Natural gas from reservoirs now being explored is of increasingly poorer quality. By contrast, demands on gas quality are rising. This is particularly true when the gas is used as feedstock for liquefied natural gas (LNG) production. Polishing the gas from trace contaminants such as COS, mercury and specifically, mercaptans is becoming evermore important; aside from classic hydrogen sulfide (H2S), carbon dioxide (CO2) and water removal task.
The OmniSulf concept encompasses the following proprietary key processes: Acidic components are eliminated using BASF’s aMDEA process (AGR). The cleaned gas is routed to a DMR unit that removes moisture and mercaptans with Zeochem’s special 13X zeolite technology. Where necessary, the sweet gas can be routed further to a mercury removal unit operated with impregnated activated carbon. The DMR is thermally regenerated at regular intervals. Mercaptans are recovered from the regeneration gas using Purisol technology. The gas can then be fed to the fuel gas system.
All gas streams containing sulfur are routed to a sulfur recovery unit (SRU). Elemental sulfur is produced in the Claus process (equipped with Lurgi Multi-Purpose Burner). A Lurgi tail gas treating and acid gas enrichment (LTGT) system is combined with the Claus unit to boost sulfur recovery. The sulfur product is then treated further applying an AQUISULF degassing process (AQU) which removes H2S concentrations below 10 ppm. Vent gases are incinerated (INC) before being released to the atmosphere.
As the sulfur market is saturated, acid gas re-injection is increasingly selected as a viable alternative. The OmniSulf concept can be tailored to gas re-injection.
Licensor: Lurgi Oel-Gas-Chemie GmbH