biodiesel - Page 3 - PeachParts Mercedes-Benz Forum

TomJ · #31 06-16-2004, 12:31 AM

Quote:

Originally posted by coachgeo
Hey Tom,

want to say thanks for your mention of "acrolein". My (and others) environmental and health concers took a quick jump at this and have been looking for more info. Here is one of the latest that helps me breath with much less concern.

Yes. I've read that it dissipates or breaks down rapidly, I just can't find WHERE it states this property? I thought it was on the EPA link that discusses it, but I can't find it there.

I did find this interesting though:

"... * Acrolein can be formed from the breakdown of certain pollutants found in outdoor air, from burning tobacco, or from burning gasoline. (1)
* Airborne exposure to acrolein may occur from breathing contaminated air, from smoking tobacco or proximity to someone who is smoking, or from being near automobiles or oil or coal power plants. In several large cities, acrolein has been measured at 9 parts per billion (ppb). (1)
* Occupational exposure to acrolein could occur in industries that use acrolein to make other chemicals. (1)
* Small amounts of acrolein may be found in some foods, such as fried foods, cooking oils, and roasted coffee. (1)
* Acrolein has not been detected in drinking water, and is not commonly found in surface water. (1)....."

Tabacco, cooking oils and coffee, interesting!

EPA link

oldnavy · #32 06-16-2004, 07:29 AM

Look's like we had another knee jerk reaction without proper investigation and research. When I was a kid we called it "jumping to conclusions" and we made fun of those who did.

coachgeo · #33 06-16-2004, 09:30 AM

Quote:

Originally posted by oldnavy
Look's like we had another knee jerk reaction without proper investigation and research. When I was a kid we called it "jumping to conclusions" and we made fun of those who did.

possibly some conclusions were jumped too, but Im glad it was brought up cause it has gotten several of folk "researching" over at the Maui Green board.

Here is another recent post from one who jumped on the research band wagon. His remarks are on a study that was written using the term WVO Methyl Esters. His point is good that it's possible it caused confusion cause WVO Methyl Esters is NOT WVO.

Quote:

Methyl ester of waste oil (WVO) is biodiesel, plain and simple.
...
...free glycerine in unwashed biodiesel causes acrolein. Do any of the papers you list mention svo emissions including acrolein?

coachgeo · #34 06-16-2004, 09:35 AM

Quote:

Originally posted by TomJ
...Tabacco, cooking oils and coffee, interesting!

:p we are all doomed lol

:p

TomJ · #35 06-16-2004, 09:42 AM

Quote:

Originally posted by oldnavy
Look's like we had another knee jerk reaction without proper investigation and research. When I was a kid we called it "jumping to conclusions" and we made fun of those who did.

No not really, we're actually trying to knee-jerk "minimize" the issue of Acrolean in SVO/WVO to not stifle the alternative fuel movement. Fact is, the volume of SVO that is run in a vehicle and the high amount of concentrated Acrolein that is produced in burning these oils (the glycerine content) is still a major issue with it's use AFAIC.

#36 06-16-2004, 09:50 AM

Recently there appeared in a SE Virginia news source an item stating that Smithfield Corporation is planning to replace some of the worst of their hog waste settling ponds (the ones which usually overflow every time a hurricane or noreaster comes through, which is often) with a system for recovering the methane from the waste and converting it to methanol, which they then plan to sell to a northern Virginia biodiesel plant which makes fuel for boaters. I don't know any further details.

TomJ · #37 06-16-2004, 09:54 AM

Quote:

Originally posted by coachgeo
possibly some conclusions were jumped too, but Im glad it was brought up cause it has gotten several of folk "researching" over at the Maui Green board.

Here is another recent post from one who jumped on the research band wagon. His remarks are on a study that was written using the term WVO Methyl Esters. His point is good that it's possible it caused confusion cause WVO Methyl Esters is NOT WVO.

Not sure where the relevance is here? What they're saying is that there is an issue with the glycerine that may be unreacted from the WVO/SVO that is used to make BD? If this is so, it seems there would be MORE of an issue with using straight WVO or SVO as there would be ALL of the glycerine left in it.

Remember, the glycerine is what is removed (replaced) from the SVO/WVO to make BD, so if the -whatever- percent of glycerine that is left in the BD that is unreacted or not removed is an issue, then even more so the 100% of glycerine that is in WVO/SVO.

Another way, their statement means little for SVO/WVO use except to say that if the little glycerine that is left in partially reacted BD is an Acrolein hazard or issue, then all the more the oil that has ALL of it's glycerine content.

But..., we actually need to do the research to determine the amounts (volume) and concentration of Acrolein in combusted SVO/WVO. The BD studies will mean little to us, except to point out that if combusted BD is an Acrolein hazard from the little glycerine that may be left over, then all the more the problem with SVO/WVO that has 100% of its glycerine content.

If we actually get this research, then we might be able to come up with an oilseed, algae, etc. that can minimize this output?

boneheaddoctor · #38 06-16-2004, 10:05 AM

DOOMED.....DOOMED.......we are all DOOMED

Breathing causes cancer, Water causes cancer, Beeing born dooms you to eventual death...........

oldnavy · #39 06-16-2004, 12:17 PM

Cough, cough, hack, hack, wheeze, ack, ack, wheeze, pant, pant, aaaugh!!! :p

coachgeo · #40 06-16-2004, 11:23 PM

Quote:

Originally posted by TomJ
...
Remember, the glycerine is what is removed (replaced) from the SVO/WVO to make BD, ......

This is NOT correct as you state it here. As stated earlier there is basically no glycerin in SVO/WVO. There is in unwashed/poorly washed biodiesel. That being said let me use the below to clarify this a little more

Quote:

by Habanero:
there should be almost no free glycerine in the (SVO/SVO) oil entering the combustion chamber. What happens at that point, however, may produce free glycerine at some point in the combustion process. I am assuming one of the first steps in the combustion process would be to break apart the glycerol backbone, sort of like making biodiesel. At this point, you would have free glycerine running around that could potentially be formed into acrolein. If, however, during the combustion process the backbone breaks up before the fatty acids are cleaved, then acrolein formation would be impossible.

As far as general composition of SVO goes, I can get exact numbers from my supervisor when she gets back tomorrow, but most refined oils are about 98-99% triglycerides with the remainder made up of bioactive compounds, small amounts of free fatty acids, etc.

It is very difficult to say general composition of WVO, though, since so much depends on how it was used and what was fried in it. It is still going to be mostly triglycerides, but there will be some di and mono glycerides where the fatty acids have broken off the backbone to become free fatty acids.

TomJ · #41 06-17-2004, 12:32 AM

Quote:

Originally posted by coachgeo
This is NOT correct as you state it here. As stated earlier there is basically no glycerin in SVO/WVO. There is in unwashed/poorly washed biodiesel. That being said let me use the below to clarify this a little more

WTF???? Who stated that there is "no glycerin" in SVO. Glycerine is REMOVED from SVO to make BD.

SVO and WVO is the base stock used to make BD from - the Glycerine is separated from the SVO AND WVO to MAKE BD, so how do you get the idea that SVO contains no Glycerine?

coachgeo · #42 06-17-2004, 12:02 PM

Quote:

Originally posted by TomJ
WTF???? Who stated that there is "no glycerin" in SVO. Glycerine is REMOVED from SVO to make BD.

SVO and WVO is the base stock used to make BD from - the Glycerine is separated from the SVO AND WVO to MAKE BD, so how do you get the idea that SVO contains no Glycerine?

Glycerin is the "result" of the reaction of acid and alcohol on components of the oil. It does not exist as "glycerin" in the SVO without *those two reactants.

Once the reactants form glycerin from "some" of the components in SVO it then seperates and is easly removed. The remaining material is what is called bio-diesel.

Again. Glycerin is NOT in SVO/WVO. It only forms AFTER reactions from *the alcohol and acid.

*or some other way that breaks some of the molecular bonds within the oil.

Habanero · #43 06-17-2004, 12:28 PM

I guess since I am getting quoted over here, I should speak up and clarify any confusion. As I stated before, there should be very little free glycerin in the waste oil. I will qualify here, as I later realized I should have qualified there, that there may be a very minute amount of free glycerin from triglyceride molecules from which all three fatty acids have broken off during the abuse of high-temperature cooking. Even then, the waste oil should still be at least 95% tri-, di-, and monoglycerides and 3-4% fatty acids. The remaining percentage would be comprised of randomly polymerized particles from the heat, moisture, salts, etc., etc.
There is a big difference between glycerine and glycerides and I think that is where the confusion is coming in. Glycerides have the fatty acids attached to a glycerol backbone, where glycerine has no fatty acids.

Now what happens in the combustion chamber is where the whole question gets a little sticky. Maybe at some point in the combustion mechanism there is a time during which free glycerin exists in the combustion chamber. But, at that time there would also be countless numbers of free radicals running around under high temperature and pressure conditions, so it is sort of a guessing game to try to say what side-reactions are taking place. Until I see a scientifically-valid, peer-reviewed study specifically on acrolein emmissions, I am going to sit on the fence on this issue. In the meantime, I will happily continue to spew vile emmissions, ruin the IP, and coke the injectors (I will try to keep the rings of the uncoked variety-there has to be limits to the destruction one is willing to cause) of my veggie-burning SDL.

Old300D · #44 08-06-2004, 02:53 PM

In my first WVO conversion, I used the factory fuel system to supply the WVO. I fashioned a marine tank in the trunk to supply biodiesel. I had read that new fuel line withstands biodiesel, so I plumbed the purge fuel with regular fuel line. This summer I was running B100 exclusively to start and purge, and as a result I was plugging the factory fuel filters about every other week. The material seemed to be fine black particles in the primary filter, and black paste in the secondary. I had been running B20 previously since last November when I got the car running, and thought my filter pluggings were behind me.

My conclusion: Biodiesel EATS fuel lines. None of my new lines are leaking, but they are noticeably larger around, and obviously the insides are dissolving. The biodiesel I use is Blue Sun, nothing homemade (yet!).

My second conversion, working on presently, I am using the factory tank and steel lines to run my biodiesel, and all flexibles lines are Viton save the cigar hose. My WVO will be the add-on fuel system, just like everyone elses. I seem to have to learn lessons the hard way.