Revamp of the SRU Sour Gas Treatment Station at Aderklaa

The existing Sour Gas Treatment Plant at Aderklaa Gasstation, located near Vienna in !\ustria, was extended in 1972 with the addition of a -.5() t/d Claus sulfur recovery unit to process the acid gases generated from the upstream amine gas sweetening unit. Due to the high CO2:H2S ratio in the raw feed gas, the acid gas processed in the sulfur recovery unit contains 86% (vol) CO2 and 13% (vol) H2S. The technology selected in 1972 to process this lean acid gas was based on a novel liquid sulfur recycle and injection process to achieve combustion of the lean acid gas. This was followed by two Claus catalytic stages to yield a nominal 92% overall sulfur recovery efficiency. Given the age of the existing sulfur recovery unit and the need to raise overall sulfur recovery efficiency to meet both current and anticipated future standards, a new high-efficiency sulfur recovery unit is now being designed for start-up in the Fall of 1996. The new sulfur recovery unit is based on front-end acid gas enrichment followed by conventional modified-Claus and Claus tail gas hydrogenation technologies. The front-end acid gas enrichment and tail gas amine absorption sections share a common selective amine system. A highly-selective MDEAbased amine solvent, Union Carbide HS-101 CE, will he utilized with the Aderklaa Plant being the world's first commercial demonstration unit of this new solvent formulation. This new amine formulation results in very high CO2 slip along with low H2S residual levels and is highly- efficient in view of energy consumption. An overall sulfur recovery efficiency of 99.8% in the new sulfur recovery unit will he obtained.