6 replies to this topic

[Process_Nerd]

hi everyone,

I need information about economical and optimized processes for the removal of aromatics from kerosene and diesel.Any help would be appreciated.

Regards and Thanks.

[Technical Bard]

The only process I have seen used for this is hydrocracking/treating to saturate the aromatics and possibly open the rings.

I have seen processes for extracting aromatics from naphtha via liquid extraction using solvents like Morphylane, Sulfolane and others. I haven't heard of this done for heavier fractions. Others may have other ideas.

[Chellani]

Not very sure about kero but for diesel - hydrotreating with lot of NiMo catalyst.

Some of the vendors have specific process for this e.g. KBR's PTU. Check-out below link

http://www.kbr.com/N...lean-diesel.pdf

[Process_Nerd]

Thanx for your hep Technical Bard and Chellani.

I know about the hydro treating/processing but these are very expensive processes. I am in search of alternative economical processes.

[sheiko]

Alternative to HDT is the Solvent Recovery Process. In this case, certain solvents will selectively dissolve aromatics but not paraffins, olefins, or naphthenes.
For kerosene, liquid SO2 or Furfural can be used as the solvent.

Edited by sheiko, 28 June 2012 - 06:05 PM.

[Himanshu Sharma]

Here you find a variety of Aromatic Solvent extraction processes

• The Udex extraction process became popular in the United States during the 1970s. It uses a class of chemicals known as glycols as solvents. Both diethylene glycol and tetraethylene glycol are used because they have a high affinity for aromatic compounds.
• The Sulfolane process was created by the Shell company in 1962 and is still used in many extraction units 40 years later. The solvent used in this process is called sulfolane, and it is a strong polar compound that is more efficient than the glycol systems used in the Udex process. It has a greater heat capacity and greater chemical stability. This process uses a piece of equipment known as a rotating disk contractor to help purify the kerosene.
• The Lurgi Arosolvan Process uses N-methyl-2-pyrrolidinone mixed with water or glycol which increases of selectivity of the solvent for contaminants. This process involves a multiple stage extracting towers up to 20 ft (6 m) in diameter and 116 ft (35 m) high.
• The dimethyl sulfoxide process involves two separate extraction steps that increase the selectivity of the solvent for the aromatic contaminants. This allows extraction of these contaminants at lower temperatures. In addition, chemicals used in this process are non-toxic and relatively inexpensive. It uses a specialized column, known as a Kuhni column, that is up to 10 ft (3 m) in diameter.
• The Union Carbide process uses the solvent tetraethylene glycol and adds a second extraction step. It is somewhat more cumbersome than other glycol processes.
• The Formex process uses N-formyl morpholine and a small percentage of water as the solvent and is flexible enough to extract aromatics from a variety of hydrocarbon materials.
• The Redox process (Recycle Extract Dual Extraction) is used for kerosene destined for use in diesel fuel. It improves the octane number of fuels by selectively removing aromatic contaminants. The low aromatic kerosene produced by these process is in high demand for aviation fuel and other military uses.

[Process_Nerd]

thanks a lot for your help sheiko and Himanshu Sharma for your detailed answer Sir.. i really appreciate it,