Consumer Energy Report is now Energy Trends Insider -- Read More »

By Robert Rapier on Jul 4, 2010 with 15 responses

Introduction to the MixAlco Process

In this essay, I am going to talk about my graduate school work at Texas A&M. Since leaving A&M there have been a lot of developments related to the technology I worked on, so in the essay following this one I will discuss more details on the nature of the technology and the developments toward commercialization.

My Ag Background

I may have mentioned once or twice that I grew up on a farm in Oklahoma. Farming is still very much a major activity within my extended family, and needless to say I have had a lifelong interest in agriculture. After receiving undergraduate degrees in chemistry and mathematics, I decided to attend graduate school at Texas A&M University. For those who may not know, “A&M” is short for “Agricultural and Mechanical.” Based on my background and the fact that I wasn’t far-removed from the farm, I felt more at home at Texas A&M than at other campuses I visited.

There were two fundamental areas that I was interested in for my graduate school research: Sustainable agriculture and sustainable energy. Within the Department of Chemical Engineering, there wasn’t much going on in the area of sustainable agriculture, but there was some interesting work going on in sustainable energy. There were three professors I was interested in possibly working with: Professor Bruce Dale, now at Michigan State University, Professor James Liao, now at UCLA, and Professor Mark Holtzapple. After looking at the nature of the research and speaking with the professors and their students, I chose Professor Holtzapple as my research advisor.

Life in the Lab

I spent many hours over the following two years in Professor Holtzapple’s labs, working to develop a process called the MixAlco Process. I will get into more details of the process and provide links to background information in the next story. In a nutshell, we were using naturally occurring microbes that could efficiently convert cellulose into chemical intermediates that could be turned into fuels. Our focus when I was there was on the rumen digestive system. Cattle are efficient digesters of cellulose; they eat grass – largely cellulose – and in their digestive system a combination of microbes works to turn the cellulose into acetic, propionic, and butyric acid that the cattle then use for energy. But those acids can also be converted into mixed alcohols – ethanol, propanol, and butanol (and trace amounts of higher alcohols).

Our goal was to replicate the rumen digestive system in the lab, and potentially modify it to optimize the yield of desired products. We collected microbes from a pair of fistulated steers on campus. Somewhere out there is a photograph of me with my  arm up to my shoulder in one of those steers collecting fluid for the reactors. There is another of me in a white lab coat running from ostriches, which were being raised in the same area as the steers. You had to be really careful around those ostriches, because they could really hurt when they pecked you. But I digress.

Our feedstock was a combination of municipal solid waste (MSW) and sewage sludge. The sewage sludge provided nutrients for the microbes that were consuming and converting the cellulose in the MSW. One of the themes of my research was to determine optimal sewage sludge inoculation levels for the reactors. I spent an entire Saturday morning once at the city wastewater treatment plant shoveling sewage sludge into my pickup, which we then later spread on Professor Holtzapple’s lawn to dry. (I never did ask how his neighbors reacted to that).

Bio When Bio Wasn’t Cool

We made progress while I was there; the kind of progress that these days would generate multiple press releases. But things were different way back in the ancient days of the early 90′s. The link above on the MixAlco process noted that “Dr. Holtzapple was doing bio when bio wasn’t cool.” So there were no reporters sniffing around asking what we were doing (although that would come later), because the clean tech industry wasn’t like it is today.

We were being partially funded at the time by Hoechst Celanese (who I would go to work for making butanol after graduation) and progress was reported to them – not through press releases. We managed to push the concentration of organics in our reactors up to a higher level than had been reported in the literature, and made good progress on many fronts. I also had the idea at one point to try out termite microbes. It occurred to me that the termite digestive system is one of the most effective at digesting cellulose, and thus mining termite guts seemed promising.

I had mixed success with the termite experiments. I realized afterward that trying to replicate a termite digestive system is probably an extensive research project in itself. At the time, I couldn’t find anything in the literature indicating where anyone had tried it before, so I didn’t have anything to guide me. Maybe I was just ahead of my time with the termite experiments, because fifteen years later I started reading news stories like this one:

Termites may hold the answer to cheap, efficient ethanol fuel production

Moving On

I defended my thesis and graduated in 1995. The title of my thesis was Volatile Fatty Acid Fermentation of Lime-Treated Biomass by Rumen Microorganisms. I left Texas A&M to go to work for Hoechst Celanese, but joined my research group the following year in Washington D.C. when we won the 1996 Presidential Green Chemistry Challenge Award.

Since I left Texas A&M, Professor Holtzapple and I have had sporadic contact, but I was mostly out of the loop with the continued development of the process. However, he recently contacted me and sent me some presentations and literature on their current status. I asked him if he would mind if I wrote a story about what they are doing – drawing on the information he sent me – and he agreed.

The technical details and progress toward commercialization will be addressed in the follow-up to this essay.

  1. By Benny BND Cole on July 5, 2010 at 1:16 pm

    Interesting read. By the time I realized I was way more interested in science than any other topic, I was well out of school, deep into a career, kids on the way etc. But, at least I can live vicariously through real scientist-engineers such as RR.

    [link]      
  2. By takchess on July 5, 2010 at 2:29 pm

    Nice Post. Sounds like a lot of fun. I imagine there are 20 somethings doing similar type of work at Mascoma here in NH.

    I’m interested in hearing the next stage of that work . Don’t be to hard on the press releases without them the general public would hear nothing. One shouldn’t hide one’s light under a bushel.

    [link]      
  3. By rrapier on July 5, 2010 at 3:11 pm

    Don’t be to hard on the press releases without them the general public would hear nothing. One shouldn’t hide one’s light under a bushel.

    I don’t have a problem with press releases in general. Just those that are excessive and overhyped – primarily utilized to bring in funding. But if you have something noteworthy to say, I don’t have a problem at all with them.

    RR

    [link]      
  4. By savro on July 5, 2010 at 3:38 pm

    Tak, which part of the Granite State do you hail from? I may be heading that way in a few weeks.

    As far as press releases go, there’s a big difference between reporting information and raw data vs. using a press release to make a hyped-up pitch to investors and taxpayers (a.k.a. government).

    [link]      
  5. By paul-n on July 5, 2010 at 7:01 pm

    As I recall, universities used to issue things called “research reports” or something similar, which were very factual and, mostly reliable, as they were written for a peer audience.  Press releases used to be written for the “press”, meaning everyone, but now they seem to be written to hype project x to show politicians how much popular support there will be for funding it.

    I’ll bet my money based on what the research reports do (or don’t) say, I wish the politicians could do the same.

    As for the mix alco process, I came across this a couple of years ago while casually researching butanol, it seems like a good idea, and gets higher yields from cellulose than ethanol.  But it does not appear to have progressed out of the lab – I’ll be interested to see the follow up post to this.

    I like the product because it is a mixed alcohol, and can be used straight up, or blended with methanol for an even better fuel.

    Naturally, if it this turns out to be a better and more economic cellulosic process than ethanol, we can expect Rufus to support it wholeheartedly!

    [link]      
  6. By takchess on July 5, 2010 at 9:11 pm

    Sam, I live in Nashua which has around 85,000 people which makes us NH 2nd largest city. Where are you going?

    I do agree on the press releases that they are trying to accomplish something and are purposely vague. Sometimes things sound very interesting and then you spend time wondering what is happening with ….. ie,

    http://www.popularmechanics.co…..gy/4243793

    [link]      
  7. By Wendell Mercantile on July 5, 2010 at 9:13 pm

    …it seems like a good idea, and gets higher yields from cellulose than ethanol. But it does not appear to have progressed out of the lab – I’ll be interested to see the follow up post to this…

    Paul,

    Probably because it has no backing from Big Ag and Corn Belt politicos.

    [link]      
  8. By savro on July 5, 2010 at 9:34 pm

    I know Nashua quite well, being that I’ve driven by it on the Everett Tpke. no less than 10 times. If I recall correctly, the Northeastern air corrcidor is directed by the FAA’s installation there.

    Not sure where I’m headed yet, but possibly the Wolfeboro area/Winnipesaukee region. It’s beautiful there.

    [link]      
  9. By Rufus on July 5, 2010 at 9:43 pm

    Paul, you can “Bet” on it. I want to burn American, non-fossil fuel in my car. Everything else is fluid.

    [link]      
  10. By Wendell Mercantile on July 6, 2010 at 10:17 am

    I want to burn American, non-fossil fuel in my car.

    Rufus~

    I understand the American part, but limiting yourself to non-fossil fuels takes corn ethanol out of the calculus — there would be no corn ethanol without the consumption of fossil fuels.

    [link]      
  11. By Wendell Mercantile on July 6, 2010 at 11:01 am

    Rufus~

    I will also ask why you’ve been so negative about methanol and DME made from using celluose, lignin, and waste organic material (trash and garbage) feedstock in bio-gasifiers? That would certainly be American, and could be made w/o fossil fuel input.

    You do seem biased against any alcohol fuel other than ethanol.

    [link]      
  12. By Rufus on July 6, 2010 at 1:55 pm

    I’m not “agin” those things, Wendell. I just don’t think they’re going to “get there.” We’re well along the way to Ethanol, and it seems to me like it would take a rather large happenstance to cause the caravan to “change direction.”

    [link]      
  13. By Wendell Mercantile on July 6, 2010 at 3:57 pm

    Rufus~

    Except the “way” to corn ethanol has been distorted by lobbying, politics, backroom shenanigans, subsidies, and tax credits, while the way to methanol and DME would be pure and technically sweet.

    [link]      
  14. By Rufus on July 6, 2010 at 4:20 pm

    Whatever you say, Wendell; personally, I’m not interested in all that. I’m just up for whatever works.

    [link]      
  15. By jfinlayson on July 9, 2010 at 6:18 pm

    Robert Rapier said:

    Since I left Texas A&M, Professor Holtzapple and I have had sporadic contact, but I was mostly out of the loop with the continued development of the process. However, he recently contacted me and sent me some presentations and literature on their current status. I asked him if he would mind if I wrote a story about what they are doing – drawing on the information he sent me – and he agreed.

    The technical details and progress toward commercialization will be addressed in the follow-up to this essay.


     

    Looks like Prof. Holtzapple has a paper on MixAlco in this month’s issue of Journal of Industrial Microbiology and Biotechnology:

    http://www.springerlink.com/co…..162206253/

    [link]      
Register or log in now to save your comments and get priority moderation!