3 replies to this topic

[engg]

G'DAy GENTS

I am asked to cost an LPG TERMINAL, offloading from ship, storage in tanks (50000 tonnes) and transfer to cylinders and tankers.

I have no clue about the typical PFD of an LPG terminal. Will appreciate if some one can share or advise what are the main items there in offloading, storage and filling.

What type of storage tank is normally used in LPG storage?

Is there some costing software online that takes care with CPCI index and give eqipment costs

I will appreciate your positive inputs

[kkala]

A feasibility study for a power station was realized (1997) , including 2x220 m3 propane bullets. Now 50000 ton ~ 100000 m3 is a huge capacity (better to reconfirm?). Probable capacity upper limit is 220 m3 for LPG bullets, 8000 m3 for LPG spheres. Limit for refrigerated storage is not known.
You may use refrigerated storage for such a big storage capacity. Special ships can transfer refrigerated LPG, which shall be stored on land. I suppose there are trucks transferring refrigerated LPG (not existing here), but some trucks would be loaded with pressurized LPG, which will be also distributed through road transport. So you have to install also bullets or spheres for pressurized LPG. And pumps for the transfer. And truck loading stations. Facility to load LPG from refrigerated storage into smaller ships is also possible. So first priority may be to clarify all above through the person having good knowledge on the future project (if realized), making something like "block flow diagram".
After finding the necessary pieces of mechanical equipment (and their capacities), two parallel activities can follow, equipment data sheet (even in preliminary form) and layout. Local legislation and safety distances have to be taken into account for layout. See http://www.cheresour...ne-storage-tank. Connecting lines will be also drawn and sized. Filling line will connect ship and LPG storage during unloading.
It is assumed that Cost Estimating Dept will elaborate the capital cost from data sheet and layout. Civil Engineers may help on foundations, swers, buildings, roads, general civil works. An electrical Engineer will sketch and estimate cost of substations and cables. Instruments are usually roughly estimated by Cost Dept (e.g. as percentage of mechanical equipment).
Basic drawing in that estimate of 1997 was the layout. A simplified flow sheet was also made, but no PID. If a more precise estimate is needed (sort of FEED) then you have to make PIDs.
Hope above is a bit useful. Besides the info that you will receive now, it is a good idea to come again, when storages and capacities have been decided.

Note 1: Despite the info on max drum capacity = 220 m3, drums up to 330 m3 have been listed http://standby.com/propane/tanks.html.
Note 2: For several aspects of LPG storage, see http://www.eemua.org..._VESSELS.html

Edited by kkala, 07 January 2012 - 04:22 PM.

[kkala]

In continuation of the previous post, attached are two documents on LPG storage, probably useful.

Attached Files

•  Gastech 2005 N Chodorowska LPG paper rev3 approved(3).doc   192KB   172 downloads
•  Biswas.pdf   146.21KB   198 downloads

[kkala]

Wishing to update post No 2 with data found out, following is noted.
1. Mentioned maximum LPG bullet (drum) capacity of about 220 m3 is a practical approximative limit advised by a local fabricator of such vessels in 1997. Locally seen bullets comply with such maximum size.
Bullet of 240 m3 is recently reported in http://www.cheresources.com/invision/topic/15865-nitrogen-purging, while propane drums up to 90000 gal (341 m3) are reported by a fabricator - http://standby.com/propane/tanks.html.
2. If site is not accessible by ships, limitations on road transport should be taken into account, since prefabrication at vendors shop is cheaper than on field in the majority of cases. Limitations differ from place to place, see http://ec.europa.eu/transport/road_safety/vehicles/doc/abnormal_transport_guidelines_en.pdf - para 3.4 / Table 1 for EU target in the future. Allowable lengths seem excessive to me, advice would be appreciated. Also see http://www.businesslink.gov.uk/bdotg/action/detail?itemId=1078039380&type=RESOURCES.
3. In the recent years there is a tendency for bigger LPG bullets, as indicated in attached Sunrise-energy's request, page 42, Chapter 4.2.1 - pressurised storage, along with some explanation (document attached, time can make link disappear, rather useful data, http://sunrise-energy.co.za/images/Nersa%20Licence%20Application.pdf):
"Pressurised bullets have traditional been smaller than spheres but larger bullets over 3500 m3 have been constructed. There has been a move away from using pressurized storage spheres towards the increased use of mounded bullets mainly due to several accidents / explosions involving LPD spheres. A leak or rupture within a pressurized vessel can cause the formation of a large vapor cloud in a short space of time. Pressurised spheres are therefore more susceptible to what is referred to as a boiling liquid expanding vapour explosion (BLEVE). This does not occur with dedicated refrigeration systems. In Europe spheres have to be surrounded by concrete enclosures to prevent damage to and impact from external fires".
High capacity bullets are expected to have higher capital costs than spheres of same volume (sphere needs less steel than cylinder of same volume).
4. Concerning the ratio L/D (length/diameter) of a bullet, see http://www.eng-tips.com/viewthread.cfm?qid=48142. Some freedom seems to exist on horisontal pressure drums. Transport limitations (if any) can also play a role.
5. http://www.eng-tips.com/viewthread.cfm?qid=48142 indicates a preliminary layout (bullets and piping). Local regulations for safety distances have to be taken into account. Relevant info can be also found in http://www.cheresour...ne-storage-tank '> http://www.cheresour...ne-storage-tank .

Attached Files

•  LPG Nersa Licence Application.pdf   1.11MB   118 downloads

Edited by kkala, 19 August 2012 - 10:31 PM.