Innovative temperature measurement in Claus process

Innovative solutions from Endress+Hauser enable accurate temperature measurement in the Claus process, ensuring reliable sulfur recovery, operational efficiency and environmental responsibility in refineries, writes Michele Pietroni, Industry Manager - Oil & Gas and Chemical, Endress+Hauser

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THE Claus process is the industry standard for recovering elemental sulfur from hydrogen sulfide gas, crucial for refineries processing sour crude oil.

Conducted in a Claus furnace or Sulfur Recovery Unit (SRU), this process efficiently removes pollutants and prevents the emission of harmful gases.

The Claus process involves two steps:

Burning a portion of H2S to form SO, in the reaction furnace.

The reaction of H2S and SO, in a 2:1 ratio forms elemental sulfur.

These reactions are turbulent and aggressive, with the acid gas stream being partially oxidised with a low amount of O2, releasing significant exothermic energy.

Temperature control is challenging as the feedstock temperature often exceeds 1600 deg C (2912 deg F), making thermocouple temperature measurement technology essential for monitoring this process.

The inner temperature of the reactors during the sulfur reaction must be continuously and accurately monitored to prevent plant shutdowns and optimise the energy consumption:

It must be high enough to sustain the reactions.

It must not be too hot to avoid damaging the refractory lining, which protects the structure against quenches and destruction caused by severe thermal conditions and aggressive process media.

It must be steady and homogeneous to maintain the plant's efficiency.

THE CHALLENGE

This application is highly corrosive and combines numerous high temperature phenomena, making it exceptionally challenging and requiring a highly experienced and knowledgeable supplier for design and installation.

The long-term accurate temperature measurement combined with high mechanical and thermal strength of the instrument is crucial to ensure plant integrity and optimised process.