Coskata Joined in Race for Cellulosic Ethanol

Although Coskata may be getting the most amount of press and attention these days for their work towards mass producing cellulosic ethanol, they definitely are not the only ones working on the problem. Louisiana based Verenium Corporation has announced plans to enter the cellulosic ethanol race with a pilot-scale plant of their own in Jennings, Louisiana. The company plans to have a scaled up commercial plant capable of producing 30 million gallons of ethanol per year by 2010, which would put it approximately on schedule with Coskata.

However, there are some major differences that give Verenium the advantage in terms of hurrying production along and disadvantages. Verenium produces cellulosic derived ethanol using an enzyme pretreatment and then genetically engineered e. coli stains that possess the genes to convert 5-carbon sugars, such as xylose, into ethanol. This is an improvement over yeast, which are only able to convert 6-carbon sugars, such as glucose, into ethanol. With the e. coli stain possessing an additional pathway that is abundant in cellulosic ethanol, it allows the plant to move forward quickly with relatively novice technology. In other words, existing corn-ethanol plants could easily be retrofitted with this new bacteria and would become cellulosic ethanol plants. However, the downside is that the technology does not escape many of the problems that currently plague corn-based ethanol. Sure, the feedstock would be more flexible, owing to the company's claim that they will be able to produce ethanol forl around $1.84 per gallon including their debt responsibilities. But they don't escape the massive amounts of energy needed in the pretreatment step, which Coskata gets around by gasifying the biomass, and it doesn't seem as though Verenium has improved any of the downstream applications, such as separation of ethanol and water after the fermentation step.

The bottom line is that Verenium is going to be a fast mover towards cellulosic ethanol, much like South Dakota based Poet. However, in the long run, Coskata will have a definite advantage over these two players as its holistic approach towards cellulosic ethanol production that seeks to address many if not all of the problems found in corn-based ethanol, will eventually prove to be the winner.

Below are graphics provided by Verenium on their process stream and on their calculated costs to produce a gallon of ethanol.

GM & Coskata

Coskata held a media day over the weekend to update the press and public about its ongoing efforts to produce cellulosic ethanol using a gasification followed by fermentation process. The event released some interesting results, indicating that although Coskata has yet to delve into the realm of reengineering their clostridia species to produce different types of fuel besides ethanol, they have been effective in their screening methods in producing larger amounts of ethanol from their bacteria. Their graphic, which is shown below, indicates that Coskata has improved their system a great deal in the past few months and managed to produce moderate amounts of ethanol from their system.

The development allows Coskata and GM to move forward in their goals to get a pilot plant up and running in Pennsylvania by the start of next year and a 50million gallon per year ethanol plant running by 2011. Coskata believes that by using multiple gasifiers, they will be able to process between 1,500 and 3,000 tons of biomass per day. Their business plan also estimates that by using and reinvesting these profits, Coskata will be able to expand to establish 20 biorefineries per year by 2015, which would allow for the widescale production of ethanol from cellulosic wastes and allow up to 35% of gasoline fuel demand to be offset by ethanol.

This is all good news but highly hypothetical, of course. Although I'm sure they are aware of the difficulties, Coskata mentions the goal of engineering their bacteria to produce bio-butanol, a fuel that would have an energy density much closer to that of gasoline. However, butanol is highly toxic to bacteria, even at relatively low levels, so it remains to be seen whether this idea will pan out or not.