Talk:Biodiesel production

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[edit] Biodiesel production

This material is a very good start on an article on the production process of biodiesel. Way too detailed for the main biodiesel article, but good to have here. It needs to have the "recipe" components and second person references stripped out and/or moved into How to make Biodiesel. - Taxman 16:51, Jul 2, 2004 (UTC)

I disagree with above comment and, instead, agree with comment preceding main article that: "This article or section is in need of attention from an expert on the subject." I suggest a chemist or chemical engineer (I am one but know nothing about biodiesel) who, for example can write the basic chemical reaction correctly, showing alcohol as a main component of the reaction rather than as a catalyst. Other process steps need better description.

I decided to strip out the purely recipe components and leave them here for now:

Like a recipe for making a cake, a biodiesel recipe specifies quantity of every ingredient required, and the steps for combining and processing them to make biodiesel fuel. The most common recipe uses waste vegetable oil (WVO), alcohol (methanol or ethanol) and sodium hydroxide (caustic soda), to produce biodiesel and glycerol. To produce 1 tonne of biodiesel:
  • One needs 1 t of biolipids (animal or vegetable oil) and 0,1 t of methanol.
  • One receives 0,1 t of glycerol.

Then I need to check the material in Biodiesel recipe and likely delete it since it is a duplicate. - Taxman 00:02, Dec 8, 2004 (UTC)

Wikipedia is not an instruction manual. --Treekids (talk) 00:01, 17 February 2008 (UTC)

Given there are now a number of ways of making biodiesel and in the future there will of course be even more, I went ahead and moved all the transeterification material to Biodiesel Transesterification and made this a stub for an article to cover only the common issues. --Treekids (talk) 00:03, 17 February 2008 (UTC)

This article has been improved substantially over the last year by two ChemE students and me. We're still working to make this page complete and technically correct. BTW, there is no "washing" in alcohol process.--E8 (talk) 02:57, 17 February 2008 (UTC)

Every article can use help, this one is no exception. Completely wiping it to a stub isn't the answer. I would suggest that Treekids discuss this further before dismantling an article. Most people here are pretty reasonable, but undiscussed wholesale changes are not reasonable. PHARMBOY (TALK) 14:34, 17 February 2008 (UTC)

I was too bold; and I do apologize. That said, I did not destroy the content, I moved it to a page with more specificity. Being too bold resulted in some friction but it also resulted in some clarification as to what biodiesel is and what various processes can be used to make it. Thanks all for putting up with the process- it achieved a good result. --Treekids (talk) 20:37, 21 February 2008 (UTC)

Please comment on the revisions I am proposing for Biodiesel production.--E8 (talk) 08:39, 19 February 2008 (UTC) (copied from my talk page --Treekids (talk) 20:37, 21 February 2008 (UTC))

  • I like it. Very much an improvement. Tho I can't comment on the chemistry bits. --Treekids (talk) 18:19, 19 February 2008 (UTC) (copied from my talk page --Treekids (talk) 20:37, 21 February 2008 (UTC))

Outstanding issue:

  • If Biodiesel Production is to remain the main article for biodiesel transesterification, then should Biodiesel Transesterification be deleted? I'm certainly not qualified to maintain that content, and it's now redundant. --Treekids (talk) 20:37, 21 February 2008 (UTC)

[edit] Inaccuracies

A few bones to pick with the existing article:

  • "Conversion index" - Is this a common term? I would "yield" is more accurate.
  • "Bioalcohol" - the source does not matter. If ethanol from ethylene hydration is so much cheaper than corn alcohol, why use corn alcohol?
  • Lipid - not all lipids are triglycerides. I don't think biodiesel can be easily synthesized from steroids which are lipids as well.
  • "Titration of WVO sample. Optimal pH for Biodiesel is 7 (neutral), the same as distilled water (and most tap water). Some fat has a high level of free fatty acids which require an acid esterification (to obtain an pH lower than 3) before the alkaline transesterification."
Titration - is there any value discussing pH in a mostly-nonaqueous context? Also, can someone explain what/how you acid esterify the FFA before you undergo base transesterification? I would imagine that all you need to do is add an excess of base (first to neutralize the FFA, then to serve as a catalyst) and an alcohol, with perhaps a drying agent to remove the water formed to prevent any hydrolysis.
  • "Mixing the bioalcohol (methanol or ethanol) and catalyst (sodium hydroxide) in exact amounts. This is often incorrectly referred to as methoxide but is not, though methoxide can be used. The key point is that the reaction needs strong alkaline conditions to proceed. A common variant is to use potassium hydroxide."
Why do you need exact amounts if firstly, base is catalytic (a little will help, more won't hurt) and secondly, the alcohol is in excess anyway?
Rifleman 82, I would encourage you to be bold and change the page, as you see fit. It looks like you make some good points. Anything that makes the production of biodiesel more accurate and clear to the reader is needed. Mytwocents 17:02, 30 April 2006 (UTC)


I know the corrections rae not copmlete but I only have that much time. I should be done with the rest in a few days. If anyone cares to help, please feel free. --Rifleman 82 18:50, 30 April 2006 (UTC)
Wow dude, You've really taken the ball and ran with it! I think the page is better for your work, thanks.
Mytwocents 05:06, 1 May 2006 (UTC)

[edit] Oil Preparation

Oil preparation Biodiesel processor machines, need the vegetable oil to have some specific properties:

  • Suspended particles lower than 1% (mass/mass) and than 5 micrometres. Because of this, the following are necessary:
    • Filtration to 5 micrometres.
    • Washing with hot water.
    • Decantation.
    • Heating of the oil.
    • Second decantation.
  • Anhydrous (waterless). Because of this, the final step of preparation, after the second decantation is drying.
  • Easy solubility in the alcohol to use.

I'll leave this here until I can find a way to incorporate it into the main article. -- Rifleman 82 17:58, 4 May 2006 (UTC)

[edit] Dissertation

As I am pretty much writing a dissertation on this subject, then I shall upload gradually to my user space and then copy it over here - this article is a mess Stui 13:42, 20 March 2007 (UTC)

[edit] Biodiesel production equipment merge

Biodiesel production equipment just has a short paragraph and way too many links. --Lijnema 16:29, 21 March 2007 (UTC)

Agreed. We have a company that continues to push it's production methods in this section. They discuss benefits only - no technology; Wikipedia isn't a brochure. Feel free to delete any materials that seem out-of-place. E8 16:01, 28 September 2007 (UTC)

I finally edited out the material that was specific to one manufacturer (and read like a brochure). I also added "Supercritical Process" information from the Biodiesel main page. Numerous other edits made as well. E8 (talk) 19:27, 24 December 2007 (UTC)

[edit] Notes on Methoxide

Removed this statement from the main page:

  • User Dieselhead disputes the above statement; the pKa's of water and methanol are 15.7 and 15.5 respectively (source: Evans pKa table <http:/daecr1.harvard.edu/pdf/evans_pKa_table.pdf>); therefore a solution of sodium hydroxide in methanol will be approximately 1:1 NaOH:NaOMe."

This should be discussed and formatted properly before adding it to the main page. I've seen substantial support indicating the contrary (which is currently noted on the main page) and the explanation given by Dieselhead is wholly insufficient in swaying my viewpoint. Dissociation of salts (like the organic salt, methoxide) is different than acid dissociation (polar versus covalent bonds). E8 09:19, 27 July 2007 (UTC)

It should be noted that methoxide is produced by this reaction. Methoxide is necessary intermediate in transesterfacation reactions. The main page mentions that the equilibrium constant is way to the left, which is true, but that doesn't mean methoxide is non-existent. Instead, methoxide will only form in very small quantities and more methoxide will not form until the previous methoxide has been reacted with the ester. Any more methoxide that is formed will shift the equilibrium and cause another methoxide molecule to revert to methanol. The Base catalysed mechanism section is misleading and should be changed. TheFatMonkey (talk) 04:28, 10 December 2007 (UTC)

[edit] Equilibrium and mechanism

I found a source ("Biodiesel from Rapeseed Oil, Methanol and KOH 2. Composition of Solution of KOH in Methanol as Reaction Partner of Oil" by Komers et. al. that directly contradicts the claim that the methanol-methoxide equilibrium is highly unfavorable; this work cites a value of K of about 0.12, which increases hyperbolically depending on the ratio of the inititial concentrations of methanol and KOH. Anyone care to confirm this? 68.118.192.197 (talk) 00:04, 26 November 2007 (UTC)

  • An equilibrium constant (K) of 0.12 indicates the reactants (Methanol and KOH), NOT products, are strongly favored. Please post a link to the article (or e-mail me a copy) as I've been unable to attain a complete copy on-line. E8 (talk) 01:34, 26 November 2007 (UTC)
  • I intended that it wasn't as favored as the article indicates, though indeed the reactants are still favored. I will email you the article since it doesn't appear to be freely available. 68.118.192.197 (talk) 21:55, 26 November 2007 (UTC)
  • According to the wiki software you have not specified an email address; I am pretty sure I have so you can email me if you want and I'll send you the article; or just let me know if you specify one. Mattb112885 (talk) 21:57, 26 November 2007 (UTC)
  • Matt, I couldn't find your e-mail address. This system is a bit cumbersome at times. I did, however, make it possible for Wikipedians to send me e-mail. E8 (talk) 23:48, 26 November 2007 (UTC)
  • I read this thread of discussions after my post. Please read my comment above in the Notes on Methoxide section and offer any opinions that you have. Thanks TheFatMonkey (talk) 04:31, 10 December 2007 (UTC)
  • Monkey, would you like a copy of the paper Matt sent me? We were working on an appropriate fix for this section, but I've been busy writing finals, and this project isn't something I can complete soon. E-mail me if you want a copy and are willing to work on making this section more accurate. Thanks for helping! E8 (talk) 04:37, 10 December 2007 (UTC)
  • I've removed the unsourced information from the main page. The source Mattb112885 provided offers experimental evidence that indicates a vastly different value, but I'd like a better chemist/chemical engineer to look the paper over and write up the conclusions.--E8 (talk) 20:30, 24 February 2008 (UTC)
Good for removing the "A word on..." section. I know people mean well, but this stuff has to be sourced and not editorialized within the article. PHARMBOY (TALK) 21:05, 24 February 2008 (UTC)

[edit] Methods of production

Only one of the listed methods generates Biodiesel to the production standards; the other processes can produce biologically-derived fuels similar to Biodiesel, but they are alkanes, not Methyl Esters. There are substantial chemical and process differences.--E8 (talk) 03:59, 17 February 2008 (UTC)

[edit] Page revision

I has become abundantly apparent that this page is in need of serious revision / clean up. I'm beginning editing my sandbox. Feel free to constructively comment or critique.--E8 (talk) 06:11, 19 February 2008 (UTC)

[edit] Workup

This section needs sources, needs to be retitled, and needs cleanup for readability. I appears just to be a block of ideas that didn't fit in other sections. What would be an appropriate title for this section? I removed the information on emulsions, as it's more "how-to" than encyclopedic content (and it's been uncited for over a year).--E8 (talk) 18:00, 25 March 2008 (UTC)

  • The information is, however, accurate, as it is the final step in biodiesel production. It isn't a how to because it doesn't explain "how to" do the steps, only that the steps exist in the production, and Biodiesel production is the exact title of the article. It is the final step, so having it at the end seems appropriate, so placement isn't an issue. The subtitle is weak, as is the language, but the overall content is accurate. I changed to "final process" and added single line that glycerine is produced and sinks to bottom of mix. That fact needs to be present. PHARMBOY (TALK) 18:46, 25 March 2008 (UTC)
  • Thanks for explaining, Pharmboy. I see how the content fits in now. I'm still working on an overhaul of this page, as it's still in need of substantial work. I'm hoping to recruit some help as its the busy time of year for us.--E8 (talk) 22:54, 25 March 2008 (UTC)