Method for upgrading synthetic oils boiling above gasoline boiling material

Claim 1

A method for upgrading products of Fischer-Tropsch Synthesis boiling above 300° F comprising hydrocarbons and oxygenates which comprises: hydrotreating the synthesis product boiling above 300° F in the presence of added sulfur component to provide up to 250 ppm sulfur in the feed and under conditions to catalytically convert oxygenates to hydrocarbons and saturate olefins in the synthesis product, separating a hydrogenated product of said hydrotreating to recover a relatively high boiling hydrocarbon fraction comprising material boiling above 400° F from a lower boiling fraction, separating the lower boiling fraction to recover a hydrogen rich gas stream, a gasoline product stream and a light diesel boiling range material, selectively cracking said high boiling hydrocarbon fraction with a catalyst comprising a crystalline zeolite selective for the purpose intended at a temperature within the range of 550° to 770° F and a hydrogen pressure of at least 200 psia, separating the product of said selective cracking to recover a hydrogen rich gas stream suitable for recycle to said cracking step, a low pressure gaseous product, a gasoline product of higher octane rating than recovered from said hydrotreating step and a bottoms product fraction higher boiling than said gasoline fraction and further separating said bottoms product fraction to recover a medium fuel oil fractions separate from a heavy diesel product.

Claim 2

A method for upgrading products of Fischer-Tropsch Synthesis boiling above 300° F comprising hydrocarbons and oxygenates which comprises: hydrotreating the synthesis product boiling above 300° F in the presence of added sulfur component to provide up to 250 ppm sulfur in the feed and under conditions to catalytically convert oxygenates to hydrocarbons and saturate olefins in the synthesis product, separating a hydrogenated product of said hydrotreating to recover a relatively high boiling hydrocarbon fraction comprising material boiling above 400° F from a lower boiling fraction, separating the lower boiling fraction to recover a hydrogen rich gas stream, a gasoline product stream and a light diesel boiling range material, selectively cracking said high boiling hydrocarbon fraction with a catalyst comprising a crystalline zeolite selective for the purpose intended at a temperature within the range of 550° to 770° F and a hydrogen pressure of at least 200 psia, separating the product of said selective cracking to recover a hydrogen rich gas stream suitable for recycle to said cracking step, a low pressure gaseous product, a gasoline product of higher octane rating than recovered from said hydrotreating step and a bottoms product fraction higher boiling than said gasoline fraction and further separating said bottoms product fraction to recover a medium fuel oil fractions separate from a heavy diesel product.

Claim 9

A method for hydrotreating a product of Fischer-Tropsch Synthesis boiling above 300° F comprising olefins and oxygenates which comprises admixing a product a Fischer-Tropsch Synthesis boiling above 300° F with hydrogen and heating the mixture under conditions to limit vaporization thereof not to exceed about 85% passing the heated feed sequentially through a plurality of separately arranged catalyst beds of hydrogenating catalyst maintained in a sulfided condition by the addition of a sulfur compound with the feed and under a hydrogen partial pressure of at least 200 psia, restricting the exothermic temperature gain in any one bed of catalyst not to exceed about 75° F, charging a cool hydrogen rich gas stream between catalyst bed, as quench gas to the reactant stream passing from one catalyst bed to another and separating the product of said hydrotreating operation to recover a product comprising gasoline and lower boiling components from a higher boiling hydrogenated fraction boiling generally above said gasoline boiling product.

Claim 10

A method for hydrotreating a product of Fischer-Tropsch Synthesis boiling above 300° F comprising olefins and oxygenates which comprises admixing a product a Fischer-Tropsch Synthesis boiling above 300° F with hydrogen and heating the mixture under conditions to limit vaporization thereof not to exceed about 85% passing the heated feed sequentially through a plurality of separately arranged catalyst beds of hydrogenating catalyst maintained in a sulfided condition by the addition of a sulfur compound with the feed and under a hydrogen partial pressure of at least 200 psia, restricting the exothermic temperature gain in any one bed of catalyst not to exceed about 75° F, charging a cool hydrogen rich gas stream between catalyst bed, as quench gas to the reactant stream passing from one catalyst bed to another and separating the product of said hydrotreating operation to recover a product comprising gasoline and lower boiling components from a higher boiling hydrogenated fraction boiling generally above said gasoline boiling product.