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Print 60 comment(s) - last by EricMartello.. on Nov 13 at 8:16 PM

The process was inspired by an explosives making method

What can't palladium do?  Named after the mythological statue erected by Greek goddess Athena in honor of Pallas, the daughter of her cousin whom she slew in a friendly fight, the platinum group metal (PGM) is used in everything from catalytic converters to explosives making.

I. From Explosives to Biofuel

Researchers at U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (referred to as LBNL or Berkeley Lab) -- located on the campus of the University of California, Berkeley -- have devised a way to use palladium to catalyze the production of gasoline, diesel, or jet fuel from fermented biomass.

Traditionally biomass, fermented by genetically engineered bacterium, produces a slurry of low-carbon byproducts -- acetone and the alcohols butanol and ethanol (known collectively as ABE).

The LBNL researchers were inspired to use palladium as a means of producing higher-carbon byproducts based on a similar technique used to produce cordite, a type of smokeless explosive.  While largely made obsolete by newer formulations in the improved military rifle (IMR) nitrocellulose smokeless powders, cordite played a key role in military history, being used heavily by the British in World War II.

Palladium bar
The new work is one more example of the value of multi-functional palladium.
[Image Source: Unknown]

Co-author Harvey Blanch describes the pickup of this throwback catalysis process, remarking, "In some ways, this work is a step back in time in which a very old fermentation process is being used with some new engineering and chemistry.  While there has been some progress in engineering microbes to produce advanced biofuels, the quantities produced thus far – technically, the solution’s titer – tend to be very limited. A hybrid method, combining microbial production with chemical catalysis, might provide a pathway to more efficient production of these advanced biofuels."

Biomass bacteria
The process begins by bacterial fermentation. [Image Source: Toste Group]

From a layman's perspective, the bacteria takes biomass -- say yard waste -- and "digests" it to produce a byproduct that is three parts acetone, six parts n-butanol, and one part ethanol.  The acetone is the key to move to longer chains, as it can be used to "tack" on carbons onto the short-chain alcohols, building long carbon chains that mirror those found in traditional fossil fuel-derived gasoline.

The acetone's nucleophilic alpha-carbon undergoes alkylation reactions to produce longer chain carbons.  But the process is slow and energetically unfavorable, so a catalyst is needed to lower the energy barrier.

Many catalysts were tested, but the LBNL team found one worked much better than the rest -- palladium.  Researchers say the process, which they tested in small vats, is amenable to commercial production.

II. Challenges Remain

One limiting factor will be the cost of palladium.  While fuel is valuable as anyone who drives a car recognizes, palladium is an even more expensive resource.  It sells for approximately $20,500 USD per kilogram [source].  Therein lies one problem; the longer the ABE spends on the palladium, the more long-chain byproducts are produced.  So if you had more palladium and more vats, you could spread the ABE out for more palladium TLC.  But the high costs are somewhat limiting to that approach.  That said, process engineers could optimize the process to maximize yields and minimize cost.

Still, the process is much better than other ABE techniques, such as hydrogenation from a yields perspective.  States Professor Blanch, "Integrating chemistry and fermentation is a useful way to capitalize on the best of both worlds. The chemistry described in our Nature paper is exciting because new carbon-carbon bonds are being formed between molecules and oxygen is being rejected without the need of hydrogenation. This results in very high yields."

The researchers have published their work in the prestigious peer-reviewed journal Nature.  The paper's co-authors include Professor Blanch, plus Pazhamalai AnbarasanZachary BaerSanil SreekumarElad GrossJoseph BinderDouglas Clark, and corresponding author Dean Toste..

The research was funded by the Energy Biosciences Institute.

lawn waste
Coming up with a viable biomass supply change is a key challenge.
[Image Source: DeCamp Trucking]

Looking ahead, while the researchers exhaustively tested a series of PGM catalysts, they are hopefully that they may discover even better novel catalysts.  Comments Professor Toste, who splits his time between UC Berkley and LBNL, "While palladium on carbon was the best catalyst in these tests, we have already identified other transition metal catalysts that could be even better."

Tough challenges for a biomass-based fuel economy remain -- including how to funnel/transport common biomass sources (yard waste, forestry byproducts, farm waste, etc.) into a steady supply chain to fuel production facilities.  But work like this gives biomass fermentation a leg up over other struggling biofuel offerings like the highly unattractive corn ethanol.


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RE: Or...
By Mint on 11/9/2012 2:46:55 PM , Rating: 2
Oh, and regarding coal, you can't just look at overall production averages. You have to evaluate on the margin.

EVs are overwhelmingly charged at night, when electricity demand is low. Natural gas peaker plants are already built to handle the daytime peak, but they sit idle at night. EV adoption will simply result in them running at night. Only natural gas consumption will go up. Incidentally, this will also reduce the per-kWh price for that peaker, as it ends up running at higher capacity factor. That will eventually get passed onto all consumers.

So no, EVs won't result in any new coal construction. They fit very well into our existing infrastructure.


RE: Or...
By Spuke on 11/9/2012 2:53:50 PM , Rating: 2
How is more usage at night result in lower prices but during the day it's the exact opposite? That makes NO sense at all but I'm all ears.


RE: Or...
By Mint on 11/9/2012 3:11:26 PM , Rating: 2
Peaker plants get more per kWh generated than baseline plants precisely because they idle at night, wasting electricity generating capital. They place a high bid for electricity (say 10c/kWh), and when the city needs more electricity, they win the bid and produce, but otherwise they idle. They are in competition with others, so they can't make an arbitrarily large bid, but it needs to be profitable enough to make up for the O&M and construction costs.

When plants get called upon at night due to EVs, they now get more revenue with minimal extra cost (~3c/kWh for the natural gas). Through competition, they are then more willing to lower prices on their bids during the day.


RE: Or...
By JediJeb on 11/9/2012 3:43:56 PM , Rating: 2
In my area all the power plants are coal based, so even at night it would be coal producing the electricity.

In the end nuclear would be the only carbon neutral high output power plants that could be built anywhere in the country that a normal coal or natural gas plant could be built.


RE: Or...
By Mint on 11/9/2012 4:33:29 PM , Rating: 3
That's highly unlikely. I bet your area gets power from neighboring regions to fulfill the daytime peak.

Coal plants don't do daily ramping up and down. It causes too much wear from thermal cycling. Nuclear plants also have such low fuel costs that it just isn't worth it to ramp up and down. These are used for baseload power, and are built under the assumption that they will running at a high capacity factor and getting revenue around the clock to amortize the construction costs. Even the more expensive, highly efficient CCGT plants are built primarily for baseload power.

For the daytime peak, though, it's better to build a cheap gas turbines are built to ramp up and down. If there's enough capacity to satisfy nightime demand in your area, nobody will build another coal plant if they can only get daytime revenue yet have to keep burning coal at night. Instead, your area will import electricity from others during the day.

I'm pro-nuclear, BTW. I'm just telling you what the market is like. We have a lot of natural gas capacity already built to handle extreme situations. Extra nightime demand will be supplied by them. Even with new baseload construction, natural gas got so cheap recently that it's probably the #1 choice.


RE: Or...
By Spuke on 11/9/2012 5:45:14 PM , Rating: 2
Great education!!! Thanks very much.


RE: Or...
By JediJeb on 11/9/2012 6:21:30 PM , Rating: 2
I live in Ky, in the middle of the coal fields, with no really large cities so the difference in base and peak probably isn't that large. I have at least 5 coal fired power plants within a 40 mile radius of where I live and one small hydro plant at the end of Kentucky Lake. Not sure where the closest natural gas plant is, but I think they are going to build one in Louisville which is 150 miles from us.

I do know that during the ice storm in 2009 when the main transmission towers went down they almost lost one plant because they could not shut it down fast enough and they were making too much power with no where for it to go.

One of the small coal plants nearby normally idles at night and gets fired up during the day, not sure how much it produces wattage wise but the whole facility isn't very large at all, looks something like and old brick 4 or 5 story warehouse. It doesn't completely shut down at night but comes pretty close to it.


RE: Or...
By Mint on 11/9/2012 10:41:04 PM , Rating: 2
In that case, it's highly likely that the coal plants around you are mostly generating the baseload for other areas. A few hundred miles of reasonably low loss transmission is a piece of cake.

Still, even if someone's electricity all comes from coal, increasing their night time consumption would almost never result in any more coal burned. There would simply be less exported, and in the neighboring areas there would be more natural gas burned.

As for that small coal plant that idles at night, AFAIK it's an outlier.


RE: Or...
By EricMartello on 11/13/2012 8:16:50 PM , Rating: 2
quote:
In the end nuclear would be the only carbon neutral high output power plants that could be built anywhere in the country that a normal coal or natural gas plant could be built.


I'm also for more nuclear power plants, however they do require a lot of water to operate which limits their construction to either coastal areas or in close proximity to a river or lake. Coal plants can be built pretty much anywhere.


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