Jump to content



Featured Articles

Check out the latest featured articles.

File Library

Check out the latest downloads available in the File Library.

New Article

Product Viscosity vs. Shear

Featured File

Vertical Tank Selection

New Blog Entry

Low Flow in Pipes- posted in Ankur's blog

Natural Gas Dew Point


This topic has been archived. This means that you cannot reply to this topic.
13 replies to this topic
Share this topic:
| More

#1 dhns

dhns

    Gold Member

  • Members
  • 65 posts

Posted 14 July 2009 - 08:03 AM

Dear sirs,

Could any one please explain about the Natural Gas-dew point control,

what is the need to control the dew point for Natural Gas?

If am selling that natural gas, in that point of view what is the relation
with the dew point.

if any notes regarding that please notify the same,

anticipated kind thanks,




#2 ethylene

ethylene

    Brand New Member

  • Members
  • 9 posts

Posted 14 July 2009 - 09:18 AM

hi

my understanding on natural gas dewpoint.

Natural gas normally transported in pipeline at high pressure. If the surrounding temp is low enough, liquid may formed by condensation of high molecular weight HC. To avoid this, the gas is dewpointed which heavies is removed by reducing temperature and separate the liquid formed to achieve lower dewpoint at pipeline operating pressure.Typical dewpointing method include turbo-expander process and mechanical refrigeration.

rolleyes.gif

#3 ankur2061

ankur2061

    Gold Member

  • Forum Moderator
  • 2,484 posts

Posted 14 July 2009 - 11:49 AM


dhns,

A very nice article on dew-point & moisture control at the following link is available:

http://www.iceweb.co.....ent Paper.doc.

Read, learn and enjoy!

Regards,
Ankur.

#4 Art Montemayor

Art Montemayor

    Gold Member

  • Admin
  • 5,780 posts

Posted 14 July 2009 - 02:56 PM

dhns:

I am glad you brought this subject up. I am presently marking up some erroneous equipment specifications and concepts on how to transport, treat, dehydrate, and maintain natural gas in a Pipeline quality condition in order to distribute it nation-wide for sales and an expected profit. I am currently slated to go into a meeting tomorrow morning at 10 am to try to convince some very aged and educated engineers on what they are doing wrong. I am on my second bottle of wine and I may need a new red pen before I get through marking up all this documentation in front of me. It is truly sad that some engineers just don’t get the “picture” yet.

Natural Gas-dew point control is a requirement because:
  1. Pressurized natural gas in contact with liquid water will form solid hydrates. These hydrates will clog and plug up pipelines, valves, and any transport equipment;
  2. Any liquid water in natural gas pipelines will cause corrosion and eventual failure of transport equipment;
  3. Any excess water in a natural gas pipeline is a freezing threat to the transport of the gas.
  4. Water content in natural gas decreases its heating value.

There is a definite need to control the dew point for Natural Gas because without it the gas can’t be successfully and continuously transported and distributed when it is needed. Here, the dew point is that of water - not of other hydrocarbons as erroneously stated by ethylene. As stated above, solid hydrates of methane will form and corrosion will appear.

If you are in the business of selling natural gas, the dew point of the same natural gas is very important to control and maintain because if you don’t, you won’t be able to transport the gas and sell it successfully. If you can’t sell the gas, then you can’t raise any revenue to justify your investment. The end result is that you will go bankrupt. I think this more than enough reason for you to take an interest in protecting your investment by drying the natural gas to a safe dew point and controlling it there. – Don’t you?


#5 dhns

dhns

    Gold Member

  • Members
  • 65 posts

Posted 14 July 2009 - 11:56 PM


Dear sirs,

Thanks for your delicious reply for my doubt,

once again thanks for mr. art to lighted the correct raw resons, behind the dew point controlling of natural gas.

thanks,


#6 Padmakar Katre

Padmakar Katre

    Gold Member

  • ChE Plus Subscriber
  • 992 posts

Posted 15 July 2009 - 09:15 AM

QUOTE (Art Montemayor @ Jul 15 2009, 01:26 AM) <{POST_SNAPBACK}>
[size=4][font="Times New Roman"]dhns:

I am currently slated to go into a meeting tomorrow morning at 10 am to try to convince some very aged and educated engineers on what they are doing wrong. I am on my second bottle of wine and I may need a new red pen before I get through marking up all this documentation in front of me. It is truly sad that some engineers just don’t get the “picture” yet.


Dear Art,
Indeed one of the nicest replies by you.

#7 Qalander (Chem)

Qalander (Chem)

    Gold Member

  • ChE Plus Subscriber
  • 829 posts

Posted 15 July 2009 - 10:53 AM

Splendid focused Reply! Dear Art.

#8 Muneeb

Muneeb

    Brand New Member

  • Members
  • 3 posts

Posted 15 July 2009 - 12:40 PM


In case you need to calculate/estimate the dew point temperature for your natural gas compositions at their given Pressure, you can use this online calculator at this link:

http://www.chemsof.com/flash/flash.htm

it can caculate the dew P, T, and Bubble P, T as well.

#9 ethylene

ethylene

    Brand New Member

  • Members
  • 9 posts

Posted 16 July 2009 - 09:48 AM

Dear Art

Thank you for enlighten me. Could you please further explain why there is specification for hydrocarbon dewpoint in some natural gas pipeline.

rolleyes.gif


#10 shan

shan

    Gold Member

  • ChE Plus Subscriber
  • 692 posts

Posted 20 July 2009 - 03:38 PM


To avoid two phase flow, low point accumulation (slug forming), and higher BTU/SCF.

#11 NGL Licensor

NGL Licensor

    Veteran Member

  • Members
  • 40 posts

Posted 22 July 2009 - 01:14 PM


Hi

Dew point control is to provide a sales gas quality that meets HD dew point and water dew point specifications

The process scheme mainly depends on:
- Feed gas composition and conditions
- Sales gas product conditions and battary limit conditions
- Onshore or offshore
- Ambient conditions

If you can drop the answers for the above then you may expect a realstic answer

Thx

AF.King

#12

  • guestGuests
  • 0 posts

Posted 12 March 2010 - 11:00 PM

<!--quoteo(post=30889:date=Jul 15 2009, 01:26 AM:name=Art Montemayor)--><div class='quotetop'>QUOTE (Art Montemayor @ Jul 15 2009, 01:26 AM) <a href="index.php?act=findpost&pid=30889"><{POST_SNAPBACK}></a></div><div class='quotemain'><!--quotec-->[size=4][font="Times New Roman"]dhns:

<b>I am currently slated to go into a meeting tomorrow morning at 10 am to try to convince some very aged and educated engineers on what they are doing wrong. I am on my second bottle of wine and I may need a new red pen before I get through marking up all this documentation in front of me. It is truly sad that some engineers just don’t get the “picture” yet.</b><!--QuoteEnd--></div><!--QuoteEEnd-->

Dear Art,
Indeed one of the nicest replies by you.


It's really bad to hear this that even these people are still learning.So what is the use of seniors....

#13 kkala

kkala

    Gold Member

  • Banned
  • PipPipPipPipPip
  • 1,939 posts

Posted 13 March 2010 - 01:37 PM

It's really bad to hear this that even these people are still learning.So what is the use of seniors....

Well, to be senior does not mean you know everything, even in your own narrow field. Knowledge is so broad nowadays. Of course it sounds strange that these old engineers do not know the significance of moisture in natural gas. But did all of us know it? After all these may not be involved in gas operation / design, but in pipeline construction or general design. However this is not the main point I want to express.
The point is that even seniors should seek learning in order to face the ever changing situations. Experience may create background, knowledge, confidence; but you should first learn and understand the new situation before you act. Then every task will most probably need additional knowledge that has to be gained. Seniors should have known how to learn and do it in a more systematic and calmer way. Apart from assessing a critical decision, also a sort of gained knowledge.
What if this desire to learn stops? You may have been too old, at least as an engineer.
Personally I have met several "officers" not having adequate knowledge. Judgment on them depends on their behavior in front of missing knowledge; it strikes mainly in case of arrogance.
Note: In the above "you" means "one" or "everybody".

#14 kkala

kkala

    Gold Member

  • Banned
  • PipPipPipPipPip
  • 1,939 posts

Posted 14 March 2010 - 04:27 AM

If my previous post had caused negative feedback to marlindaniel post (newbie), I am sorry for it and do not agree to it personally. My intention (shown in my post) was merely to point out that senior engineers, or even experts, need to learn continuously.
I understand from previous posts that you do not know who sent the negative feedback. This should change in my opinion.

Edited by kkala, 14 March 2010 - 04:28 AM.





Similar Topics