Process for improving cold flow properties and increasing yield of middle distillate feedstock through liquid full hydrotreating and dewaxing
Novel liquid-full process for improving cold flow properties and increasing yield of middle distillate fuel feedstock by hydrotreating and dewaxing the feedstock in liquid-full reactors.
1. A liquid-full process for hydroprocessing a middle distillate fuel feedstock, comprising:
(a) contacting the feedstock with (i) a diluent and (ii) hydrogen, to produce a feedstock/diluent/hydrogen mixture, wherein the hydrogen is dissolved in the mixture to provide a liquid feed;
(b) contacting the feedstock/diluent/hydrogen mixture with a hydrotreating catalyst in a first reaction zone, to produce a first product effluent; and
(c) contacting the first product effluent with a dewaxing catalyst in a second reaction zone, to produce a second product effluent comprising naphtha and a middle distillate product;
wherein the middle distillate product has at least one improved cold flow property compared to the middle distillate fuel feedstock and has the yield of at least 85 wt %, and wherein the middle distillate fuel feedstock has a nitrogen content of at least 200 wppm, and the middle distillate product has an iso- to n-paraffin ratio increase of at least 1.5 compared to the middle distillate fuel feedstock.
2. A liquid-full process for hydroprocessing a middle distillate fuel feedstock, comprising:
(a) contacting the feedstock with (i) a diluent and (ii) hydrogen, to produce a feedstock/diluent/hydrogen mixture, wherein the hydrogen is dissolved in the mixture to provide a liquid feed;
(b) contacting the feedstock/diluent/hydrogen mixture with a hydrotreating catalyst in a first reaction zone, to produce a first product effluent; and
(c) contacting the first product effluent with a dewaxing catalyst in a second reaction zone, to produce a second product effluent comprising naphtha and a middle distillate product;
wherein the middle distillate product has at least one improved cold flow property compared to the middle distillate fuel feedstock and has the yield of at least 85 wt %, and wherein the middle distillate fuel feedstock has a nitrogen content of at least 90 wppm, and the middle distillate product has an iso- to n-paraffin ratio increase of at least 18 compared to the middle distillate fuel feedstock.
3. The process of claim 1 , wherein the first product effluent includes H 2 S and NH 3 dissolved therein and is fed directly into the second reaction zone without separating ammonia, hydrogen sulfide and remaining hydrogen from the first product effluent.
4. The process of claim 1 , wherein the dewaxing catalyst comprises a zeolite.
5. The process of claim 2 , wherein the first product effluent includes H 2 S and NH 3 dissolved therein and is fed directly into the second reaction zone without separating ammonia, hydrogen sulfide and remaining hydrogen from the first product effluent.
6. The process of claim 2 , wherein the dewaxing catalyst comprises a zeolite.
7. The process of claim 1 , wherein the dewaxing catalyst is selected from the group consisting of catalysts comprising a non-precious metal and an oxide support, catalysts comprising a crystalline, microporous oxide structure without metal loaded on it, and catalysts comprising a molecular sieve without metal loaded on it.
8. The process of claim 1 , wherein the dewaxing catalyst comprises a crystalline, microporous oxide structure without metal loaded on it.
9. The process of claim 1 , wherein the dewaxing catalyst comprises a zeolite without metal loaded on it.
10. The process of claim 9 , wherein the zeolite has a 8-member ring structure, a 10-member ring structure, or a 12-member ring structure.
11. The process of claim 1 further comprising contacting the second product effluent with a hydrotreating catalyst in a third reaction zone to produce a third product effluent.
12. The process of claim 1 , wherein both the middle distillate fuel feedstock and the middle distillate product are diesels.
13. The process of claim 2 , wherein the dewaxing catalyst is selected from the group consisting of catalysts comprising a non-precious metal and an oxide support, catalysts comprising a crystalline, microporous oxide structure without metal loaded on it, and catalysts comprising a molecular sieve without metal loaded on it.
14. The process of claim 2 , wherein the dewaxing catalyst comprises a crystalline, microporous oxide structure without metal loaded on it.
15. The process of claim 2 , wherein the dewaxing catalyst comprises a zeolite without metal loaded on it.
16. The process of claim 15 , wherein the zeolite has a 8-member ring structure, a 10-member ring structure, or a 12-member ring structure.
17. The process of claim 2 further comprising contacting the second product effluent with a hydrotreating catalyst in a third reaction zone to produce a third product effluent.
18. The process of claim 2 , wherein both the middle distillate fuel feedstock and the middle distillate product are diesels.