Production of paraffin fuels using renewable materials by a continuous hydrotreatment comprising a pre-treatment step

Patent metadata

Field	Value
Publication number	US-9321970-B2
Application number	US-201213671708-A
Country	US
Kind code	B2
Filing date	Nov 8, 2012
Priority date	Nov 8, 2011
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A process for hydrotreatment of a feed from renewable sources such as vegetable oils for the production of paraffinic hydrocarbons comprising pre-treatment by crystallisation and/or precipitation allowing the elimination of insoluble inorganic impurities under hydrotreatment conditions. The flow of the total feed is divided up into a certain number of different, part flows equal to the number of catalytic zones in the reactor, and the different part flows are injected in the successive catalytic zones in increasing proportions to produce an effluent containing paraffinic hydrocarbons.

First claim

The invention claimed is:

1. A process for the hydrotreatment of a feed originating from renewable sources in order to produce paraffinic hydrocarbons comprising:
a) mixing a total feed flow F 0 with a flow RPP comprising at least a portion of a liquid fraction R containing paraffinic hydrocarbons from the separation d), said mixture being heated to a temperature of between 130 and 320° C.;
b) introducing said mixture into a pre-treatment zone in which flow of said mixture takes place via a porous medium comprising a fixed particle bed , said fixed bed having a void fraction of between 0.25 and 0.8;
c) hydrotreating effluent from the pretreatment zone in the presence of hydrogen in excess of theoretical hydrogen consumption and under hydrotreatment conditions in a fixed bed reactor having a plurality of catalytic zones disposed in series and comprising a hydrotreatment catalyst, by dividing effluent resulting from the pre-treatment zone (F+εRPP), ε being between 0 and 1, into at least a certain number of different part flows (F 1 +ε 1 RPP) to (Fn+ε n RPP) equal to the number of catalytic zones n in a fixed bed reactor, injecting a first part flow (F 1 +ε 1 RPP) into a first catalytic zone, injecting a second part flow (F 2 +ε 2 RPP) into the second catalytic zone and so on, if n greater than 2, the sum of the ε i being equal to ε; the various part flows are injected into successive catalytic zones in increasing proportions such that F 1 /F is less than or equal to F 2 /F, which itself is less than or equal to F 3 /F and so on until F(n-1)/F is less than or equal to Fn/F, in order to produce an effluent containing paraffinic hydrocarbons;
d) subjecting said effluent containing paraffinic hydrocarbons to at least one separation allowing separation of at least one gaseous fraction and at least one liquid fraction containing the paraffinic hydrocarbons;
e) dividing at least a portion R of said liquid fraction containing the paraffinic hydrocarbons from b) mixing RPP into at least a flow RLC and into said recycle flow RPP upstream of a) and with the total feed flow F 0 , dividing said flow RLC into at least a certain number of different part flows R 1 -Rn less than or equal to the number of catalytic zones n in the reactor, said flows R 1 -Rn being recycled upstream of the catalytic zones 1 -n, the flow of paraffinic hydrocarbons (R 1 +ε 1 RPP) sent to the first catalytic zone and the part flow F 1 of the feed introduced into the first catalytic zone having a weight ratio greater than or equal to 10.

2. The process according to claim 1 in which said feed originating from renewable sources is oils or fats of vegetable or animal origin or mixtures thereof, containing triglycerides and/or free fatty acids and/or esters.

3. The process according to claim 1 wherein the flow RPP introduced in a) in relation to the flow of total fresh feed F 0 has a mass flow ratio RPP/F 0 between 0.1 and 5.

4. The process according to claim 3 in which the mass flow ratio RPP/F 0 is between 0.5 and 3.

5. The process according to claim 1 in which catalyst particles in the fixed bed are materials with a specific surface of between 0.5 and 320m 2 /g.

6. The process according to claim 5 in which said particles are porous refractory oxides, oxide ceramics, non-oxide ceramics, composite ceramics, silicon carbides, activated carbons, calcium aluminates, metals or graphite.

7. The process according to claim 6 in which said particles are porous refractory oxides that are alumina, silica, activated alumina, silica-aluminas, metal oxides or non-metal oxides.

8. The process according to claim 1 in which the effluent from the pre-treatment zone (F+εRPP) is introduced into a separation zone in order to separate a paraffin-rich effluent (1-ε) RPP.

9. The process according to claim 1 having a in which the total recycle rate (RT)less than 1.0.

10. The process according to claim 1 wherein the flow RPP is introduced into a) in relation to the total recycle flow R at a mass flow RPP/R ratio between 0.1 and 0.9.

11. The process according to claim 1 in which said feed originating from renewable sources is treated in a mixture with oil cuts that are gas oils, kerosenes or gasolines from oil refining processes.

12. The process according to claim 1 in which at least a portion of the liquid fraction containing the paraffinic hydrocarbons from separation d) not recycled is hydroisomerized in the presence of a hydroisomerization catalyst.

Assignees

• IFP Energies Nouvelles

Inventors

• Dupassieux Nathalie
• Chapus Thierry

Classifications

• C10G2300/4081

  Recycling aspects · CPC title

• C10G45/00

  Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds · CPC title

• C10G3/50

  in the presence of hydrogen, hydrogen donors or hydrogen generating compounds · CPC title

• C10G45/58

  to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins (C10G32/00 takes precedence; improving or increasing the octane number or aromatic content of naphtha C10G35/00) · CPC title

• C10G3/42 Primary

  Catalytic treatment · CPC title