Integrated processes and systems for reforming and isomerizing hydrocarbons

Abstract

Processes and systems are provided for reforming and isomerizing hydrocarbons to produce octane upgraded hydrocarbons. The process involves providing a reforming feedstream to a reforming zone containing a reforming catalyst and operating the reforming zone at reforming conditions including reforming pressure in a range of from about 1 to about 18 atmospheres to generate a reforming zone effluent. The reforming zone effluent is separated to form a net gas stream comprising primarily hydrogen and a liquid reforming product stream, and then providing the net gas stream and an isomerization feedstream to an isomerization zone containing an isomerization catalyst. The isomerization zone is operated at an isomerization pressure that is greater than the reforming pressure, to produce an isomerization zone effluent. The system for reforming and isomerizing hydrocarbons includes a reforming zone containing a reforming catalyst, a reforming separator, an isomerization zone containing an isomerization catalyst, and an isomerization separator.

What is claimed is: 
     
         1 . A process comprising the steps of:
 providing a reforming feedstream to a reforming zone containing a reforming catalyst;   operating the reforming zone at reforming conditions that comprise a reforming pressure in a range of from about 1 to about 18 atmospheres to generate a reforming zone effluent;   separating the reforming zone effluent to form a net gas stream comprising primarily hydrogen and a liquid reforming product stream;   providing the net gas stream and an isomerization feedstream to an isomerization zone containing an isomerization catalyst; and   operating the isomerization zone at isomerization conditions that comprise an isomerization pressure that is greater than the reforming pressure, to produce an isomerization zone effluent.   
     
     
         2 . The process according to  claim 1 , wherein the step of separating the reforming zone effluent to form a liquid reforming product stream comprises forming a liquid reforming product stream with a Research Octane Number (RON) in a range of from about 90 to about 101. 
     
     
         3 . The process according  claim 1 , wherein the isomerization pressure is in a range of from greater than about 18 to about 70 atm. 
     
     
         4 . The process according to  claim 1 , wherein the step of operating the isomerization zone is performed with a single pass-through of the net gas stream. 
     
     
         5 . The process of  claim 1 , further comprising the step of separating the isomerization zone effluent to form a total net gas stream and a liquid isomerization product stream. 
     
     
         6 . The process according to  claim 5 , further comprising the steps of:
 providing both the liquid reforming product stream and the liquid isomerization product stream to a separation zone; and   operating the separation zone to generate a product stream enriched in C 5  and heavier hydrocarbons and an overhead stream enriched in C 4  and lighter hydrocarbons.   
     
     
         7 . The process according to  claim 5 , further comprising the step of recycling at least a portion of the total net gas to the net gas stream prior to the step of providing the net gas stream to the isomerization zone. 
     
     
         8 . The process according to  claim 5 , further comprising:
 compressing the net gas stream prior to the step of providing the net gas stream to the isomerization zone; and   compressing at least a portion of the total net gas stream to form compressed total net gas;   
       wherein the steps of compressing the net gas stream and compressing at least a portion of the total net gas stream are performed using a single power source to operate independent compressors to compress each of said streams. 
     
     
         9 . The process according to  claim 8 , further comprising the step of providing at least a portion of the compressed total net gas to a hydrogen-consuming process. 
     
     
         10 . The process according to  claim 9 , wherein the hydrogen-consuming process comprises a naphtha hydrotreating process, a diesel hydrotreating process, or both. 
     
     
         11 . The process according to  claim 9 , wherein the hydrogen-consuming process comprises a diesel hydrotreating process, and
 the process further comprises the steps of:   operating the diesel hydrotreating process to generate a recycle gas stream;   compressing the recycle gas stream; and   recycling the recycle gas stream back to the diesel hydrotreating process;   
       wherein the steps of compressing the net gas stream, compressing at least a portion of the total net gas stream, and compressing the recycle gas stream from the diesel hydrotreating process are all performed using a single power source to operate independent compressors to compress each of said streams. 
     
     
         12 . An integrated process for reforming and isomerizing hydrocarbons comprising the steps of:
 providing a reforming feedstream to a reforming zone containing a reforming catalyst;   operating the reforming zone at reforming conditions that comprise a reforming pressure in a range of from about 1 to about 18 atmospheres to generate a reforming zone effluent;   separating the reforming zone effluent to form a net gas stream, comprising primarily hydrogen, and a liquid reforming product stream;   compressing the net gas stream;   providing the net gas stream and an isomerization feedstream to an isomerization zone containing an isomerization catalyst;   operating the isomerization zone with a single pass-through of the net gas stream and at isomerization conditions that comprise an isomerization pressure that is greater than the reforming pressure and is in a range of from greater than about 18 to about 70 atm to produce an isomerization zone effluent;   separating the isomerization zone effluent to form a total net gas stream and a liquid isomerization product stream; and   compressing at least a portion of the total net gas stream to form compressed total net gas,   wherein the steps of compressing the net gas stream and compressing at least a portion of the total net gas stream are performed using a single power source to operate independent compressors to compress each of the net gas and total net gas streams.   
     
     
         13 . A system for reforming and isomerizing hydrocarbons, the system comprising:
 a reforming reactor configured for containing a reforming catalyst and having a reforming feedstream inlet and a reforming zone effluent outlet;   a reforming separator having an inlet in fluid communication with the reforming zone effluent outlet of the reforming zone and having at least a net gas outlet and a liquid reforming product outlet;   an isomerization reactor configured for containing an isomerization catalyst and having an isomerization feedstream inlet, a net gas inlet in fluid communication with the net gas outlet of the reforming separator, and an isomerization zone effluent outlet;   an isomerization separator having an inlet in communication with the isomerization zone effluent outlet of the isomerization zone and having a total net gas outlet and a liquid isomerization product outlet.   
     
     
         14 . The system according to  claim 13 , wherein the isomerization reactor comprises two or more isomerization reactors, each capable of withstanding isomerization pressures of from greater than about 18 to about 70 atmospheres. 
     
     
         15 . The system according to  claim 13 , further comprising a post-reforming compressor having a net gas inlet in fluid communication with the net gas outlet of the reforming separator and a compressed net gas outlet in fluid communication with the net gas inlet of the isomerization reactor. 
     
     
         16 . The system according to  claim 15 , further comprising a post-isomerization compressor having a total net gas inlet in fluid communication with the total net gas outlet of the isomerization separator, and a compressed total net gas outlet. 
     
     
         17 . The system according to  claim 16 , further comprising a single power source which provides power for operating each of the post-reforming and post-isomerization compressors. 
     
     
         18 . The system according to  claim 17 , further comprising a multi-compressor apparatus on which the single power source and each of the post-reforming and post-isomerization compressors are mounted and wherein each of the post-reforming and post-isomerization compressors is in communication with the power source. 
     
     
         19 . The system according to  claim 18 , wherein the multi-compressor apparatus further comprises a diesel recycle compressor mounted thereon and also in communication with the power source, for compressing a gaseous stream derived either from operation of the system or operation of a another separate system. 
     
     
         20 . The system according to  claim 13 , further comprising a combined product separator having an inlet in fluid communication with both the liquid reforming product outlet of the reforming separator and the liquid isomerization product outlet of the isomerization separator, and having a product stream outlet and an overhead stream outlet.