ABE Fermentation (acetobutylicum fermentation of starches to acetone, butanol, and ethanol)
posted 2 years ago
I would like to know if anyone has any experience in Acetobutylicum fermentation from starches (jerusalem artichokes for example) and fermented and distilled into acetone, butanol, and ethanol. I've read that butanol can be used as a gasoline alternative, and the math I've done is that 1 acre could potentially yield over 7000 gallons of butanol. I'm interested in attempting this this summer. So any help would be useful.
You've made a turn down a deserted cul-de-sac, Hunter. The last time that technology was being actively used or researched was World War I. After the war, as part of the rebuilding, the construction of oil refineries took off, and fermentation just couldn't compete with all the easily available crude oil. Consequently, anything related to ABE fermentation got shelved and just withered away.
However, it does make a lot of sense from the point of view of renewable biofuels. And being oxygenated, A, B, and E all burn cleaner than petroleum-based hydrocarbon gasoline.
But how to revive the technology? Part of the problem is that those strains that gave high yields of B and A probably aren't around any more. Oh, they could be re-developed by a selective breeding program, selecting for the strains that have high conversion rates, but I don't think you are going to be able to find them commercially available . You are going to have to become a microbiologist-with-a-mission to find them and get them working again. If you look on Google Scholar, you can find lots of references about the technology, but the vast majority of them are more than 30 years old, more like 70 and 80 years.
But being that Permies are generally oddballs out of step with the rest of the world, you're asking at exactly the right place. I would be very interested in seeing this technology take off once again. What is it you want to do this summer, and how well are you set up to do bulk fermentations?
William Bronson wrote:
Good news is,as of 2012 research was ongoing and up to date.
Bad news is that it seems very high tech and probably proprietary.
There's ongoing and then there is ongoing. If ongoing means the government is funding some university research into the topic, then don't hold your breath waiting to fill up your tank with ABE fuel. If ongoing means some for-profit company is taking out patents and expecting to turn a profit, then it may come to market quickly, but as you say, it will likely be proprietary and not something you can cook up on your own (like biodiesel).
However, if the old technology can be redeveloped, it wouldn't be proprietary, as it would have passed into the public domain. The proprietary angle comes in if there is new technology, biological or genetic engineering that is used that can be the basis of putting the process, or key parts of it, under patent.
This is probably going to need to be a team effort. I've looked into it before, but I'm a chemist, not a microbiologist. I'm fine with the post-fermentation processing, but as far a culturing the strains to get the fermentation started, that's not my area. Can we get a team of Permies together, with the right amount of experience, to tackle this problem?
its the yeild issue that looks like the biggy . To give an example with ethanol you can get a yeild of about 20% before distillation thats a big yeild and I suspect butanol yeildto be less than 10 thus giving it a massive hurdle to get over in profitability or in permie terms getting more energy out than you put in .
Living in Anjou , France,
For the many not for the few
posted 2 years ago
So my research as led me to the conclusion it is TOTALLY plausible.
The strain is Clostridium Acetobutylicum you can buy it online from culture vendors for less than 15 dollars. The main issue would be maintenance of the culture over time (one that I have struggled to solve, due to the necessity for cryopreventatives to be used in freezer preservation and in fridge preservation you only get a couple weeks of viability.)
I would imagine that using a continual fermentation process (an packed "bed" of the culture at the bottom of a refillable barrel (anaerobic of course) could be plausible. I've seen on youtube ONE and only ONE video of a set up for this. But the culture is readily available, weissmans organism or clostridium acetobutylicum (its widely used in colleges for anaerobic studies). I've read obscure hard to find material that Sunchokes are the BEST source of carbon and in my own research I'd have to concur the growing time mixed with the "invasive" (read: resilient) nature of the plant would be extremely valuable. I am going to attempt this process this summer after my harvest.
But the culture IS Available and cheap, the process is fairly simplistic and the yield is 2 (acetone) - 6 (butanol) -1 (ethanol).
For one acre of jerusalem artichokes planted 1 foot apart the yield COULD be over 7000 gallons of butanol, or enough gasoline alternative to fuel 10 cars every week at 10 gallons a tank for a year.
posted 2 years ago
I do agree however that strains of the organism that give higher yields of butanol to ethanol or acetone are probably non-existent outside of BP and Shell R&D facilities (since they own the patents) but I could easily get enough butanol from a regular strain to make it worthwhile. at 2-6-1 ---- A-B-E I think it will be worthwhile, the number I gave for 1 acre of yield was pulled from the numbers of a recently done study on jerusalem artichokes and the culture and extrapolated into gallons from liters (the butanol) and from pounds of artichoke material into how many pounds per square foot, and how many square feet in an acre. The number I got was around 7800 gallons so I rounded down to 7000 in effort to buffer the margin of error. If I built 3 or 4 different fermentation units (possibly using a shlenk line in combination with a sealed distiller) I could over time artificially select the most butanol friendly culture. But I do enjoy the prospect of a natural source for a solvent like acetone, something I would probably use heavily in certain extraction methods for medicinal constituents, and even as paint or varnish remover. Seeing as ethanol is the lowest yield and butanol is such a high yield in comparison I don't see as big an issue with finding "industrial" strains of the bacteria to produce more yield.
The strain used by this experiment was actually Clostridium saccharobutylicum, I don't know the specific differences of this strain and Acetobutylicum
posted 2 years ago
In a comparable study, C.
acetobutylicum L7 was used for hydrolyzate fermentation of
Jerusalem artichoke with 62.9 g l1 sugars, resulting in
a solvent concentration of 17.2 g l1
, corresponding to a yield
of 0:29 gSolvent g1
sugar , which appears to be lower than the
results obtained in this study, however a larger amount of
sugars could be converted. It has been reported raising the
initial carbohydrate concentration in the medium above
60 g l1
, as was the case for the work of Chen et al. (2010), will
reduce the fermentation efficiency . Additional deviation
can be potentially explained by strain characteristics of the
Clostridia (L7 vs. DSM 13864).
posted 2 years ago
It's my understanding that one must hydrolyze the starches prior to inoculation with Clostridium.
The experiment used extracted inulinase but I wonder if just inoculating the substrate with black mold would suffice, or if the black mold would convert the necessary starches so much that the clostridium wouldn't be able to convert it to volatiles. So first issue is hydrolyzing the inulin and fructose of the tubers, using A. Niger.
Then the second problem is then inoculating the substrate with the proper strain (either Acetobutylicum or saccharobutylicum.)
I wonder if a crude experiment could be done where a batch of the starches were hydrolyzed by inoculating aerobically with A. Niger, (probably a few different batches inoculated to different degrees) and then pasteurized or sterilized and then inoculated with the bacterium. I just don't know if live cultures of A. Niger would produce enough Inulinase for the hydrolysis of the inulin in a natural non-extract scenario. Or if there is a way to "Farm" black mold and make your own extractions of the inulinase itself.