Spare sulfur plant?

[ponderer]

We have a sulfur plant designed to process the sour gas from the hydrotreating unit.

It is a claus reactor with TGTU.

We find the reliability of the system is not so good, especially the TGTU.

Our refinery is located very close to the local resident.

Do we need a spare sulfur plant?

What is the situation in other refinery?

Is there any refinery installing spare sulfur plant?

 

[aleximor]

There are all sorts of varieties of Claus plant configuration, the choice of which depends on the composition of the acid gas being processed. There are also a number of different types of tail gas treatment process, some of which may influence the operation of the main plant because they feed the arrested sulphur values back into the sulphur plant. (Others don't). So I think before anyone can give you a sensible answer to this question you need to provide quite a bit more information about your plant and the conditions under which it is being asked to operate.

Since the Claus process depends for efficient operation on close control of the air (or oxygen) supply to keep it and the acid gas input at the correct stoichiometric ratio, any fluctuation in the flow rate and/or the H2S content of the acid gas will adversely affect the conversion efficiency. The TGTU may or may not be able to accommodate the increased residual sulphur content of the Claus tail gas, depending on the type of process it uses.

If the problems in your plant are mainly caused by acid gas flow and H2S content fluctuations, it probably means that the process control system needs to be uprated to make it more responsive. If, on the other hand, the installation generally does not achieve the required level of efficiency, even under steady operating conditions, it may indicate the presence of impurities - for example, ammonia (which will be present if you are feeding sour water stripper off-gas to the Claus unit) or droplets of alkanolamine solution accidentally aspirated in the acid gas removal system - in quantities not allowed for in the original design of the plant. Or it may simply be because you are now feeding more H2S through the plant than it was originally designed for.

It should be possible to avoid the need for a duplicate plant by modifying and upgrading the existing unit, or by eliminating upstream malfunctions which may be causing poor operation. But, of course, a single SRU will have to be shut down periodically for maintenance, and if the pollution control regulations in your area and the refinery's commercial targets do not allow for that, then you will have to provide a stand-by facility, although it seems an expensive option.

More than that I cannot really say, unless you can provide more precise information about the plant and what you are feeding into it.

There is a lot of published literature about the principles and operation of the Claus process in its various embodiments and there are numerous specialists who should be able to help you.

aleximor@yahoo.com

 

[npf]

Hello,

If you can provide the gas compostion, process conditions and acid gas concentration, I can be in the position to discuss different sour gas treatment techniques with Capex and Opex

Regards
sj