Talk:Propionic acid

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	Chemistry Portal Propionic acid is within the scope of WikiProject Chemicals, a daughter project of WikiProject Chemistry, which aims to improve Wikipedia's coverage of chemicals. To participate, help improve this article or visit the project page for details on the project.
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Article Grading: The following comments were left by the quality and importance raters: (edit · refresh) Article is B-Class alright, but in dire need of references. Wim van Dorst (Talk) 22:48, 7 March 2007 (UTC).

A Wikipedian removed Propionic acid from the good article list. There are suggestions below for improving areas to satisfy the good article criteria. Once the objections are addressed, renominate the article as a good article. If you disagree with the objections, you can seek a review. Removal date: No date specified. Please edit template call function as follows: {{DelistedGA|insert date in any format here}}

Contents 1 Delisting from GA 2 Diagram 3 (Minor) outstanding issues 4 Merge request

[edit] Delisting from GA

No statement of references, so I'm delisting this article from the Good Article list. References are required to become a GA.

[edit] Diagram

I think the diagram is a bit unclear. In the first place: is it correct? It should have 3 carbons, but I see only one.

This is due to the "line-angle" formula style- all three are there. I will be drawing a bigger picture for this page very soon. Walkerma 16:57, 15 July 2005 (UTC)

[edit] (Minor) outstanding issues

• Are we sure that the production of propionic acid as a byproduct of acetic acid manufacture is that minor? BP Chemicals keeps an outdated acetic acid plant near Kingston upon Hull (UK) open simply because of the high value of the byproducts (of which EtCOOH is by far the most important). Acetic acid production even by methanol carbonylation typically produces 1% EtCOOH (which would be 40 kt/a globally). Physchim62 11:00, 15 July 2005 (UTC)
  • The latest Kirk-Othmer (late 90s) says that propionaldehyde oxidation is the principal route to propionic acid, and gives the old butane oxidation route to acetic acid little more than a couple sentences. If I had to guess, I'd say the market supports a few of the old plants profitably, but not as the principal production route. A lot of multiple-product processes face this problem; a few producers can get away with it, but the bulk of producers are unwilling to face demand uncertainty for two products rather than just one. Shimmin 12:31, July 15, 2005 (UTC)
• Does the halogenation of propionic acid replace the methyl hydrogens or merely the methylene hydrogens: I suspect it only replaces the CH₂ hydrogens. Physchim62 11:03, 15 July 2005 (UTC)
  • Halogenation alpha to the carboxyl group (-CH2-) is most likely. I do believe that halogenation of the primary carbon (CH3-) is more difficult and only possible after the alpha-carbon is fully halogenated. Question: Why do we care about halogenation of propionic acid? ~K 15:09, 15 July 2005 (UTC)
    • I propose we change "very minor" to "minor". The Monsanto process (which we are talking about here) is still one of the major production methods in use, according to a recent (2001?) review article, and so EtCOOH must be produced in significant quantities this way- I don't think the newer Ir/Ru process has fully displaced it by any means. I have a recent student term paper on acetic acid production at home if people need some figures. And K is right, alpha halogenation is really the only significant reaction- but I am more sure of the HVZ reaction, I amended the page accordingly- feel free to make further changes. I think I will put together a stub on the HVZ, we need one, and the PBr3 page already has a scheme.Walkerma 16:54, 15 July 2005 (UTC)
  • Acetic acid production is about 5.5 Mt/a, of which about 3.5 Mt/a is by the Monsanto process and 1 Mt/a by Cativa (Ir/Ru). This gves a figure of about 40 kt/a EtCOOH as a Monsanto byproduct and over 100 kt/a from the two butane oxidation plants mentioned above. The question is: what is the annual consumption of propionic acid? 1000 kt/a (wild guess)? Physchim62 15:42, 16 July 2005 (UTC)

[edit] Merge request

I request you NOT merge the Propionic acid chemdata supplement with propionic acid. If you feel you have a valid reason to merge them, please discuss it with the WikiProject Chemicals. ~K 05:50, 6 November 2005 (UTC)