Synthetic hydrocarbon products

Abstract

The invention includes a process for producing synthetic middle distillates and synthetic middle distillates produced therefrom. In one embodiment, the process comprises fractionating a hydrocarbon synthesis product to at least generate a light middle distillate, a heavy middle distillate, and a waxy fraction; thermally cracking the waxy fraction; and isomerizing the heavy middle distillate. A synthetic diesel or blending component is formed by the combination of at least a portion of the light middle distillate; at least a portion or fraction of the thermally cracked product; and at least a portion or fraction of the isomerized product. In some embodiments, the hydrocarbon synthesis product and/or the thermally cracked product may be hydrotreated. In other embodiments, a synthetic middle distillate comprises at least two fractions: a light fraction with not more than 10% branched hydrocarbons, and a heavy fraction with at least 30% branched hydrocarbons.

1 . A synthetic middle distillate suitable for use as a fuel or a fuel blend comprising hydrocarbons of varying boiling points from lightest hydrocarbons to heaviest hydrocarbons, wherein the synthetic middle distillate comprises at least a first boiling range and a second boiling range; 
 wherein the first boiling range comprises up to about 60 percent by volume of the lightest hydrocarbons in the synthetic middle distillate and further comprises at least about 80 percent of linear hydrocarbons; and    wherein the second boiling range comprises up to about 40 percent by volume of the heaviest hydrocarbons in the synthetic middle distillate and further comprises at least about 30 percent branched hydrocarbons.    
   
   
       2 . The synthetic middle distillate of  claim 1 , wherein the second boiling range comprises at least about 40 percent branched hydrocarbons.  
   
   
       3 . The synthetic middle distillate of  claim 1 , wherein the first boiling range is characterized by a 5% boiling point less than about 360° F. and a 95% boiling point between about 425° F. and about 475° F.  
   
   
       4 . The synthetic middle distillate of  claim 1 , wherein the second boiling range is characterized by a 5% boiling point between about 525° F. and about 575° F. and a 95% boiling point greater than about 630° F.  
   
   
       5 . The synthetic middle distillate of  claim 1 , wherein the synthetic middle distillate is a diesel fuel.  
   
   
       6 . The synthetic middle distillate of  claim 5 , wherein the synthetic middle distillate is a diesel fuel characterized by a 5% boiling point between about 340° F. and about 360° F. and a 95% boiling point between about 620° F. and about 640° F.  
   
   
       7 . The synthetic middle distillate of  claim 1 , wherein the synthetic middle distillate is a jet fuel.  
   
   
       8 . The synthetic middle distillate of  claim 7 , wherein the synthetic middle distillate is a jet fuel characterized by an initial boiling point of about 250° F. and a final boiling point between about 475° F. and about 550° F.  
   
   
       9 . The synthetic middle distillate of  claim 1 , wherein the second boiling range comprises at least about 50 percent branched hydrocarbons.  
   
   
       10 . The synthetic middle distillate of  claim 1 , wherein the second boiling range comprises at least about 70 percent branched hydrocarbons.  
   
   
       11 . The synthetic middle distillate of  claim 1 , wherein the second boiling range comprises at least about 80 percent branched hydrocarbons.  
   
   
       12 . The synthetic middle distillate of  claim 1 , wherein the second boiling range comprises up to about 35 percent by volume of the heaviest hydrocarbons in the synthetic middle distillate.  
   
   
       13 . The synthetic middle distillate of  claim 1 , wherein the first boiling range comprises at least about 85 percent of linear hydrocarbons.  
   
   
       14 . The synthetic middle distillate of  claim 1 , wherein the first boiling range comprises at least about 90 percent of linear hydrocarbons.  
   
   
       15 . The synthetic middle distillate of  claim 1 , wherein the first boiling range comprises up to about 50 percent by volume of the lightest hydrocarbons in the synthetic middle distillate.  
   
   
       16 . The synthetic middle distillate of  claim 1 , wherein the linear hydrocarbons comprise primarily normal alkanes.  
   
   
       17 . The synthetic middle distillate of  claim 1 , wherein the branched hydrocarbons comprise primarily branched alkanes.  
   
   
       18 . The synthetic middle distillate of  claim 1 , wherein the synthetic middle distillate has a cloud point of less than about 40° F.  
   
   
       19 . The synthetic middle distillate of  claim 1 , wherein the synthetic middle distillate has a cloud point of less than about 30° F.  
   
   
       20 . A synthetic middle distillate suitable for use as a liquid fuel or fuel blend comprising primarily about C 10 -C 22  hydrocarbons, said synthetic middle distillate comprising at least two fractions, 
 a light fraction characterized by a 5% boiling point less than about 360° F. and a 95% boiling point between about 500° F. and 550° F., wherein said light fraction has at least about 90 percent linear hydrocarbons; and    a heavy fraction characterized by a 5% boiling point between about 500° F. and 550° F. and a 95% boiling point greater than about 630° F., wherein said heavy fraction has at least about 30 percent branched hydrocarbons.    
   
   
       21 . The synthetic middle distillate of  claim 20 , wherein the heavy fraction has at least about 40 percent branched hydrocarbons.  
   
   
       22 . The synthetic middle distillate of  claim 20 , wherein the heavy fraction further comprises linear hydrocarbons.  
   
   
       23 . The synthetic middle distillate of  claim 22 , wherein the branched hydrocarbons in the heavy fraction of the diesel material are provided by at least a fraction of an isomerized Fischer-Tropsch heavy diesel product stream.  
   
   
       24 . The synthetic middle distillate of  claim 20 , wherein said light fraction has at least about 95 percent linear hydrocarbons.  
   
   
       25 . The synthetic middle distillate of  claim 20 , wherein said light fraction comprises not more than about 10 percent branched hydrocarbons.  
   
   
       26 . The synthetic middle distillate of  claim 20 , wherein the linear hydrocarbons in the synthetic middle distillate are provided by at least a fraction of a hydrotreated Fischer-Tropsch synthesis product stream.  
   
   
       27 . The synthetic middle distillate of  claim 26 , wherein the linear hydrocarbons in the synthetic distillate are further provided by at least a fraction of a hydrotreated thermally-cracked Fischer-Tropsch synthesis waxy product stream.  
   
   
       28 . The synthetic middle distillate of  claim 20 , wherein the synthetic middle distillate comprises an amount of the heavy fraction sufficient to improve at least one cold-flow property of the synthetic middle distillate selected from the group consisting of pour point, cloud point and cold filter plugging point.