Fruit May Have Potential as Fuel Source
Date: 18.7.2006
Researchers at the University of Wisconsin-Madison have found a more economical way to use fructose, the sugar in fruit, as an alternative to petroleum in the development of raw materials used to build plastics, fuels and pharmaceuticals.
They hope it will be an important step toward building more everyday products from renewable sources and reducing our reliance on fossil fuels.
The new method, published Friday in the journal Science, makes the production of the versatile molecule HMF cheaper and more efficient, according to chemical engineer James Dumesic, who developed the technique with colleagues.
Converting Biomass
Until now, manufacturing of HMF was too expensive for it to be used commercially.
Joseph Bozell, a professor of biomass chemistry at the University of Tennessee who was not involved in the research, sees these results as a first step in moving toward petroleum alternatives in the chemical industry.
"Once you get to the point of thinking about HMF," Bozell said, "you have a material analogous to something from the petrochemical industry that is a building block for thousands of other things."
The building block Bozell refers to is terephthalic acid. This compound is used in the production of polyesters such as PET, the recyclable plastic in soda bottles. HMF is easily converted into another compound, FDCA, which is the biofuel equivalent of terephthalic acid.
Converting biomass -- waste material from plants -- into chemical compounds is a growing area of research.
"Just as people learned to process crude oil, we are learning to process carbohydrate molecules from biomass," said Juben Chheda, a UW graduate student who worked on the project.
Replacing petroleum-derived products with biomass alternatives can also reduce global warming.
Fossil fuels move carbon that has been trapped in the Earth into the atmosphere. Renewable processes, on the other hand, do not introduce any new carbon into the atmosphere, said Yuriy Roman-Leshkov, a UW graduate student and first author of the paper. In these processes, plants are used to make fuels and plastics. The carbon that is released into the atmosphere returns to plants through photosynthesis, and the process can begin again.
Dumesic's method for HMF production meets three key criteria: First, the process has a high yield. Roughly 85 percent of the fructose is turned into HMF. Second, the reaction results in a high concentration of HMF. Finally, it is easy to separate the HMF from the solvent when the reaction is complete.
Ten-Minute Process
To make HMF, or 5-hydroxymenthylfurfural, scientists put water, fructose and an acid catalyst in a reactor. These components are known as the "aqueous phase."
Then they add the organic solvent, which is composed of a solvent called "MIBK" and butanol.
The aqueous phase and the organic solvent are like oil and water -- the two don't mix.
The catalyst turns the fructose into HMF. Then the MIBK and butanol draw the HMF out of the aqueous phase. If the HMF were left in the aqueous phase, it would react with fructose and produce unwanted byproducts.
The solvent is heated to 180 degrees Celsius, evaporating the MIBK and butanol and leaving the HMF behind. The solvents are returned to the reactor and can be used again.
The entire reaction takes about 10 minutes.
Last year, Dumesic and his colleagues patented a method to convert HMF into liquid alkanes, which are used in diesel fuels. This result, coupled with other research on turning HMF into FDCA, prompted their study.
They will continue to work on HMF production and hope to replace fructose with other carbohydrates, such as glucose, starch or cellulose.
Researchers at the University of Wisconsin-Madison have found a more economical way to use fructose, the sugar in fruit, as an alternative to petroleum in the development of raw materials used to build plastics, fuels and pharmaceuticals.
They hope it will be an important step toward building more everyday products from renewable sources and reducing our reliance on fossil fuels.
The new method, published Friday in the journal Science, makes the production of the versatile molecule HMF cheaper and more efficient, according to chemical engineer James Dumesic, who developed the technique with colleagues.
Converting Biomass
Until now, manufacturing of HMF was too expensive for it to be used commercially.
Joseph Bozell, a professor of biomass chemistry at the University of Tennessee who was not involved in the research, sees these results as a first step in moving toward petroleum alternatives in the chemical industry.
"Once you get to the point of thinking about HMF," Bozell said, "you have a material analogous to something from the petrochemical industry that is a building block for thousands of other things."
The building block Bozell refers to is terephthalic acid. This compound is used in the production of polyesters such as PET, the recyclable plastic in soda bottles. HMF is easily converted into another compound, FDCA, which is the biofuel equivalent of terephthalic acid.
Converting biomass -- waste material from plants -- into chemical compounds is a growing area of research.
"Just as people learned to process crude oil, we are learning to process carbohydrate molecules from biomass," said Juben Chheda, a UW graduate student who worked on the project.
Replacing petroleum-derived products with biomass alternatives can also reduce global warming.
Fossil fuels move carbon that has been trapped in the Earth into the atmosphere. Renewable processes, on the other hand, do not introduce any new carbon into the atmosphere, said Yuriy Roman-Leshkov, a UW graduate student and first author of the paper. In these processes, plants are used to make fuels and plastics. The carbon that is released into the atmosphere returns to plants through photosynthesis, and the process can begin again.
Dumesic's method for HMF production meets three key criteria: First, the process has a high yield. Roughly 85 percent of the fructose is turned into HMF. Second, the reaction results in a high concentration of HMF. Finally, it is easy to separate the HMF from the solvent when the reaction is complete.
Ten-Minute Process
To make HMF, or 5-hydroxymenthylfurfural, scientists put water, fructose and an acid catalyst in a reactor. These components are known as the "aqueous phase."
Then they add the organic solvent, which is composed of a solvent called "MIBK" and butanol.
The aqueous phase and the organic solvent are like oil and water -- the two don't mix.
The catalyst turns the fructose into HMF. Then the MIBK and butanol draw the HMF out of the aqueous phase. If the HMF were left in the aqueous phase, it would react with fructose and produce unwanted byproducts.
The solvent is heated to 180 degrees Celsius, evaporating the MIBK and butanol and leaving the HMF behind. The solvents are returned to the reactor and can be used again.
The entire reaction takes about 10 minutes.
Last year, Dumesic and his colleagues patented a method to convert HMF into liquid alkanes, which are used in diesel fuels. This result, coupled with other research on turning HMF into FDCA, prompted their study.
They will continue to work on HMF production and hope to replace fructose with other carbohydrates, such as glucose, starch or cellulose.
Source:[ http://www.linuxinsider.com/story/O9Ty0gUXguOKM5/Fruit-May-Have-Potential-as-Fuel-Source.xhtml]
