Video transcript: From food waste to fuel in 6 days

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October 2012

Professor Keith Waldron, Director of Biorefinery Research Centre, IFR
My name is Keith Waldron, I am the Director of the new Biorefinery Research Centre at the Institute of Food Research on the Norwich research Park.

Video shows inside and outside views of the building

The new Research Centre has been funded by the BBSRC and by EDA. The aim of the Centre is carry out research and development in order to exploit and improve the exploitation of biomass produced in the agri-food chain. There is a lot of waste produced in agri-food chain and much of this has the potential to have added value through the conversion to other materials such as fuels and platform chemicals. One of the major waste streams that we are focussing on at the moment is wheat straw.

Video shows samples of wheat straw in a bag, then the raw material in the field

This is produced in very large tonnages in the UK because we grow a lot of wheat. The wheat straw itself is relatively low value but under the right conditions it can be converted into fuel bioethanol. In principle this sounds rather straightforward, wheat straw is full of cellulose and if the cellulose use can be degraded using for example cellulose degrading enzymes the glucose released can then be fermented to ethanol.

Video shows the complex and tightly weaved structure of straw made of lignin, viewed under a microscope

Unfortunately the cellulose in the straw is locked up in a very complex structure of lignite and the other way to liberate the cellulose so that it can be digested is to blast part of the cell walls using a pre-treatment facility that we also installed. The stream explosion pre-treatment facility uses high pressure and high temperature to blast open the structure of the plant cell walls liberating the cellulose and allowing access by cell wall degrading enzymes.

Video shows the steam explosion equipment in use

David Wilson, IFR
We use this machine as in the first stage of the process chain for converting cellulose biomass into bioethanol. The sample is introduced into the reactor vessel and is pumped up with steam to high temperatures and pressure and then the pressure is released suddenly and this has the effect of blowing the material apart that should be opened up the structure nicely to allow access to the enzymes.

Video show the steaming, loose straw after the steam explosion equipment has finished

Professor Keith Waldron
Once the straw has been steam exploded the structure of the straw has changed. The cellulose components within the straw are much more available to cell wall degrading enzymes so what we do now is to digest the residual material with cell wall degrading enzymes to release the sugars and we then ferment those sugars using yeasts.

Video shows microscopic view of yeast

We are very fortunate in collaborating under these projects under the National Collection of Yeast Cultures at the Institute of Food Research they have 4,000 yeast strains which enable us to optimise the fermentation process.

Video shows the large collection of yeast types at the National Collection of Yeast Cultures

This is also being done in conjunction with the Wolfson Fermentation Laboratories at the University of East Anglia. Once the ethanol has been produced we also have to consider where it is going to be used.

Video shows a Lotus sports car testing on a track

We have a close collaboration with Lotus Engineering who are developing engines and improving engine performance to make the best use of biofuels such as bioethanol in order to make driving green and learner.