Das Projekt "Use of scavengers in the pretreatment of lignocellulosic biomass for improved chemicals production" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Verfahrenstechnik durchgeführt. Combined production of fuels and chemicals from wood This project examines an innovative approach for pre-treating wood in order to produce fuels and chemicals. In this approach, the researchers combine hot water treatment with so-called radical scavengers. Background Biofuels from wood have economic and ecological advantages as compared to fuels from corn starch and sugar cane (costs, availability, no conflict with food production). However, it is much more difficult to transform wood into biofuels. This is because the components of wood-cellulose, hemicelluloses and lignin-are strongly interwoven to protect the plant against external forces, in particular. In the production of biofuels, this impedes the enzymatic degradation of cellulose and lignocellulose into their respective sugars, which can subsequently be fermented to produce, for example, bio-ethanol. Therefore, it is necessary to pre-treat the wood in order to break up its structure and improve the enzymatic access. Aim One possible treatment of biomass would be to dissolve it in hot water, but this is hampered by cross-linking reactions of emerging lignin fragments. So-called 'radical scavengers' can stop these undesired reactions and make the wood much more soluble. This procedure is aimed at achieving, on the one hand, a cellulose fraction with improved enzymatic access and, on the other hand, a high-quality lignin fraction. The latter serves as a starting material for the production of aromatic chemicals. Significance The examined approach is aimed at producing fuels and aromatic chemicals which are today still gained from petrochemical resources. This opens up new avenues for gradually replacing fossil oil with biomass.
Das Projekt "Enhanced direct fermentative production of chemicals from forestry residues in a membrane biofilm reactor by enzymatic in-situ lignin modification" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Verfahrenstechnik durchgeführt. One-stage fermentation of wood into ethanol in a membrane biofilm reactor This project focuses on procedural improvements for the production of bio-ethanol from wood, which serves as an alternative to fossil fuels and emits only very small amounts of the environmentally harmful CO2. With the help of a special reactor and suitable microorganisms, several process steps that were separate until now will be integrated and the production of ethanol out of wood simplified. Background The use of bio-ethanol as fuel reduces the emission of greenhouse gases such as CO2. Bio-ethanol has so far mainly been produced from sugar cane and corn starch and has therefore competed with the production of food and fodder. Although difficult in technical terms, ethanol can also be produced from lignocellulose, e.g. wood. In the current biotechnological procedure, the biomass is initially thermochemically treated. In the next step, the enzymes split the cellulose into monosaccharides, which is then fermented into ethanol by microorganisms. This process needs to be strongly simplified and made more cost-efficient, however, before it can be used commercially. Aim The research work focuses on a simplified, integrated process for producing ethanol from pre-treated lignocellulose. In a multi-species biofilm membrane reactor (MBM reactor), the enzymes are produced, the hemicelluloses and cellulose saccharified, the resultant monosaccharides fermented and the ethanol ultimately separated. It is, however, difficult to transform lignin-rich wood into ethanol biotechnologically. For this reason, the researchers are expanding the microbial consortium used with lignin-degrading fungi strains to see whether the yield and reaction rate can thereby be improved and the energy consumption at the pre-treatment stage reduced. Significance Climate policy and resource economy offer good reasons for increasing the share of renewable fuels made from lignocellulose. The simple MBM procedure has the potential to produce ethanol sustainably, efficiently and decentrally in a forested or agricultural environment with short transport routes for the required biomass.