Reforming chamber with multiple electrodes to generate hydrogen

Abstract

Embodiments described herein generally relate to a reforming chamber housing a hydrocarbon-water mixture and receiving a control voltage signal to cause molecular breakdown of the mixture and create a feed of hydrogen and carbon dioxide that can be supplied to fuel cells. The reforming chamber includes multiple electrodes positioned across from a ground plane inside a cylindrical support structure. An input tube receives and directs the mixture to the vertical cavity where the mixture rises past the electrodes. Mixture that is not broken down is recycled back to the bottom of the vertical cavity by a fan while the resultant hydrogen and carbon dioxide is allowed to rise to a trap that separates the hydrogen from the carbon dioxide. The hydrogen can then be directed to the fuel cells or other hydrogen-dependent devices.

1 . A system, comprising:
 a reforming chamber, comprising:
 an input configured to receive a hydrocarbon gas mixture; 
 a tubular structure enveloping a cavity coupled to the input and configured to contain the received gas mixture; and 
 two or more electrodes supported by the tubular structure and exposed in the cavity to the hydrocarbon gas mixture; 
   a drive circuit configured to generate an AC control signal for application to said two or more electrodes to produce an electrical discharge within the cavity that is sufficient to molecularly break down at least a portion of the hydrocarbon gas mixture and produce hydrogen mixed with residual hydrocarbon gas material; and   a feedback loop configured to feed the residual hydrocarbon gas material output from the reforming chamber back to said input.   
     
     
         2 . The system of  claim 1 , wherein said drive circuit comprises:
 a variable supply circuit configured to generate a variable DC control signal;   a DC-to-AC conversion circuit configured to convert the variable DC control signal to generate said AC control signal;   a sensing circuit configured to sense characteristics of the variable DC control signal and determine therefrom whether said electrical discharge is occurring; and   a control circuit configured to change the variable DC control signal that is output from said variable supply circuit in response to the sensing circuit determination as to whether said electrical discharge is occurring.   
     
     
         3 . The system of  claim 2 , wherein said variable supply circuit comprises:
 a variable voltage supply configured to generate a variable DC voltage; and   a DC-to-DC converter configured to convert the variable DC voltage to said variable DC control signal.   
     
     
         4 . The system of  claim 3 , wherein said sensing circuit senses the characteristics of the variable DC control signal at an output of the DC-to-DC converter to determine whether said electrical discharge is occurring. 
     
     
         5 . The system of  claim 2 , wherein the DC-to-AC conversion circuit comprises:
 a DC-to-AC inverter circuit configured to convert the variable DC control signal to an AC signal; and   a transformer configured to receive the AC signal and output the AC control signal.   
     
     
         6 . The system of  claim 2 , wherein the characteristics of the variable DC control signal sensed by the sensing circuit comprise a current signature indicative of a time rate of change in current of the variable DC control signal. 
     
     
         7 . The system of  claim 6 , wherein the control circuit controls operation of said variable supply circuit to change the variable DC control signal dependent on a slope of the current signature. 
     
     
         8 . The system of  claim 7 , wherein the control circuit causes the variable supply circuit to increase the variable DC control signal if the slope indicates that no electrical discharge is occurring. 
     
     
         9 . The system of  claim 7 , wherein the control circuit causes the variable supply circuit to decrease the variable DC control signal if the slope indicates that electrical discharge is occurring. 
     
     
         10 . The system of  claim 2 , wherein the characteristics of the variable DC control signal sensed by the sensing circuit comprise a power signature indicative of a time rate of change in power of the variable DC control signal. 
     
     
         11 . The system of  claim 10 , wherein the control circuit controls operation of said variable supply circuit to change the variable DC control signal dependent on a slope of the power signature. 
     
     
         12 . The system of  claim 10 , wherein the control circuit causes the variable supply circuit to increase the variable DC control signal if the slope indicates that no electrical discharge is occurring. 
     
     
         13 . The system of  claim 10 , wherein the control circuit causes the variable supply circuit to decrease the variable DC control signal if the slope indicates that electrical discharge is occurring. 
     
     
         14 . The system of  claim 1 , further comprising a fuel cell configured to receive the produced hydrogen and generate electricity therefrom. 
     
     
         15 . The system of  claim 2 , further comprising a current signal line connecting an output of the variable supply circuit to an input of the DC-to-AC conversion circuit, and wherein said sensor comprises a current sensor configured to sense current in said current signal line, said sensed characteristics comprising change in sensed current over time. 
     
     
         16 . The system of  claim 15 , wherein change in sensed current over time comprises a current slope whose sign is indicative of whether said electrical discharge is occurring. 
     
     
         17 . The system of  claim 1 , wherein the hydrocarbon gas mixture includes water vapor. 
     
     
         18 . The system of  claim 1 , further comprising a vaporizer configured vaporize condensed residual hydrocarbon gas material. 
     
     
         19 . A system, comprising:
 a reforming chamber having two or more electrodes, an input for receiving a hydrocarbon gas mixture, a tubular structure enveloping a cavity coupled to the input through which the hydrocarbon gas mixture passes, and an output generating hydrogen gas and residual hydrocarbon material;   a drive circuit receiving a variable voltage and configured to generate a drive signal for application to the two or more electrodes;   a feedback loop configured to feed the residual hydrocarbon material from the reforming chamber output back to the reforming chamber input; and   a control circuit including a sensor configured to sense an operational parameter of the drive circuit and make a determination therefrom as to whether an electrical discharge is occurring in the cavity at said two or more electrodes, the control circuit configured to control a setting of the variable voltage to maintain said electrical discharge.   
     
     
         20 . The system of  claim 19 , wherein the variable voltage is increased when the determination indicates the electrical discharge is not present in the cavity and decreased or maintained when the determination indicates the electrical discharge is present in the cavity. 
     
     
         21 . The system of  claim 19 , wherein at least one of the two or more electrodes is a ground plane. 
     
     
         22 . The system of  claim 19 , wherein the control circuit comprises:
 a DC-to-DC converter configured to reduce the variable voltage before detection by the sensor;   a DC-to-AC inverter configured to produce an AC voltage based on the reduced voltage from the DC-to-DC converter; and   a transformer configured to generate the drive signal based on the AC voltage.   
     
     
         23 . The system of  claim 22 , wherein said transformer comprises a first and second transformer, further comprising a multiplexer configured to switch between the first and second transformers based on which of the electrodes are experiencing the electrical discharge. 
     
     
         24 . The system of  claim 22 , wherein the operational parameter is sensed at an output of the DC-to-DC converter. 
     
     
         25 . The system of  claim 19 , wherein the operational parameter comprises a measure of current or power. 
     
     
         26 . The system of  claim 19 , wherein the sensed operational parameter comprises a current or power signature indicative of a time rate of change in current or power of the drive circuit. 
     
     
         27 . The system of  claim 26 , wherein the control circuit controls setting of the variable voltage dependent on a slope of the current signature. 
     
     
         28 . The system of  claim 27 , wherein the control circuit causes the variable voltage to increase if the slope indicates that no electrical discharge is occurring. 
     
     
         29 . The system of  claim 27 , wherein the control circuit causes the variable voltage to decrease if the slope indicates that electrical discharge is occurring.