how to make biofuel using glycerine?

Question

methodology, references, literature review

Answer 1

Glycerine (glycerin, glycerol) is the main by-product of making biodiesel. The name comes from the Greek word glykys meaning sweet. It is a colourless, odourless, viscous, nontoxic liquid with a very sweet taste and has literally thousands of uses. That is, pure glycerine has thousands of uses -- the biodiesel by-product is crude (and it's not colourless, and it's not only glycerine).

There is a market for the glycerine once you've separated it from the soaps and the lye that's also in the by-product (see Separating glycerine, below) and probably refined it too, neither of which is cheap, and then only if you can supply it by the tonne on a regular basis, unless you're lucky enough to find a small niche market.

But there are other things you can do with it other than sell it, read on.

Lots of information on glycerine, from a Japanese manufacturer (in English) -- Sakamoto Yakuhin Kogyo Co., Ltd.:
http://www.sy-kogyo.co.jp/english/sei/1_gly.html

Glycerin -- King's American Dispensatory, by Harvey Wickes Felter, M.D., and John Uri Lloyd, Phr. M., Ph. D., 1898
http://www.mail-archive.com/[e-mail]/msg13553.html

Burning glycerine

Three milk-carton glycerine-sawdust "logs" are enough to heat our bath.

Filling a milk carton with wood shavings...

... adding the by-product, then tamp it down hard with a piece of 2x2 -- the soiled newspaper makes a good fire-starter.

The glycerine by-product burns well, but unless it's properly combusted at high temperatures it will release toxic acrolein fumes, which mainly form at between 200 and 300 deg C (392-572 deg F).

We've used it to heat a wood-fired bath (see next, Sawdust "logs") and to pre-heat the vegetable oil for biodiesel processing (below, Burners).

Sawdust "logs"
We thought of mixing the by-product with sawdust to make briquettes, and in a message to the Biofuel mailing list Tony Clark suggested using milk cartons instead of making briquettes, which need to be pressed: "By mixing this with sawdust to make a dry paste, and filling used milk cartons with this mixture, the use of timber for fuel can be significantly reduced. A 1-litre milk carton (about 1 quart US) of this mixture will give off more heat than twice or three times that weight in firewood."

We used wood shavings, not sawdust. A 1-litre milk carton holds 450 gm of wood-shavings and 750 gm of glycerine by-product. Used for heating the traditional Japanese iron-cauldron bath at our previous house, three milk cartons burned for about 45 minutes and heated 80 litres of water from room temperature to 60 deg C (140 deg F). In sub-zero C winter weather it took five cartons instead of three. We started the fire with wood to get the burning chamber to a high temperature before adding the milk-carton "logs". We heated the bath this way for more than a year.

Burners
Using the by-product in a burner to pre-heat the vegetable oil for biodiesel processing would be an elegant solution, if it worked well enough.

It's an elusive goal. Prof. Michael Allen thinks complete and clean combustion of the by-product requires a burning temperature in excess of 1,000 deg C (1,800 deg F) "and you will probably need a mean residence time in the Hot Box of about 5 seconds". And perhaps pre-heating and atomisation as well.

With the sort of low-tech burners backyard brewers have made so far, what happens instead is that the burner might burn for long enough to pre-heat the oil, but then it gets gunged up with sticky black stuff that won't burn (mostly soap) and it goes out. If you want more heat you have to clean it out and start it up again.

Another disadvantage is that it's not a clean burn, it smokes, especially towards the end of the burn when it's trying to combust the soap.

We've used a Turk burner for pre-heating. It works, but we prefer using our kerosene pressure stove, which burns pure biodiesel.

We don't believe any Turk-type burner will overcome these combustion problems, we haven't heard of anyone successfully using a Babington-type burner with biodiesel by-product either.

We've found that Mother Earth News waste oil heaters also won't burn the by-product for long before coking up. We'd hoped a modified version using a forced air-supply, which burns much hotter, would solve the problem, but it didn't.

Instead we developed a cheap and simple bioheating oil to use with heaters and burners. See Journey to Forever's forced-air biofuel heater. We're adapting this method for pre-heating WVO for biodiesel processing, etc.

Both the bioheating oil and biodiesel work well in Turk burners, and so does the separated FFA from the by-product (see next, Separating the glycerine).

More interesting than trying to burn the glycerine by-product efficiently is the prospect of using it as part-feedstock for a methane digester to produce biogas, a clean-burning and efficient cooking gas which can be used for heating in the biodiesel process. See next, Glycerine and biogas.

Glycerine and biogas
A visitor to our website told us this:

"I work at a wastewater treatment plant and I was doing a search on glycerin and biofuels and came across your website. It has good information, thanks.

"Here's another use of glycerin: Our treatment is accepting the glycerin from a biofuel producer, we feed it to our digesters, slowly very slowly. The addition of glycerin has dramatically increased our gas production, so that we run all three engines that produce electricity for our plant and occasionally need to flare off the excess methane (we have four4 flares).

"This might be of interest to your readers who use digestion for electricity."

The biogas is used as fuel in diesel engines which power electricity generators. But this wasn't raw by-product, it was separated glycerin from a commercial producer:

"The glycerine is agricultural grade and looks similar to thin maple syrup.

"As for pH, since the chemistry in the anaerobic digester is healthy, a high pH wasn't much of a concern. Our main concern was foaming with the introduction of glycerin, and we did see an increase hence the slow feed rate to the digester."

Can the unseparated by-product, the whole glycerin-catalyst-soap cocktail, also be used to increase biogas production?

Biofuel mailing list member, researcher Pannirselvam in Brazil, said:

"Very good news to make the gas and liquid biofuel in an integrated way.

"There are many published papers about the enhanced production of biogas from oily wastes and glycerine is a good intermediate metabolite, hence the results agree with theory.

"But here too we need a mixed microbial population to work well and they will need a lot of adoption time for glycerine, otherwise one may totally fail to produce gas.

"There are two routes to get energy from waste of the BioDiesel making process, bioconversion and thermo-conversion. I believe the combined Biogas generation is better than combustion. The correct mixture of proteins and glycerine and salt needs to be carefully solved by practical work."

We'll be constructing biogas digesters here in Tamba soon, starting with this one: "Methane Digesters for Fuel Gas and Fertilizer, With Complete Instructions For Two Working Models", by L. John Fry, Chapter 10: Building an Inner Tube Digester.

We'll investigate glycerine by-product digestion as a priority. We've been wanting to do this since 2001 -- see Appropriate transport (though not quite this way).

Some home-brewers have pointed out that wastewater treatment systems should be able to handle the glycerin by-product without problems. It mixes with water, it's biodegradable, and if you reclaim the excess methanol first, it's non-toxic. As for the lye and the soap, lye is a drain-cleaner after all, and wastewater plants are no strangers to soap. Even the methanol might be an advantage, some of the digester bacteria like it.

But it's best not to pour by-product down the drain or the toilet without checking with your local authority first.

Separating the glycerine
What sinks to the bottom of the biodiesel processor during the settling stage is a mixture of glycerine, methanol, soaps and the lye catalyst. Most of the excess methanol and most of the catalyst remains in this layer. Once separated from the biodiesel, adding phosphoric acid to the glycerine layer precipitates the catalyst out and also converts the soaps back to free fatty acids (FFAs), which float on top. You're left with a light-colored precipitate on the bottom, glycerine/methanol/water in the middle, and FFA on top. The glycerine will be approx. 95% pure, a much more attractive product to sell to refiners. Here's how to do it: Separating glycerine/FFAs

A commonly asked question: How much glycerine do you get? A better question would be: How much of the "glycerine layer" is actually glycerine? The rule of thumb is 79 milliliters of glycerine per liter of oil used -- 7.9%. In fact there's usually more soap -- the "glycerine" layer is more of a "soap" layer than anything else. Unless you use Aleks Kac's "Foolproof" acid-base two-stage process, that is -- see this photograph and the caption for an idea of how much less soap you'll make.

Purifying glycerine
Biodiesel can be made with ethanol (which you can make yourself), instead of methanol (which is toxic, fossil-fuel derived, and you can't make it yourself). Here's a recipe: Optimization of a Batch Type Ethyl Ester Process. But the ethanol has to be anhydrous -- free of water -- which can't be achieved by distillation. One way to dry it is to use the by-product of making biodiesel -- glycerine. Here's how:

Absolute Alcohol Using Glycerine -- Mariller-Granger Processes, from E. Boullanger: Distillerie Agricole et Industrielle (Paris: Ballire, 1924). Mariller's absolute alcohol production process by dehydration using glycerine, various systems examined and explained. Translation from the French by F. Marc de Piolenc.

But -- the glycerine has to be 99%+ pure. Purifying it is no simple matter -- it's difficult to distill it because glycerine has a very high boiling point (290 deg C). Here's one way:

Solvent purification distillers by Recycling Sciences, Inc. Set the temperature and leave it alone. It'll purify the glycerine, at a price. They offer a special unit for biodiesel makers, price US$31,000 for a unit that will do 100 gallons an hour of any solvent recycling -- methanol/ethanol recovery from a biodiesel/glycerine solution before separation, pure glycerine from the crude process by-product, etc, in a very safe manner. Second-hand units can be found for as little as $5,000, but make sure it's the biodiesel model (much quicker). (Information provided by David Hollenback at the University of Idaho and Steve Woolcott, HarvestEnergy, Sydney, Australia)
http://www.rescience.com

Answer 2

1

Answer 3

A plant is a plant or part of a flower used as food

Answer 4

Both are good for you, each fruit/vegetable has different vitamins. Thus as more variety, as better. Vegetables have generally less sugar than fruits.

Answer 5

Biofuel, such as biodiesel, is not made with glycerin, glycerin is a leftover, or by-product, after the fuel is made. You can take the waste grease from fryolators and make biodiesel out of it; there is a guy in my town that does this. He gets his grease from restaurants (they have to pay to get rid of it anyway) and he sells the glycerin to soap manufacturers afterward, so he makes money on both ends and he will eventually recoup the cost of the equipment he bought. Search on biodiesel for more details on the equipment you need and how to go about it. I got most of this information from a newspaper article about that guy in town.

Answer 6

glycerine is the byproduct of BioDicel
And is used to make soap

Answer 7

you'll never get an answer
glycerine is a bomb making ingredient, it would be against the law to even have it

Answer 8

I used it as an antifreeze. I sprayed moist dirt that I did not want to freeze. The dirt was covering a trap.... (sorry, folks...that was a LONG time ago when fur trapping was not frowned upon)

Answer 9

challenging issue try searching with bing and yahoo it can assist

Answer 10

my god, some of you are so ... you fill in the blanks.

nitroglycerine, the explosive is made by titrating nitric acid and sulphuric acid together, and then mixing with glycerine. its done on a one legged stool, so as to stop the poor smuck who was stirring the mixture falling asleep. (read Afred Nobel..yes they guy who gave us a peace prize)

biofuel is reclaimed vegetable oil. Dr Diesel originally designed his motor to run on coconut oil... so we can use almost any vegetable oil, rapeseed, cooking oil, sunflower...etc etc

the main problems using biofuel is that (this) oil is acidic and it eats diesel injectors, injector pumps, and anything else it touches. the oil must be treated to balance the Ph, and passed thru a <5micron filter, or it will foul the injectors.

how do i know this; i bought a vovlo diesel, and the owner ran it on oil....but not nice clean oil, or dirty oil from teh chinese takeaway...this guy went to dirty dans burger van...oh no...it smelled horrible, smoked awfully and cost almost 600 pounds to put right...but that was 3 years ago, and the swedish tank hasnt missed a beat since...

one method is to test the oil, adjust the Ph using LYE, bring it to the boil, and test until neutral. (alkalines eat hydrocarbons and oils, and acids eat the metal parts, so you have to get it right.) then leave it to cool. gravity drags all teh crap to the bottom of the 45 gallon drum, leave it standing for two weeks, and then draw off the top 40 gallons, leaving the bottom five to remain undisturbed and hold onto the sludge and other nasties.

Answer 11

I'd rather U didn't.
Add the wrong ingredient at the wrong time & BOOM!