Apparatus and method for producing sulfur from hydrogen sulfide

Abstract

An apparatus is provided for producing sulfur from hydrogen sulfide. The apparatus includes a container containing a solution that includes hydrogen sulfide. Within the container, and at least partially submerged in the solution, is a photo-anode, formed of an N-type semiconductor, and a photo-cathode, formed of a P-type semiconductor. Each electrode is at least partially covered with a catalyst material. The photo-anode and photo-cathode are electrically coupled to each other and develop charges of opposite polarity when exposed to a light source, which causes the sulfur to separate from the hydrogen in the solution. Also provided is a method for producing sulfur from hydrogen sulfide.

1 . An apparatus for producing sulfur, the apparatus comprising: 
 a container;    a solution including hydrogen sulfide, the solution provided within the container;    a photo-anode formed of an N-type semiconductor, being at least partially coated with a first catalyst material, and at least partially submerged in the solution; and    a photo-cathode formed of a P-type semiconductor, being at least partially coated with a second catalyst material, and at least partially submerged in the solution, the photo-cathode being electrically coupled to the photo-anode, the photo-cathode and photo-anode developing charges of opposite polarity when exposed to a light source so as to separate sulfur from hydrogen in the hydrogen sulfide of the solution and deposit sulfur within the container.    
   
   
       2 . The apparatus according to  claim 1 , wherein the photo-anode comprises one of cadmium selenide, cadmium sulfide, and cadmium telluride.  
   
   
       3 . The apparatus according to  claim 1 , wherein the photo-anode further comprises a stainless steel support.  
   
   
       4 . The apparatus according to  claim 1 , wherein the first catalyst material comprises a plurality of ruthenium deposits on a surface of the photo-anode.  
   
   
       5 . The apparatus according to  claim 4 , wherein the ruthenium deposits cover approximately 10 to 20 percent of the surface of the photo-anode.  
   
   
       6 . The apparatus according to  claim 4 , wherein the ruthenium deposits are each approximately 0.2 mm in diameter.  
   
   
       7 . The apparatus according to  claim 1 , wherein the photo-cathode comprises gallium phosphide.  
   
   
       8 . The apparatus according to  claim 1 , wherein the second catalyst material comprises a plurality of platinum deposits on a surface of the photo-cathode.  
   
   
       9 . The apparatus according to  claim 8 , wherein the platinum deposits cover approximately 10 to 20 percent of the surface of the photo-cathode.  
   
   
       10 . The apparatus according to  claim 8 , wherein the platinum deposits are each approximately 0.2 mm in diameter.  
   
   
       11 . The apparatus according to  claim 1 , further comprising a membrane separating the container into at least two chambers, the photo-anode being disposed in one of the chambers and the photo-cathode being disposed in another of the chambers.  
   
   
       12 . The apparatus according to  claim 1 , wherein the solution further includes NaOH.  
   
   
       13 . A method for producing hydrogen and sulfur, the method comprising the steps of: 
 providing a solution including at least hydrogen sulfide within a container;    providing an N-type photo-anode that is at least partially covered with a first catalyst material and at least partially submerged in the solution;    providing a P-type photo-cathode that is at least partially covered with a second catalyst material and at least partially submerged in the solution;    exposing the photo-anode and the photo-cathode to at least one light source; and    collecting sulfur from the container, the sulfur being the byproduct of a reaction between the solution and the photo-anode.    
   
   
       14 . The method according to  claim 13 , further comprising the step of: 
 bubbling hydrogen sulfide through the solution before the exposing step.    
   
   
       15 . The method according to  claim 13 , wherein the solution further includes NaOH.  
   
   
       16 . The method according to  claim 13 , further comprising the step of providing a membrane that separates the container into two chambers, one of the chambers including the cathode and one of the chambers including the anode.  
   
   
       17 . The method according to  claim 13 , further comprising the step of: 
 adding cadmium acetate and Na 2 SeSO 3  to the solution.    
   
   
       18 . The method according to  claim 13 , further comprising the step of: 
 heating the solution to a temperature of between about 80°-90° C.