Production of stable olefinic Fischer-Tropsch fuels with minimum hydrogen consumption
The present invention relates to a stable, low sulfur, olefinic distillate fuel blend component derived from a Fischer-Tropsch process and a process for producing this stable, low sulfur, olefinic distillate fuel blend component. The stable, low sulfur, olefinic distillate fuel comprises olefins in an amount of 2 to 80 weight percent, non-olefins in an amount of 20 to 98 weight percent wherein the non-olefins are predominantly paraffins, oxygenates in an amount of less than 1 weight percent, and sulfur in an amount of less than 10 ppm by weight. A distillate fuel comprising the above blend component forms less than 5 ppm peroxides after storage at 60° C. for four weeks.
1. A blended distillate fuel comprising:
a) a distillate fuel fraction comprising olefins in an amount of 2 to 80 weight %; non-olefins in an amount of 20 to 98 weight %, wherein the non-olefins comprise greater than 50 weight % paraffins; and
oxygenates in an amount of less than 1 weight %; and
b) a distillate fuel fraction selected from the group consisting of a hydrotreated Fischer-Tropsch derived distillate fuel, a hydrocracked Fischer-Tropsch derived distillate fuel, a hydrotreated petroleum derived distillate fuel, a hydrocracked petroleum derived distillate fuel, and mixtures thereof;
wherein at least a portion of the blended distillate fuel is derived from Fischer-Tropsch synthesis products and the blended distillate fuel comprises sulfur in an amount of less than 10 ppm by weight, has a total acid number of less 1.5, and forms less than 5 ppm peroxides after storage at 60° C. for 4 weeks.
2. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel comprises sulfur in an amount of less than 5 ppm by weight.
3. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel comprises sulfur in an amount of less than 1 ppm by weight.
4. A blended distillate fuel according to claim 1 , wherein the distillate fuel fraction of (a) comprises at least 10 weight % olefins.
5. A blended distillate fuel according to claim 1 , wherein the non-olefins of the distillate fuel fraction of (a) comprises greater than 75 weight % paraffins.
6. A blended distillate fuel according to claim 1 , wherein the distillate fuel fraction of (a) is derived from Fischer-Tropsch synthesis products.
7. A blended distillate fuel according to claim 1 , wherein the olefins of the distillate fuel fraction of(a) are comprised of greater than 50 weight % linear primary olefins.
8. A blended distillate fuel according to claim 1 , wherein the olefins of the distillate fuel fraction of (a) are comprised of greater than 65 weight % linear primary olefins.
9. A blended distillate fuel according to claim 1 , wherein the paraffins of the distillate fuel fraction of (a) have an i/n ratio of less than 1.
10. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel further comprises less than 5 weight % aromatics and nitrogen in an amount of less than 5 ppm by weight.
11. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel comprises a total acid number of less than 0.5.
12. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel meets specifications for a diesel fuel as defined in ASTM D-975-98.
13. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel forms less than 4 ppm peroxides after storage at 60° C. for 4 weeks.
14. A blended distillate fuel according to claim 1 , wherein the blended distillate fuel forms less than 1 ppm peroxides after storage at 60° C. for 4 weeks.
15. A blended distillate fuel comprising:
a) a Fischer-Tropsch distillate fuel fraction comprising:
(i) olefins in an amount of 2 to 80 weight %;
(ii) non-olefins in an amount of 20 to 98 weight %, wherein the non-olefins comprise greater than 75 weight % paraffins and the paraffins have an un ratio of less than 1; and
(iii) oxygenates in an amount of less than 1 weight %; and
b) a distillate fuel fraction selected from the group consisting of a hydrotreated Fischer-Tropsch derived distillate fuel, a hydrocracked Fischer-Tropsch derived distillate fuel, a hydrotreated petroleum derived distillate fuel, a hydrocracked petroleum derived distillate fuel, and mixtures thereof;
wherein the blended distillate fuel comprises (i) sulfur in an amount of less than 1 ppm by weight, (ii) nitrogen in an amount of less than 5 ppm by weight;
(iii) aromatics in an amount of less than 5 weight % and (iv) a total acid number of less than 1.5; wherein the blended distillate fuel forms less than 5 ppm peroxides after storage at 60° C. for 4 weeks.
16. A blended distillate fuel according to claim 15 , wherein the blended distillate fuel forms less than 4 ppm peroxides after storage at 60° C. for 4 weeks.
17. A blended distillate fuel according to claim 15 , wherein the blended distillate fuel meets specifications for a diesel fuel as defined in ASTM D-975-98.
18. A blended distillate fuel according to claim 15 , wherein the Fischer-Tropsch distillate fuel fraction of (a) comprises at least 10 weight % olefins.
19. A Fischer-Tropsch distillate fuel blend component comprising:
a) olefins in an amount of 2 to 80 weight %;
b) non-olefins in an amount of 20 to 98 weight %, wherein the non-olefins comprise greater than 75 weight % paraffins and the paraffins have an i/n ratio of less than 1;
c) oxygenates in an amount of less than 1 weight %;.
d) sulfur in an amount of less than 1 ppm by weight;
e) aromatics in an amount of less than 2 weight %;
f) a total acid number of less than 1.5; and g) a boiling range of C 5 to 800° F.
20. A Fischer-Tropsch distillate blend component according to claim 19 , wherein the distillate blend component comprises at least 10 weight % olefins.