I have made my first two batches from the Dr. Pepper method and am having some trouble getting acceptible results. I followed the instruction for virgin oil, I heated 1L soy oil to 55C and added 250ml methoxide (250ml methenol, 4g NaOH). The first batch, I shook pretty hard for 30 seconds. This batch never separated at all, it just made a big gelatinous blob with some liquid around it. I used the same receipe for the second batch. I didn't shake this one, I swirled it in the container for 30 seconds. It started to separate, but only about 10% had separated after about 2 hours.
I've attached some pictures, one is looking into the top of the container (this was the first batch). The side view is of the second batch after a little over 2 hours. I'm going to titrate the oil and attempt a third batch, but if anyone can give me some insight into what might be going wrong, it would be greatly appreciated.
I used HEET (yellow bottle) from the auto parts store for the methanol and Red Devil drain cleaner (says on the label that it is 100% NaOH) for the lye. The oil is from Walmart and says that it is Soybean oil. I think that I am going to try some other cooking oil that I have and see if the result is any different.
Do you have a scale that is very accurate at that low of a weight ? I started out with a really cheap balance type scale from Harbor Freight . When I got a good scale I found out that the cheapo one I started with was very inaccurate . I weighed out 1 gram on the cheap scale and it weighed 3.5 on a good scale . Good Luck , Shannon
The scale that I have is an el cheapo from walmart. Would having too much NaOH cause a reaction like what I am seeing? When I weighed out what the scale said was 4g it did seem like more than what I expected 4g to look like.
What was the amount of 4 grams on your scale as compared to a teaspoon or measuring cup ? I am not sure if this might be your problem or not , but so far it seems to be the only weak link . Soybean oil is one of the most common oils used in the production of biodiesel , mostly because it is one of the most common oils . Try measuring out 4 grams and then measuring it with a measuring spoon if you have one . This way we can get an idea of how accurate your scale is .
As soon as I read your post, I read the DP instructions again and noticed that it said that 4g would be about half a teaspoon. What I measured out was more like a full tablespoon full. I'm going to try another batch in the morning with half a teaspoon of NaOH and see how that turns out.
You might have just made alot of soap with that much excess lye . Try it with 1/2 teaspoon and hopefully it will go better . I got my scale from ebay and it was fairly inexpensive , you might want to try looking there . Good Luck , Shannon
The adjustment of the NaOH looks like it may have fixed the problem that I was seeing. After about 2 hours the third batch looks like the attached picture.
Is there a website that has information on testing the quality of biodiesel, one that is for the layman and not for the rocket scientist? I would like to make sure that the quality of my product is good before I put into my truck.
Thanks for the help everybody, I really appreciate it.
That certainly looks alot more like biodiesel than the other batches . For testing your fuel you cen use the search at the top of the page and you will find several different tests that can be preformed on your fuel . There are also a few listed on the CBT site here : http://www.biodieselcommunity.org/ This is a great site with alot of good information for beginners trying to get started . You might also want to consider ordering Girl Mark's Homebrew Guide here: http://www.localb100.com/book.html This is a really handy refernce guide to have with you when getting started . Good Luck, Shannon
Here is a link to one like mine , but I am not sure I would say that it is really a high quality scale , just better than the first one I had . This scale will not weigh 1 gram very accurate , I weigh 10 and then divide for titrations . It is only accurate to +/- 1 gram , but is alot better than the first one I had . This vendor was really easy to deal with and shipped fast , but the shipping is a little over priced . http://cgi.ebay.com/NEW-KITCHEN-POSTAL-LAB-diet-bowl-SC...QQrdZ1QQcmdZViewItem
These scales are accurate enough to measure specific gravity (which is handy if you're recovering your methanol by distillation and want to know if you have water contamination), and also to perform my patented quantitative water test for wvo. Handy handy handy.
Good luck and have fun!
Location: north america somewhere close to the midwest, or not | Registered: May 29, 2004
Just did my first test batch via the DP method. I got results similar to bbooks 1st batch. I then re-shook the blend & it looks cloudy with a clear 5-10% ring at the BOTTOM of the bottle. Not having a scale, I measured out a half teaspoon of lye, and used a glass measuring cup with ml increments for the methanol(Heet). What gives? I did mix all at room temps, is that the difference? Very confused, but not giving up yet! DK.