Successful Startup for Aqueous Phase Reforming; Direct Sugars-to-Hydrogen System Powers Generator
27 January 2006
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| The Virent 10kW APR/HICE demonstration system, in service with MG&E. |
In a demonstration of the capability of its Aqueous Phase Reforming (APR) process, Virent Energy Systems announced the successful startup of a 10kW power generation system that converts sugars and glycerin directly into hydrogen and natural gas as fuel for a Ford 1.6-liter, four-cylinder combustion engine genset.
This is the first production demonstration of a system of this type, and promises a more energy-efficient mechanism for the direct conversion of bio feedstocks into hydrogen and other fuel gases than current thermoconversion technologies.
The demonstration system, purchased by Madison (Wisconsin) Gas & Electric (MGE), is based on Virent’s patented Aqueous Phase Reforming (APR) process, a carbon-neutral, one-step method for on-demand production of hydrogen, natural gas and/or other fuel gases for distributed power systems from fuel stocks derived from widely available renewable biomass.
The level of excitement generated by this APR system start-up is very high because the system greatly exceeded all of our targets for power output and performance with an integrated ICE. It is very clear that the APR system represents a compelling option for cost effective, clean, distributed energy generation.
With the global availability of CO2 neutral feedstocks and the ability to fuel microturbines, fuel cells, and ICEs in an untethered fashion, the market opportunities are enormous.
—Eric Apfelbach, CEO Virent
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| The APR process. Click to enlarge. |
Aqueous Phase Reforming. Virent’s APR system offers a cost-effective method for low-temperature (180º–260º C) production of hydrogen and/or fuel gas from oxygenated compounds, such as ethylene glycol, biomass-derived glycerol, sugars and sugar-alcohols. The APR systems can be designed to deliver predominantly hydrogen or alkanes (natural gas, ethane, butane and propane), or a customized blend of these fuels (which Virent has tagged with the term “Supernatural Fuels”).
Modification of the catalyst and/or the temperature of the process modifies the composition of the resulting gas. For example, in earlier work Virent founders discovered that the aqueous-phase reforming of sorbitol, glycerol, and ethylene glycol solutions produced an effluent gas stream composed of 50-70 mol% H2, 30-40 mol% CO2, and 2–11 mol% alkanes (dry basis) at high conversion.
Addition of Sn (tin) to Ni (nickel) in the catalyst improved the selectivity for production of H2 by ethylene glycol reforming from 35% to 51% at a Ni:Sn ratio of 270:1, while the alkane selectivity was reduced from 44% to 33%. At a Ni:Sn ratio of 14:1, the hydrogen selectivity increased to 90%, while alkane production was nearly eliminated.
The efficiency of the reactor and the composition of the output also depends on the nature of the feedstock. Virent has found that while the selectivity for hydrogen production is insensitive to different concentrations of sugar-alcohols such as sorbitol, hydrogen selectivity from the reforming of glucose decreases as the liquid concentration increases from 1 to 10 wt% because of undesired hydrogen-consuming side reactions that occur in the liquid phase.
The addition of a Pressure Swing Adsorption (PSA) system or palladium membrane to the process could produce hydrogen pure enough for use in fuel cells. Such systems are easily integrated into the APR process, especially since the gas leaves the reactor at 400–500 psi.
The APR process offer a number of cost and efficiency benefits:
It generates hydrogen without the need to produce high-temperature steam, which represents a major energy saving over other multi-step processes for the generation of hydrogen from hydrocarbons;
It is efficient in its use of catalyst. APR processing of sorbitol at 215º C over a platinum-based catalyst will generate about 15 watts H2/gram of catalyst. A conventional high-temperature, multi-step process generates about 1 watt H2/gram of catalyst, according to Virent. Put another way, APR generates about 15 times more hydrogen per mass of catalyst than existing steam reforming process.
It occurs at temperatures and pressures where the water-gas shift reaction is favorable, making it possible to generate hydrogen with low amounts of CO (less than 100 ppm) in a single chemical reactor;
It occurs at pressures (typically 15 to 50 bar) where the hydrogen-rich effluent can be effectively purified, if desired, using either pressure swing adsorption or membrane technologies;
It takes place at low temperatures that minimize undesirable decomposition reactions typically encountered when carbohydrates are heated to elevated temperatures;
It uses widely available bio feedstocks or by products of other biofuel processing (i.e., the glycerin produced from the biodiesel production process.
The demonstration system. The MGE system integrates a Virent APR System with a hydrogen/natural gas fueled generator set provided by City Engines. (Earlier post.) The system has demonstrated the ability to deliver a minimum of 10kW of power to the MGE grid since its startup at the beginning of this year at Virent’s location in Madison, Wisconsin.
Virent customized the gas production from its APR system to deliver an effluent gas composed of approximately 30% hydrogen; 10% methane; 10% ethane; 10% propane; and 40% CO2. (The CO2 vents to the atmosphere, but as it is derived from biomass, is greenhouse neutral.) Gas flows into the engine at the rate of 90 liters/minute.
City Engines modified the 1.6-liter engine to run on a gaseous mixture of about this type. Although fine-tuning is still underway, the engine is performing well and has delivered efficiencies as high as 38% on the genset at 10 kW, according to Apfelbach. (Virent is claiming an overall 32% efficiency.) The engine has an electronic control feature so to allow for the easy tuning of the fuel/air ratio and timing.
Virent has not yet measured the emissions from the system, but expects them to be comparable or slightly lower than those from engines running hydrogen-CNG mixtures (HCNG).
The exhaust heat from the engine is recycled as process heat for the APR. The system may require the burning of about 10% of the gas stream to add more heat at lower power levels.
Currently the APR system is using a 50% concentration of gylcerol as the feedstock, consuming it at the rate of 2.2 gallons/hour. In the future, Virent will use a lower grade of glycerol that is generated as a byproduct of the biodiesel production process. Virent also intends to use sugar in the form of sorbitol and glucose as a feedstock for this initial unit. (Sorbitol or glucose will have slightly less net efficiency.)
We are proud to have played a role in the first ever demonstration of direct conversion of biomass derived liquids to fuels. This furthers our commitment to finding clean sources of fuel from renewable sources. We think the Virent process holds the potential for reshaping how people think about renewable energy.
Gary Wolter, MGE Chairman, President and CEO
Futures. Virent is in the early stages of commercializing this work, and the demonstration (beta) unit will go through numerous refinements as the project team gathers data and tweaks the system.
However, the prospect of producing CO2-neutral hydrogen and fuel gas out of renewable feedstocks with greater efficiency is a compelling proposition with implications for many markets and uses.
As an example, one possible application Virent is exploring is the production of “green LPG” for vehicle fuels—the APR can process glucose (a six-carbon sugar) with fairly high selectivity to propane (3 carbon alkane) and butane.
| APR versus Reforming Ethanol | |||
|---|---|---|---|
| Corn to Ethanol | H2 from Ethanol | APR: Corn to H2 | |
| Gross Energy Produced (BTUs/bushel) | 196,042 | 230,702 | 230,453 |
| Process Energy consumed (BTUs/bushel) | 134,625 | 232,646 | 80,659 |
| Net Energy (BTUs/bushel) | 61,417 | -1,945 | 149,794 |
| Production Output/Input Ratio | 1.46 | -0.04 | 2.86 |
As another example, taking corn to hydrogen via the APR rather than processing corn to ethanol delivers more than 2.4 times the BTUs per bushel of crop, according to Virent’s calculations. That includes the wet mill processing of the corn to produce the input sugar solution for the APR.
The cost of the process will largely be driven by the cost of the sugar feedstock. One reason Virent is working with glycerol is the glut being put on the market by biodiesel manufacturing. For every 10 pounds of biodiesel produced (about 1.4 gallons), one pound of glycerol is produced. For every 10 lbs of glycerol, Virent can generate 1 lb of hydrogen or 3 lbs of alkane fuel gas.
Or, to put it in another context, 20 gallons of 70% liquid sugar could produce sufficient hydrogen to take a Honda FCX 350 miles, according to Apfelbach. The hydrogen, with today’s sugar prices, would cost less than $3/kg.
Resources:
Virent technology presentation
“Production of Liquid Alkanes by Aqueous-Phase Processing of Biomass-Derived Carbohydrates”; George W. Huber, Juben N. Chheda, Christopher J. Barrett, James A. Dumesic; Science 3 June 2005: Vol. 308. no. 5727, pp. 1446 - 1450 DOI: 10.1126/science.1111166
“Raney Ni-Sn Catalyst for H2 Production from Biomass-Derived Hydrocarbons”; G. W. Huber, J. W. Shabaker, and J. A. Dumesic; Science 27 June 2003 300: 2075-2077 [DOI: 10.1126/science.1085597]
This is a very well written, upbeat article that presents no down side (or balanced reporting) -- does any one know the down side? -- or if this artile is true then WOW this could be huge -- nearly 2X the input/output ratio of corn to ethanol and it's carbon nuetral -- I wonder if you can grow sugar cane in Nebraska?? lol (smile).
NOTE: I'm noramlly a glass is half full person but this article?? -- OR -- see quote below:
"The optimist sees opportunity in every danger; the pessimist sees danger in every opportunity."
Sir Winston Churchill (1874 - 1965)
Posted by: JJ | 27 January 2006 at 09:51 AM
This is basically PR. It needs to be independently analyzed. The energy ratio is suspect as it doesn't seem to consider all input, just what they call "process", whatever that is.
Posted by: t | 27 January 2006 at 10:00 AM
Biodiesel production results in huge quantities of glycerin by-product (10 - 20 gallons per 100 gallons of biodiesel), often with zero or little commercial value. If the glycerin could be used to provide process heat/energy, it would be truly closing the loop!
Posted by: JN2 | 27 January 2006 at 10:52 AM
It is true that this is all PR. I looked through the powerpoint, and on the surface I don't smell anything that stinks. They have a reasonable mix of people running it, they have been getting Federal $ for research and so forth. They don't seem to be begging for people to further underwrite the thing. They have gotten patents on some of their ideas, and are thinking of licensing it to other companies. So far, so good.
Since they now have something they can sell, it won't be tough for people to figure out whether the thing is being oversold or not. In the end, that is the true test of all of these sorts of ideas. A few early-adopters will plunk down the cash to buy the things, and if they are still going strong a year or two later we can afford to become a bit more optimistic.
Posted by: eric | 27 January 2006 at 11:36 AM
Keep in mind also that hydrogen consumed in a fuel cell vehicle translate the energy in hydrogen into miles on the road 2-3 times more efficiently than an internal combustion engine would translate ethanol into miles.
So since this process is nearly twice as efficient on a corn to fuel basis...now you would be talking about 4-6 times more efficient on a corn to wheels basis.
The UC Berkley study posted yesterday states basically that while ethanol is no blockbuster helper of energy independence...it does make a marginal improvement over gasoline.
As you can see from the corn to wheels results that could be achieved with APR and fuel cells...that marginal improvement could be raised to dramatic improvement.
Now factor in we are talking about renewable energy here who's cost will only go down with the additional application of human ingenuity versus be costed out based upon a limited feedstock...and you can see the huge economic benefit potential. Additionally, hydrogen of course can be created from many other clean renewable sources like wind, wave, tidal, geothermal, and solar. So this need not be the only way to create clean hydrogen.
You can add in the lack of pollution as another giant environmental plus.
Posted by: Dairy Queen | 27 January 2006 at 12:45 PM
Glycerin can be reprocessed to propylene glycol, but I doubt that we really need that much antifreeze. If ethylene glycol was banned like in europe, maybe that market would expand. Who knows...
Posted by: Brett | 27 January 2006 at 12:46 PM
This would be much better than bio-diesel. You ever wonder why no one is pushing B100? Only B5? And maybe B20 if you are lucky?
Well the truth is that a gallon diesel requires 25% more oil to produce than a gallon of gasoline. So B20 makes us significantly more dependent on oil than we already are. Oil companies love it and they get green wash the folks making them think they are doing something when the reality is all they are doing is increasing the amount oil they sell.
As for diesel getting better gas mileage...that's using the fake EPA numbers. It was a diesel Jeep Liberty that Consumer Reports recognized as the worst MPG mis-calculation offender. With an EPA rating of 22 mpg and they were only able to get a pathetic 11 mpg. Now exposed the EPA is completing re-doing their EPA mpg methodology.
Bio-diesel is about selling more oil and oil companies have mounted a false campaign against hydrogen in favor of promoting ethanol and bio-diesel. Why? Because hydrogen can be made from so many different sources beyond sources that oil companies control...and thus it will hit them in the wallet...it's as simple as that.
Anyone with a solar panel could potentially setup their own hydrogen refinery (i.e. a home electrolyzer).
"To meet the Tier 2 standards, low-sulfur diesel fuel will be required by federal law starting in mid-2006. Unfortunately, Department of Energy modeling shows this fuel to be more oil- and carbon-intensive than reformulated gasoline. Each gallon, for example, requires 25 percent more oil and emits 17 percent more heat-trapping gases than gasoline reformulated with MTBE (the formulation used in our report), and requires 17 percent more oil and emits 18 percent more heat-trapping gases than gasoline reformulated with ethanol. So, although diesel's higher energy content, along with efficient engines, allows cars meeting the Tier 2 standards to travel 30 to 40 percent farther than gasoline models, these fuel economy improvements do not provide equivalent reductions in oil use and heat-trapping emissions."
You can see there UCS report here:
http://www.ucsusa.org/publications/catalyst/sp04-catalyst-diesel-or-gasoline-fuel-for-thought.html
Posted by: Diesel Truth | 27 January 2006 at 03:20 PM
DT,
You are full of it!
Here is a quite from the link you provided: "Thanks to its higher energy content and efficient combustion process, diesel enables cars to travel at least 30 percent farther on a gallon of fuel than comparable gasoline models. As a result, diesel engines generally release less carbon dioxide—the heat-tapping gas primarily responsible for global warming—from the tailpipe. The improved efficiency of diesel engines can also help reduce oil consumption."
So even if diesel takes 25% more oil per gallon than gasoline, you get more miles per barrel of oil going the diesel route. Add to that any percentage of biodiesel and diesel gets even further ahead.
Now there is a "Diesel Truth"!
Posted by: An Engineer | 27 January 2006 at 05:01 PM
I agree that, on balance, diesel probably emits less GHG than gasoline, even correcting for the possible difference in the amount of oil requied to produce each refined product. However, if one compares a hybrid like the Prius to a diesel, gasoline probably has the edge. Now, if we produce diesel hybrids, the equation may change.
I would like to see something definitive on the amount of oil required to produce diesel vs gasoline, but it still seems that there is little agreement on this issue. One would think it would be a simple matter of getting this info from the refiners. But then, would we trust those numbers.
Posted by: t | 28 January 2006 at 07:02 AM
Agreed - the knock on diesel was completely incorrect. Diesel also requires less energy to refine than gasoline. The accepted well-to-wheel efficiencies for each show diesel to have a significant advantage. About 11% of the energy from the crude makes it's way to propelling a vehicle via gasoline. Using diesel, that number jumps to 16%. That is a huge boost.
Furthermore, the TOTAL well-to-wheel greenhouse gas emissions are far less using diesel. Gasoline winds up emitting 600 grams for every mile, whereas diesel is only 400.
Until we have sufficent supply of some other fuel to replace petroleum, switching as many vehicles to diesel is one of the most effective things we could do over the NEAR future.
Too often, hybrids technologies are pitted against diesel. Well, they can and will be used together - companies are already developing this. As of right now, a diesel hybrid has virtually the same well-to-wheel efficiency of a hydrogen fuel cell. Plug-in options could further improve these efficiencies, as could the continued developments in biodiesel and Fischer-Tropsch diesel.
I'm not saying hydrogen is not the long term solution, but we can have plug-in diesel hybrids that run on percentages of biodiesel/FT on the road in less than 5 years. The same cannot be said for fuel-cell vehicles.
Seriously, using that crappy diesel engine in the Jeep Liberty to make your case? Look at one of the more modern diesels that are used in Europe, please!
Posted by: Angelo | 28 January 2006 at 07:05 AM
You've been smoking too many diesel fumes Angelo. The simple truth is it requires 25% more oil to produce a gallon of diesel fuel than is required to produce a gallon of gasoline.
Diesel won't help us at all with energy independence, but it would do a lot to create a mass pollution catastrophe.
Posted by: And Jello | 30 January 2006 at 04:14 AM
Angelo, do the arithmetic: if it takes 25% more oil to produce a gallon of diesel than one of gasoline, but diesel delivers 30% more driven miles per gallon (USC study, above, and that's the most conservative one I've seen), then diesel IMPROVES energy independence, every single gallon.
However, those figures do not include the enormous adavantage diesel has when all energy costs are loaded in, and divided into driven miles deliverd-this is the 16 to 11 ration posted above, by t.
And, the substitution of 20 (or any) percentage of bio-derived oils improves the energy independence further. There is considerable controversy about whether farm crop oils (soybean, corn, etc.) are produced efficiently enough to be worth the trouble (yes, they do on balance yield more energy than the energy consumed in growing and making them), but there is no controversy over whether they reduce reliance on foreign oil.
And, if we can get serious about recycling cooking oils and producing biodiesel from that source (as is now done on a small scale), then the advantages are huge.
Posted by: brendan | 30 January 2006 at 07:44 PM
For the record, it was myself, ANGELO, who posted the defense of diesel and the 16:11 ratio! It was "Diesel Truth" and "And Jello" who continues to dispute this, despite the abundance of information on the topic that could be extracted with a simple Google search.
....be a little more careful before you start heckling someone.
Posted by: Angelo | 31 January 2006 at 04:36 AM
So far no manufacturer has used the atkinson cycle to its full advantage yet. It can be more efficient than current diesels and still have an exhaust free of particulates, sulphur, and NOx.
Posted by: tom deplume | 31 January 2006 at 11:18 AM
Wow, And Jello and Diesel Truth are as close to insane as I can imagine in this setting. What possible motive could they have to argue that 1+1=3? Guys, the math is simple at the simplest level. You can broaden the scope of diesel benefits to include: longer life engines (2-3 times that of gasoline equivalent engines), lower maintenance (less oil changes), and of course biodiesel and waste vegetable oil additives or replacements. If you add that all up over the gasoline infrastructure, the amount of energy that gets to the wheel with diesel is LEAPS & BOUNDS greater. The carbon footprint of diesel over gasoline is LEAPS & BOUNDS less than gasoline. Yeesh, get your heads out of your butts and in front of a shrink. :)
Posted by: Chingy | 31 January 2006 at 02:15 PM
We are very interested to communicate with companies & people re: the production of fuels from NAPIER FODDER (Native to africa, ELEPHANT GRASS) SUGAR CANE, MOLASSES. Countries we are looking at ZAMBIA,DEMOCRATIC REP of CONGO,MOZAMBIQUE,ZIMBABWE.
Posted by: Louis Uys | 01 February 2006 at 12:25 AM
I think Dairy Queen hit the nail on the head with the best way to use biomass for producing fuel. The number one problem with ethanol production is removing the water from the aqueous ethanol solution. Water is very detrimental in fuels that will be burned in an internal combustion engine, so great energy is expended to remove this water prior to the completion of the ethanol production cycle.
The key advantage to aqueous phase reforming (APR) is that you leave the water in...and it's actually an advantage not a detriment. Aqueous phase reforming actually gets hydrogen from both the water and the ethanol molecules. You don't waste energy getting the water out and you gain energy by leave the water in. A win win situation. This is why aqueous phase reforming of corn to hydrogen is twice as efficient corn to ethanol.
Hydrogen internal combustion engines which are available today and require zero research get about 50% better mileage than an internal combustion engine running on ethanol.
So the energy in the biomass is used 2.5 times more efficiently via APR and hydrogen in an internal combustion engine than ethanol in an internal combustion engine. Said differently...APR/H2 ICE has a 2.5 times advantage in energy balance corn to wheel over ethanol/ICE.
When fuel cells are available, of course the efficiency over internal combustion goes up by a factor of 2 to 3 times. So corn to wheels with APR/H2 FC has a 4 to 6 times advantage in energy balance corn to wheels over ethanol/ICE.
This means we can benefit from investment in APR and H2 today as well as tomorrow.
Posted by: Queen Bee | 01 February 2006 at 07:20 AM
Where will all this corn be grown? If it hasn't already become apparent, population is outstripping resources in some places simply for food alone.
This situation will only get worse with time as poorer countries get equality and require transport. If we are left with our butts in the wind with regards to oil, and required corn or soy to make biodiesel and sugar based fuels, then where in hell will we find the land to grow them?
We will need all the edible plants we can produce in hospitable environments just to sustain our stomachs (this also includes milk and meat producing animals like cows and others).
For this reason, some serious research needs to be done into genetically modifying fuel producing plants so they grow in deserts and the tundra regions of the world. Other then that, the only other option is large artificial domes errected to shelter fuel and food producing plants form the harsh elements.
Either route is an expensive one. I just hope people don't loose sight of this aspect after spending lots of time and resources debating about what makes the perfect engine.
Posted by: Adrian | 02 February 2006 at 06:22 PM
Professor Michael Briggs at the University of New Hampshire estimates that the cultivation of Algae over a surface of 38,500 km2, if situated in a zone of high sun-exposure such as the Sonora Desert, would make it possible to replace the totality of petroleum consumed in the United States………In order to have an optimal yield, these algae need to have CO2 in large (13% of total flue gas emissions) quantities in the basins or bioreactors where they grow.
1. Source: An algae-based fuel - Olivier Danielo - Biofutur, No. 255 / May 2005
2. Widescale Biodiesel Production from Algae - Michael Briggs, University of New Hampshire, Physics Department (revised August 2004)
http://www.greenfuelonline.com/emissions_to_biofuels.htm
Posted by: Jag | 05 February 2006 at 04:17 AM
Don’t worry - Congress will change its mind and approve Ethanol imports from either Brazil or anywhere else if we need the fuel bad enough. Like if we have to nuke Iran over its illegal nuclear weapons program. A long-term shutoff of Iranian oil would cause oil prices to zoom to well over >$100 a barrel overnight. What congressperson is going to back to their home state and tell his or her people they don’t have a plan to fix this problem? Congress should at least mandate that all new vehicles sold in our country be fuel flexible. You can’t buy bio-fuels (except bio-diesel) if it doesn’t run in you car.
Posted by: Jag | 05 February 2006 at 03:07 PM
This sort of thing would be a good way to produce hydrogen for the catalytic conversion of sugar to hydrocarbons.
Posted by: Paul Dietz | 02 November 2006 at 08:32 AM