System for generating electricity or hydrogen from natural gas

Abstract

A system for generating electricity or hydrogen from natural gas can be connected between a gas backbone pipe and a local gas distribution pipe. The system includes a thermal energy storage unit containing a thermal energy storage material heated by an energy source. The system also includes a heat exchanger in fluid communication with the thermal energy storage unit that receives a flow natural gas from the gas backbone pipe and a heated fluid from the thermal energy storage unit to heat the flow of natural gas. The system also includes an expander in fluid communication with the heat exchanger and that receives a flow of heated natural gas from the heat exchanger and to expand the flow of heated natural gas to cool it and reduce its pressure. A generator connected to the expander generates electricity from the expansion of the flow of heated natural gas by the expander.

1 . A system for generating electricity or hydrogen from natural gas, the system configured to be connected to a gas backbone pipe and a local gas distribution pipe, comprising:
 a thermal energy storage unit that contains a thermal energy storage material, the thermal energy storage unit configured to receive energy from an energy source to heat the thermal energy storage material;   a heat exchanger in fluid communication with the thermal energy storage unit, the heat exchanger configured to receive a flow of natural gas from the gas backbone pipe and a heated fluid from the thermal energy storage unit that heats the flow of natural gas;   an expander in fluid communication with the heat exchanger, the expander configured to receive a flow of heated natural gas from the heat exchanger and configured to expand said flow of heated natural gas to cool it and reduce its pressure; and   a generator connected to the expander and configured to generate electricity from an expansion of the flow of heated natural gas by the expander.   
     
     
         2 . The system of  claim 1 , wherein the thermal energy storage unit, heat exchanger, expander and generator are part of a standalone transportable unit. 
     
     
         3 . The system of  claim 1 , wherein the energy source is a renewable energy source. 
     
     
         4 . The system of  claim 1 , wherein the energy source is a photovoltaic plant. 
     
     
         5 . The system of  claim 1 , wherein the energy source is a concentrated solar power plant. 
     
     
         6 . (canceled) 
     
     
         7 . The system of  claim 1 , wherein the thermal energy storage material is water. 
     
     
         8 . (canceled) 
     
     
         9 . The system of  claim 1 , wherein the thermal energy storage material comprises a solid material. 
     
     
         10 . The system of  claim 1 , wherein the thermal energy storage material comprises rocks. 
     
     
         11 . The system of  claim 1 , wherein the thermal energy storage material comprises packed gravel. 
     
     
         12 . The system of  claim 1 , wherein the expander comprises a first expander and a second expander. 
     
     
         13 . The system of  claim 1 , wherein the heat exchanger comprises a first heat exchanger between the gas backbone pipe and a first expander and a second heat exchanger between the first expander and a second expander. 
     
     
         14 . The system of  claim 1 , further comprising an electrolyzer configured to receive the generated electricity from the generator to generate hydrogen. 
     
     
         15 . The system of  claim 14 , wherein the generated hydrogen is injected into the local gas distribution pipe. 
     
     
         16 . The system of  claim 14 , wherein the generated hydrogen is injected into a pipe separate from the local gas distribution pipe. 
     
     
         17 . (canceled) 
     
     
         18 . A method for generating electricity or hydrogen from natural gas, comprising:
 heating via a heat exchanger a flow of natural gas flowing between a gas backbone pipe and a local gas distribution pipe;   expanding via an expander the flow of heated natural gas received from the heat exchanger; and   generating electricity from an expansion of the flow of heated natural gas by the expander.   
     
     
         19 . The method of  claim 18 , wherein heating the flow of natural gas includes receiving a heated fluid in the heat exchanger from a thermal energy storage unit to heat the flow of natural gas. 
     
     
         20 . The method of  claim 18 , wherein expanding the flow of heated natural gas includes cooling and reducing a pressure of the flow of heated natural gas. 
     
     
         21 . The method of  claim 18 , wherein expanding the flow of heated natural gas occurs in multiple stages. 
     
     
         22 . The method of  claim 18 , further comprising generating hydrogen via an electrolyzer powered by the generated electricity. 
     
     
         23 . The method of  claim 22 , further comprising injecting the generated hydrogen into the local gas distribution pipe. 
     
     
         24 . (canceled) 
     
     
         25 . (canceled)