2 replies to this topic

[Tween]

Dear Friends,

I have some queries on Ethylene Pipeline transportation,Queries follows:

1. What should be the ideal suction and discharge Pressure/temperature for boosters in cross country pipelines for transportation of ethylene.And boosters may be compressors or pumps?

Ans : ?

2. Transportation of ethylene in supercritical phase is advisable or not?

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3.Whether compressors are available for supercritical ethylene?

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4.If available means please let me know the vendors(address) of those compressors/pumps?

ans?

5. Whether it is advisable to transport ethylene in liquid phase if sdo what should be the design criteria?

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6.How will we manage to avoid ethylene temperature to become equal to ground temperature and thus become supercritical?

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7. Whether any extra precautions for selection of material, wall thickness,internal coating ,corrosion allowance or any other safety factors for pipeline to transport ethylene at any phase?

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Advance thanks for your answers friends.And i will appreiciate if any experienced answer means.


Thank u

Sankar

[ankur2061]

Sankar,

Check this out. this might be of help:

http://www.lyondellb... cryo guide.pdf

http://help.intellis...papers/2140.pdf

Regards,
Ankur.

[kkala]

1. A local polyethylene project in 1980 considered only liquid ethylene transport through ships, so I was thinking that ethylene is not long-transfered through pipelines for economic & safety reasons. Second reference by Ankur (Polymer grade ethylene measurement by J. Gallagher) clearly cancels this view. A "feasibility" survey can select proper way of ethylene transportation, since liquid transfer by ships or road trucks is widely used.
2. Mentioned reference reports that:
- ethylene is a very dangerous fluid to transfer (risk of auto-decomposition or polymerization)
- nowadays polymer grade ethylene is pipe-transfered at "dense phase fluid" conditions
- (advisable) conditions of transfer are 900-2160 psig & 35-120 oF (ethylene critical properties are 49.5 oF & 727.4 psig)
3. Above range indeed corresponds to supercritical phase conditions, as attached EthylenePH.doc indicates. This is reasonable in order to eliminate the risk of two phase flow.
4. Long pipe-transfer of liquid ethylene has not been heard of; it is not certain that such pipeline exists. If fed from liquefied atmospheric storage, at least first kilometers of pipe has to be suitable for cryogenic liquid. Only dense phase fluid is considered in present post.
5. In case of buried pipeline, fluid operating temperature will approach soil temperature without apparent problem. Two phase will occur only below 9.7 oC (49.5 oF) and under a serious ΔP (bringing pressure below advisable operating range). This may be quite improbable in some countries.
When pressure approaches (advisable) low limit, centrifugal compressors can be locally installed. At least based on natural gas pipelines (pressure about 1160 psig), such compressors exist in the market (sometimes burning transfered fluid to operate).

Attached Files

•  EthylenePH.doc   36.5KB   230 downloads

Edited by kkala, 18 April 2010 - 08:17 AM.