Siirtec Nigi is an engineering and contracting company operating internationally in the field of sulfur recovery, acid gas removal, oil and gas processing and environmental cleanup. Focusing on sulfur technologies, the processes most commonly provided by Siirtec Nigi are described below:
Acid gas removal and enrichment
Acid gases (H2S, CO2) are removed from gases with a variety of alkanolamines (including special amines) to meet gas specifications and produce streams with high enough H2S concentration to be treated in the Claus unit.
Sour water stripping
Impurities (such as NH3, H2S) are removed from process water up to the most stringent specifications. If required, selective stripping of NH3 and H2S can be achieved.
Sulfur recovery unit
The company provides a full range of, more specifically:
- Modified Claus for both rich and lean acid gases, with and without fuel gas support.
- Advanced ammonia Claus for treatment of sour gases beyond the current chartered NH3/H2S.
- Oxygen enrichment: mostly applied for increasing capacity in revamps of existing SRUs in refineries.
Siirtec Nigi also supplies SRU critical equipment as loose items, including equipment for jumbo SRU plants.
Tail gas clean up
Over 99.9% sulfur recovery can be achieved by complementing the Claus unit with Siirtec Nigi’s latest advanced HCRTM tail gas cleanup unit. The unit is based on a new generation of catalysts for the reduction of sulfur species.
The HCRTM makes use of the hydrogen contained in the tail gas as the reducing agent, avoiding the importation of hydrogen or the installation of a reducing gas generator.
Tail gas thermal oxidation
Traces of CO, H2 and other pollutants contained in Claus/HCRTM units are converted into less pollutant species by means of thermal oxidation.
H2S and polysulfides are removed from liquid sulfur in order to match the most stringent specification, through a combination of spray action and air stripping. Recent improvements to the sulfur degassing box design lead to better performance and more reliable operation.
Figure 1. Siirtec Nigi's degassing box.
Read the article online at: https://www.hydrocarbonengineering.com/refining/11052016/siirtec-nigi-introduces-advanced-sulfur-technologies-3266/