Hydroisomerization and isomerization process using reactive rectification column
View Patent ↗A reaction-rectification process is performed in an integrated reaction-rectification system which combines catalytic isomerization and hydroisomerization reactors and distillations zones in an integral column.
1. A method of hydroizomerization and isomerization of C4-C8 hydrocarbon fractions during simultaneous chemical reaction and distillation, the method comprising:
feeding a fraction of C4-C8 hydrocarbons into a distillation zone column disposed between an isomerization reaction zone reactor and a hydroisomerizarion reaction zone reactor, the hydrocarbons comprising from about 0% to about 30% mass of benzene;
supplying paraffin C4-C6 hydrocarbon from a feed of a reaction-rectification column to an isomerization reaction zone disposed higher than the feed;
supplying aromatic, naphthenic and paraffin hydrocarbons C7 and heavier from the feed of the reaction-rectification column to a hydroisomerization reaction zone disposed lower than the feed;
feeding paraffin hydrocarbons C5 and lighter from a distillation zone disposed between the izomerization reaction zone and the hydroisomerization reaction zone into a second isomerization zone disposed higher than a lateral selector of the reaction-rectification column;
obtaining C5 and heavier paraffin hydrocarbons by a stream out of the top of the reaction-rectification column, then condensing the stream and blowing off a hydrogen-containing gas;
obtaining C6 paraffin hydrocarbons of a normal and iso-structures from a stream out of the lateral selector of the reaction-rectification column; and
obtaining C6 and heavier naphtenic hydrocarbons and C7 and heavier hydrocarbons from a stream out of the bottom of the reaction-rectification column.
2. The method of claim 1 , comprising performing the isomerization reaction and the hydroisomerization reaction in three catalytic zones inside the reaction-rectification column.
3. The method of claim 1 , comprising performing the isomerization reaction in catalytic zones outside of the reaction-rectification column, wherein a stream from a catalytic zone outside of the reaction-rectification column returns to the column for separation and return of the non-reacted components.
4. The method of claim 1 , wherein at least one reaction zone is disposed inside the reaction-rectification column.
5. The method of claim 1 , further comprising hydroisomerizing of benzene in a lower reaction zone of the column.
6. The method of claim 1 , further comprising mixing of hydrogen and hydrocarbons in a reaction zone, wherein the hydrogen is separately supplied to each reaction zone in varying quantities.
7. The method of claim 1 , further comprising selectively isomerizing C6 hydrocarbons by contacting them with hydrogen on a catalyst in the isomerization reaction zone dispose between the feed of the reaction-rectification column and the lateral selector.
8. The method of claim 1 , further comprising selectively hydroisomerizing aromatic hydrocarbons by contacting them with hydrogen on a hydroisomerization catalyst in a hydroisomerization reaction zone disposed lower than the feed of the reaction-rectification column.
9. The method of claim 1 , further comprising selectively isomerizing C5 hydrocarbons by contacting them with hydrogen on an isomerization catalyst in an isomerization reaction zone disposed in an upper portion of the reaction-rectification column.
10. The method of claim 1 , wherein the stream out of the top of the reaction-rectification column comprises isopentane.
11. The method of claim 1 , wherein the stream out of the lateral selector of the reaction rectification column comprises isohexanes, including 2-,3-methylpentanes, 2,2-,2,3-dimethylbutanes.
12. The method of claim 1 , wherein the stream out of the bottom of the reaction-rectification column comprises cyclohexane and methylcyclopentane.
13. The method of claim 1 , wherein a pressure in the reaction-rectification column is in a range from about 10 atm to about 40 atm.
14. The method of claim 1 , wherein a temperature of the reaction-rectification column is in a range from about 80° C. to about 300° C.
15. The method of claim 1 , wherein hydrocarbons are mixed with hydrogen in a molar ratio of hydrogen to hydrocarbons is in a range from about 0.1 to 1 to about 3 to 1.
16. The method of claim 1 , further comprising using a group VIII metal deposited on a zeolite as a catalyst in a lower hydroisomerization zone.
17. The method of claim 1 , further comprising using a group VIII metal deposited on a group IV metal oxide as a catalyst, which is enhanced with sulfate and/or tungsten ions.