GM Invests in Coskata, Who Claims it Can Produce Ethanol for $1.00/gallon

General Motors is investing in Coskata, a start-up biofuels company that says it can produce ethanol from a wide range of feedstocks for less than $1.00 per gal, compared with a wholesale selling price of more than $2.00 per gal today. GM will receive the first ethanol from Coskata’s pilot plant in the fourth quarter of 2008. Acccording to Chemical & Engineering News the first commercial-scale plant will be running in 2011, making 50 million to 100 million gal of ethanol (per year).

Coskata’s process is feedstock flexible, and enables the use of cost-effective, locally abundant materials to achieve the lowest ethanol production cost targets in the industry. This groundbreaking approach addresses many of the constraints lodged against current renewable energy options, including environmental, transportation and land use concerns.

Using patented microorganisms and transformative bioreactor designs, Their process can turn virtually any carbon-based feedstock, including biomass, municipal solid waste, bagasse and other agricultural waste into ethanol, making production a possibility in almost any geography. The three steps of the process are:

1. Incoming material converted to synthesis gas (gasification)
2. Fermentation of synthesis gas into ethanol (bio-fermentation)
3. Separation and recovery of ethanol (separations)

During gasification, carbon-based input materials are converted into syngas using well-established gasification technologies. After the chemical bonds are broken using gasification, Coskata's proprietary microorganisms convert the resulting syngas exclusively into ethanol by consuming the carbon monoxide (CO) and hydrogen (H2) in the gas stream. Once the gas-to-liquid conversion process has occurred, the resulting ethanol is recovered from the solution using "pervaporation technology."

Coskata's proprietary microorganisms eliminate the need for costly enzymatic pretreatments, and the bio-fermentation occurs at low pressures and temperatures, reducing operational costs. In addition, the Coskata process has the potential to yield over 100 gallons of ethanol per ton of dry carbonaceous input material, reducing both operational and capital costs.

Together, Coskata's proprietary microorganisms and bioreactor designs lead to the highest conversion rates of feedstock to ethanol in the industry, as well as greater resistance to phage infections and bacterial contaminants.

As syngas fermentation leads to lower ethanol concentrations than corn fermentations, the energy and cost to separate the ethanol from water is proportionally higher. Coskata's exclusively licensed membrane separation technology dramatically improves the separations and recovery component of ethanol production, reducing the required energy by as much as 50%.

Coskata’s process technology is ethanol-specific and enzyme independent, requiring no additional chemicals or pre-treatments; environmentally superior, reducing carbon dioxide emissions by as much as 84% compared to conventional gasoline; and has the ability to generate 7.7 times as much energy as is required to produce the ethanol, compared to corn ethanol which generates approximately 1.3 times as much energy according to Argonne National Labs.

The partnership between the two companies was revealed Sunday, Jan. 13, at the North American International Auto Show in Detroit. Coskata, based in Warrenville, IL, was initially formed with funding from Advanced Technology Ventures (ATV), GreatPoint Ventures and Khosla Ventures.

This post based on materials found on Coskata's website and press releases.

Comments

[Paul F. Dietz]

Or they could make methanol from the syngas (and possibly gasoline from the methanol using Shell's well proven zeolite technology.)

[Grass Man]

The real revolution will come if they can simplify and shrink that down to the size of a washing machine that I can put in my garage and dump grass clippings and kitchen waste into, then we're talking about really living off the grid.

[bigTom]

If this stuff is real it should spell the end of corn based ethanol.

Of course issues like waste products, and soil depletion need to be resolved. Hopefully the waste products can be put back onto the fields recycling nutrients and trace minerals.

[Roger Brown]

In my mind one of the big questions about the economics of this process is the performance of the gasifier. Biomass gasification has been proposed for a number of application but has proven to have high capital costs relative to alternatives. Also it has proven difficult to make the gasification yields feedstock independent.

[Cyril R.]

Roger is correct, it's not easy to gasify some biomass types, and gasifiers are expensive. High capital costs make fast adoption problematic; it comes as no surprise that the projected scale-up is slow. A drop in the bucket by 2011. That means this technology will likely be competing with cellulosic. It'll be interesting to see which one proves to be better.

A biofuel processing plant technology (and in fact, any energy technology) with very low capital costs could make a big difference I think.

What bothered me was that there is no mention of the exact yield (output/input*100%). Right here it says that it has the highest conversion rates of feedstock to ethanol in the industry. Compared to what? Corn ethanol? That's not too difficult is it now!? If it's better than cellulosic then that would be a real accomplishment. Yield is crucial as there will be a limited amount of biomass available we'd want to get the most out of it as possible.

The Coskata website mentions 100 gallons per dry ton carbonaceous. That sounds a lot better than conventional corn ethanol, perhaps similar to future cellulosic yields. But then, how many MJ's are in a "dry ton carbonaceous"? Where are the numbers?

[Cyril R.]

Or they could make methanol from the syngas (and possibly gasoline from the methanol using Shell's well proven zeolite technology.)

Paul Dietz, would that yield more than Coskata's process?

[Paul F. Dietz]

Paul Dietz, would that yield more than Coskata's process?

I don't know, but would not be surprised if it did. The waste heat also would come out at a higher temperature, which would make it more valuable. More practically, it would involve off the shelf, proven technology, so the risk would be lower.

[Cyril R.]

That's true. This source gives some figures:

Advantages of the process
• The synthetic gasoline is free of sulphur and nitrogen.
• The overall energy efficiency of the MTG process including processing energy is high, about 92-93%. The energy balance is extremely favourable, 95% of the thermal energy of the methanol feed is preserved in the hydrocarbon product. The remaining 5% is liberating as heat of reaction. However, if one includes the thermal efficiency for the methanol synthesis process from natural gas (~60%), then the overall energy efficiency (natural gas to gasoline) is about 50-60%.
• The product meets or exceeds existing gasoline specifications.
• Methanol conversion is virtually complete. Gasoline yield high.

It appears NG to methanol has a rather low yield. Biomass to methanol would probably be more like 70-80%. The Hynol process claims higher than 85% with a much lower cost target per gallon of methanol than Coskata's for a gallon of ethanol. I'm not sure how much the zeolite process would add to the cost though. Considering methanol's high octane number, it would be more efficient to use the methanol itself as a fuel. Right now making gasoline is probably best.

Possibly >80% yield of HHV? I did not think such high conversion yields would be possible, especially with gasoline as the end product and using off the shelf equipment. It looks like you may be right Paul.

[Cyril R.]

OK, so ethanol contains about 89 MJ per gallon. Coskata's 100 gallon per ton (I'll take it that's a metric) means they get about 9 GJ per metric ton of dry biomass.

The problem is the biomass. Typical dry biomass energy content would be 10-20 GJ per metric ton, which means Coskata's yield would be between 45% and 90%. That's not very informative and if they're using non-metric tons... Sigh.

[PatCawley]

Why isn't this process being developed for producing butanol instead of ethanol? Butanol has been proven to be easier to handle (non-corrosive), and to have a BTU/gallon rating very close to gasoline.

[PatCawley]

Why isn't this process being developed for producing butanol instead of ethanol? Butanol has been proven to be easier to handle (non-corrosive), and to have a BTU/gallon rating very close to gasoline.