Single stage process combining non-noble and noble metal catalyst loading

Abstract

The present disclosure relates to a process for reducing the amount of aromatics in a raw feed stream comprising hydrocarbons, more than 200 ppmw sulfur or 1000 ppmw sulfur as either hydrocarbon heteroatoms or as other sulfide compounds as well as at least 10% by weight di-aromatics or poly-aromatics and at least 30% by weight aromatics in total said process comprising the steps of hydrotreating said raw feed stream in the presence of hydrogen and a material catalytically active in hydrotreatment with a severity resulting in a conversion of sulfur hydro-carbon heteroatoms to hydrogen sulfide of at least 50% providing a pre-treated stream, separating said pre-treated stream at least into a second stage feed stream and a stream rich in hydrogen sulfide, directing said second stage feed stream to contact a material catalytically active in hydrocracking and ring opening, and to contact a material catalytically active in saturation of aromatics, wherein the material catalytically active in hydrocracking and ring opening is positioned upstream, downstream or mixed with said material catalytically active in saturation of aromatics, and withdrawing a dearomatized stream, wherein said the amount of aromatics of said dearomatized stream is less than 50%, 70%, 90% or 95% of the amount of aromatics in said raw feed stream, with the associated benefit of said process of providing efficient dearomatization with low yield loss.

1 . A process for reduced the amount of aromatics in a raw feed stream comprising hydrocarbons, more than 200 ppmw sulfur or 1000 ppmw sulfur as either hydrocarbon heteroatoms or as other sulfide compounds as well as at least 10% by weight di-aromatics or poly-aromatics and at least 30% by weight aromatics in total said process comprising the steps of
 i. hydrotreating said raw feed stream in the presence of hydrogen and a material catalytically active in hydrotreatment with a severity resulting in a conversion of sulfur hydrocarbon heteroatoms to hydrogen sulfide of at least 50% providing a pre-treated stream,   ii. separating said pre-treated stream at least into a second stage feed stream and a stream rich in hydrogen sulfide,   iii. directing said second stage feed stream to contact a material catalytically active in hydrocracking and ring opening, and to contact a material catalytically active in saturation of aromatics, wherein the material catalytically active in hydrocracking and ring opening is positioned upstream, downstream or mixed with said material catalytically active in saturation of aromatics, and withdrawing a dearomatized stream,
 wherein said the amount of aromatics of said dearomatized stream is less than 50%, 70%, 90% or 95% of the amount of aromatics in said raw feed stream. 
   
     
     
         2 . The process according to  claim 1  wherein said material catalytically active in hydrocracking and ring opening first material comprises a base metal and is provided in presulfided form and said and said material catalytically active in saturation of aromatics comprises a noble metal and is provided in prereduced form. 
     
     
         3 . The process according to  claim 1 , wherein the material catalytically active in hydrocracking and ring opening comprises one or more base metals preferably taken from the group comprising group 6 elements and Ni or Mo. 
     
     
         4 . The process according to  claim 1 , wherein the material catalytically active in hydrocracking and ring opening comprises an acidic support, such as a zeolite or silica-alumina. 
     
     
         5 . The process according to  claim 1 , wherein the material catalytically active in saturation of aromatics comprises one or more one or more noble metals preferably taken from the group comprising Ru, Rh, Pd, Os, Ir and Pt, and more preferably taken from the group comprising Pt and Pd. 
     
     
         6 . The process according to  claim 1 , wherein the material catalytically active in saturation of aromatics comprises an acidic support, such as a zeolite or silica-alumina 
     
     
         7 . The process according to  claim 1 , wherein the maximum temperature of the first catalytically active material is 250° C.-350° C. 
     
     
         8 . The process according to  claim 1 , wherein the maximum temperature of the second catalytically active material is 250° C.-350° C. 
     
     
         9 . The process according to  claim 1 , wherein the difference between the outlet temperature of the first catalytically active material and inlet temperature of the second catalytically active material is less than 40° C. 
     
     
         10 . A process plant for conversion of a stream of heavy aromatic hydrocarbon mixture in to a hydrocarbon mixture rich in middle distillate comprising a first stage reactor unit containing a hydrotreatment catalyst, said first stage reactor unit having an inlet and an outlet, a means for gas/liquid separation having an inlet and a gas outlet and a liquid outlet, and a second stage reactor unit comprising one or several reactors and containing at least a presulfided material catalytically active in hydrocracking and a prereduced material catalytically active in hydrodearomatization, said second stage reactor unit having one or more inlets and a single outlet,
 in which the stream of heavy aromatic hydrocarbon mixture is in fluid communication with an inlet of the first stage reactor,   the outlet of the first stage reactor unit is in fluid communication with the inlet of the means for gas/liquid separation,   the outlet for liquid of the first means for gas/liquid separation is in fluid communication with the inlet of the second reactor unit,   a stream of hydrogen is optionally in fluid communication with a further inlet of the second reactor,   the outlet of the second reactor unit provides the hydrocarbon mixture rich in middle distillate.