WFU Biofuels

Wake Forest students, faculty, staff and associates making and testing vegetable-oil based fuels.

Monday, October 31, 2005

Molecular Scissors

A guy named Richard Carpenter has recently raised a question about B100 use in modern diesel engines on the Biofuels Interest Group (BIG). His observations have centered on the potential problems of using B100 in modern diesels given the differences in viscosities between B100 and petrol diesel. Here are the viscosities of petrol and B100 at 27 and 75C:

27C 75C
petrol 4.3 1.5 (mm^2/s)
B100 (soy) 11 4.3 (mm^2/s)

So B100 only approaches the viscosity of "cold" petrol diesel when heated to 75C. From what I understand the forces in the injection systems skyrocket given these differences. The fuel is injected at about 22,000 to 26,000 psi!!! In a nutshell, without software changes the engines run less efficiently. There are also increased stresses in the injection pump systems causing some "unconfirmed" premature failures. This does not help B100 acceptance but does create a need to blend.

I started looking for articles that address this problem in B100. I knew ozonlysis of FAME would produce shorter chain esters and that would produce a less viscous fuel. So I search and found this:

A recent paper by Ramani Narayan in Biomacromolecules 2005, 6, 1334-1344 looks at the ozonlysis of FAME. He is Chemical Engineer at Michigan State University. They treated methyl soyate (FAME) with ozone in a process called ozonlysis. The reaction will take double bonds cleave them by either oxidative or reductive pathways. The end result is the production of 9, 6 and 3 carbon chain esters from the UNSATURATED esters. They did not report any viscosities on the ozonized FAME but did report a change in volatilization temp of 135C to 73C (petrol diesel is ~76C). They also reported no change in temperature for the onset of crystallization in region 1 (long chain saturated esters) but a depression in region 2 (unsaturated esters) from -63C to -86C. They did not measure the viscosity of the ozonized product but I wager the numbers are lower.

Since the reaction is cheap and easy I bet we may see more about this. Especially for mono and polyunsaturated B100 derived from oils like Canola, Peanut and Soybean. I also wonder what effect we would see on the ozonlysis of SVO. So if and when we are able to measure viscosity we have some measuring to do.

Tuesday, October 25, 2005

What's coming out of that pipe?

I've been reading a lot of papers on testing and production of B100. I found a very good review article (Analytical Methods Used in the Production and Fuel Quality Assessment of Biodiesel, Transactions of the ASAE, Vol 44(2), 193-200). There are several methods used to monitor fuel quality; Gas, High Performance Liquid and Gel Permeation Chromatography. As well as spectroscopic methods; proton and carbon 13 NMR and Near IR. Other methods are viscometry, titrations and enzymatic reactions.
I was surprised to find that Near IR or Viscometry are the methods of choice for routine evaluation in production. Soy oil has a viscosity of 32.66 mm^2/s at 38C and Soy FAME has a value of 4.41 mm^2/s at 40C. This method is suitable for process-control purposes. So if you are producing B100 and the viscosity changes a lot then you go to GC analysis to figure out what’s wrong. A lot cheaper and faster.
I’ve also been reading about continuous reaction processes. I have many more questions than answers. I’d like to go and tour a B100 plant to see how the big boys do this. I have learned that without some technical advantage then only scale of economy will allow you to be competitive in the market place. Here’s an example of a company that has spun off from CARNEGIE MELLON UNIVERSITY. Full article here: (full article here: http://www.innovations.harvard.edu/news/7954.html )

“Conventional biodiesel plants use batch processing, mixing together alcohol and liquid catalysts that are stirred and heated to produce a methylester from a pure plant oil or animal fat, along with the by-product, glycerine. The processing of pure oils prevents them from thickening too much in colder temperatures.
By contrast, Capital Technologies' equipment and process involves microwave heating, proprietary solid catalysts and continuous processing that can be expanded by adding production modules that the company is assembling at a South Side manufacturing facility, said Marc Portnoff, senior scientist at CMU's Center for Advanced Fuel Technology.
The CMU center developed the new process with financial sponsorship from Capital Technologies, which until recently was a research and development venture backed by investors, including Jackson and John Sununu, former New Hampshire governor and onetime chief of staff during the first Bush administration.
Among the advantages of the new technology are that it takes up less space, in part because of the microwave heating, and can be readily expanded, said Portnoff. He, along with the CMU center's director, David Purta, expects to leave his CMU post to join the new venture in several weeks.
In addition, because it uses solid rather than liquid catalysts, "Our cleaning process [to remove impurities from the biodiesel] is a lot easier," and the manufacturing facility can be much smaller, Portnoff said. Production rates also are double the rates for conventional processes, he added.”

I have found papers reporting FAME synthesis using microwaves and solid catalysis. The technical advantages are faster reaction times (less energy input) and little or no washing. That’s right, little or no washing!!! Now imagine a centrifuge at the end and you have a nice continuous process. So as we build a batch processor I’d like to see someone build a small bench-top continuous processor, sort of a proof of concept project.

Monday, October 17, 2005

DOE

Who says the gov't is lame on alternative energy? At least they make pretty and informative web sites, like this one from DOE. It has a great biofuels section.

Grants

The Sorcerer's Apprentic and I are ready to submit 1-2 Pro Humanitate grants on November 9th and The Educator is working up an EPA curriculum grant. Should we move into the big leauges? Here are a couple of sites with links to grants that I think we might be able to land. From the biology side there are some simple things that we could do with algal stocks and oil degrading organisms that would be competitive, I think. Here is the NREL biofuels site, and there are some great links to grants at the Oak Ridge biofuels site.

Should we make a list of tasks and deadlines to keep the project rolling?

Friday, October 14, 2005

Shaman says: make a hexane still

Yesterday afternoon the Shaman, the Sorcerer's Apprentice, and I were talking about producing BioD from virgin oil rather than waste. Now, we're not looking to upset the apple cart on the plans for the bigger reactor, but we were doing some brainstorming. In particular, we were looking at the economics of making biodiesel from oil that we grow cooperatively with local farmers.

The oil yield per bushel (and per acre) varies a lot among crops, and the ways that oil is extracted varies a lot, from mortar and pestle, to mechanical (ram and screw presses) all the way up to the solvent methods that the big-boys use. Looking at straight oil extraction, it doesn't look like traditional crops are going to be cost effective unless you factor in the profit gained by using the meal. Home-pressed sunflower oil comes out to >$10/gallon, and soybean oil comes out to ~$4.50 a gallon, the latter just figured on yield per acre and the cost that an acre of soybeans can bring. Canola seed and other oil crops might be able to do better, particularly if you can find a way to use the meal (like feeding it to my pigs or cows).

So, where does hexane play into all of this? Well, the Shaman was talking about making a hexane still to extract the oil out of flaked soybeans, or whatever other crop we use. Hexane is cheap, and super flammable (two qualities that endear it to pyros) and also gives a super efficient extraction of the oil. And, the meal can be used afterwards. Hexane in your food, you gasp? Read how the vegetable oil you use is extracted from the bean. What they don't get goes into your textured soy protein and animal feed.

Other sources of oil that the Shaman came up with were looking for vegetable oil that passed its expiration date, and also trying to find an oil processing plant somewhere around here and trying to get the tails of the batches that they can't sell for food.

So, friends, keep your noses to the ground for sources of oil. Also, Oily SOB, it might be time to contact your big batch waste producers and to try and tap into the big streams of waste oil. The amount of effort we go to to collect small batches probably will end up costing more than just heading out to buy regular diesel. While it is still nice to run biodiesel in terms of being carbon neutral, helping farmers, and sticking it to the terrorists and The Man, it sure would be nice to make it pay too!

Thursday, October 13, 2005

Now we're posting!

This should come as an email to wfubiofuels. (Test)

What does a raw soy bean taste like anyway?

I was talking to my farmer friend this morning about growing soy beans and what happens to them. I found out where they have them ground and then sold to a broker. He promptly walks over to big hopper and with one hand (equaling all muscle tissue in my entire body) and scoops out a bucket full of soy beans. He then picks a bean out and pops it in his mouth and commenced to chewing!! Not to be out done, I too picked up a bean and starting chewing and chewing and chewing. Tasted like...... uhhh, uhhh...chicken. No not really. It tasted like a raw peanut. I have about 15 to 20 lbs of soy beans (dried from last year) in my office if anyone wants to play with them.

I thought a pretty cool lab exercise would be extracting the oil from a known weight of beans. Could then try other beans to see the difference. I suppose if you are buying beans for the oil you could evaluate the beans based on oil yields rather than just bulk mass. Probably the next week's lab would then be making biod from the extracted oil, right?

Salem Hall room 9b if you want some beans otherwise, I'll give the left overs to B. and A. King (chem profs), they have chickens and goats. A goat will eat anything right?

Tuesday, October 04, 2005

Tank Report

I washed the remaining resin out of the big tank with pressurized gasoline. It worked quite nicely. We have something to start the next bonfire with as well. I found more on the tank contents and it can have up to 50 ml/L in potable water, so I imagine it isn't too nasty.

The next tanks that we're getting from the super-donor contained Silastol PHP 26, which is a finishing agent for fabric fibers. The MSDS looks benign, and it is fully miscible with water, which is a definite plus. Translation: awesome!

Oil update


Just back from checking the bins at the Dixie Classic Fair. We had a bit of a SNAFU this morning as I hadn't gotten all the ammonium resin out of the big tank. We dropped off some extra oil collection tanks, so everything should be okay as far as our responsibilities to collect oil.

After getting back, I took the tank over to the Chemistry department and the Shaman and I tried to figure out how to clean the tank goo out. It looks a bit more difficult than expected. Soap doesn't touch it, acetone, methanol and ethanol don't do too well with it, and toluene is marginal. Petroleum ether does a good job, as does cooking oil, so we thought that gasoline might be the best solvent. We'll give that a try this afternoon. It might be good to pressure wash the tank as well. I've ordered the MSDS sheet and will take a look. As we're going to be getting 20 of these big tanks, we'll need to find some easy way to deal with the contents!