Ethanol from orange peel

19 February 2010

His approach is said to be greener and less expensive than the current methods available to run vehicles on the fuel.

According to UCF, Daniell’s method can also be applied to several non-food products, including sugarcane, switchgrass and straw.

Daniell said: ‘This could be a turning point where vehicles could use this fuel as the norm for protecting our air and environment for future generations.’

Daniell’s technique — developed with US Department of Agriculture funding — uses plant-derived enzymes to break down orange peels and other waste materials into sugar, which is then fermented into ethanol.

Corn starch is currently fermented and converted into ethanol but ethanol derived from corn produces more greenhouse gas emissions than petrol. Ethanol created using Daniell’s approach is claimed to produce much lower greenhouse gas emissions.

There is also an abundance of waste products that could be used without reducing the world’s food supply or driving up food prices. In Florida alone, discarded orange peels could create about 200 million gallons of ethanol each year, Daniell said.

More research is needed before Daniell’s findings, published this month in Plant Biotechnology Journal, can move from his laboratory to the market. However, other scientists conducting research into biofuels describe the early results as promising.

Mariam Sticklen, a professor of crop and soil sciences at Michigan State University, said: ’Daniell’s team’s success in producing a combination of several cell wall degrading enzymes in plants using chloroplast transgenesis is a great achievement.’

Daniell said no company in the world can produce cellulosic ethanol — ethanol that comes from wood or the non-edible parts of plants.

Depending on the waste product used, a specific combination or ’cocktail’ of more than 10 enzymes is needed to change the biomass into sugar and eventually ethanol.

Orange peel needs more of the pectinase enzyme, while wood waste requires more of the xylanase enzyme. All of the enzymes Daniell’s team uses are found in nature, created by a range of microbial species, including bacteria and fungi.

Daniell’s team cloned genes from wood-rotting fungi and produced enzymes in tobacco plants. Producing these enzymes in tobacco instead of manufacturing synthetic versions could reduce the cost of production by a thousand times, which should significantly reduce the cost of making ethanol, Daniell said.

Tobacco was chosen as an ideal system for enzyme production for several reasons: it is not a food crop and it produces large amounts of energy per acre.