Methods, systems, and apparatuses for low-temperature, fischer-tropsch wax hydrogenation

Abstract

A process for hydrogenating a Fischer-Tropsch (“FT”) wax includes placing hydrogenation catalyst particles within a low-temperature hydrogenation reactor having a mixing sub-system and a vent at the top for excess hydrogen, placing the FT wax at a low temperature up to a predetermined level within the low-temperature, hydrogenation reactor, leaving a vapor space above the predetermined level, adding hydrogen under a desired pressure into the low-temperature hydrogenation reactor, mixing the input FT wax, the hydrogen gas and the hydrogenating catalyst particles together to create a mixture using the mixing subsystem and continuing the mixing until the FT wax has hydrogenated, stopping the mixing to allow the hydrogenation catalyst particles to settle, and removing an hydrogenated FT wax with residual hydrogenating catalyst particles from the low-temperature hydrogenation reactor. The hydrogenated FT wax may be filtered and subjected to vacuum distillation. Other embodiments are also disclosed.

1 . A method of hydrogenating a Fischer-Tropsch (“FT”) wax, comprising:
 a. placing an input FT wax up to a predetermined level within a low-temperature hydrogenation reactor, having a mixing sub-system and a vent at the top and containing hydrogenation catalyst particles, leaving a vapor space above the predetermined level; 
 b. adding hydrogen gas under pressure to the low-temperature hydrogenation reactor, bringing the low-temperature hydrogenation reactor up to a pre-determined operating pressure; 
 c. mixing the input FT wax, the hydrogen gas and the hydrogenation catalyst particles together using the mixing subsystem under operating conditions including a low temperature and the pre-determined operating pressure to create a mixture, thus permitting the FT wax to become hydrogenated; 
 d. stopping the mixing and allowing the hydrogenation catalyst particles to settle for a period of time; 
 e. removing the hydrogenated FT wax from the low-temperature hydrogenation reactor; 
 f. sending the hydrogenated FT wax with the residual hydrogenation catalyst particles through a catalyst filter to remove at least a portion of the residual hydrogenation catalyst particles and to create a filtered hydrogenated FT wax; and 
 g. subjecting the filtered hydrogenated FT wax to a vacuum distillation process to produce at least a first FT wax product having a first range of carbon numbers and a second FT wax product having a second range of carbon numbers. 
 
     
     
         2 - 3 . (canceled) 
     
     
         4 . The method of  claim 1 , further comprising:
 h. storing the filtered hydrogenated FT wax;   i. heating the filtered hydrogenated FT wax.   
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 1 , further comprising:
 j. pre-heating the FT wax prior to placing the FT wax as the input FT wax in the low temperature hydrogenation reactor.   
     
     
         7 . The method of  claim 1 , wherein the operating pressure is low and the low temperature hydrogenation reactor comprises a low-temperature, low-pressure hydrogenation reactor. 
     
     
         8 . The method of  claim 1 , further comprising:
 k. removing the mixture from the low-temperature hydrogenation reactor;   l. sending the mixture through a heat exchanger to adjust the temperature of the mixture; and   m. returning the temperature-adjusted mixture to the low-temperature hydrogenation reactor.   
     
     
         9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein the first FT wax product has a congealing point between about 50° C. and about 70° C. 
     
     
         11 . The method of  claim 1 , wherein the second FT wax product has a melting point between about 85° C. and about 100° C. and further comprising sending the second FT wax product to the low-temperature hydrogenation reactor, for supplemental hydrogenation. 
     
     
         12 . (canceled) 
     
     
         13 . The method of  claim 1 , wherein the vacuum distillation comprises a short path distillation system. 
     
     
         14 . (canceled) 
     
     
         15 . The method of  claim 1 , wherein the removed, residual hydrogenation catalyst particles are recycled to the low-temperature hydrogenation reactor using a back-flush fluid, wherein the back-flush fluid comprises FT wax to be used as the input FT wax. 
     
     
         16 - 17 . (canceled) 
     
     
         18 . The method of  claim 1 , wherein the input FT wax was produced using a natural gas feedstock to create a syngas and using an FT reactor and a cobalt-based catalyst to change the syngas into FT products, including the input FT wax. 
     
     
         19 . (canceled) 
     
     
         20 . The method of  claim 1 , wherein the hydrogenation catalyst particles comprise a skeletal nickel-based catalyst. 
     
     
         21 . The method of  claim 1 , wherein the catalyst filter comprises at least one catalyst candle filter suitable for use in filtering catalysts from hydrogenated edible oils. 
     
     
         22 . The method of  claim 1 , further comprising, after step b:
 (1) passing a fluid including the input FT wax from the low-temperature, low-pressure hydrogenation reactor to a heat exchanger to adjust the temperature of the FT wax; and   (2) returning the fluid at the adjusted temperature to the low-temperature, low-pressure hydrogenation reactor.   
     
     
         23 . (canceled) 
     
     
         24 . The method of  claim 7 , wherein the low pressure for the operating conditions is below about 350 psig. 
     
     
         25 . (canceled) 
     
     
         26 . The method of  claim 1 , wherein the low temperature for the operating conditions is below about 280° C. 
     
     
         27 . The method of  claim 26 , wherein the low temperature for the operating conditions is below about 200° C. 
     
     
         28 . The method of  claim 1 , wherein the hydrogenation catalyst particles comprise a catalyst mixture of at least two catalysts. 
     
     
         29 . The method of  claim 28 , wherein at least one of the types of catalysts in the catalyst mixture has a function other than hydrogenation. 
     
     
         30 . A method of hydrogenating a Fischer-Tropsch (“FT”) wax, comprising:
 a. placing an input FT wax, at a low temperature of below about 200° C., up to a predetermined level within a low-temperature, low-pressure hydrogenation reactor leaving a vapor space above the predetermined level, the low-temperature, low-pressure hydrogenation reactor having a vent at the top, containing hydrogenation catalyst particles, and including a mixing sub-system comprising a motor and gear box, a seal, a hollow shaft gas impeller system; 
 b. adding hydrogen gas under pressure to the low-temperature low-pressure hydrogenation reactor, bringing the low-temperature low-pressure hydrogenation reactor up to a pre-determined low operating pressure of below about 100 psig; 
 c. mixing the input FT wax, the hydrogen gas and the hydrogenation catalyst particles together using the mixing subsystem under operating conditions including a low temperature and the pre-determined operating pressure to create a mixture, thus permitting the FT wax to become hydrogenated; 
 d. depressurizing the low-temperature low-pressure hydrogenation reactor; 
 e. flushing the hydrogen gas from the vapor space of the low-temperature low-pressure hydrogenation reactor using nitrogen at a low pressure; 
 f. stopping the mixing and allowing the hydrogenation catalyst particles to settle for a period of time, leaving at least one residual hydrogenation catalyst particle suspended in the hydrogenated FT wax; 
 g. removing at least a portion of the hydrogenated FT wax and the at least one residual hydrogenation catalyst particle from the low-temperature, low-pressure hydrogenation reactor through a dip tube by adding nitrogen under a low pressure to the low-temperature, low-pressure hydrogenation reactor; 
 h. sending the removed hydrogenated FT wax and the at least one residual hydrogenation catalyst particle through a catalyst filter to remove at least one residual hydrogenation catalyst particle and to create a filtered hydrogenated FT wax; 
 i. degassing the filtered hydrogenated FT wax; 
 h. subjecting the degassed, filtered hydrogenated FT wax to a vacuum distillation process in a short path distillation system to produce at least a first FT wax product having a congealing point between about 50° C. and about 70° C. and a second FT wax product having a congealing point between about 85° C. and about 100° C.; and 
 i. sending the second FT wax product to the low-temperature, low-pressure hydrogenation reactor, for supplemental hydrogenation. 
 
     
     
         31 . The method of  claim 30 , further comprising:
 j. removing the mixture from the low-temperature, low-pressure hydrogenation reactor;   k. sending the mixture through a heat exchanger to adjust the temperature of the mixture; and   l. returning the temperature-adjusted mixture to the low-temperature, low-pressure hydrogenation reactor.   
     
     
         32 - 46 . (canceled) 
     
     
         47 . A Fischer-Tropsch (“FT”) wax produced according to the method of  claim 1 .