You are currently viewing: Literature



Claus tail gas treating - low temperature SCOT process

Applications: The Shell Claus Off -gas Treating (SCOT) process has been developed to remove sulfur compounds from Claus tail gas to comply with stringent air emissions regulations. The conventional SCOT process is able to easily meet less than 250 ppmv total sulfur in the SCOT off gas, which corresponds to an overall sulfur recovery efficiency of 99.9% on intake. The Low Temperature (LT)-SCOT has the same recovery capabilities, but it reduces the total installed cost (TIC) by 15% compared to the conventional SCOT unit. LT-SCOT will save utility cost when compared to regular SCOT.

Description: The LT-SCOT process essentially consists of a reduction section and an ADIP absorption section with a special hydrogenation catalyst. The Claus tail gas feed to the LT-SCOT is heated to 220°C (compared to 280°C - 300°C for a regular SCOT). This lower temperature allows the use of a HP (40 barg, 600 psig) steam heater which eliminates risk of catalyst fouling by mis-operation of the burner which is used in the regular SCOT, therewith drastically improving the reliability of the LT-SCOT reduction section.

The heated gases then flow through a catalyst bed where sulfur compounds, including CS2 and COS, are reduced to H2S. The gas from the reactor is cooled by direct contact cooling with water to 40°C. Water vapor in the process gas is condensed, and the condensate is sent to a sour water stripper. The cooled gas is counter-currently washed with an alkanolamine solvent in an absorption column designed to absorb almost all H2S but relatively little CO2. The treated gas from the absorption column contains only traces of H2S and is oxidized in a standard Claus incinerator. Concentrated H2S is recovered from the rich solvent in a conventional stripper and is recycled to the Claus unit. The LT-SCOT units are designed for minimum pressure drop so that they can be easily added to existing Claus units. If insufficient pressure is available, a gas booster can be installed, preferably between the cooling tower and the absorption tower.

Other Literature

Plant control - advanced burner control (plus)

Applications: The design intent is to have accurate SRU tail gas quality control in order to optimize sulfur recovery. ABC provides that. It is clearly superior over conventional SRU control and has always been Jacobs Comprimo®’s control system of choice for the EUROCLAUS®/SUPERCLAUS® ...


Sulfur recovery - claus process

Applications: The Claus process has been developed to recover elemental sulfur from H2S containing gases originating from gas treating plants such as alkanolamine units or physical solvent plants. Modern Claus plants should be able to process H2S/NH3 containing gases as well, originating from Sour Water ...


Sulfur recovery - EUROCLAUS® process

Applications: The EUROCLAUS® process recovers elemental sulfur from H2S-containing gases originating from gas treating and sour water stripper plants. The EUROCLAUS® process is an improvement of the SUPERCLAUS® process. Yields from 99.3 up to 99.5% overall sulfur recovery, without any further ...


Gas treating (refinery / natural gas) ADIP process

Applications: The ADIP process is a regenerative process developed to selectively reduce H2S in gas to very low concentrations in the presence of CO2. The ADIP process uses an aqueous solution of diisopropanol amine (DIPA) or the aqueous solution of methyldiethanol amine (MDEA). MDEA is used for those ...


Liquid hydrocarbon treating (LPG/PP/BB) - ADIP process

Applications: Besides its use as a regenerative process for the reduction of H2S to very low levels in gases, the ADIP process is also used to selectively reduce H2S and COS to very low levels in liquid hydrocarbons, such as propane-propylene (PP), butanebutene (BB), LPG and NGLs. The process is based ...


Claus tail gas treating - low temperature SCOT process

Applications: The Shell Claus Off -gas Treating (SCOT) process has been developed to remove sulfur compounds from Claus tail gas to comply with stringent air emissions regulations. The conventional SCOT process is able to easily meet less than 250 ppmv total sulfur in the SCOT off gas, which corresponds ...


Claus tail gas treating - SCOT process

Applications: The Shell Claus Off -gas Treating (SCOT) process has been developed to remove sulfur compounds from Claus tail gas to comply with stringent air emissions regulations. The standard SCOT process is able to easily meet less than 250 ppmv total sulfur in the SCOT off gas, which corresponds ...


Sulfur recovery - subdewpoint - SUPERCLAUS® process

Applications: The SubDewPoint (SDP)-SUPERCLAUS® combi-process is a convenient solution for existing SDP units to increase the overall sulfur recovery to at least 99.5% without any further tail gas clean up.

Description: The SDP-SUPERCLAUS® process adds the selective oxidation stage ...


Sulfur handling - Shell sulfur degassing process

Applications: The Shell Sulfur Degassing Process has been developed to remove H2S and H2Sx from liquid sulfur eliminating potential toxic and explosion hazards associated with handling, transport and storage of liquid sulfur. Elemental sulfur produced by the Claus process contains both physically dissolved ...


Sour water stripper

Applications: Many process units throughout a refinery generate significant quantities of sour water. Sour water collected within a refinery contains both H2S and NH3. These components are present as ammonium hydrosulfide (NH4HS) within the sour water. NH4HS is the salt of a weak base and a weak acid. ...