New, Inexpensive Process Converts Sugars to Hydrogen

The Aqueous Phase Reforming (APR) process, invented by J. A. Dumesic and co-workers at the University of Wisconsin, is a unique process that can produces carbon-neutral hydrogen, fuel gas, liquid fuels or value added chemicals from a wide range of oxygenated compounds, such as ethylene glycol, biomass-derived glycerol, sugars and sugar-alcohols.  Specifically, Virent, a company founded by Dumesic and others is developing a system to generate hydrogen from aqueous solutions of these compounds in a single step reactor process as compared to the three or more reaction steps required for hydrogen generation via conventional processes that utilize non-renewable fossil fuels.

In January the company announced that in a system purchased by Madison, Gas & Electric (MGE), it has successfully started up a demonstration system capable of directly converting sugars and glycerin into power. The system (see schematic below) has demonstrated the ability to deliver a minimum of 10kW of clean power to the MGE grid since its startup at the beginning of 2006 The system is utilizing the waste heat from the ICE to provide the limited amount of process heat required for the reactor.The system currently operates on pure glycerin. In the future, the Company will use a lower grade of glycerin that is generated as a byproduct of the biodiesel production process.

The process (US. Patent No. 6,699,457) will enable localized production of hydrogen using readily available sugar-based feedstocks effectively eliminating hydrogen transport, storage and safety roadblocks that impede adoption of hydrogen fueled power systems. Due to the low temperature operation of APR, the economics are scalable to small home and office use applications. Depending on the feedstock, the process is capable of producing green hydrogen at a total cost of between $1.80-$4.00/kg. This is dramatically less than alternative renewable sources, such as wind and solar, and very competitive with mature, capital intensive hydrogen production methods such as natural gas reformation, coal gasification or electrolysis.

For comparison the energy contained in a kg of hydrogen is comparable to the energy in a gallon of gasoline, thus the cost to operate an internal combustion engine (ICE) on this hydrogen, produced from a distributed production system would be competitive to an ICE running on gasoline and the cost of operating a fuel cell would be about one-third that of an ICE.

Contained in a single reactor vessel, APR is a combined process whereby a catalyst reforms oxygenated hydrocarbons to produce relatively clean hydrogen which is then passed to a second-stage ultra-shift catalyst where carbon monoxide is removed and the hydrogen made even more pure.

Dumesic and his team tested more than 300 catalysts to find a nickel-tin-aluminum combination that reacts with biomass-derived oxygenated hydrocarbons to produce hydrogen and carbon dioxide without producing large amounts of unwanted methane.

When the sugar or alcohol molecules touch the surface of the catalyst, chemical reactions break and rearrange many of the carbon bonds, causing the atoms to be “reformed” into new configurations and liberating hydrogen in the process. In fact, about half the product is hydrogen gas. The researchers estimate that, if the system is fully developed, it will be able to turn a liter of biomass into about 1,000 watts of power.

Dumesic and coworkers found a room-temperature substitute for the entire water-gas procedure: letting CO react with a liquid “oxidizing” compound, at room temperatures.  The compound, made from tiny clusters of molybdenum oxide, containing 12 molybdenum atoms, 40 oxygen atoms as well as a central phosphorous atom is an environmentally benign polyoxometalate (POM) compound.  When CO mixed with this agent in the presence of nano-gold particles about 1,000 times thinner than a human hair, nearly every carbon monoxide molecule was converted to CO2. The compound not only removes CO from gas streams for fuel cells, but also converts the energy content of CO into a liquid that subsequently can be used to power a fuel cell.  The advance will make possible a new generation of inexpensive fuel cells operating with solutions of reduced POM compounds. While higher current densities can be achieved in fuel cells using electrodes containing precious metals, the researchers found that good current densities can be generated using a simple carbon anode.

The remaining byproducts consist of carbon dioxide and methane (or other readily combustible hydrocarbons). In a commercial application, the hydrocarbons could be separated and burned to provide all the heat needed to run the reactor, making the whole process energy-neutral.

Because the process occurs in a liquid phase at low reaction temperatures (e.g., 225^oC), the hydrogen is made without the need to vaporize water. That represents a major energy savings compared to ethanol production or other conventional methods for producing hydrogen from fossil fuels based on vapor-phase, steam-reforming processes.

• Capability to generate hydrogen from renewable biomass-derived feedstocks
• Capability to provide on-demand hydrogen with low capital requirements
• Significantly lower operating temperatures (220 ^○C v 800 ^○C) enabling easier assimilation into heat sensitive environments
• Fuel-cell grade hydrogen is made in a single-step process
• Ability to use conventional distribution infrastructure to deliver feedstocks with little or no safety concerns
• Generation of 10 times more hydrogen per gram of catalyst than steam reforming processes

Virent has developed a cost model to develop cost projections for production of hydrogen and alkane fuels. The following assumptions were made to arrive at these projections:

• An APR reforming unit that generates roughly 500 kg of gas per day
• Capital cost which includes the cost of precious metal catalyst for the ultra-shift catalyst
• Operation and maintenance expenses are included
• 10% return on investment with system depreciation over 15 years
• For H2, reactor thermal efficiency of 70% and catalyst performance of 6 watts per gram
• For mixed alkanes, reactor thermal efficiency of 85% and 100% (less heat should be required) and catalyst performance of 6 watts per gram
• There is no consideration of carbon or renewable tax credits, which can have significant impact on overall economics in Kyoto geographies

The chart below shows preliminary cost projections for APR production of H2 from glycerol.

Because of the tremendous cost and energy advantages that the APR process has shown, Virent is targeting smaller (< 10 KW) H2ICE, SOFC, and PEM FC applications. The process also offers a compelling alternative to ethanol production by squeezing 60% more net energy out of each sugar molecule than the energy intensive fermentation/dewatering process.

Dumesic and Dr Randy Cortright, a UW-Madison College of Engineering researcher, formed Virent Energy Systems to move the technology from the engineering laboratory to the marketplace. The Wisconsin Alumni Research Foundation (WARF) is pursuing two additional patents based on the technology and has granted Virent Energy Systems an exclusive license. In lieu of licensing fees, WARF has taken an equity stake in Virent.

Resources:

Virent Energy Systems, Inc., Madison, WI
Successful Startup for 10kW Virent System that Generates Power from Biomass, Press Release, January 26, 2006
Biomass to Power, APR Virtual tour, Energy Center of Wisconsin
Raney Ni-Sn catalyst for H₂ Production from biomass-derived hydrocarbons, Dumesic, Science, 2075 (2003)

Comments

[Mel.]

Very, very interesting. I'd love to see the prospective downsides of this application from some of the other (See: smarter than me) posters on this wonderful site.

[amazingdrx]

A big breakthrough for hydrogen technology, but at the end you have hydrogen instead of liquid fuel.

Hydrogen is not a good fuel source for vehicles, it is too hard to store. And hydrogen fuel cells are too expensive so far.

And the feedstock is sugar, produced with chemical agriculture that destroys soil as a carbon sink and uses fossil fuel based fertilizer and contaminates groundwater. There is also the byproduct CO 2 to consider.

None of this is sustainable and the whole process releases as nearly as much CO 2 as burning fuel produces.

Renwable electricity from wind, wave, and water power used in plugin vehicles produces no CO 2. The hydrogen economy is a political scam to delay renewable energy, it is not a practical plan to eliminate reliance on foreign oil and stop greenhouse gas global climate disaster.

The simple technology of battery powered vehicles combined with the simple technology of wind, solar, and water electric power generation is practical right now.

Using excellent research like this to delay that outcome is less than helpfull in the battle against global climate disaster. Hurricane warnings are out for the east coast this season, as well as the gulf coast.

How much will a Katrina sized storm hitting New York City cost? It cost about 2 trillion in the gulf coast region. The financial/trade center of the planet underwater?

Have all the financial institutions duplicated their systems further inland? Who would know? FEMA, the department of homeland security? Are there even any evacuation plans? Where would all those people evacuate to?

It is way past time to stop all these delaying tactics encouraged by the politicians that are frontmen for fossil and nuclear power and the auto industry. We are facing unprecedented disaster with nothing but self deception.

Add in the veiled administration threats to use nuclear bunker busters on Iran, which absolutely would raise gas prices overnight to 10 bucks per gallon, or more, and it is easy to see the immediate economic threat from relying on oil and oil wars as usual for a transportation energy source.

[amazingprofessorx]

Very nice posting, Jim

One of main byproducts of biodiesel production is glycerine. If you use the biodiesel for trucks and automobiles, use the glycerine to produce hydrogen for fixed location power plants, and use the bio-waste for cellulosic ethanol--you have a very efficient use of plants for energy production.

This is a very useful advance, when combined with all the other advances taking place due to higher oil costs, will make a distinct difference.

Producing hydrogen for fixed location power generation is incredibly useful. Being able to substitute renewable hydrogen for natural gas and gasified coal is a superb step toward cleaner power production..

Negative doompuppies are a dime a dozen. You'd think they'd wise up after a while and try contributing something productive to society instead of their whinish negativity.

[JesseJenkins]

If this small-scale system could be paired with the biodiesel microreactor being developed at Oregon State University - i.e., with the biodiesel microreactor taking virigin oils as a feedstock and producing biodiesel and glycerine which can then be used to feed the hydrogen production process - you'd have quite a nice little farm-sized fuel production facility. If they can be made small enough and cheap enough for farmers (or a coop of farmers at least) to purchase, they could begin supplying all the fuel they need to run their operations and become energy self-sufficient. Any excess fuel could be sold to neighbors or they could form a larger coop to distribute the fuel elsewhere. Sounds like another way to reinvigorate rural communities to me...

[jcwinnie]

I can see it in lights now... Jumping Jim Fraser and the Negative Doom Puppies

[Thomas Covert]

I'm curious if this process is efficient, durable, and cost-effective on a smaller level. Imagine making one the size of a fuel tank + basic 4-banger ICE, feeding the H2 to a PEM fuel cell on the fly, instead of lugging around a high-pressure tank. Any speculation on the feasibility of this?

[Robert]

I'm curious if this process is efficient, durable, and cost-effective on a smaller level. Imagine making one the size of a fuel tank + basic 4-banger ICE, feeding the H2 to a PEM fuel cell on the fly, instead of lugging around a high-pressure tank. Any speculation on the feasibility of this?

Probably not in the form discussed above. The product is not just H2, but a mixture of H2, alkanes, and carbon dioxide. So you'd need a separation system between the reformer and the fuel cell, and you lose the energy content of the alkanes. So in the present form, it's probably not useful for Small Things That Go.

Now for Big Things That Go, like large oceangoing ships, maybe rail, or for stationary generators, you might think about using the output of this to power a solid oxide fuel cell, which isn't so picky about its fuel. You still can't do away entirely with the hydrogen storage problem, because if you need a burst of power, the reforming system can't provide that immediately, so you need some stock of reformed fuel available for higher-performance situations. The applications I mentioned above tend not to change loads quickly, so that's not so much of a problem. You could also use the hydrogen continuously and store the alkanes for performance.

If this technology really can undercut natural gas reforming for hydrogen production, the first place you'll see it is in syngas-based chemical processing: ammonia, methanol, and acetates all require hydrogen, and less expensive hydrogen is immediately useful for these applications.

[Don]

Glycerine is flammable (though it needs to be heated). Seems to me it would be easier to burn it directly than go though a multi-step process to produce and burn hydrogen. On the other hand, hydrogen is a good thing to have for other reasons (fuel cells, chemical processes, etc.)

[Potassium Chloride]

Good post again.Thank you for sharing, I hope you happy and wish you good luck! this helpful information.