UW-Madison Engineers Produce Higher-Energy Liquid Transportation Fuel From Sugar
20 June 2007
Engineers at the University of Wisconsin-Madison have developed a two-stage process for converting biomass-derived sugar into 2,5-dimethylfuran (DMF), a liquid transportation fuel with 40% greater energy density than ethanol.
The work by Professor James Dumesic and his research team, reported in the 21 June issue of the journal Nature, leverages the process they developed last year for the production of the chemical intermediate hydroxymethylfurfural (HMF) from sugar. (Earlier post.)
In addition to its higher-energy content, DMF also addresses other ethanol shortcomings. DMF is not soluble in water and therefore cannot become contaminated by absorbing water from the atmosphere. DMF is stable in storage and, in the evaporation stage of its production, consumes one-third of the energy required to evaporate a solution of ethanol produced by fermentation for biofuel applications.
The first stage of the DMF process is the conversion of sugar to HMF in water using an acid catalyst in the presence of a low-boiling-point solvent. The solvent extracts HMF from water and carries it to a separate location. Although other researchers had previously converted fructose to HMF, Dumesic’s research group made a series of improvements that raised the HMF output and made the HMF easier to extract. For example, the team found that adding salt (NaCl) dramatically improves the extraction of HMF from the reactive water phase and helps suppress the formation of impurities.
The next step is the conversion of HMF to DMF over a copper-based catalyst. The conversion removes two oxygen atoms from the compound lowering the boiling point and making it suitable for use as transportation fuel. Salt, while improving the production of HMF, presented an obstacle in the production of DMF by contributing chloride ions that poisoned the conventional copper chromite catalyst. The team instead developed a copper-ruthenium catalyst providing chlorine resistance and superior performance.
Dumesic says more research is required before the technology can be commercialized. For example, while its environmental health impact has not been thoroughly tested, the limited information available suggests DMF is similar to other current fuel components.
There are some challenges that we need to address, but this work shows that we can produce a liquid transportation fuel from biomass that has energy density comparable to petrol.—James Dumesic
Earlier this month, a team of researchers at the Pacific Northwest National Laboratory (PNNL) reported in the journal Science on their work to convert glucose directly to HMF. (Earlier post.)
"“Production of dimethylfuran for liquid fuels from biomass-derived carbohydrates”; Yuriy Román-Leshkov, Christopher J. Barrett, Zhen Y. Liu and James A. Dumesic; Nature 447, 982-985 (21 June 2007) | doi:10.1038/nature05923
Never did I see any reference to whether this could be a replacement for gasoline, or for diesel. Can this be burned in an ICE engine with no modifications? Or is this a component transported to a remote location to be converted into a biodiesel or gasohol? Also, how does this DMF compare to regular gasoline, energy density wise?
Posted by: Mark A | 20 June 2007 at 11:21 AM
I assume if you want to use a cellulosic feedstock you'd have to break it down into glucose first.
Posted by: Neil | 20 June 2007 at 11:30 AM
Dimethylfuran is 13 % oxygen by weight, as opposed to ethanol's 35 % (6 carbons in DMF vs 2 in ethanol, both with one oxygen atom). It should therefore have a much higher energy content than ethanol. It should also readily blend with gasoline and its octane number should be high, as it contains oxygen, is aromatic, and is branched. These all contribute to a high octane number. It's boiling point is only slightly higher than ethanol's, at 92 vs 80 C. In warmer climates it should be possible to run a gasoline engine on neat DMF, or perhaps with a small quantity (like E85) of gasoline to aid in starting. The only draw back, which is minor, is that this compound is likely a great solvent, and therefore some fuel system components would have to be upgraded such that they would not dissolve over time.
Posted by: miket1 | 20 June 2007 at 11:44 AM
The big corn lobby will descend and destroy this in record time.
Posted by: Joesph | 20 June 2007 at 12:48 PM
Chemical formula: C6H8O - furanes feature degenerate aromatic rings with five sides (4 Cs plus 1 O). In this case, positions 2 and 5 (symmetrical wrt the oxygen atom) are methylated.
molecular weight: 96
melting point: -62 degC (usable in arctic conditions)
boiling point: 92-94 degC
flash point: 29 degC
density @ 25degC: 0.9 (cp. gasoline ~0.75, diesel ~0.85)
Current applications: pharmaceuticals, flavors & fragrances
volumetric energy density *claimed by UWM*:
1.4 * 26.8MJ/kg * 0.9kg/l = 33.8 MJ/l
cp. 42MJ/kg * 0.75 kg/l = 31.5 MJ/l for gasoline
cp. 42MJ/kg * 0.85 kg/l = 35.7 MJ/l for diesel
research octane number: ?
motor octane number: ?
ring decomposes at 1050-1270K, producing CO
ergo, don't expect high octane numbers
cetane number could be high enough to be useful
other properties: ?
Lit ref: Lifshitz, Tambura, Shashua; Thermal Decomposition of 2,5-dimethylfuran, Experimental results and computer modeling; J. Phys. Chem. A, vol102 (1998), pp10655
General hazard classification from
H=2 (warning: may be harmful if inhaled or absorbed)
F=3 (warning: flammable liquid flash point below 100F)
R=0 (stable: will not react with water)
SI (no special information applicable)
About what you'd expect for a volatile hydrocarbon candidate fuel.
The compound is, however, also used as a blood marker to identify smokers:
Many (not all) furanes are confirmed carcinogens.
Posted by: Rafael Seidl | 20 June 2007 at 12:49 PM
If it's not soluble in water, then presumably it addresses the biggest problem currently with ethanol, the high energy requirement for distillation. Presumably they can pick a solvent that separates easily. At that point, cornstarch (likely to be the first feedstock used for this) gets exonerated as an impractical fuel on an energy basis. Corn is still not as efficient or high-yield as some other plants in the pipeline, but is certainly a global warming advance (as well as, of course, an oil dependence moderator).
Posted by: P Schager | 21 June 2007 at 03:27 AM
One wonders how clean this fuel would burn in the present day vehicle mix.
Posted by: gr | 21 June 2007 at 08:11 AM
What is the octane number?
Higher energy density does not necessarily mean better fuel mileage. Take ethanol, it has lower energy density, but since it has higher octane number than gasoline, it gives more mileage when used in high compression engine specifically designed for burning ethanol.
If this octane number is lower than gasoline, it will be give worse mileage.
Posted by: SM | 21 June 2007 at 08:50 AM
What's the big news? Doesn't everything have a 40% greater energy density than ethanol? Energy densities by themselves have no significance.
Posted by: Kerry Buehrt | 21 June 2007 at 02:18 PM
Key factors for its use as gasoline engine fue1 are:
1. Octane number of pure material and octane number in blends. Niether are predicable from structure; need extensive test engine data.
2. If proposed for diesels, the need similar cetane number data.
3. Need to do early engine and other performance tests on fuel characteristics compared to specifications and standards for existing fuels.
Posted by: marty | 22 June 2007 at 03:52 PM
The solvent they use is butanol which has better fuel characteristics than ethanol or DMF and can be used in IC and diesel engines. Butanol also has 24% more energy than ethanol and can be fermented from the same feed stocks, http://www.butanol.com . New methods of butanol fermentation can also produce an additional 18% energy as Hydrogen gas. DMF could require less energy to produce than butanol, but that might not be true. We need to compare the cost and energy requirements for production of DMF to butanol not ethanol which is not a good replacement for gasoline. Butanol can replace gasoline gallon for gallon in todays vehicles using our current infrastructure.
Posted by: adamone9999 | 25 June 2007 at 11:20 AM
H=3 on the site referenced below. I was concerned that t
2,5-DIMETHYLFURAN might be as hazardous to health as ANILINE, but apparently not. However, both butanol and ethanol are safer. I do not see this as a neat fuel, but rather as a blending component.
ETHANOL, Health Hazard:
VAPOR: Irritating to eyes, nose and throat. LIQUID: Not harmful. (USCG, 1999)
2,5-DIMETHYLFURAN, Health Hazard:
SYMPTOMS: Exposure to this compound may cause skin, eye and mucous membrane irritation. Other symptoms of exposure include conjunctivitis, corneal damage, nausea, vomiting, abdominal pain, headache, dizziness, cyanosis, dermatitis, collapse, respiratory distress, convulsions, blistering and ulceration of skin, gangrene, erythema, vertigo, lowered body temperature, chronic lung disease, kidney and liver damage, and coma.
ACUTE/CHRONIC HAZARDS: This compound may be harmful by inhalation, ingestion or skin absorption. When heated to decomposition it emits toxic fumes of carbon monoxide and carbon dioxide. It may cause irritation to the skin, eyes and mucous membranes. (NTP, 1992)
Posted by: John Schreiber | 28 June 2007 at 04:34 AM
I fail to see the logic of converting food into fuel. Methanol which can be produced from straw and what may be considered to be waste and was the basis of many special fuels usually referred to as 'dope'. Most bikes ridden on dirt tracks had "Five-stud JAP" engines with a compression ratio of 13.5 to 1 used such fuel.
Posted by: Antony C.P.Clarke | 25 November 2007 at 10:27 PM
Keep up the good work, guys. Ethanol from corn is only going to raise the price of beef, and there go my shares in Macdonalds
Posted by: John Watts | 26 December 2007 at 03:57 PM
this is really great thing. energie generation from biomass. this is survival of thw world
Posted by: keloolan | 16 February 2008 at 12:03 PM
The fossil fuels created many a problem -ecologically and environmentally.The bio fuels created another set of problems never envisaged when people went into ethanol - deforestation, destruction of the ice caps and glaciers those connected with them, global warming.
Sugar based fuels being biofuels cannot better the problems we face. The solution defined has to be connected with aforestation and reforestation.
Furthermore, both HMF and DMF require additional energy to synthesize and thus expensive.Collaterally the energy required for the synthesis will come from fossil fuels.
These are great inventions.But not practical. They are going to make a bigger hole in our pocket/purse.
There are solutions which are based on ethanol and not cellulosic ethanol, which will meet the problems of global warming, hydrological deficit shift of tropics, you name it, it is there.This will also help to reduce the cost of liquid fuel at the pump by at least 40%.
Find me a University that will accept my thesis for a D.Phil, I will publish the results of my study.
I have also completed another study- this I did first- to make starch based hydrous ethanol cheaper by a factor over 50% of the present cost.This I wish to present for a D.Sc.
Final result - a simple solution which will male spark ignition engines run on fuels very much cheaper at the pump.
I have also identified a modification to compression ignition engines which will make them run at a price factor 90% cheaper than the cost of diesel.
Posted by: Upali Wickramasinghe | 16 March 2010 at 12:23 AM