Background Various vegetable oils and animal fats are used in the production of biodiesel, which is seen as a more environmentally friendly alternative to mineral diesel. However, despite the advantages of these biofuels, there are still significant costs attached to their production. Growing crops for the production of oilseed and breeding animals for fats and oils both take up large areas of land and consume significant amounts of energy. Producing biodiesel from used cooking oil has fewer costs, since the raw material is already available as a waste product. In Spain alone, the catering industry produces around 400 000 tonnes of used cooking oils every year, of which around 58 000 tonnes are produced in the region of Andalusia. Exploiting used cooking oils for the production of biodiesel also avoids costs associated either with their management and appropriate disposal, or - in even worse cases - their inappropriate disposal. In Andalusia, only around 34% of used cooking oils (20 000 tonnes) are currently collected and treated properly. Objectives The LIFE BIOSEVILLE project aims to develop an integrated and sustainable system for the recovery and processing of used cooking oils to produce a new, more competitive and efficient biofuel. It aims to demonstrate the feasibility of using this biofuel in the local bus fleet in Seville to significantly reduce air pollution and greenhouse gas emissions. The project will construct a pilot processing plant to produce biodiesel from used cooking oils. The first of two production modules will use an innovative transesterification technology to produce methyl esters. The second will use membrane technology to produce technical grade glycerine with a high degree of purity, which it will then process with acetic acid - through acid catalysis - to produce glycerine esters. The team will mix these methyl esters and glycerine esters to produce a more efficient biofuel. They will test at least 40 m3 of four different biofuel mixtures for use in the city bus fleet (TUSSAM) in Seville. Testing will take place in an engine bench and under real operating conditions, to measure both performance of the combustion process and emissions. Finally, the project will establish a programme to encourage the collection of used cooking oils by local citizens. TUSSAM will examine the possibility of providing discounted bus tickets to those supplying a certain amount of used domestic cooking oil. Expected results: Demonstration of the feasibility of recovery and management of used cooking oils to produce a new biofuel; Development of a prototype module for the production of biofuel from 55 m3 of used cooking oils, achieving the following purity targets: o Methyl esters of 99.5% purity from an innovative transesterification technology; o Technical grade glycerine of at least 95% purity, produced using membrane technology; o Glycerine esters of 80% purity, produced through acid catalysis of the technical grade glycerine; Production of at least 4 000 litres of glycerine esters for use in biofuel mixtures; Production of at least 40 m3 of a new, high quality biofuel – meeting European standards (EN 14214); Demonstration of the technical and economic viability of using the new biofuel in the local bus fleet in Seville; Reduced emissions in the bus fleet for each of four tested biofuel mixtures: o Carbon monoxide (CO) and hydrocarbon (HC) emissions reduced by up to 30%; o Particulate matter emissions reduced by up to 50%; o NOx emissions reduced by up to 5%; Global CO2 emissions reduced by 50-85% compared with conventional diesel, considering the full life cycle of the fuel - including the collection of the used cooking oils, processing of the oils, and consumption of the biofuel in the urban bus fleet.