Electrolytic generation of nitrogen

Abstract

The invention provides methods and devices for the electrochemical generation of nitrogen from organic nitrogen compounds, such as hydrazides (RCONHNH 2 ), the corresponding organic hydrazino-carboxylates (RCO 2 NHNH 2 ) and amino-guanidine salts (e.g. aminoguanide bicarbonate H 2 NNHC(NH)NH 2 .H 2 CO 3 ). A variety of organic hydrazides and hydrazino-carboxylates may be used, and empirically tested for performance. For example, in the hydrazides and hydrazino-carboxylates “R” may be an alkyl, alkenyl, alkynyl or aryl group, in some embodiments methyl, ethyl, or benzyl. The alkyl, alkenyl and alkynyl groups may be branched or unbranched, substituted or unsubstituted. The utility of such compounds may be routinely assayed in accordance with the guidance provided herein, including the Examples set out herein in which alternative nitrogen compounds may be substituted for routine test purposes.

What is claimed is:  
     
         1 . An electrolytic nitrogen gas generator comprising: 
 a. a cathode and an anode connected as part of an electrical circuit that may be switched on or off;    b. an electrolyte in contact with the anode comprising an active nitrogen compound selected from the group consisting of organic hydrazides, organic hydrazino carboxylates and amino guanidine salts;    c. wherein nitrogen gas is generated at the anode from the active nitrogen compound when the electrical circuit is switched on.    
     
     
         2 . The electrolytic nitrogen gas generator of  claim 1 , further comprising a cathode depolariser to suppress hydrogen generation.  
     
     
         3 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrical circuit comprises a battery.  
     
     
         4 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrical circuit comprises a resistor.  
     
     
         5 . The electrolytic nitrogen gas generator of  claim 4 , wherein the resistor is a variable resistor.  
     
     
         6 . The electrolytic nitrogen gas generator of  claim 1 , wherein the active nitrogen compound comprises methyl hydrazino-carboxylate.  
     
     
         7 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises urea.  
     
     
         8 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte is an ionic compound selected from the group consisting of salts, acids and bases.  
     
     
         9 . The electrolytic nitrogen gas generator of  claim 8 , wherein the ionic compound is selected from the group consisting of ammonium sulphate, sodium chloride, sulphuric acid.  
     
     
         10 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte is held in an absorbent material.  
     
     
         11 . The electrolytic nitrogen gas generator of  claim 10 , wherein the absorbent material comprises an absorbent solid selected from the group consisting of sponges, felts and gels.  
     
     
         12 . The electrolytic nitrogen gas generator of  claim 10 , wherein the absorbent material is selected from the group consisting of cellulose sponges and carbopol gels.  
     
     
         13 . The electrolytic nitrogen gas generator of  claim 1 , wherein the active nitrogen compound comprises oxalic dihydriazide.  
     
     
         14 . The electrolytic nitrogen gas generator of  claim 1 , wherein the active nitrogen compound comprises aminoguanidine bicarbonate.  
     
     
         15 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises aqueous sulphuric acid.  
     
     
         16 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises an antifreeze.  
     
     
         17 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises nitroethanol.  
     
     
         18 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises nitromethane.  
     
     
         19 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises nitroguanidine.  
     
     
         20 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises a cupric salt.  
     
     
         21 . The electrolytic nitrogen gas generator of  claim 1 , wherein the electrolyte comprises copper sulphate.  
     
     
         22 . The electrolytic nitrogen gas generator of  claim 1 , wherein the anode comprises graphite.  
     
     
         23 . The electrolytic nitrogen gas generator of  claim 1 , wherein the anode comprises graphite fibre impregnated with a polymer.  
     
     
         24 . The electrolytic nitrogen gas generator of  claim 1 , further comprising an ion permeable membrane separating the cathode and a catholyte from the anode and the anolyte, wherein the ion permeable membrane electrically couples the catholyte to the anolyte.  
     
     
         25 . The electrolytic nitrogen gas generator of  claim 24  wherein the ion permeable membrane is selected from the group consisting of cation selective membranes and anion selective membranes.  
     
     
         26 . The electrolytic nitrogen gas generator of  claim 1 , further comprising a bipolar electrode separating the cathode and a catholyte from the anode and the anolyte, wherein the catholyte electrically couples the cathode to the bipolar electrode and the anolyte electrically couples the bipolar electrode to the anode.  
     
     
         27 . The electrolytic nitrogen gas generator of  claim 26  further comprising an oxidant in contact with the cathode.  
     
     
         28 . The electrolytic nitrogen gas generator of  claim 27  wherein the oxidant is selected from the group consisting of manganese dioxide and a bromate salt.  
     
     
         29 . The electrolytic nitrogen gas generator of  claim 27  wherein the oxidant is sodium bromate.  
     
     
         30 . The electrolytic nitrogen gas generator of  claim 26  further comprising a reductant in contact with the bipolar electrode.  
     
     
         31 . The electrolytic nitrogen gas generator of  claim 30  wherein the reductant is selected from the group consisting of zinc powder and aluminium powder.  
     
     
         32 . The electrolytic nitrogen gas generator of  claim 26  wherein the electrolyte further comprises a depolariser for depolarising the cathode of the bipolar electrode.  
     
     
         33 . The electrolytic nitrogen gas generator of  claim 32  wherein the depolariser comprises a dissolved salt of a metal and the metal is deposited on the bipolar electrode to depolarise the bipolar electrode when the circuit is switched on.  
     
     
         34 . The electrolytic nitrogen gas generator of  claim 32  wherein the depolariser comprises a reducible organic compound selected from the group consisting of nitroethanol, nitromethane, and nitroguanidine.  
     
     
         35 . The electrolytic nitrogen gas generator of  claim 1  further comprising a transducer for capturing the nitrogen gas generated at the anode and producing mechanical energy therefrom.  
     
     
         36 . The electrolytic nitrogen gas generator of  claim 35 , wherein the transducer is mechanically coupled to a fluid dispenser so that a fluid is dispensed from the fluid dispenser when nitrogen gas is generated at the anode.  
     
     
         37 . A housing for an electrolytic cell comprising an anode, a cathode and an electrolyte biased together in electrical contact, the electrolyte being contained by a flexible membrane adapted to accommodate compression of the electrolyte, the housing having an opening to permit passage of gas evolved from the electrolyte during electrolysis.