Patent Publication Number: US-4732655-A

Title: Means and method for providing two chemical products from electrolytes

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to electrochemical processes in general. 
     SUMMARY OF THE INVENTION 
     A method and apparatus for providing two chemical products includes a reaction cell having an anode chamber and a cathode chamber. The anode chamber is separated from the cathode chamber by an ionic transfer membrane. Each chamber has an electrode connected to a source of DC voltage. A first electrolyte with a first sparging gas is provided to the anode chamber, while a second electrolyte with a second sparging gas is provided to the cathode chamber. The DC voltage, in cooperation with the electrolytes and the sparging gases caused products to form, one in each chamber. The first product is removed from the reacted electrolyte that emerges from the anode chamber while the second product is removed from the reacted electrolyte emerging from the cathode chamber. 
     The objects and advantages of the invention will appear more fully hereinafter, from a consideration of the detailed description which follows, taken together with the accompanying drawing, wherein one embodiment is illustrated by way of example. It is to be expressly understood, however, that the drawing is for illustrative purposes only, and is not to be construed as defining the limits of the invention. 
    
    
     DESCRIPTION OF THE DRAWING 
     The FIGURE shows a simplified block diagram and reaction cell of an apparatus, constructed in accordance with the present invention for forming two products from electrolytes having sparging gases. 
    
    
     DESCRIPTION OF THE INVENTION 
     With reference to the drawing, a reaction cell 3 has passageways 5, 7, 9 and 11. Passageways 5, 7, 9 and 11 provide the entrances and exits for electrolytic solutions as hereinafter explained. Reaction cell 3 has a cathode chamber 14 in which a cathode 19, made of platinum, is maintained. Reaction cell 3 also has an anode chamber 24 in which an anode 28, made of platinum, is maintained. 
     Cathode chamber 14 is separated from anode chamber 24 by an ionic transfer, membrane 32, which may be a Nafion separator. Spacers 36, which also acts as seals, keep separator 32 in proper relationship to cathode chamber 14 and anode chamber 24. 
     A nitrogen source 40 provides nitrogen by way of a line 43 having a control valve 46 to anolyte means 50. An anolyte source 53 provides an electrolyte, which may be methanol with 0.1M of tetrabutylammonium perchlorate, to anolyte means 50 by way of a line 59 having a control valve 62. Anolyte means 50 provides the anolyte with nitrogen to passageway 9 of reaction cell 3 by way of a line 66 having a control valve 70 and a pump 74. The anolyte with nitrogen enters anode chamber 24 and exits anode chamber 24 by way of passageway 11 and line 77 to product removal means 80. Product removal means 80 might be in the form of a separation column. One such separation column is a distillation column. The product is provided by product separation means 80 by way of a line 84 and the remaining anolyte with nitrogen is provided back to electrolyte means 50 by way of feed line 86. 
     A source 86 of oxygen provides oxygen by way of a line 90 having a control valve 92 to catholyte means 96. A catholyte source 100 provides a catholyte, which may be a mixture of methanol, benzene and tetrabutylammonium perchlorate via a feed line 104 having a control valve 112, to catholyte means 96. Catholyte means 96 provides the catholyte with oxygen to passageway 5 of reaction cell 3 by way of a line 118 having a control valve 122 and a pump 130. The catholyte with oxygen from passageway 5 enters anode chamber 14 and exits reaction cell 3 by way of passageway 7 and a line 134. The reacted catholyte in line 134 is provided to product removal means 138. Product removal means 138, which may be of a similar type as product removal means 80, provides a product by way of a line 142. The catholyte without the product is returned to catholyte means 96 by way of feed line 144. 
     A D.C. voltage sourve 150 has its &#34;+&#34; terminal electrically connected to anode 28 and its &#34;-&#34; terminal connected to cathode 19. The D.C. voltage provided by source 150 cooperates with the sparging gas and the electrodes in the reaction of the electrolytes. 
     In the reaction, the oxygen and nitrogen are used as sparging gases in cathode chamber 14 and in anode chamber 24, respectively. The reaction in cathode chamber 14 yields phenol as a product which is removed by product removal means 82 as previously explained. The reaction in the anode chamber 24 forms a product of dimethoxymethane which is removed by product removal means 82, as previously explained. 
     In one example of the present invention 0.1M of benzene was added to a methanol solution containing 0.1M tetrabutylammonium perchlorate. The passage of one electron/mole through the solution of a current density of 3 mA/cm 2  yielded phenol at approximately 40 to 60 percent current efficiency. A smaller amount of a second product, benzene related was also formed with increase in yield and the number of electrons/mole were passed through the solution.