Honda CEO Outlines Three-Year Powertrain Technology and Fuel Economy Targets
Clean Air Program Renews Contract for Truck Replacement

Boosting Biomass-to...Butanol?

From Ohio to California and back on butanol.

An Ohio inventor has taken to the road to promote butanol as an alternative fuel to ethanol as well as his process for producing it from the anaerobic fermentation of biomass waste. The two-stage, dual-path process, which relies on two different Clostridia strains (earlier post), also yields hydrogen as a product.

According to the inventor, David Ramey, his butanol process delivers about 42% more energy than ethanol for a given amount of feedstock, based on the higher energy content of butanol (some 25% greater than ethanol), plus the hydrogen.

Select Properties
a David Ramey, Environmental Engineering, Inc.
b EIA Annual Energy Review, Appendix A1
Formula C4H10O C2H6O Many
BTU/gallon 105K a 84K b 123K b
Vapor Pressure @ 100 F 0.33 psi 2.0 psi 4.5 psi
Air-to-fuel ratio 11.1 9 12–15

Butanol (C4H10O) is a four-carbon alcohol in widespread use as an industrial solvent, with a US market size of some 370 million gallons per year at a price of about $3.75 per gallon (approximately $1.4 billion).

Originally produced by fermentation starting nearly 90 years ago (using Clostridia acetobutylicum), butanol shifted to becoming a petrochemically-derived product in the 1950s as the price of petrochemicals dropped below that of starch and sugar substrates such as corn and molasses. Virtually all of the butanol is use today is produced petrochemically.

In conventional fermentations, the butanol yield from glucose is low—between 15%–25%—and the butanol concentration in the fermentation is usually lower than 1.3%. (Butanol at a concentration of 1% can significantly inhibit cell growth and the fermentation process.) There have been numerous efforts over the years to improve butanol yield by using a variety of techniques to minimize product inhibition.

Environmental Energy Inc.’s Biomass-to-Butanol Process

Ramey took the approach of using two types of microbes in two separate process steps. Other processes had tried multiple strains of bacteria, but in synergy within the same slurry.

The first, Clostridium tyrobutyricum, optimizes the production of hydrogen and butyric acid, while the other, Clostridium acetobutylicum, converts the butyric acid to butanol. (Diagram at right, Click to enlarge.)

Ramey claims his butanol yield from this process is 42% from glucose.

The conventional fermentation process produced a number of products as well as butanol: acetic, lactic and propionic acids, acetone, isopropanol and ethanol production. Ramey’s fermentation only produces hydrogen, butyric acid, butanol and carbon dioxide, and doubles the yield of butanol from a bushel of corn from 1.3 to 2.5 gallons per bushel—equivalent to corn ethanol’s fermentative yield, but with higher heat content and hydrogen as a co-product.

Butanol’s energy content is closer to gasoline than ethanol’s. It is non-corrosive, can be distributed through existing pipelines, and can be—but does not have to be—blended with fossil fuels. Butanol itself could be reformed for hydrogen for use in fuel cells, and the production process itself produces hydrogen.

As good as that might sound, however, there are a number of unknows.

Primarily, the economics of production using Ramey’s process are unproven. He is seeking some $3 million to build a 250-gallon/week prototype and then a 1,250-gallon/week pilot plant. (From 1991, his company, Environmental Energy, Inc., has operated on $1.5 million provided by 40 private investors and by several federal research grants.)

He has produced butanol from his process in small amounts here and there—but for the promotional drive, he and his team bought four barrels of conventional butanol from Ashland Chemical.

Assuming he finds his funding, and the process scales, his plans call initially to sell the butanol into the commercial solvents market to generate a sustainable revenue stream. (It’s a big, existing market, always on the lookout for a less expensive product.)

Ramey ultimately envisions small, turnkey biorefineries of 5 to 30 million gallons per year capacity for small municipalities and surrounding farming communities that would produce butanol as a gasoline substitute.


(A hat-tip to Robert Schwartz!)



I read this article with interest until the line about using petro derived butanol in the car. You'd think after more than 10 years of work that wouldn't be necessary. It doesn't give a good vibe, a bit like finding the hidden battery in a perpetual motion machine.

Lance Funston

Clearly the point was to test its feasability and performance as a fuel in a conventional vehicle on an existing stock of butanol before ramping up to produce it in quantity from biomass.

I think Butanol may very well be the Cindarella Fuel if he figures out how to scale prodution.

John McConnell

It seems to me this is a good example that maybe the best possible transportation fuel isn't even figured out yet. I really get frustrated by hearing the administration say we really can't do anything about global warming -- what, are we a bunch of idiots?? How about saying that we are absolutely going to do something and lets go for it. Certainly there are more ideas like this out there that would be helped by a forward looking federal government instead of with hits head buried in the sand and it's hands buried in the deep money pockets of the oil industry.


The way this is being pitched (sugars from maize rather than e.g. hydrolized wood waste), this is one more attempt at subsidy of farmers rather than energy independence.  Is there any calculation of how much corn would be required to meet demand, vs. how much is available?  Not that I can see.

This is a system with small-to-middling potential, and deserves a similar level of research support.  The big support should be aimed at schemes with much larger potential, from 20% to 100% or more of vehicular energy requirements.


What are the emission characteristics of butanol compared to ethanol and gasoline? We know ethanol is cleaner overall but is butanol?


Hi I posted the trip blog on

But greencarcongress seems to be where the dialog is.

At dramey756 are the proformace data at various Emissions testing facilities across the nation.

Lance is right we did it for demonstration purposes. To make the statement that Butanol replaces gasoline in YOUR CAR today without modifications if we had it.

No one knew the efficacy of Butanol to replace gasoline in all the years.

Now Butanol is at least on the table as an alternative fuel.

Tom we did have Butanol tested in Denver against 100% Ethanol so he said and we are cleaner they looked for 2.5000 and Butanol was 0.1214 grams per mile Hydrocarbons. But I think the HC of 2.5 is more like a gasoline standard than ethanol. Maybe he pushed the wrong toggle. I will post the data in a more formated form (Excel) on the blog in the next couple of days.

All in all it is great being home and back to my critters.

Butanol performed flawlessly everywhere we went. I use to know it was a good fuel but now I am in awe. There is no hidden battery Butanol stands on its own. And ehtnaol at one time was a stepping stone till we found a better solution.



how I can preparation clostridium for produce acetone and butanol?


Frankly I am not even sure if the Oil Companies have a back up plan come the day when Oil supplies are dwindling to nothing but for now as long as people are fed the belief that Oil is our only fuel source available then no one will ever know that we DO infact have a replacement for gasoline I.E. butanol! However with the oil companies having such power will the day ever come when we can start pushing butanol and replacing gasoline? If anything our country won't get anything out of the deal infact I think we are just waiting for Europe to create the alcohol fuel market because no one can see the economical benefits if we are the ones to reach it first... :/



I've recently come across this area after a routine check of wikipedia on biofuels. In case anyone is interested, I've posted about what I found here: (and also off topic in a kater thread on that site). For what it's worth, there are a number of obvious approaches to try that might reduce the problem of butanol build up inhibiting the processes. The most obvious is low pressure fermentation, which would have worked by allowing butanol to boil off as a vapour - only the water would boil off first. Luckily there are a number of variants that could still work; may


Great Idea! Watch out for the Big Oil Thugs that will try to ruin your day... Good luck ,This planet needs a sensible energy solution like yours.


How can one make biobutanol at home ? (in a similar way to homemade biodiesel)?.


How can one make biobutanol at home ? (in a similar way to homemade biodiesel)?.


This could really help third world countries that are heavily dependant on diesel. If the technology were made available biobutanol would explode in a year.

Its a shame that no one really wants to work with a company from a third world to really make this commercial before thye big oil or chemical companies

Eva Markiewicz

I'm shocked I hadn't heard of this before last week. Did this make national news? Why hasn't someone made a documentary about this?


This is all every exciting but it doesn't sound like it will actually be available any time soon.

But I have a few questions anyway...

How to convert a vehicle to run biobutanol?

How much would the conversion cost?

How would an average person get access to the fuel and what would the fuel cost?

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.


Post a comment

Your Information

(Name is required. Email address will not be displayed with the comment.)