Process for the distillation of decanted oils for the production of petroleum pitches

Abstract

This invention describes a process for the distillation of decanted oil to improve the efficiency of the production of pitches having excellent physical and chemical properties through the development of a distillation process which basically comprises the introduction of a stage of condensation of light volatile compounds derived from distillation of the decanted oil, causing these light compounds to be recycled to the hot zone of the still and react with the raw material acting as a solvent phase which has a lower viscosity than the reaction system, within a particular temperature range and for a particular time.

1 . Process for the distillation of decanted oils for the production of petroleum pitches, characterised in that it comprises the introduction of a stage of condensation of the light and volatile compounds deriving from the distillation of decanted oil which makes these compounds suitable for recycling to the hot zone of a modified still ( 1 ), reaching a maximum temperature within the range between 430° C. and 435° C. for a total distillation time in the range between 7 and 10 hours. 
   
   
       2 . Distillation process according to  claim 1 , characterised in that the said still ( 1 ) is equipped with a reflux system comprising a coil ( 2 ), preferably of copper, surrounding the distillation column ( 3 ) and in that a cooling fluid, which may be selected from water, compressed air and any other fluid capable of meeting the heat-exchange capability requirements, flows within the coil ( 2 ). 
   
   
       3 . Process of distillation according to  claim 1 , characterised in that the light compounds recycled:
 react with the raw material;   act as a solvent phase of lower viscosity than the reaction system;   inhibit the rapid condensation of components of greater molecular weight;   assist the breaking of chains in components of greater molecular weight which delay the formation of compounds which are insoluble in quinoline; and   do away with the need to introduce external solvent compounds into the system.   
   
   
       4 . Distillation process according to  claim 1 , characterised in that the stage of condensing the light compounds is performed by attaching a coil ( 2 ) containing a cooling fluid which circulates within it around a distillation column ( 3 ) of a still ( 1 ).