Fractionation process of surplus biomass by autohydrolysis in subcritical water obtaining added value products

Abstract

In the last years, the challenge is a society based on the concept of bioeconomy. This term refers to the sustainable production and conversion of biomass into a range of food, health, fibre, industrial products and energy developed in futures biorefineries. In order to reach this challenge, new policies have been promoted to use the renewable resources and new policies will be necessary to develop a decentralized local-scale production to produce bio-products according to the biomass availability in each area. The decentralized local-scale production results in a major flexibility and versatility in the process due to the use of different biomass generating diversification of products. However, it is required a better knowledge of chemical and structural properties of biomass which would be obtained from research works in science and technology of biomass. The hydrothermal process has been proposed to develop sustainable and efficient conversion of natural resources into fuels and chemicals. This technology is a promising alternative to perform the fractionation of biomass because the reaction medium allows the transformation of the different fractions of biomass by choosing the appropriate conditions. Furthermore, water is a clean, safe and environmentally benign solvent. The use of semicontinuous reactors has been proposed to study the behaviour of hydrothermal processes being the results obtained ¿acceptable¿ compared with the investment and equipment required. The aim of this PhD thesis is to develop a process capable of obtaining added value products from lignocellulosic biomass using the fractionation hydrolysis process and using subcritical water as solvent. A semicontinuous reactor was designed and constructed. The maximum working temperature is 400ºC and pressure is 25 MPa.