BIODIESEL & SVO DISCUSSION FORUMS





Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Acid Esterification    acid base questions
Page 1 2 3 

Moderators: Shaun, The Trouts
Go
New
Find
Notify
Tools
Reply
  
acid base questions
 Login/Join
 
member
posted Hide Post
Biotom; My interpretation of the paper you posted is in part; Acid-Catalyzed Process...Transesterification...methanolysis of Soy Bean Oil+H2SO4+Methanol at 65 degrees centigrade (149 degrees F) takes 50 hours to reach complete conversion (transesterification) of the vegetable oil (>99%). I think this is done with constant stirring/mixing. Using 1-butanol at 117 degrees centigrade(242.6 degrees F) it took 3 hours. Using ethanol at 78 degrees centigrade (172.4 degrees F) transesterification took 18 hours. It is worth noting that they used a lot of alcohol and a little vegetable oil compared to what we use in AE it is a 30 to 1 molar ratio that's about 1382.1 grams ethanol to about 850 grams of oil. Without doing the calculations I would guess that's about 1.5 liters of ethanol to 1 liter of oil and it would be roughly 4 milliliters of concentrated sulfuric acid. But they claimed to get 99% or so conversion. My numbers may be a little rough, I didn't do it precisely. Sorry for any spelling errors, I'm not much of a speller.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
member
posted Hide Post
Biotom; I made ethyl biodiesel not methyl biodiesel using the reaction I described. I already did the base reaction. There is none of the acid catalyzed reaction product left to test. I can't do a 3/27 test now because it is gone. What I do have is crude ethyl biodiesel that I haven't de-ethed or purified yet using magnesium silicate dry wash.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
Member
posted Hide Post
WB; WOW that paper was pretty much a foreign language to me, thanks for a proper interpretation. I find it interesting that when they used methanol at 65C it took 50 hours to react. They used so much methanol and much more acid than we use for AE, YET the critics here say the reactions are simultaneous. Maybe I put the wrong emphasis on simultaneous? I don’t think there is much if any transesterfication happening at 45c using .5ml acid and 50ml methanol in 500 ml oil.When you use ethanol, does it float on top of the oil the same as methanol, I know the oil desolves into some alcohols (IPA) No worry about spelling, I’m the worlds worst!!!!
My funnels are in Pembina ND I just have to go for them.
Bio go go has posted in this thread under a different name hmmm thought that was against the rules!


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
member
posted Hide Post
For corn oil it is about 876.04 grams per mole. The paper uses soy bean oil which is a little different. So if they were using corn oil for methanol it would be 30 moles which is about 1214.556482 milliliters and about 942.3655914 milliliters of corn oil. The Burmese were interested in ethyl biodiesel a while back, that might mean the Chinese. I wonder who this BioGoGo is. There is a restaurant here in town called China GoGo. If more alcohol is used in this acid catalyzed transesterfication reaction, it proceeds more readily. If less alcohol is used it still proceeds but less quickly, but it still occurs a little. That's why I used 20% ethanol by volume. I wanted to speed up the acid catalysed transesterification reaction. In new corn oil there's little ffa's to react. That's why I used new corn oil rather than used, In part I wanted to force other reactions than AE. That's also why I kept it hot about 68 degrees centigrade for 28 hours, to force it to react if it would. Any questions?
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
Member
posted Hide Post
Do you feel people are criticising you when they correct some of your mistaken chemistry statements?

Simultaneous means happening at the same time. It does not necessarily mean finishing at the same time.
For example, all the time you are performing Acid Esterfication, Transesterfication is also occuring. Esterfication and transesterfication are happening simultaneously.

HTH

quote:
Originally posted by Biotom:
YET the critics here say the reactions are simultaneous. Maybe I put the wrong emphasis on simultaneous?
 
Registered: October 04, 2010Reply With QuoteReport This Post
member
posted Hide Post
Biotom; Initially when I put the oil, acid and dry ethanol into the flask, the alcohol floated on top of the vegetable oil. It took medium to fast stirring to make the alcohol and vegetable oil mix at the first of the reaction. They were not miscible initially. After reacting for 28 hours with stirring at 76 to 79 degrees centigrade, the reaction liquid did not separate.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post



Member
posted Hide Post
WB; No more questions for now, but I'm sure as I go through the steps using methanol corn oil and lower heat I may have. I'm so sick of the tilly clones here, I will contact you by PM thanks again Tom


" I don't know what I don't know until I know"
1994 GMC 6.5 Tubo 2005 Dodge ram 3500, 3 VW's 2000, 2002, 2005.
 
Location: Manitoba Canada | Registered: March 24, 2009Reply With QuoteReport This Post
member
posted Hide Post
When I compare the ethyl biodiesel I made using H2SO4 and KOH as catalyst to make ethyl biodiesel to that I used only KOH as catalyst, the H2SO4 ethyl biodiesel has a darker transparent yellow color. I think the H2SO4 reacted with some of the double bonds in the fatty acids that have double bonds in the solution in a reaction that is called electrophilic addition reaction. I don't want to spend hundreds of dollars to have it tested at a professional lab though. Someone wrote to me that no one had reported that, well I'm reporting it. The vegetable oil I used was new corn oil in both instances. That's probably where some of the sulfuric acid catalyst goes in the AE reaction.
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
Member
posted Hide Post
Wesley,
It has been known for a long time that Acid/Base biodiesel is darker than Base only Biodiesel.
If I remember correctly, the chemists who used to participate on this forum said that is because the H2SO4 "burned" some of the oil.
At one time there was even a fellow on the forum selling something to lighten biodiesel made using the A/E method.

Unfortunately this forum is not set up to retain important information so it is easily accessible to future users. So people are constantly "discovering" things that were discovered 6 or 8 years ago.
All that info will be in the archives and it is pretty hard to dig out any information once it has gone there.
quote:
Originally posted by WesleyB:
...the H2SO4 ethyl biodiesel has a darker transparent yellow color... Someone wrote to me that no one had reported that, well I'm reporting it. The vegetable oil I used was new corn oil in both instances. That's probably where some of the sulfuric acid catalyst goes in the AE reaction.
 
Registered: October 04, 2010Reply With QuoteReport This Post
member
posted Hide Post
I've dry washed twice with 10 grams magnesium silicate after boiling off some of the excess alcohol. I'm dry washing using white magnesium silicate powder that is insoluble in biodiesel. The magnesium silicate is brownish orange after the dry wash. I filter the biodiesel through vacuum filtration using a one micron filter paper. After the two dry washes the biodiesel is a lighter color. It is removing the discolored (darker component) biodiesel that probably reacted with the sulfuric acid. The density of my ethyl biodiesel is about 0.84 grams per milliliter. Its color now is just a little darker than ethyl biodiesel I made using only KOH as catalyst. I'm doing it on a small scale. I got 375 milliliters of product. I started with 500 milliliters of new corn oil. I don't know if a soap test on this product will have any validity.

This message has been edited. Last edited by: WesleyB,
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
member
posted Hide Post
I did a HCl, Bromophenol Blue, 91% isopropyl alcohol, ethyl biodiesel soap test. I had only added 4 drops of 0.01 Normal HCl aqueous solution to get a bright yellow color. If my test is right that is about 17 parts per million of potassium soap content. Does using sulfuric acid in an earlier step make this soap test results meaningless? Maybe no one knows. Thanks
 
Location: Texas | Registered: April 27, 2011Reply With QuoteReport This Post
  Powered by Social Strata Page 1 2 3  
 

Sponsors    Biodiesel and SVO Forums Home    Forums  Hop To Forum Categories  Biodiesel  Hop To Forums  Acid Esterification    acid base questions

© Maui Green Energy 2000 - 2014