Sawdust to gasoline: A process called catalytic pyrolysis converts biomass, such as sawdust, into valuable chemicals. From left to right: sawdust; sludge-like chemicals produced without the catalyst; the powder catalyst; the mixture of aromatic molecules made with the catalyst.
Torren Carlson, UMass
A startup's catalytic process converts biomass directly into components of gasoline.
An early-stage company spun out of the University of Massachusetts, Amherst, plans to commercialize a catalytic process for converting cellulosic biomass into five of the chemicals found in gasoline. These chemicals are also used to make industrial polymers and solvents. Anellotech, which is seeking venture funding, plans to build a pilot plant next year.
Anellotech's reactors perform a process called "catalytic pyrolysis," which converts three of the structural molecules found in plants--two forms of cellulose and the woody molecule lignin--into fuels. Ground-up biomass is fed into a high-temperature reactor and blended with a catalyst. The heat causes the cellulose, lignin, and other molecules in the biomass to chemically decompose through a process called pyrolysis; a catalyst helps control the chemical reactions, turning cellulose and lignin into a mix of carbon-ring-based molecules: benzene, toluene, and xylenes.
The global market for this group of chemicals is $80 billion a year and growing at a rate of 4 percent a year, says Anellotech CEO David Sudolsky. "We're targeting to compete with oil priced at $60 a barrel, assuming no tax credits or subsidies," he says. The company's founder, George Huber, says his catalytic pyrolysis process can create 50 gallons of the chemicals per metric ton of wood or other biomass, with a yield of 40 percent. The other products of the reaction include coke, used to fuel the reactor.
"The advantage of pyrolysis is that it uses whole biomass," says John Regalbuto, an advisor to the Catalysis and Biocatalysis Program at the National Science Foundation. On average, lignin accounts for 40 percent of the energy stored in whole biomass. But because it can't be converted into sugars the way cellulose can, lignin can't be used as a feedstock for fermentation processes such as those used by some biofuels companies to convert sugarcane into fuels.
Pyrolysis is also different from gasification, another process for using whole biomass. Gasification results in a mixture of carbon and hydrogen called syngas, which can then be used to make fuel. Pyrolysis, by contrast, turns biomass into liquid fuels in a single step. And while gasification can only be done economically at a very large scale, says Regalbuto, catalytic pyrolysis could be done at smaller refineries distributed near the supply of biomass.
Pyrolysis is an efficient way to use biomass, but it's difficult to control the products of the reaction, and it's difficult to get high yields. The keys to Anellotech's process, says Huber, are a specially tailored catalyst and a reactor that allows good control over reaction conditions. Huber's group at UMass, where he is a professor of chemical engineering, was the first to develop a catalytic process for converting biomass directly into gasoline, and Anellotech's processes are based on this work.
Newly engineered E. coli streamline the conversion of cellulose into fuel.
Let's take good ol' wood and turn it into some of the most dangerous chemicals we can think of. Benzene, toluene, and xylenes? Why not put our friends up at Connecticut Yankee in charge of this deal, I hear they're running low on cesium. Let's put some DIY kits in Make magazine too.
The only good product of this reaction is the coke, it would make a great soil amendment. In a perfect world it would be too valuable to burn for fuel. We might need it to cleanse our biosphere from the other pollutants soon.
Guest (OtherDoug)
The chemicals referenced are basic feedstock items for most of the synthetic materials used by our society: solvents, adhesives, resins, nylon, polyurethane, polystyrene and carbon nanotubes. If we can use a process like this to make those materials from biomass instead of petroleum I think we'll be making a significant leap towards a sustainable economy.
Your only good point here is that the production of coke would be helpful as a soil amendment and as a carbon sink. If it is combined with organic material you could use it for terra preta.
there's a possibly prophetic sci-fi short story:
an interstellar survey expedition out from earth returns from a 20 year trip for them, stretched by near light speeds to 200+ years local time.
They find the atmosphere filled with hydrocarbon smog and most larger life forms dead.
They want to find the cause so they land, finding signs of desperation and struggles. They find monuments to a person all over the globe. Oddly this person was first revered as a hero but near the end the statues were torn down. Turns out this person had found a near perfect way to convert biomass to food and fuel.
Solved the problem, so humanity kept growing and using all available biomass as food / fuel, till nothing was left and the ecosystem decayed to stinking mess, and they realized what he had enabled near the end.
Certainly biomass is better than fossil fuels for some reasons but it can't be our only energy source.
There's evidence now that mass sugarcane production in brazil is now displacing other farmers such as soy who are starting to encroach on the amazon for example.
http://www.foreignpolicy.com/articles/2010/04/09/the_dirty_underside_of_lulas_clean_energy_revolution?page=full
I continue to see Huber articles trying to make it sound like using ZSM-5 to make BTX from biomass is new. There are papers from as early as 1979 (from ZSM-5 inventors) talking about this. A lot of work at NREL, Prof. Williams (UK), and Prof. Bakshi (Canada), Prof. Vasalos (Greece). Long story short - this is a lot of hype, but nothing new in this chemistry. No idea if reactor is novel, but this looks like greenwash to me - lots of hype, but like a lot of "new" energy ideas, already long ago invented in first energy crisis. Getting chemistry to work at small scale is easy (and not new) - building plants and making money with it is a lot tougher.
Commercialization of Biomass Pyrolysis
There is an interesting company that is based in Ottawa, Ontario Canada, called Ensyn Technologies Inc. http://www.ensyn.com. Ensyn was incorporated in 1984 to commercialize its proprietary biomass-to-liquid technology, known as Rapid Thermal Process (RTP). It is a short residence time, pyrolysis process that reaches 500ºC, followed by rapid cooling. The company reports a yield for RTP of about 75% by weight (liquid “bio-oil” from residual forestry or agricultural biomass).
Ensyn has designed, built, and commissioned seven commercial plants in the United States and Canada, the largest of which has a capacity of 100 tonnes (feedstock) per day. Ensyn's current projects are for plants with 5-10 times this capacity. Outputs from plants using Ensyn’s RTP process are used in the manufacture of more than 30 chemical and fuel products.
I'm not familiar with Coskata; however, my understanding of the Ensyn process is that feedstock is heated by mixing it in tubular reactors with pre-heated sand. The mix of feedstock and sand moves very rapidly through the reactor. Ensyn's literature uses the word "tornado" to describe the flow within the reactor. Residence time is a couple of seconds. Upon exiting the reactor tube, the sand is separated from the reactant mixture and reheated/recycled back. The sand is heated using combustible outputs from the reaction itself. As far as I know, there is no use of a plasma torch.
The technology was developed at the University of Western Ontario by the company's founders: Dr. Robert Graham and Barry Freel, and is patented.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
On Twitter
Become a Fan on Facebook
Subscribe to the Feed
epcotint
3 Comments
From Biomass to Chemicals in One Step
Hello Katherine:
In your biomass to chemicals article, you suggest yield of 40%. This number according to my calculation is about twice what it should be. The rationale is as follows. Let us assume that the density of the chemical liquid is 10 pounds per gallon. This would mean that we have 500 pounds of liquid. With one metric tone i.e. 2200 pounds as the feed, the yield would be =22.72% (500/2200). If the yield is about 23% the process needs LOT OF HELP. Converting to aromatics is good but I need to see more data.
Reply
DaveD
16 Comments
Re: From Biomass to Chemicals in One Step
That is a very heavy liquid if you assume 10 lbs per gallon. Water weighs only 8.3lbs/gallon and gas is less than 6.5lbs/gallon.
Reply
GaryB
119 Comments
Re: From Biomass to Chemicals in One Step
with a yield of 40 percent. The other products of the reaction include coke, used to fuel the reactor [snip] On average, lignin accounts for 40 percent of the energy stored in whole biomass.
This is really ambiguous. 40% is lignin ... and the yeild of that is 40% for 16% yield from the biomass?
Also, how much energy is used here? The wood has to be transported to a site, then ground to dust, then heated to 600 degrees (presumably by burning the coke). One simple way of thinking about the question is: Could you construct a truck, that would run this process to produce enough Gas to haul the wood X number of miles leaving Y% of the wood left. That would tell you something about the actual yield.
Reply