Why not make propanol or some fuel other than ethanol that isn't corrosive?

This article is inaccurate in several key ways, which can be misleading.

First a minor point. Corn ethanol does not account for most ethanol production. It accounts for virtually all of it. Your use of "most" could mislead readers to think that cellulosic ethanol claims a significant share of production.

More importantly, cellulosic ethanol processes comprise more than two substantive steps, meaning that this use of microbes would not reduce production to a simple "biomass-in, ethanol-out" process. Again, that's too rah-rah and misleading. Pretreatment is an important step for its costs and inefficiencies, including the loss of about half of the available cellulose. Finally distillation has huge energy costs of its own. There are no cellulosic processses (to my knowledge) that produce higher than a 4% solution. This requires three times the distillation of corn ethanol.

It's also quite inaccurate to suggest that this process would work equally well on all the proposed cellulosic feedstocks. Experience with virtually every experimental process has shown relative success with just one or two feedstocks, meaning that separate technologies must be provided to make full use of them all.

Pretreatment and distillation are two deal-breakers for cellulosic ethanol. The amounts and costs of enzymes have been another, though this is one area of improvement. The article mentions that use of the microbes reduces the need for enzymes. Does anyone know a rough figure for this reduction yet? Is it 5%, or is it much better?

Finally, it's worth pointing out the dangers of mass-producing genetically engineered microbes for use in uncontrolled settings. Some such microbes have been recently approved for field tests but ended up being virulent to crops. It's a good thing the mistake was caught before the field test. The researcher believes it could have destroyed vast areas of farmland.

Many of the microbes under study commonly grow within humans and livestock. E. Coli is one example. Do we want to produce a new version of E. Coli having new capabilities to feed on a wide variety of sugars and so on, then possibly have those E. Coli populate our intestines? I personally vote against that.

I've said it many times. The most efficient and cost effective way to use biomass for energy is to burn it for electricity. If it's too expensive to do that, then it will be too expensive for anything.

Thank you Mr. Patel-Predd for trying to make Ethanol better. I am quite sure that you have given up a lot of your own time to get this far.  Hopefully you can ignore the negativity expressed here by some of the posters.

After spending 40 years in business I find nothing wrong with a difference of opinion followed by at least a suggestion or recommendation for change because that's what get's stuff done.  Everyone can learn from working together as a team but negativity followed by more negativity just makes most people not even want to listen.

Tom G
tomgarven@hotmail.com