quote:

chilling costs energy.

Not where I live

Really want to run B100 or as close as possible now but...need to get to work in the morning!

quote:

The point is to not add diesel. Plus chilling costs energy.

Maybe your point, not mine. I have no problem using BD-ULSD blends, in fact that's what all biodiesel should be used for to reduce air pollution from all diesels. In my case chilling is free.

quote:

chilling costs energy.

Actually if done right it won't cost any more energy and actually might save some.
Use a heat pump chiller to extract heat from finished biodiesel till it's cold enough to settle the troublesome precipitates, and use the extracted heat to warm a new batch.

Once the fat/PHO BD drops out, the resulting clear BD can be used in blends to -40 without any problems. It won't separate from the diesel.

I've got something similar, although probably a more complicated process, and it's not from vegetable oil.

I read about this company Amyris making diesel from sugar cane in the Technology Review. Here's a link:

http://www.energy.ca.gov/2009-ALT-1/...esentation.pdf

They call it "No Compromise Diesel"

Bump, I've written an article on this subject for www.make-biodiesel.org. It pretty much just background info on the subject.

I've sourced several pounds of urea and want to give it a try. My starting recipe will be 1 liter of raw unwashed biodiesel, 4 liters of methanol, and 1 kg of urea.

quote:

Originally posted by RickDaTech:
Bump, I've written an article on this subject for www.make-biodiesel.org. It pretty much just background info on the subject.

I've sourced several pounds of urea and want to give it a try. My starting recipe will be 1 liter of raw unwashed biodiesel, 4 liters of methanol, and 1 kg of urea.

Rick,

The following was posted as a comment to your article (grammar and formatting preserved from the original):

quote:

Using Urea, I could make winter grade Biodiesel not Cloud or pour point down to -19 to -21Deg.C (Min.lowest tem.of refrigerator) without difficulty if small amounts. Sample Biodiesel:500g Original Urea:200g Methanol:3 times of urea I tried three step wise processes(1st:urea:200g,2nd:recovered175g,3rd;recovered150g) to minimize consuming methanol and ureas. It is also to do one step process,but require more ureas(500g) and methanols(1500CC or more). By changing ureas and corresponding methanols,I could make several types of Biodiesel were obtained from -5 ,-8,10,-15, and -20Deg.C of Cloud point. I used fertilizer grades of Ureas,not chemicals grade. This urea based methods are not new ones and several researchers were tried since 1950-2010 time frame. I would not use this method for lowering C.P. of Biodiesel. Main reasons are : 1) Too much volumes of methanols compare to Biodiesel(3-5 Times) and not easy to methanol recovery within closed circuit system.. 2) Not so easy to remove urea and purify biodiesel completely. 3) Saturated Biodiesel were recovered by using water or heating methods. If use water method,urea condensation from water was not easy and urea molecules becomes ammonia gas(approximately at 130 Deg.C),if use heating methods I hope above information us some help for you.

The problems this person brings up sound pretty tough to get past. What are your thoughts?

quote:

Originally posted by RickDaTech:
Bump, I've written an article on this subject for www.make-biodiesel.org. It pretty much just background info on the subject.

I've sourced several pounds of urea and want to give it a try. My starting recipe will be 1 liter of raw unwashed biodiesel, 4 liters of methanol, and 1 kg of urea.

1 liter of bio and four liters of methanol? In addition to the 22% in the original processing? That is gonna be some expensive bio!

quote:

Originally posted by fabricator:
1 liter of bio and four liters of methanol? In addition to the 22% in the original processing? That is gonna be some expensive bio!

Agreed- recovering the methanol and urea well enough for re-use probably shifts this into the "not worth it" category. I hope I'm wrong though.

You'd need to recover the methanol for sure, but the urea/water solution could be used as a nitrogen fertilizer, I think. Can't speak to the economics, but it could be more efficient than trying to reclaim it. Hugh

Kumar,

If you have an efficient methanol recovery system, I don't see a problem with using the extra methanol. The problem for the commercial producer is recovering the urea. You have to add enough water to dissolve the urea, mechanically separate the water from the oil, then use low temperature distillation techniques to separate the urea from the water.

Yes it will be energy intensive to make, but think of the marketing. Biodiesel that when blended with diesel, lowers the gel point of diesel. Not something that would sell well in warm climates, but will definitely be a product to offer in northern states that mandate blending. The product will be a niche within the biodiesel market, but I do see that as long as it is not over produced, it will be able to draw the premium pricing.

Is this something a home brewer would do? I doubt it. The process requires a really good methanol recovery system to work, much less be cost effective. The home brewer does have the advantage of having small enough quantities that he could use or trade the urea water without having to recycle it. A commercial producer would be forced to reuse it or potentially risk having to dispose of more urea water than is used by farmers in a several hundred mile radius.

Rick

Rick, in general I agree with your points. The urea distillation bothers me as the big unknown.

I certainly understand the marketing potential!

I see urea and butanol (both as the transesterifying alcohol, and as an additive) as the two big cold flow technologies on the horizon. Not sure which will happen first, or be more cost effective.

Kumar,

recycling the urea may not be as difficult as you think. Add just enough heat to overcome the latent heat of evaporation and use a vacuum pump to boil off the water. The problem becomes getting the urea to form the beads. To do that calls for a rotating flash tank containing roller balls to break up the urea as it crystallizes. The fertilizer industry makes urea by dropping small droplets of high concentration urea water(sludge) from a tower so the final evaporation takes place while it's in the air. When it hits the bottom, it's a solid bead.

You know, there might be some potential in partnering with a urea plant to recycle the urea, particularly if you were to reduce the water content before attempting to transport it.

quote:

Biodiesel that when blended with diesel, lowers the gel point of diesel.

Anyone can achieve the same cold weather fluidity by cold filtering and mixing with kerosene. What possible advantage is gained by additionally messing about with methanol and urea, since both are made from petroleum?

Our winter grade petro diesel is temperature adjusted each month from Sept to Apr with -40 grade for Dec--Feb. I blend cold filtered canola biodiesel with winter grade diesel and experience no separation problems with the mix. When the temperature drops to the gel temp the whole sample gels a few degrees warmer the pure diesel gels, no separation. I've tested this to -35. The BD blend is adjusted with the ambient operating temperature. The fuel mix is stored in a barrel in an unheated shed. Finished BD blend is pumped from 3/4s down the storage barrel and through a 5µ filter into the vehicle tank. If biodiesel is chilled and filtered then winter fuel blending problems are avoided.

For the most part commercial bio diesel is just barely profitable as it is now, to make the process more complex with more physical processing apparatus and more chemical input and more energy input and then another waste stream to deal with, I don't see it happening.

quote:

Originally posted by fabricator:
For the most part commercial bio diesel is just barely profitable as it is now, to make the process more complex with more physical processing apparatus and more chemical input and more energy input and then another waste stream to deal with, I don't see it happening.

Well, down here it would not sell at all, but I do see a potential for it by government fleet managers in cold weather states rather than by the individual consumer. Government fleets are mandated to use a minimum percentage of alternative fuels. It's these fleet managers that would be interested in such a product. The bureaucrats that are responsible for overseeing alternative fuel use in government fleets are often insulated from the cost of fuel.

Rick

I can see this improving the tarnished image biodiesel has developed for being a sub-standard fuel, especially in cold weather. Just as there is a market for cold weather-grade diesel (#1), so too is there a market for a cold-weather-grade biodiesel. At present, there is only one "biodiesel" product. When well publicised tests have failed due to fuel gelling issues (Seattle Ferries are an example still cited locally), the entire biodiesel industry is assumed to make a low-quality product. By offering a specific "low temperature" product, fleet managers will understand how to use it, since it mimics the diesel model they are already used to. So, too, will fuel distributors who already blend for local weather conditions. Offering it at a premium appeals only to niche markets, but then again not enough can be produced to actually displace petroleum diesel.

For homebrewers, such a complicated method is impractical, especially compared to cold settling and scalping the liquic fractions that collect on top.

The "waste" stream of urea dissolved in water is just liquid fertilizer, and still retains much of it's original market value. For a farm, this would be quite useful, considering the tons applied by the local farmers. The quantity represents an enormous amount of fuel, had it been used to make cold weather biodiesel. If you don't have access to a farm for disposal, then a different process is likely to be better.

Cheers,
JohnO

Almost all of the problems relating to cold weather biodiesel can be traced directly to the animal fats and hydrogenated oils in the BD feedstock from recycled fryer oil. These fractions make excellent hot weather BD, but problematic winter BD. Separating these fractions either before or after BD processing isn't difficult and does not require any more chemical reactions. It does however require an understanding of the process and attention to detail.

quote:

Originally posted by johno:
The "waste" stream of urea dissolved in water is just liquid fertilizer, and still retains much of it's original market value. For a farm, this would be quite useful, considering the tons applied by the local farmers. The quantity represents an enormous amount of fuel, had it been used to make cold weather biodiesel. If you don't have access to a farm for disposal, then a different process is likely to be better.

Interesting angle. I believe that urea/water would qualify for application on organic farms. This could be meaningful around here.

I'm glad to see someone else experimenting with this.

I think the process is useful, but the gross amounts of methanol are a pain in the rear. Many people are not set up to handle 4x by volume of methanol vs bio-diesel. You can lessen the amount of methanol needed by not trying to make -67F fuel....but rather something more like 0F or -20F fuel. Not many people need -67F fuel. You can do this by decreasing the amount of Urea and then you can cut back the methanol slightly. You just need enough methanol to allow the urea to go into solution at temperature.
I'm sure a formula could be written to allow easy adjustments.

This process is harder than one would think...but worth it if it can be simplified.

There really isn't any 'added' material cost. The ethanol and urea can be reused over and over again. The only added cost is the heat cycles.

Another thing to think about is that this process can also be done with ethanol. It is also very tolerant of water overall. This process could happen before the final cleaning/de-water and de-meth/eth op?

You also don't need to make ALL your bio-diesel this way, you only need to use this process for the cold months. Depending on where you live this might be ALL the time, but I think its workable.

I'm thinking about designing a dedicated processor system for this on the home shop scale. I think being able to process 10 gallons of biodiesel along with 40 gallons of meth/eth could be realistic.

I like the idea of using the urea water as fertilizer. I don't think the urea adds a TON of cost to the fuel even if you don't reuse it. The urea quantity can be lowered if you don't need the full -67F fuel. Feed stock for the BD will also dictate Urea quality and overall yield.