Greencell), a company belonging to the Abengoa Bioenergy group (one of the biggest companies involved in bioethanol production as much in USA as in the EU).