LICENSED TECHNOLOGY | SUPERCLAUS

> SUPERCLAUS^® Process

Goar, Allison & Associates has provided the SUPERCLAUS process to several facilities in North America. We apply two principles when incorporating the SUPERCLAUS process into a Goar, Allison & Associates design package.

1. The Claus plant is operated with excess H₂S in order to suppress the SO₂ content in the Claus tail gas. Alternatively, all sulfur components in the tail gas are converted to H₂S by hydrogenation; and
2. The remaining H₂S in the Claus tail gas undergoes selective oxidation in the presence of a special catalyst, which efficiently converts the remaining H₂S in the presence of water vapor and excess oxygen to elemental sulfur only.

The SUPERCLAUS catalyst possesses some unique properties:

• Complete oxidation of H₂S to sulfur with no sensitivity to water vapor
• Further oxidation of SO₂ is negligible, even in the presence of excess oxygen
• Components such as H₂, CO and other combustibles are not affected
• The catalyst does not establish the Claus equilibrium reaction

The SUPERCLAUS process consists of a thermal stage followed by three or four catalytic reaction stages. The first two or three reactors are filled with Claus catalyst while the last reactor is filled with the selective oxidation catalyst. In the thermal stage, the acid gas is burnt with a sub-stoichiometric amount of controlled combustion air so that the tail gas leaving the second reactor contains 0.8% to 1.5% by volume of H₂S.

The catalyst in the selective oxidation reactor oxidizes the H₂S to sulfur at very high efficiency. Depending on the composition of the Claus feed gas, a total sulfur recovery in excess of 99% can be achieved since the catalyst neither oxidizes H₂S to SO₂ and H₂O, nor reverses the reaction of sulfur and water to H₂S and SO₂.

Typical results include sulfur recovery of 99% to 99.5% for rich H₂S streams; sulfur purity of 99.9%; and a reduction in SO₂ emissions ranging from 50% to 90% of baseline SO₂ emissions.

SUPERCLAUS^® is a registered trademark of Jacobs Nederland B.V.

© 2009 by Goar, Allison & Associates, Inc.