Overcoming Operational Problems in a Claus Tail Gas Unit

Presented By

Claus Brostrom Nielsen - Haldor Topsoe A/S

Conference: Budapest 2017

In today’s oil and gas industry, maximizing sulfur recovery from off-gases is extremely important. Regulations get tighter, forcing operators to constantly optimize the efficiency of their sulfur management units. A Claus tail gas treating plant enables you to meet the most stringent emission targets for final sulfur removal from the off-gases.

The feed for the tail gas unit consists mainly of nitrogen and water; however, it also contains compounds, such as SX, SO2, COS, CS2, CO H2S, and H2, which need further treatment. In a Claus tail gas hydrogenation unit, these compounds are hydrotreated and hydrolyzed to H2S and CO2. The H2S is recycled for conversion in the Claus unit, allowing for overall maximum sulfur recovery of up to 99.9%.

However, during operation of a Claus tail gas plant, different problems may arise. In fact, end- of-run for Claus tail gas catalysts is typically caused by an operational upset rather than the gradual loss of catalyst activity.

In this presentation, the potential problems arising during operation, such as pressure drop issues, sooth formation, etc., will be discussed. Knowing the chemistry that takes place in the plant has led to the development of Topsoe’s specialty grading products. As will be shown in this presentation, these have proven an excellent solution to overcoming issues related to pressure drops.

Some units are struggling with capacity constraints and high start-of-run pressure drop. This presentation will also touch upon how the catalyst design can play a crucial role in the plant operation potential in dealing with these types of constraints.

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