 Hi. My name is Hanno Richter. I'm working as a research associate in the Engine and Lab at Cornell University. In our current publication in biotechnology and bioengineering, we describe our results of a one-and-a-half-year investigation on how to turn beauty rates into butanol. Our lab's interests lie in the broad field of bioenergy. We have developed anaerobic digesters that harbor mixed microbial communities that convert lichen cellulosic biomass or other organic waste materials into short-chain fatty acids. These carboxylates, for example beauty rates, are a valuable precursor for the production of bioalcohols, for example butanol. In this video, we show our fermentation setup for conversion of end-butyric acid into the biofuel end-butanol. We use pure cultures of clostridium saccharoperbutyl as a tonicum to do the job. The conversion of end-butyrate to butanol and growing the necessary microorganisms requires a source of metabolic energy and electrons, since it is an endothermic biological reduction. Our source is the sugar, glucose, a lot of glucose. From a reservoir containing growth medium with glucose, we are feeding the third fermentation stage, or growth stage, to grow our bacteria. Then the biocatalyst is pumped together with the remaining glucose into a second stage, the production stage, which is 10 times larger in volume. This is where end-butyrate is converted into an end-butanol. The beauty rate is set from a separate reservoir on demand. Whenever the pH value in stage 2 increases above a certain threshold value, this is the signal that most of the beauty rate present has been converted into the corresponding alcohol and addition of more beauty rate is triggered. This way we control the beauty rate concentration at a pretty constant level. The butanol and other solvents that are co-produced are toxic for the bacteria. For that reason we strip them continuously from the reactor. In this process we pump the headspace gas, which is saturated with the produced solvent from our fermentor through a condenser and collect the stripped solvents. The then dry gas is bubbled back into the cementor to take up more solvents and continue their removal. Gas stripping has another advantage. The solvents become concentrated without distillation. During phases of high productivity it can even happen that the butanol concentration in the stripped solvents becomes so high that it separates out by itself and swims on top of the aqueous phase. You can collect it and burn it directly. If you want to know more details about our process, I recommend that you read our paper. Thanks for watching and see you back with your in depth.