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[edit] Biodiesel production

Work in progress - all helpful comments appreciated

The big question I have is, is this new structure headed in the right direction? worthwhile? I don't want to waste time doing a page revamp without the support of other editors.

[edit] First thoughts

Hi E8, had a quick look. First thoughts are: Reaction section. If you put the first scheme (the skeletal one) without "catalyst" on the equilibrium sign, this would do for all mechanisms - however you do it, this is the reaction that you do. I think that just the second scheme with R1 R2 and R3 is sufficient on its own, as it mostly duplicates the first with 3xR, but that is just my opinion. Then under "Base catalysed" you can have the more detailed SN2 mechanism, and also more details for "acid catalysed" section when it is prepared.

My initial thought was to put the reaction first, as the rest all stems from it, but it could be a bit off-putting, with a lot of chemistry at the beginning.

Overall, how about:

1. reaction

2 base catalysed: by far the most common. Describe SN2 mecahnism and all the pre-treatment steps needed.e.g

2.1 Reaction mechanism

2.2 Feedstock pretreatment

2.3 Carrying out reaction and product separation

3. Acid catalysed.

3.1, 3.2 and 3.3 as above - not sure where the process differs. 4 Catalyst free supercritical - sections as above.

the problem with the way I haver described it above is that it is giving equal prominence to base catalysed and the other methods, whereas base catalysed in by far the most common. So on further reflection, the other methods could be grouped together in "other methods" section. the ultrasonic and high shear methods are a subsection of base catalysed, I think. the reaction mechanism is the same, it is just a way of getting the phases to mix better. So we now have:

1. Reaction: skeletal diagram and description

2. Base Catalysed Reaction.

2.1 Reaction mechanism. describe SN2 reaction

2.2 feedstock pre-treatment. Describe de-gumming, filtering, drying, acid titration etc. in sub-sections

2.3 Method - describe adding oil and methanol and alkali (I could add a bit about methanol to oil ratio), mixing, separating, washing etc. in sub-sections. Could possibly have a separate "post reaction treatment / product separation" section (2.4)

2.5 Refinements: describe high shear and ultrasonic methods for speeding up reaction and allowing continuous production.

3. Other methods

3.1 Acid catalysed. sub sections as required, describing reaction and how pre-treatment differs from alkali method.

3.2 Supercritical method - again describing differences from alkali method in sample pre-treatment and product separation.

Sorry for being waffly - i find it helps to get my ideas in shape. As I said, these are just m7 ideas on the organisation of the article.Stainless316 (talk) 16:48, 20 February 2008 (UTC)

[edit] User:Mike Young

There are several processes perhaps we need a list of the types of ways of making Biodiesel,

• Gasification to "syngas" (inc Fischer Tropsch) or
• Pyrolysis to bio oil or
• Dissolution followed by liquid phase processing or
• Transesterfication or
• Whatever else someone thinks of.

Then perhaps a table saying what stages are involved in what process.

Alternatively I could cope with just a description of the most common process (transesterfication from Soy beans).

I don't really like a description of transesterfication with bits and pieces added (only if we're using used cooking oil etc) We must try to simplify, not just be as complete as possible.

The reaction chemistry section could probably go into another article by itself.

I don't believe glycerol is becoming more valuable. On the contrary I have heard the price has crashed as the market has been swamped by the stuff produced as bi-product. Mike Young (talk) 22:24, 20 February 2008 (UTC)

• I removed the glycerol value content; that was spurious. I do have a few sources discussing uses for glycerol, but that really belongs on the glycerol (or uses) page. Biodiesel is defined as mono-alkyl esters in most country (EN or ASTM standards are used worldwide). Some of the techniques listed above produce alkanes, which are notably different and are NOT Biodiesel by definition. We had a disambiguation main that listed out the above, though I don't recall where it is.--E8 (talk) 02:52, 21 February 2008 (UTC)

• Transesterification will get serious attention as it is the most commonly used process (described in literature). The other reactions I included are significant enough to require inclusion.--E8 (talk) 02:52, 21 February 2008 (UTC)

• I like the table idea. My main concern has been clutter and organization, and a table may work well. I have no idea how to format that and have it look good and be readable, however. Suggestions (or examples to template) would be very helpful.--E8 (talk) 02:52, 21 February 2008 (UTC)

I think there is a fuel from biomass article, which is pretty much what you describe at the beginning, outlining the different methods of getting liquid fuel from biomass. This article should be about transeterification of oils and fats to produce the biodiesel fuel only. This fits in with the definition in the "biodiesel" article. All the reactions described are transesterification - the only distinction is acid catalysed, base catalysed or catalyst free. The high shear and ultrasonic also use catalyst (I think). So my idea to organise the article was to start with the overall reaction (not the mechanism), which explains what the article is about, then describe in more detail how to go about each different method, outlining the unique features of each. I think nearly all commercial biodiesel is made by base catalysed reaction at present, so this should be the bulk of the article. It could be that trying to explain SN2 reaction mechanism is beyond the scope of this article, and could be linked to.Stainless316 (talk) 13:34, 21 February 2008 (UTC)