Sulfur Recovery & Oxygen Enrichment for Refining
Recovery done right
With the growing need to process sour crudes, petroleum refiners and natural gas processors face the two-fold challenge of removing increased sulfur content to meet strict environmental regulations and doing it cost-effectively. The solution? Praxair’s enhanced combustion technology. It relies on oxygen enrichment to increase the capacity of Sulfur Recovery Unit (SRU) Claus plant equipment, eliminating the need for new, costly sulfur removal units.
Claus plants normally provide up to 98% of the sulfur recovery capability in a refinery or natural gas processing operation. To recover the sulfur from sour crudes, the Claus plant reaction furnace typically combusts the air and hydrogen sulfide (H2S) that result from sulfur processing. H2S is then partially oxidized and catalytically converted to produce high-purity molten sulfur.
In a Praxair oxygen enrichment system, oxygen is supplied to the Claus plant through a sparger into the air line to the reaction furnace. The oxygen can also be injected directly into the furnace through a lance or burner, or feed air can be completely replaced by oxygen through a burner in the furnace. In some cases, complete feed air replacement can double Claus plant capacity. The resulting higher oxygen concentration increases the operating temperature of the furnace, which leads to steadier operation and greater ammonia destruction. As a result, the Claus reaction furnace maximizes its ability to combust the oxygen and air mixture and the H2S produced during processing, working with system converters and condensers to recover the sulfur. Increased oxygen also means lower nitrogen volumes, which reduces gas volume in tail gas treatment.
Our sulfur recovery system also increases flexibility by providing oxygen on demand, improving conversion, offering low-cost installation and saving energy. We offer extensive safety training for proper operation, and use a computer program to help determine the effect of oxygen enrichment on your SRU. We work closely with you on piping and sparger design, as well as installation and start-up.