Fermentation is the limiting step in alcohol production using agricultural sub-products and it as been performed in batch, low yield reactors. The main objective of this project is to develop a continuous Fluidised- Bed Bioreactor -Three Phase (FBR -3P) with higher fermentation yields, that will be scaled-up and tested at semi-industrial level. A new configuration of FBR-3P, working in down- flow, will be tested, including selection of a suitable solid phase for good inoculate immobilisation. Also, a mixed inoculums of Simmons Mobilise and Saccharomyces Cerevisiae will be tested. With FBR-3P, productivity should reach values from 25 to 28 g Ethos /L.d , which means from 5 to 10 times comparing with existent batch processes, with less energy requirement. It will be possible to recover evaporated alcohol and also a big amount of carbon dioxide as a sub-product. This proposal fits in European politic of substitution of fossil fuels and valuable recovery of agricultural sub-products.