Biodiesel choices

[IXLR8]

for fead stock differences once you properly filter and convert the oil it is fuel... its like mixing concrete mix and water you get the same consistancy if you follow the directions properly. do bad mixing and get a crappy batch.

Actually your feed stock does matter as to the quality of fuel you end up with. Soy based will does not give you the same level of lubricity, cetane rating or BTU capacity as a rapeseed or canola base. This is one of the differences why the europeans okay the use BioD in their cars. Most is made from rapeseed not soy, plus they have stricter quality control. The earlier TDI engines had issues with seals, has not been an issue since they changed seal material, I believe to viton. Although any properly done BioD has better lubrication and cetane than any DinoD comercially available in the states.

 

[Kendrick]

odd I had always heard it was quantity of oil per pound of raw crop that was different. ie 1 lb of coarn has 2oz of oil where rape sead would have 4. (Numbers made up)

I would love to see some docs on the differences

 

[SPYDERLK]

Most all the rubber in fuel systems since the mid 90's will handle biodiesel, so in effect they are compatable, the question comes up with warrenty issues. Europe is 50% diesel cars, virtually all are warrented to run up to 100% BioD. In the US, the max VW will approve is 5%BioD, why... fuel quality. Most of the fuel in Europe is made from Rape Seed oil and they have fairly strick standards. The stuff in the US is made from Soy/Corn/used vegtable oil/etc. There is no consistancy to the quality, there is little enforcement to what little standards there are. The newest round of diesel cars, VW, MB, will not warrenty the use of any BioD, unless it comes from the GTL process. [[[Again... it is a quality issue as the new common rail injection pumps are running between 32,000-35,000 psi. What sort of pressues are the injection pumps running in these tractors?? That is the key to BD usage. The older MB and VW that were running pump pressures less than 10,000psi can run fine on straight vegetable oil.]]]

Key issue??? Injector hole size vs particulate or lubricity or both?
larry

 

[IXLR8]

odd I had always heard it was quantity of oil per pound of raw crop that was different. ie 1 lb of coarn has 2oz of oil where rape sead would have 4. (Numbers made up)

I would love to see some docs on the differences

You are correct as far as the yields are concerned, this is one of the big differences I forgot to mention. Rapeseed does yield about twice as much as Soy. The initial work done with Algae indicates possible 10x yield over Soy. I went looking for the data to back up my statement... looks like I didn't bookmark the threads with the discussion and graphs. Sorry. It was either on the Biodieselnow.org web page or one of the biodiesel forums. I will keep looking.

 

[IXLR8]

Key issue??? Injector hole size vs particulate or lubricity or both? larry

Larry, my limited understanding is lubricity is a question mark, ability to handle pressures is a question mark, ability to flow to provide the lubricity is apparently a big question mark. Add these up and manufacturers don't want to stick their necks out. Tolerances are very tiny in the hi pressure pumps and injectors and BioD tends to be a little thicker than DinoD due to the left over fats. My understanding with the GTL process there just aren't any fats to be left over and it flows into the area's it needs to better. I am still learning the issues with the new systems, presently my sources are limited, but I am still digging and learning. Translated... don't take my word as gospel.