The current situation of lignocellulosic bioethanol

  • Alexander Jäger (Speaker)
  • Heike Kahr (Speaker)

Activity: Talk or presentationOral presentation


The second oil crisis secured the development of a process for biothanol production from straw in a pilot plant in Upper Austria (Voest Alpine). At the end of the oil crisis, the pilot plant was closed and the equipment and know-how was sold. Multiple reasons like the rising emissions of greenhouse gases and the cost of oil caused a worldwide revitalisation of this technology. Since 2008, the working group Bioethanolics started to set up this technology at the FH Wels, Engineering and Environmental Sciences. The ethanol production process itself is already well examined and established by many working groups on a laboratory scale. The process normally is composed of several steps: the pretreatment to remove the lignin and make the cellulose accessible, enzymatic hydrolysis to obtain the pentoses and hexoses and the fermentation with yeast followed by the downstream processing. The results of the1980’s and 1990’s of so-called VABIO processes could be confirmed. A yield of approx. 90 % in enzymatic hydrolysis of straw as well as in ethanol production could be confirmed on a laboratory scale. After confirmation of the results, one aim was to improve the process with the goal of reaching ethanol concentrations of >10 % Vol. Actually, the ethanol content could be raised from 3% up to 8% just by optimization of the process control and technology. The continuous problem seems to be an inhibition during the fermentation, maybe based on the negative influence from by-products generated during pre-treatment. This is now under investigation using two strategies: removal of inhibitors as well as adaption of yeast to the inhibitors. The Wels ethanol process consists of a pretreatment by means of steam explosion without the addition of any chemicals and of an improved process control and technology to increase the substrate concentration virtually to over 25 %. Actually, there is one 2nd generation pilot and demonstration plant with a capacity of 30 t/d of straw running in Denmark. This plant is using chemicals for the pretreatment step (as do other pilot plants planned in Italy and Spain). An additional liquefication stage to achieve high substrate concentrations and in consequence to obtain ethanol concentrations higher than 10 % is integrated to those processes as well. So the FH Wels ethanol process without the necessity of the addition of chemicals and without an additional liquefication stage seems to have an advantage compared to other processes. It needs to be mentioned, that in order to introduce a competitive industrial technology, it is necessary to examine and improve the complete bioethanol process: pretreatment - enzymatic hydrolysis - ethanol fermentation and downstream processing. Each step has an influence and exerts a feedback on the other steps of the process. All economic and ecological calculations also show the necessity to combine 1st and 2nd generation bioethanol production to replace fossil fuels from the transport sector worldwide. The next step will be the establishment of a pilot plant in Upper Austria. The design of the plant is currently underway. The FH Wels team is looking for investors and scientific partners.
Period31 Mar 2011
Event titleHighlights der Bioenergieforschung
Event typeConference
LocationWieselburg, AustriaShow on map