Method and System for Production of Oxalic Acid and Oxalic Acid Reduction Products

Abstract

The present disclosure is a method and system for production of oxalic acid and oxalic acid reduction products. The production of oxalic acid and oxalic acid reduction products may include the electrochemical conversion of CO 2 to oxalate and oxalic acid. The method and system for production of oxalic acid and oxalic acid reduction products may further include the acidification of oxalate to oxalic acid, the purification of oxalic acid and the hydrogenation of oxalic acid to produce oxalic acid reduction products.

What is claimed is: 
     
         1 . A method for producing a first product from a first region of an electrochemical cell having a cathode and a second product from a second region of the electrochemical cell having an anode, the method comprising the steps of:
 contacting the first region with a catholyte comprising carbon dioxide and a non-aqueous solvent;   contacting the second region with an anolyte, the anolyte comprising MX and the non-aqueous solvent; and   applying an electrical potential between the anode and the cathode sufficient to produce an oxalate recoverable from the first region and a halogen recoverable from the second region.   
     
     
         2 . The method according to  claim 1 , where X is selected from a group consisting of F, Cl, Br, I and mixtures thereof. 
     
     
         3 . The method according to  claim 1 , wherein the halogen includes at least one of F 2 , Cl 2 , Br 2 , I 2 , F 3   − , Cl 3   − Br 3   −  or I 3   − . 
     
     
         4 . The method according to  claim 1 , wherein the cathode includes at least one of Al, Au, Ag, Bi, C, Cd, Co, Cr, Cu, Cu 2 O, Cu, Fe, Ga, Hg, In, Mo, Nb, Ni, NiCo 2 O 4 , Ni—Fe, Pb, Pd Pt, Rh, Sn, Ti, V, W, Zn, stainless steel, austenitic steel, ferritic steel, duplex steel, martensitic steel, Nichrome, elgiloy Hastelloy, Hastelloy 276, Hastelloy C, metal carbides and alloys thereof. 
     
     
         5 . The method according to  claim 4 , said cathode includes nickel or a nickel alloy. 
     
     
         6 . The method according to  claim 1 , wherein the non-aqueous solvent includes at least one of propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, dimethylsulfoxide, dimethylformamide, acetonitrile, ammonia, acetone, tetrahydrofuran, N,N-dimethylacetaminde, dimethoxyethane, diethylene glycol dimethyl ester, butyrolnitrile, 1,2-difluorobenzene, γ-butyrolactone, N-methyl-2-pyrrolidone, sulfolane, 1,4-dioxane, nitrobenzene, nitromethane, acetic anhydride, alkanes, cycloalkanes, perfluorocarbons, linear carbonates, aromatics such as benzene and toluene and their derivatives, dichloromethane, chloroform, ethers, chlorobenzene, polyols, glymes, diglymes, triglymes, tetraglymes, alcohols, alkenes, trifluorotoluene, anisole, m-cresol, and ionic liquids to include those containing cations of the types: 1,3 dialkylmidazolium, N,N dialkylpyrrolidinium, and 1-alkyl-2,3-dimethylimidazolium where N=2 or 4 and anions of the type hexafluorophosphate, tetrafluoroborate, bis(trifluoromethanesulfonyl)imide, perfluoroalkylphosphate, and halide ions such as Br— 
     
     
         7 . The method according to  claim 1 , wherein the oxalate is M N C 2 O 4 , N is 1 or 2. 
     
     
         8 . The method according to  claim 1 , wherein M is Li + , Na + , K + , Ca ++ , Ba ++ , Sr ++ , Mg ++ , a R 1 R 2 R 3 R 4 N + X −  where each of R 1-4  is independently selected from the group consisting of alkyl, branched alkyl, cycloalkyl, and aryl, tetraalkyl ammonium, tetramethylammonium, tetraethylammonium, tetrabutylammonium, tetraphenylphosphonium, tetrabutylphosphonium, tetraethylphosphonium, tetrahexylammonium, tetraoctylammonium, methyl tributylammonium, butyltrimethylammonium, 1-n-butyl-3-methylimidazolium, 1-ethyl-3-methylimidazolium, 1-ethyl-1-methylpyrrolidinium, di-n-decyldimethylammonium, choline, or ammonium. 
     
     
         9 . The method according to  claim 1 , further comprising:
 reacting the halogen recovered from the second region of the electrochemical cell with hydrogen in a reactor to form HX.   
     
     
         10 . The method according to  claim 9 , wherein reacting the halogen recovered from the second region of the electrochemical cell with hydrogen is in presence of a catalyst in the reactor, the catalyst including one or more of Pt, Pd, Rh, Ru, Ni and Ir. 
     
     
         11 . The method according to  claim 9 , further comprising:
 capturing heat produced from reacting the halogen recovered from the second region of the electrochemical cell with hydrogen in the reactor to form HX.   
     
     
         12 . The method according to  claim 9 , wherein the reacting the halogen recovered from the second region of the electrochemical cell with hydrogen to form HX is through an electrochemical cell reaction. 
     
     
         13 . The method according to  claim 9 , further comprising:
 feeding the oxalate recovered from the first region of the electrochemical cell to at least one of an anion exchange, precipitation and filtration separation device or electrochemical acidification cell to produce a purified oxalate.   
     
     
         14 . The method according to  claim 13 , further comprising:
 receiving the purified oxalate at a second reactor;   receiving the HX from reacting halogen recovered from the second region of the electrochemical cell with hydrogen at the second reactor; and   reacting the purified oxalate and HX at the second reactor to produce oxalic acid and MX.   
     
     
         15 . The method according to  claim 14 , further comprising:
 separating the oxalic acid and the MX.   
     
     
         16 . The method according to  claim 15 , further comprising:
 receiving an alcohol at an esterification device; and   receiving the oxalic acid at the esterification device wherein the alcohol and the oxalic acid react to produce a dialkyl oxalate.   
     
     
         17 . The method according to  claim 16 , wherein the alcohol and the oxalic acid react to produce a dialkyl oxalate in a reactive distillation column. 
     
     
         18 . The method according to  claim 16 , further comprising:
 receiving the dialkyl oxalate at a hydrogenation device wherein a dialkyl oxalate reduction product is produced.   
     
     
         19 . The method according to  claim 18 , wherein the hydrogenation device is a thermal catalytic hydrogenation device. 
     
     
         20 . The method according to  claim 14 , further comprising:
 receiving the oxalic acid at a thermal catalytic hydrogenation device wherein an oxalic acid reduction product is produced.   
     
     
         21 . The method according to  claim 14 , further comprising:
 feeding the MX, produced by reacting the oxalate recovered from the first region of the electrochemical cell with the HX formed from reacting halogen recovered from the second region of the electrochemical cell with hydrogen, to the second region of the electrochemical cell.   
     
     
         22 . The method according to  claim 9 , further comprising:
 receiving the oxalate recoverable from the first region of the electrochemical cell at a second reactor;   receiving the HX from reacting halogen recovered from the second region of the electrochemical cell with hydrogen at the second reactor; and   reacting the oxalate and HX at the second reactor to produce oxalic acid solution and MX.   
     
     
         23 . The method according to  claim 22 , further comprising:
 receiving the oxalic acid solution at one of a chromatography device, nano-filtration device, a solid sorbent amine column or liquid-liquid extractor to produce oxalic acid.   
     
     
         24 . The method according to  claim 23 , further comprising:
 receiving an alcohol at an esterification device; and   receiving the oxalic acid at the esterification device wherein the alcohol and the oxalic acid react to produce a dialkyl oxalate.   
     
     
         25 . The method according to  claim 24 , wherein the alcohol and the oxalic acid react to produce a dialkyl oxalate in a reactive distillation column. 
     
     
         26 . The method according to  claim 24 , further comprising:
 receiving the dialkyl oxalate at a hydrogenation device wherein a dialkyl oxalate reduction product is produced.   
     
     
         27 . The method according to  claim 26 , wherein the hydrogenation device is a thermal catalytic hydrogenation device. 
     
     
         28 . The method according to  claim 23 , further comprising:
 receiving the oxalic acid at a thermal catalytic hydrogenation device wherein an oxalic acid reduction product is produced.   
     
     
         29 . The method according to  claim 22 , further comprising:
 feeding the MX, produced by reacting the oxalate recovered from the first region of the electrochemical cell with the HX formed from reacting halogen recovered from the second region of the electrochemical cell with hydrogen, to the second region of the electrochemical cell.