5 replies to this topic

[user23145]

Hi,

I'm currently looking at two different tail gas treating technologies for the Claus process (in a natural gas treating plant), to achieve a sulphur recovery >=99.9%. My research has indicated that either the Lurgi Tail Gas Treatment (LTGT) or Shell Claus Off-Gas Treating (SCOT) technologies will work for this. However, both PFDs and descriptions of the processes appear to be very similar in terms of physical processes, units, arrangement, and operating conditions. There's so much similarity that I'm thinking they're pretty much the same thing.

Can someone please explain to me the key differences between the two processes? Did Lurgi just tag their branding onto the SCOT process and try to re-market it?

All responses/comments welcome!

[kkala]

Having superficially dealt with Sulphur Recovery Units for a while, I got aware that "SCOT" process is supplied by a lot of companies, even though each of them could add some detail of its own design. Lurgi can offer a Scot process for 99.9% sulphur recovery, as indicated at http://www.lurgi.com...Sulfur_Mmgt.pdf, where an elementary diagram of LTGT can be seen (probably a more advanced Sulfreen process for the tail gas). Most of Sulphur Recoveru Unit suppliers can offer alternative technologies too, like the one oxidising tail gas sulphur to SO3.
As it seems, Lurgi has offered a SCOT process. It may have a few differences from a SCOT process offered by another; but both will be same in main points (Claus furnace, catalytic conversion, incineration). I do not know specific characteristics of Lurgi process, though.

Edited by kkala, 07 August 2011 - 04:21 PM.

[sheiko]

My former company is a licensor. See the attached document.

Attached Files

•  SulphurRecovery.pdf   1.62MB   193 downloads

[user23145]

Fantastic stuff sheiko, Thank you so much! Definitely going to help my project a long a lot, especially with the utility requirements!

Could you tell me what happens to the recovered liquid sulfur after it goes to the pit? Does it solidify there or is it kept as a liquid and processed into bricks or something?

[kkala]

In the local Sulfur Recovery Units, liquid sulfur in the pits receives a flow rate of compressed air to "expel" H2S (degassing). Then it is transferred through vertical pumps for granulation and cooling, collected in the form of solid sulfur powder. If there were e.g. a sulfuric acid plant, liquid sulfur would be transferred there as is.

[sulphurwala]

The molten sulphur can be sent to a pelletiser where it is made into small pellets as pointed out by kkala. At the SRU where I'm working, we used to make pellets. But currently we pump out the molten sulphur from the pit and load it into trucks which transports it to fertilizer and chemical factories. It may be noted that these trucks are provided with steam coils.