Method for the valorization of heavy charges by bubbling-bed deasphalting and hydrocracking

Abstract

The invention relates to a method for treating a hydrocarbons charge comprising the following stages, in which: a) the charge is brought into contact with a solvent in order to obtain a deasphalted effluent having a content of asphaltenes below 3000 ppm by weight, b) the deasphalted effluent is cracked in the presence of hydrogen and a hydrocracking catalyst, in a bubbling-bed reactor, so as to convert at least 50 wt. % of the fraction of the deasphalted effluent boiling above 500° C. to compounds having a boiling point below 500° C., c) the effluent from stage b) is fractionated to recover gasolines, kerosene, gas oils and a first residue, and d) at least a portion of this first residue is cracked so as to obtain an effluent comprising gasolines, kerosene, gas oils and a second residue.

1 . Method of treatment of a hydrocarbon charge of which at least 95 wt. % consists of compounds having a boiling point of at least 340° C., characterized in that it comprises the following stages, in which: 
 a) the charge is brought into contact with a solvent in order to obtain a deasphalted effluent having a content of asphaltenes (insoluble in n-heptane according to standard NF-T-60-115) below 3000 ppm by weight,    b) the deasphalted effluent is cracked in the presence of hydrogen and a hydrocracking catalyst, in a bubbling-bed reactor, so as to convert at least 50 wt. % of the fraction of the deasphalted effluent boiling above 500° C. to compounds having a boiling point below 500° C.,    c) the effluent from stage b) is fractionated to recover gasolines, kerosene, gas oils and a first residue, and    d) at least a portion of this first residue is cracked catalytically so as to obtain an effluent comprising gasolines, kerosene, gas oils and a second residue.    
     
     
         2 . Method according to  claim 1 , characterized in that the hydrocarbon charge has a final boiling point above 600° C.  
     
     
         3 . Method according to any one of claims  1  or  2 , characterized in that the hydrocarbons charge consists essentially of atmospheric residues and vacuum residues from heavy crudes.  
     
     
         4 . Method according to any one of  claims 1  to  3 , characterized in that the content of asphaltenes in the deasphalted effluent is below 1000 ppm by weight.  
     
     
         5 . Method according to any one of  claims 1  to  3 , characterized in that the content of asphaltenes in the deasphalted effluent is below 500 ppm by weight.  
     
     
         6 . Method according to any one of  claims 1  to  5 , characterized in that the solvent used in stage a) contains at least 50 wt. % of hydrocarbon compounds having between 3 and 7 carbon atoms.  
     
     
         7 . Method according to any one of  claims 1  to  6 , characterized in that the deasphalting stage is carried out in an extraction column.  
     
     
         8 . Method according to any one of  claims 1  to  7 , characterized in that the catalyst of stage b) is a hydroconversion catalyst comprising an amorphous support and at least one metal or metal compound having a hydrogenating function.  
     
     
         9 . Method according to any one of  claims 1  to  8 , characterized in that, following stage c), a-separation of the solid catalyst particles is carried out.  
     
     
         10 . Method according to any one of  claims 1  to  9 , in which stage c) comprises an atmospheric distillation followed by a vacuum distillation.  
     
     
         11 . Method according to  claim 10 , in which the vacuum distillate is sent to a hydrocracking stage.