New liquid transportation fuel made from sugar
According to an article published this week on ScienceDaily.com, Professor James Dumesic, a biological and chemical engineer at the University of Wisconsin-Madison, and his team have developed a two-stage process to convert biomass-derived sugar into 2.5 -dimethylfuran (DMF), a liquid transport fuel with 40% more energy than ethanol.
The prospects of diminishing oil reserves and the threat of global warming due to the release of carbon into the atmosphere have prompted the search for a sustainable, carbon-free fuel that reduces global dependence on fossil fuels. By chemically modifying sugar through a series of steps using copper and acid catalysts, and salt and butanol as a solvent, researchers have opened a path towards developing such a fuel.
"Currently, ethanol is the only renewable liquid fuel produced on a large scale," says Dumesic. “But it has several limitations. It has a relatively low energy density, evaporates easily, and can be polluted by absorbing water from the atmosphere. In addition, it requires an energetically intense distillation process to separate fuel from water ”.
Dimethylfuran not only has a higher energy content, it solves other ethanol problems. DMF is not soluble in water and therefore cannot be contaminated by absorption of water from the atmosphere; once stored it is stable and in the evaporation phase of its production it consumes a third of the energy required to evaporate an ethanol solution produced by fermentation for its application in biofuels.
According to the new method, fructose is initially converted to HMF in water by means of an acid catalyst in the presence of a low-boiling solvent. The solvent extracts the HMF from the water and transports it to a separate site. Although other researchers have previously converted fructose to HFM, the Dumesic team has made a number of improvements that increase HMF production and facilitate its extraction. For example, the team found that adding salt (NaCl) significantly improves HFM extraction and helps prevent impurity formation.
Dumesic describes his process in the journal Nature of June 21, 2007. According to him, more research will be necessary before this technology can be commercialized, verifying, for example, its environmental impact.
Source: Science Daily