Systems and methods for syngas production and upgrading

Abstract

Systems and methods for syngas production are described herein. In some approaches, the system comprises a solid oxide electrolyzer and a syngas upgrading unit. The solid oxide electrolyzer comprises a first and a second electrode. The first electrode receives a first feedstock comprising steam. The second electrode receives a second feedstock comprising a hydrocarbon species. A control unit is in communication with the solid oxide electrolyzer. The control unit may be configured to adjust an amount of the first product stream blended with the second product stream to adjust the syngas composition. In some embodiments, the system comprises a heat integration system transfers heat from the syngas upgrading unit to the solid oxide electrolyzer. In some embodiments, the system comprises a recycle line that recycles tail gas from the syngas upgrading unit to the second feedstock. The control unit may control an amount of heat transferred and/or tail gas recycled.

What is claimed is: 
     
         1 . A method for syngas production and upgrading via a solid oxide electrolyzer having a first electrode and a second electrode disposed on opposite sides of an electrolyte, the method comprising:
 supplying a first feedstock comprising steam to the first electrode;   supplying a second feedstock comprising a light hydrocarbon species to the second electrode;   applying electrical energy to the solid oxide electrolyzer to produce a first product stream comprising hydrogen (H2) and a second product stream comprising syngas, the syngas comprising a mixture of carbon monoxide (CO) and hydrogen (H 2 );   converting the syngas in the second product stream to at least one secondary chemical via a syngas upgrading process; and   transferring heat energy released from syngas upgrading process to the solid oxide electrolyzer.   
     
     
         2 . The method of  claim 1 , wherein the second feedstock includes a non-fossil fuel-based feedstock. 
     
     
         3 . The method of  claim 2 , wherein the non-fossil fuel-based feedstock includes one or more of a biogas, or an industrial waste gas. 
     
     
         4 . The method of  claim 1 , wherein the light hydrocarbon species has a carbon number in a range of about C1 to about C7. 
     
     
         5 . The method of  claim 1 , wherein the syngas upgrading process includes one or more processes including a methanol synthesis process, a Fischer-Tropsch (FT) process, an alcohol synthesis process, a fermentation process, an electrochemical synthesis process. 
     
     
         6 . The method of  claim 1 , further comprising:
 blending a portion of the first product stream with the second product stream to adjust a composition of the syngas in the second product stream.   
     
     
         7 . The method of  claim 1 , further comprising:
 varying an amount of electrical energy applied to the solid oxide electrolyzer based on at least one of a composition or a feed rate of the second feedstock.   
     
     
         8 . The method of  claim 1 , further comprising:
 recycling tail gas from the syngas upgrading process to improve a carbon yield in the second product stream, the tail gas comprising unconverted light hydrocarbons and light hydrocarbons produced as a byproduct of the syngas upgrading process.   
     
     
         9 . The method of  claim 1 , wherein the first feedstock stream further comprises carbon dioxide (CO 2 ) and produces carbon monoxide (CO) in the first product stream and oxygen ions formed in the second electrode during operation of the solid oxide electrolyzer. 
     
     
         10 . The method of  claim 9 , further comprising:
 adjusting a ratio of steam to carbon dioxide (CO 2 ) in the first feedstock to adjust ratio of hydrogen (H 2 ) to carbon monoxide (CO) in the first product stream.   
     
     
         11 . The method of  claim 1 , further comprising:
 varying an amount of electrical energy applied to the solid oxide electrolyzer based on at least one of a composition or a feed rate of the second feedstock.   
     
     
         12 . A system for syngas production and upgrading, the system comprising:
 a solid oxide electrolyzer comprising:
 an electrolyte; 
 a first electrode disposed on a first side of the electrolyte, the first electrode to receive a first feedstock from a first feedstock source line, the first feedstock including at least one of steam, carbon dioxide; 
 a second electrode disposed on a second side of the electrolyte, the second electrode to receive a second feedstock from a second feedstock source line, the second feedstock including a hydrocarbon species; and 
 an electrical energy source coupled to the first electrode and the second electrode to apply a current to apply a voltage between the first electrode and the second electrode to convert the first feedstock to a first product stream comprising at least one of hydrogen (H 2 ) or carbon monoxide (CO) at the first electrode and to convert the second feedstock to a second product stream comprising syngas (CO+H 2 ) at the second electrode; and 
   a control unit in communication with the solid oxide electrolyzer, the control unit configured to adjust an amount of the first product stream blended with the second product stream to adjust a composition of the syngas in the second product stream.   
     
     
         13 . The system of  claim 12 , further comprising:
 a syngas upgrading unit that receives at least a portion of the syngas from the solid oxide electrolyzer and upgrades the syngas to a secondary chemical, the syngas upgrading unit in operative communication with the control unit.   
     
     
         14 . The system of  claim 13 , further comprising:
 a heat integration system configured to transfer heat energy released from the syngas upgrading unit.   
     
     
         15 . The system of  claim 14 , wherein the control unit is further configured to operate the heat integration system to control an amount heat transferred from the syngas upgrading unit to the solid oxide electrolyzer. 
     
     
         16 . The system of  claim 13 , wherein the control unit is further configured to recycle tail gas from the syngas upgrading unit into the second feedstock to improve carbon yield. 
     
     
         17 . The system of  claim 12 , wherein the control unit is further configured to adjust a ratio of steam to carbon dioxide (CO 2 ) in the first feedstock. 
     
     
         18 . The system of  claim 12 , wherein the second electrode includes a catalyst to promote partial oxidation of hydrocarbon species in the second feedstock to form carbon monoxide (CO) and hydrogen (H 2 ). 
     
     
         19 . The system of  claim 12 , wherein the control unit is further configured to vary an amount of electrical energy applied to the solid oxide electrolyzer by the electrical energy source based on at least one of a composition or a feed rate of the second feedstock. 
     
     
         20 . The system of  claim 12 , wherein the second electrode comprises a mixed ionic-electronic conductor.