Talk:Natural gas/Draft

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 Definition A gas consisting primarily of methane (CH4) which is found as raw natural gas in underground reservoirs, as gas associated with underground reservoirs of petroleum crude oil, as undersea methane hydrates and as coalbed methane in underground coal mines. [d] [e]

Wikipedia has an article of the same name

I essentially re-wrote the WP article by rewording, reformatting, deleting a number of sections, adding many new sections as well as new graphics and new tables. There is very little left of the WP article other than the section on "Natural gas processing" for which I was the original author both in Wp and CZ. Milton Beychok 21:41, 22 September 2009 (UTC)

I also made some changes suggested by Paul Wormer when he reviewed this article while it was still in my sandbox.Milton Beychok 21:41, 22 September 2009 (UTC)

Comments by Karl D. Schubert

Milton, this reads very well.... I'm reading it and responding as I go through it. (Apologies for the delay; I'm traveling today and tomorrow.) While methane is the majority component in natural gas, there is oftentimes enough ethane and butane (up to 20% or so) that I think it's worth mentioning that (e.g., http://www.naturalgas.org/overview/background.asp). For those who care, it does affect the molecular weight, flow characteristics when liquefied, and also the combustion values. [More to come....] Karl D. Schubert 01:41, 23 September 2009 (UTC)

Karl, The section entitled "Composition of raw natural gas" does discuss all of the components present in most cases. I have altered the wording of that section and of the second paragraph in the introductory section to reflect that the raw gas may contain as much as 20 volume % of ethane through pentanes plus (i.e., natural gas liguids).
As for liquified natural gas (LNG), virtually all of the higher molecular weight hydrocarbons are usually (if not always) removed before the gas is liquified. In other words, LNG is usually almost pure methane.

...continuing my comments.... very readable. (If I recall, petrochem is an area you worked in, too.) One other interesting fact area might be the combustibility. One of the additional safety values in LNG transportation is that it is actually only flammable (and/or explosive) in a fairly narrow range of concentration. Karl D. Schubert 02:00, 23 September 2009 (UTC)

The flammability range of gaseous methane is 5 to 15% by volume in air which is actually quite a large flammability range compared to that of propane (2.1 to 9.5 %), butane (1.8 to 8.4 %) and pentane (1.4 to 8.3 %). I think the the safety section's statement that natural gas is very flammable is correct.
As for the safety of LNG, if there is an accidental release of LNG (which is at its boiling point of -258 °F) from a tanker or a storage tank, it will very quickly warm up and vaporize into gaseous methane. The safety of LNG has been the subject of much study and much controversy. Many communities in the U.S. have objected quite strenuously to having LNG terminals near them for fear of a major fire or explosion. I would rather not open up that can of worms in this article about natural gas nor do I have enough knowledge of that subject to cover it thoroughly. It would be much better to cover that in a separate article specifically about LNG, written by someone knowledgeable of the subject.

...and last one for now: is the London school incident you are referring to the one where gas leaked into the sewer system and took out a major area in London when it exploded in the sewer system? If so, it was also one of the major motivators in moving to LNG for transportation and also for groups taking up the study of the spreading and flammability of heavier-than-air gases. Karl D. Schubert 02:03, 23 September 2009 (UTC)

The New London School explosion occurred in 1937 in the town of New London, Texas ... which I have now included in the safety section. It was caused by a gas pipe leak in the school's basement. I have also added a reference for that incident to avoid any confusion with sewer gas explosions in London, England.
Karl, thanks for your comments. I really appreciate them. Milton Beychok 04:34, 23 September 2009 (UTC)

In nice shape

It's pretty close to approval-ready. I'd like to suggest going through it to check where "methane" might be more appropriate than generic "natural gas", as in the environmental section. Howard C. Berkowitz 23:57, 25 September 2009 (UTC)

Good point, Howard. Consider it done. Milton Beychok 03:24, 26 September 2009 (UTC)

Two minor pre-approval corrections needed

In section 2, change this: "as much 20%" to this: "as much as 20%".

In section 9: add the unit Mt/year near the end of the sentence, ... 10,200 Mt/year, respectively.

I will nominate for approval following these minor corrections. David E. Volk 16:22, 26 September 2009 (UTC)

Done and thanks for those catches, David. Milton Beychok 17:34, 26 September 2009 (UTC)
Looks good to me, too, Milt. Good points, earlier. Karl D. Schubert 18:08, 27 September 2009 (UTC)

APPROVED Version 1.0