User talk:Beetstra/Continuous distillation

A few wording changes

Dirk, I made a few wording changes to improve the English and to avoid the use of superlative, subjective words like "huge" and "greatly". Also, industrial distillation columns are not called a "setup", so changed that to "system". - mbeychok 17:34, 29 November 2006 (UTC)

Cheers, I saw the changes. You are right, the words I choose are not always correct. Thanks! --Dirk Beetstra ^{T C} 17:41, 29 November 2006 (UTC)

More changes

The numbers about the hydrocarbons in crude oil and its cuts I gave you were generalities ... the thousands of different crude oils all vary and so do the cut ranges made in different refineries. So if the article uses numbers like "60 or more hydrocarbons", it will cause many, many edits.

I didn't realize that you were going to take my email as being a textbook and use it in the article. Therefore, I have changed the wording in the article to avoid specific numbers as much as possible. Anyhow, the basic purpose is to point out that the cuts are all multi-component fractions.

I also clarified how olefins enter the picture in a refinery. - mbeychok 17:54, 29 November 2006 (UTC)

I realised that those numbers were not specific, you already said you wrote it in a hurry, and I must confess, I have no clue about the relative sizes of the cuts and the number of compounds per cut (I know what I got, years ago, when I injected a gasoline sample into a GC, and that was impressive, and that is not 'just' a fraction from a crude oil distillation).

The article is now being edited in a private user space, it should not attract too much attention, so I don't think it is a real problem that some things are not correct, yet. Thanks again for having a look. --Dirk Beetstra ^{T C} 18:44, 29 November 2006 (UTC)

I changed the location of the images and also of the sub-section on Reflux so as to get the images and the text to coincide better. I think it would be even better yet if Image 5 were also on the right as are all the other images. What do you think, Dirk?

If you want to really keep it private, delete the categories at the bottom of the article because this page is now listed in all those categories. They can always be replaced later when you have finished. - mbeychok 18:52, 29 November 2006 (UTC)

It might indeed be better to move all images to one side, that does give a better text-flow. The problem is only, that the images then move too far to the bottom, and one has to scroll to see the appropriate picture. What might work is to exchange images 4 and 5, image 5 could maybe be moved further to the bottom.

If you think that the article is in an appropriate format, then I would not mind that it would replace the text in the original article. It was just that I did a major copy-edit where I was not sure if it would get to a good/complete version (we were discussing quite fiercely over it), and well, I blundly copied text from your mail, so that is, to say the least, a bit controversial (I hope it is not too much of a problem). But if you agree, we can copy and paste it over the article in main space. --Dirk Beetstra ^{T C} 19:01, 29 November 2006 (UTC)

Works for me! --Dirk Beetstra ^{T C} 19:08, 29 November 2006 (UTC)

More discussion

Dirk, I moved Image 5 to the right and all of the images look okay now ... and they coincide better with the text that refers to them.

I don't think the article as a whole is yet ready to replace the existing article. My most important reluctance right now is your section on "Example of an ideal, binary mixture". The image by Henry Padleckas is indeed very excellent, but it is not an image of a "continuous" distillation. It has no feed stream and no reflux. It is a batch system. I think the section on "Example of an ideal, binary mixture" belongs both in the Distillation article and in the Batch distillation article. It is just out of place in this article. And as I pointed out in our email exchange, the discussion involving A's and B's is confusing and somewhat convoluted.

Besides that section, I would prefer a day or two more to go over this version of the article more closely. - mbeychok 19:18, 29 November 2006 (UTC)

I cannot take credit for the current Image 2: simple continuous distillation scheme. That image was made by User:Quantockgoblin. I agree that the current Image 2 should not be described as a continuous distillation in the caption since it has no feed stream, and so is inappropriate for inclusion in a Continuous distillation article. It might be more fitting to include it in the Fractional distillation article. The current images 3 (Continuous Binary Fractional Distillation), 4 (Continuous Fractional Distillation, multi-component), and 5 (Tray Distillation Tower) were made by me. I previously made a simplified version of the current Image 3 (which is still available online) and then the slightly more detailed version of the current Image 3 which is presently shown. The current Image 4 is simplified in about the same style as the earlier simplified version of Image 3, but I am almost finished making a somewhat more detailed version of Image 4 in the same style as the presently-shown version of Image 3. The problem with that is the additional details were hard to fit into a picture of about that size and as a result, the picture came out looking somewhat "complicated" when viewed by a simple-minded reader. H Padleckas 06:29, 1 December 2006 (UTC)

I still would argue that it is not out of place, but might need a rewrite. Although it does not resemble in any way a true system, I do believe that it serves a purpose in the explanation. The picture is indeed not of a continuous distillation, but of a batch distillation. But, in fact, I have asked Henry Padleckas to have a look at the article as it stands, and especially to have a look at the principle and the picture, to see if he could upgrade it to a continuous distillation. I'd like to wait at least for him to give a second opinion, maybe even from a fourth party (Wim van Dorst, Martin Walker?). In the end, I think the discussions on batch and continuous should move from distillation to these two articles, but we can still discuss about that. I'll tweak a bit with it. --Dirk Beetstra ^{T C} 20:01, 29 November 2006 (UTC)

Dirk, now you are beginning to push too hard. I spent most of yesterday answering all of your emails in good faith. Today, I have been more than willing to work with you in your re-organization of the Continuous distillation article, again in good faith. As a third party, I trust Henry Padleckas who has degrees in Chemistry as well as in Chemical Engineering and I value his opinions. But now you talk of bringing in a fourth and fifth party, one of whom is a organic chemistry professor and another who is also a chemist. I would not consider either of them to have any unbiased or non-chemistry oriented opinions. You are beginning to erode my good faith in working with you. We don't need a "committee" ... just you and I and Henry are enough. If you won't do that, then that will be the end of my cooperation with you. I asked you to wait until tomorrow and I also expect you to honor that request if you want any further cooperation from me.- mbeychok 22:05, 29 November 2006 (UTC)

OK, no problem, (though I expect Wimvandorst to be a chemical engineer as well), if you prefer no further interaction from others, I will respect that. --Dirk Beetstra ^{T C} 22:23, 29 November 2006 (UTC)

This current draft of the article now has five images, including Image 2, unsuitably captioned as "simple continuous distillation scheme." It depicts a laboratory type distillation separating a two-component mixture into three distillate fractions with sizable flasks as receivers, in addition to any bottoms fraction there may be. The pic shows a fractionating column with three distillate taps. This requires a special rare or unique column for laboratory glassware. The size of the flasks implies a preparative scale distillation. I doubt this kind of a distillation set-up for only two components is used very often at all by chemists for preparative scale production. Although something like that might be done for research on distillation methodology or vapor-liquid equilibrium, only small amounts of sample need to be taken for analysis at the column taps. I myself have never seen this kind of laboratory preparative-scale distillation with multiple column taps being used for only two components. Most (if not all) lab scale distillations to separate mixtures into multiple fractions would be done in a batch distillation style taking fractions sequentially in time with more readily available equipment. I suggest we simply leave out this image from the contnuous distillation article. We will still have four pics left, which is plenty. H Padleckas 07:28, 1 December 2006 (UTC)

Removal of the principle section

I just tried in an experiment (without saving) to take out the simple principle as I had written it. And I think the flow of the article is now in such a way, that it does not make the article more difficult to read. The introduction of the article and of the section principle is now sufficient to flow into the simple industrial system-section (I removed the two headers '===example ...===' and '===simple industrial system===' and the text inbetween for a moment).

May I suggest we wait until Henry Padleckas has given his opinion, and unless he comes up with a cunning plan to make the binary example section a good one, we just cut it out, and use the article as such. Hmm .. so all it took was a reorganisation of the article. I am happy to see we are really making progress, a good moment to catch some sleep. See you tomorrow! --Dirk Beetstra ^{T C} 00:20, 30 November 2006 (UTC)

My final copy editing and other minor changes

Dirk, if I understand what you said above, I am indeed pleased that you have convinced yourself that the section on the "ideal, binary system" is not needed. Meanwhile, I have completed my final copy editing and other minor changes of your sandbox article to the best of my abilities.

So I will now get onto my other work until I hear further from you about Henry Padleckas's comments if any. Regards, - 19:43, 30 November 2006 (UTC)

You understood correctly. And as I said, I am pretty happy with the setup now. Cheers! --Dirk Beetstra ^{T C} 19:45, 30 November 2006 (UTC)

Oops

Ah, OK. My mistake, I thought the picture was yours, H.Padleckas. But no probs. Cheers anyway for having a look.

The picture is indeed not of a continuous distillation, but (realising I am pushing), could an analogous picture be made which does make this a continuous distillation? I would simply argue .. give it a feed-stream, with an appropiate number of yellow and blue dots. And then, do you believe that that would help explaining the 'example of an ideal, binary system' section of the article or do you agree that the lead-in of the article is such, that the section could go, without making it too difficult for non-chemists to understand? --Dirk Beetstra ^{T C} 07:52, 1 December 2006 (UTC)

Dirk, you know my feelings on this subject, namely that the "Example of an ideal, binary system" section could be deleted as you, yourself, had pretty well concluded above. I think that you and I have collaborated to produce a quite good article without that section. Regards, - mbeychok 08:06, 1 December 2006 (UTC)

OK, do you agree to copy the article, without that section, over the original in the main namespace? --Dirk Beetstra ^{T C} 08:18, 1 December 2006 (UTC)

I have removed the image and the section, and renumbered the images. Could you do a last check if I did not forget numbering somewhere? I agree to copy the article then to the main namespace. Cheers! --Dirk Beetstra ^{T C} 08:18, 1 December 2006 (UTC)

Dirk, I used the Find function to check for the usage of the word "Image" in the text of the article and the numbering all checked out okay as far as I can tell. I don't care whether you or I copies the article into the main namespace. If you want to do it, go ahead. If you want me to do it, I will do so in the morning. It is after midnight here now and I am going to bed in one minute. If you decide to do it, I think you should briefly explain what was done on the Talk page. Cheers! - mbeychok 09:03, 1 December 2006 (UTC)

I've been thinking out the previous Image 2 (simple continuous distillation scheme) some more. I think we can include something like it in this article if we explain that it is a simplified figurative diagram for an illustrative purpose and state that the reflux of distillate fractions back to the column is not shown for simplicity. This pic would have to be modified to show a continuous entry feed into the distilling flask and a continuous removal of the bottoms from the distilling flask. This can be done by changing the distilling flask in the pic to a three-neck flask: the left neck for the continuous for the continuous feed, the middle neck for the column, and the right neck for continuous bottons removal. I think the size of the distillate flasks can be reduced also. The article would still be OK even without the image too. H Padleckas 14:41, 1 December 2006 (UTC)
H Padleckas 17:20, 1 December 2006 (UTC)

As Milton Beychok pointed out below, the pictures might serve a purpose on distillation. I would by the way not mind that this is not going to be a laboratory setup, but a 'technical' picture, but just without things like the reflux, etc. As I see it, reflux and trays are improvements, not strictly necessary (well, your separation s***s when you don't use it, but well, for the argument). But maybe we should come up with something everybody would recognise (but .. what). --Dirk Beetstra ^{T C} 17:31, 1 December 2006 (UTC)

Transferred to main namespace

Dirk, I just transferred it a few minutes ago. Cheers!! - mbeychok 16:46, 1 December 2006 (UTC)

I think that the old image 2, which was deleted from this article, might fit into the "Case for batch distillation" section that you included in the main Distillation article. I also think if that image by Quantockgoblin were modified as suggested by H Padleckas, then perhaps it might fit into the "Case for continuous distillation" section that you also included in the main Distillation article. - mbeychok 17:00, 1 December 2006 (UTC)

I saw the change. Cheers. I also saw your work on hydrodesulfurisation, really good, my compliments (made a small change to the starting point describing the picture, it took me a moment to find the 'FEED', hope that is OK).

The discussion on the picture (see if it can be made fit for that section in distillation) can be kept on the talk page there, it might indeed be a good place for it.

Thanks for the cooperation, and I think we put down a good article here, hope to see a review. Cheers! --Dirk Beetstra ^{T C} 17:16, 1 December 2006 (UTC)

I started work on a modified version of the aforementioned old Image 2 pic. It will take me a while to finish, so don't hold your breath waiting. H Padleckas 17:33, 1 December 2006 (UTC)

Suggestions

Hello All,

Sorry, I did not realise there were so many contributing to this article.

I've made some small changes to the article and some suggestions on its discussion page, now I know I ought to have brought these here.

1. My proposal is to call the article 'Category:Chemical Engineering:Unit Operations. Perry, my 1950 edition calls it, together with solvent extraction and gas absorption one of the three diffusional operations, but Unit Operation would include Humidification Filtration and others, all categories important enough for any encyclopedia.

2. I propose to write two more sections: Variations of continuous distillation, such as vacuum fractionation steam assisted fractionation etc, and Improving separation efficiency into which would be transferred the sections under Reflux, Reboilers, and added Strippers, and Flash destillation Pots (used in refining for crudes containing too much light ends, to reduce column loadin.

3. It should be added that the Design principles ought to be properly described, beyond just finding the desired number of theoretic plates, without overelaborating them.

What we should avoid, however, is to describe petroleum processing here instead of routing the reader there with a link. Too many links are disturbing, but too much repetition also. Difficult to find a good balance.

LouisBB 16:13, 2 December 2006 (UTC)

Reinstated sandbox-version

Hi all, I have copied the article back from the main-namespace to here, and did some resorting, trying to incorporate LouisBB's additions to the article. I did also get some old things back:

Remarks and reasons: 1) Reinstated the contrast to batch distillation, it is the other technique, which is used for smaller scale industrial distillations. Hence I think there should be a link in the introduction of the article.

2) Sorting. Sorted sections back into a 'simple' principle, and moved the 'improvements' into an own section. The reason for this is to keep the setup of the article simple, and that the trays/plates/packing/reflux are not part of the principle. They are used to improve the separation. I understand that that is not the way the system is normally run, the separation would not be good enough, but this approach of explanation has several advantages: a) the principle can be explained relatively simple, which is good for people who are not familiar with the subject, and b) the separate sections on plates/trays, packing and reflux can be expanded so that they can better explain what they do, resulting in a clearer line of reasoning overall.

3) Some things have been removed, they belong probably in the own articles.

Current setup:

1) Introduction: explain what continuous distillation is, give links to the main distillation, and the main other method, batch distillation. And tell what the normal audience sees: the towers .. what is exactly going on in there comes later

2) Principle, what goes on in those towers is a distillation, basically .. heating the mixture, tapping one or more fractions from the boiling part, and one from the bottoms .. meanwhile refilling the system. I guess that is enough for the principle.

3) Design and Theory .. here could be explained that the picture is not as simple as explained in principle, but that for more complex mixtures more is needed, mention calculation methods (McCabe-Thiel / Fenske / Simulation)

4) Improving separation, the setup as described in 2) Principle is by far not enough. The separation is not good, but can be improved using several methods.

5) Mention the rest of such a setup, e.g. the overhead, if the liquid mixture contains (or generates) gases during the process, which are not condensed.

6) Provide some examples, this gives the reader the possibility to appreciate the complexity of real systems (hundreds of compounds, not boiling points but fractions, which even overlap (fractions containing unrelated components). Secondary (tertiary ..) distillations are necessary to get pure products, or fractions undergo other purification methods (e.g. hydrodesulfurisation, cracking, isomerisations).

Hope this clarifies the view that I have been trying to convey the last couple of days. Feel free to play around in my sandbox or but feel also free to ignore this view and go on with the main article. See you around! --Dirk Beetstra ^{T C} 17:39, 3 December 2006 (UTC)

Remark: I do feel that 'Design and theory' is a bit out of place, or should be expanded/incorporated. --Dirk Beetstra ^{T C} 18:16, 3 December 2006 (UTC)

The latest addition to the main-space article has resulted in a solution, the 'improving separation' and 'overhead' are now subsections of the design and theory, which now also contains a section 'column feed' --Dirk Beetstra ^{T C} 21:11, 3 December 2006 (UTC)

Hello again from Milt Beychok

Dirk, I think you are doing quite a good job thus far! I offer two points:

• I moved Image 4 up so as to eliminate the large blank space in the text of the article.
• The reflux is just as important as the trays and perhaps even more so because after the tower is built and erected, the reflux can be increased (within practical limits) to get better separation if needed ... but you cannot add more trays once the tower is built and erected. Thus, I think the "Reflux" sub-section should be moved up to be the first sub-section in the "Improving separation" section.

Your major problem is going to be that of preventing LouisBB from trying to write a textbook that includes the entire universe of distillation. He really must learn that Wiki works by linking words in the text to the other distillation and distillation-related articles when needed. You want to simplify the article, but he wants to complicate it immensely and in many cases erroneously. - mbeychok 05:09, 4 December 2006 (UTC)

Hi Milt, welcome back here. I saw indeed that the article became impressively more difficult almost immediately after it was copied to the main namespace. While there were some good additions by LouisBB, I felt that it better to again move it here, and reorder the article again (it cost me about 20 edits to get everything into place, I hate to do that in the main namespace, especially because it means that the article will have intermediate stages of unreadability). For now I will keep it here, trying to keep up to pace with the article in the main namespace, and incorporating other suggestions.

About these suggestions. You speak in 'past', but did not see any changes by you. Whatever, image moving can be done at any moment, no problem. I have moved the section 'reflux' as the first in the 'improvements' section, and added a sentence to tell why it is an important tweak (that sentence needs the attention of an expert!).

I feel that I have used all of LouissBBs changes, though I got rid of the least informative of duplicate entries. I did not see his point of duplicate entries earlier on, I don't really recall that in the previous version in this sandbox, they should have been pointing backward to earlier sections ('as stated above', or something similar). I hope LouisBB will come by and help us improve this version. See you around! --Dirk Beetstra ^{T C} 08:57, 4 December 2006 (UTC)

Hi All

I rather like this latest version. I am certain it is a great improvement, and the Feed section says everything in a nutshell

I think Milton you have misunderstood me: it is far being from me trying to write a book, but we have to tell the reader what we talk about when we mention a name or a reference.

I intend to expand the Design section SLIGHTLY, but I shall put it first into User:LouisBB:Sandbox to stop it being reverted. In any case Milton, you have lots to add to it that was not said before, in a nutshell, and to correct mistakes. You ridiculed a bit my statement of the reflux replacing one extra plate, and I know that this was an understatement, but what it meant, that it was not needed in the simple picture. I'll continue in my sandbox. LouisBB 15:28, 4 December 2006 (UTC)

Louis, PLEASE indent all your paragraphs to same level (which I just did for your above comment). Simple diagram of a simple binary distillation or not ... absolutely, no industrial distillation tower ever gets built or operates with no reflux!!! So that is why Padleckas included the reflux in that drawing. - mbeychok 17:43, 4 December 2006 (UTC)

Possible wording changes?

Dirk, since the earlier version used American English spelling rather than British spelling, would you mind if I went through the article and made it consistently use American spellings? I don't feel at all strongly about this, but Wikipedia policy does advocate staying with the earlier spellings. What I am talking about is primarily words like "vapor" and "vapour", "vaporize" and "vapourize" and "modeling" and "modelling". In any event, it ought to be one way or the other. Right now we have "vapor" (American) and "modelling" (British)

Also, I would like to change just a few phrases like "running setup" to "on-stream operation" and other such if I find any.

Of course, you can always revert my changes if you don't like them. Please let me know as soon as possible. - mbeychok 04:50, 5 December 2006 (UTC)

Milton, go ahead. The main-space article is in US-EN, but I am normally writing UK-EN. Policy is to keep one style, and that should be the 'original style', so it should be US-EN anyway. I did not notice I added so many UK words to it.

And by all means improve my terminology, I have no problem at all. At the moment I am mainly adding sentences where I think there is more info possible, and I am not reverting changes that soon, I try to incorporate them into the text (I only remove duplications).

This is the soonest I could, just out of bed. Happy editing! --Dirk Beetstra ^{T C} 07:57, 5 December 2006 (UTC)

Just got out of bed myself. There were only two cultural word changes: vaporise to vaporize and modelling to modeling. Also, "withdrawal" is the indeed the proper word for removing products from a tower.

I also deleted the proposed Modelling heading. That section would require 2-3 textbooks full of discussion and there are probably only a handful of people in the entire world who could write it correctly ... I am certainly not one of those. Also, most of the modeling development is proprietary and that would prevent inclusion of much of the core material on the subject.

As far as I can see, you are ready to transfer this to the main namespace. I have no further comments or suggestions. Regards, - mbeychok 17:09, 5 December 2006 (UTC)