Talk:Biodiesel production

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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)

[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)