Ca-Sic O (Coin Atm.) Scrubber
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United States Patent 19 (11) 4,197,421 Steinberg 45 Apr. 8, 1980 54 SYNTHETIC CARBONACEOUS FUELS AND 4,076,761 2/1978 Chang et al. .................... 260/676 R FEED STOCKS Primary Examiner-C. Davis (75) Inventor: Meyer Steinberg, Huntington Attorney, Agent, or Firm-R. V. Lupo; Leonard Belkin; Station, N.Y. Cornell D. Cornish 73 Assignee: The United States of America as 57 ABSTRACT represented by the United States This invention relates to the use of a three compartment Department of Energy, Washington, electrolytic cell in the production of synthetic carbona D.C. ceous fuels and chemical feedstocks such as gasoline, 21 Appl. No.: 934,765 methane and methanol by electrolyzing an aqueous sodium carbonate/bicarbonate solution, obtained from 22 Filed: Aug. 17, i978 scrubbing atmospheric carbon dioxide with an aqueous 51 Int. C.’................................................ CO7C 1/12 sodium hydroxide solution, whereby the hydrogen gen 52 U.S. Cl. ..................................... 585/733; 204/98; erated at the cathode and the carbon dioxide liberated in 204/101; 260/449.5 the center compartment are combined thermocatalyti 58) Field of Search ........................ 260/676 R, 449.5; cally into methanol and gasoline blends. The oxygen 204/101,98; 585/733 generated at the anode is preferably vented into the 0. atmosphere, and the regenerated sodium hydroxide (56) References Cited produced at the cathode is reused for scrubbing the U.S. PATENT DOCUMENTS CO2 from the atmosphere. 3,519,488 7/1970 Gimer .................................. 204/103 3,692,649 9/1972 Prigant et al. ....................... 204/10 10 Claims, 1 Drawing Figure NOOH 28 D- AIR'OUT AIR'N' CA-SIC O (COIN ATM.) SCRUBBER NUCLEAR ELECTRICAL POWER TURBO REACTOR GENERATOR U FUEL. CATALYTIC -30 DEHYDRATOR 32- (CH.)2n GASOLINE U.S. Patent Apr. 8, 1980 4,197,421 O2 EINITIOSV79) „LOO,HIV? „NI,HIV 4,197,421 2 mocatalytically combining the hydrogen and carbon SYNTHETIC CARBONACEOUS FUELS AND dioxide to form methanol which is thermocatalytically FEESTOCKS dehydrated to gasoline. More specifically, in the process of producing syn BACKGROUND OF THE INVENTION 5 thetic fuels and chemical feedstocks such as gasoline, This invention was made under, or during, the course methane and methanol which comprises converting a of, a contract with the U.S. Department of Energy. gaseous mixture of hydrogen and carbon dioxide to This invention relates to a process for producing methanol and then gasoline by thermocatalytic means; synthetic fuels and chemical feedstocks such as gaso the improvement which comprises electrolyzing an line, methane and methanol from gaseous CO2 and H2 10 aqueous sodium carbonate/bicarbonate solution in a by extracting CO2 from the air with a NaOH solution; three compartment electrolytic cell, said carbonate subjecting the resulting sodium carbonate solution to solution being obtained by scrubbing atmospheric car electrolysis in a three compartment electrolytic cell bon dioxide with an aqueous sodium hydroxide solu where hydrogen is formed at the cathode, oxygen at the tion, whereby the hydrogen generated at the cathode anode and CO2 is released in the center compartment; 15 and the carbon dioxide liberated in the center compart and combining the hydrogen and the CO2 ther ment are combined thermocatalytically into methanol mocatalytically to form gasoline. and gasoline blends. Raw synthesis gas containing hydrogen and carbon oxide and/or carbon dioxide useful in the synthesis of PRIOR ART methanol, methane, and gasoline are normally obtained 20 Electrolysis of electrolytic solutions in three com from the conversion of coal and other hydrocarbons by partment cells is generally known, as disclosed in U.S. a variety of known methods. The resultant synthesis gas contains impurities such as sulfur compounds, nitrogen Pat. No. 1,126,627 wherein an alkali chloride solution is compounds, particulate matter, etc., which require puri electrolyzed into NaOH and HCl; U.S. Pat. No. fication prior to its utilization in gasoline synthesis. 25 3,017,338 wherein a high purity alkali metal hydroxide It has now been found that instant invention utilizes and halogen is obtained from an alkali metal halide the atmosphere as a source of the oxides of carbon (CO solution; and U.S. Pat. No. 3,135,673 wherein an acid and CO2), from which pure CO2 is recovered in a three salt such as sodium bisulfate is recovered from the compartment electrolytic cell together with electrolytic ancie and sodium hydroxide is recovered at the cath H2 to produce synthetic fuels. 30 ode when feeding a nearly saturated sodium sulfate The advantages of using atmospheric CO2 as a source solution into the center compartment. This patent also for the synthesis gas in the synthesis of gasoline are discloses that the sodium hydroxide catholyte is con multifold. ducted to a scrubbing apparatus wherein the carbon A vast natural resource is readily available. A desir dioxide from the atmosphere is absorbed by said caustic, able CO2 balance between the biosphere and the atmo 35 forming a sodium carbonate solution which is combined sphere can be maintained by the removal of the CO2 with an equivalent amount of the anolyte effluent so from the atmosphere. A pure CO2 gas and H2 gas is dium bisulfate to regenerate the original sodium sulfate obtained from the electrolytic cell for use in the synthe which can be recycled to the electrolytic cell. sis of carbonaceous fuel. The atmospheric CO2 provides The removal of CO2 from gas streams, such as the an alternate and extended supply of premium synthetic atmosphere, by intimate contact with, and absorption carbonaceous fuel for this country thus advancing the into a solution of a strong base such as sodium hydrox goal of energy self-sufficiency. It would eliminate many ide whereby sodium carbonate is formed, and the regen environmental and safety problems inherent in fossil eration of said spent absorbent in a two compartment fuel utilization. It is more economical. electrolytic cell, using said sodium carbonate as an elec Accordingly, it is a primary object of instant inven 45 trolyte, is also well known in the prior art, as disclosed tion to provide a process for extracting CO2 from the in U.S. Pat. Nos. 3,519,488 and 3,692,649. However, atmosphere and combining this with electrolytic hydro both of aforesaid patents require the presence of sub gen to produce synthetic gas and gasoline. stantial amounts of a salt in addition to the alkali metal Another object of instant invention is to provide a hydroxide in the scrubbing solution. For example, U.S. process for extracting CO2 from the atmosphere with 50 Pat. No. 3,519,488 uses solutions of potassium hydrox sodium hydroxide, and electrolytically decomposing ide and potassium carbonate and U.S. Pat. No. the resulting sodium carbonate solution into the con 3,692,649 uses inert salts such as NaClO4, KCH3CO2, commitant generation of hydrogen and the release of NaCH3CO2, NaCl, KCl, Na2SO4 and K2SO4, together concentrated CO2 which are then thermocatalytically with the alkali metal hydroxide base. U.S. Pat. No. combined to form gasoline. 55 3,519,488 further adds a neutral electrolyte such as KF Still another object is to provide a three compartment or K2SO4 to the anolyte soltion to overcome problems sodium carbonate electrolysis cell for the concommitant encountered in the electrolysis of the spent scrubbing production of CO2 and hydrogen. solution containing the alkali metal carbonate. Accordingly, instant invention relates to a process of Other patents which disclose a two compartment producing synthetic fuels and chemical feedstocks such 60 electrolytic cell containing an alkali metal carbonate as gasoline, methane and methanol from atmospheric electrolyte useful in the collection and concentration of carbon dioxide which comprises extracting atmospheric carbon dioxide are U.S. Pat. Nos. 3,401,100 and CO2 from the air with an aqueous sodium hydroxide 3,494,842. solution whereby a sodium carbonate solution is Although the prior art discloses a three compartment formed; electrolyzing said sodium carbonate solution in 65 electrolytic cell generally, and U.S. Pat. No. 3,135,673 a three compartment electrolytic cell whereby hydro discloses a three compartment cell containing sodium gen is formed at the cathode, oxygen at the anode and carbonate as the partial electrolyte together with the CO2 is released in the center compartment; and ther bisulfate, the recovery of CO2 in the center compart 4,197,421 3 4. ment for combination with the hydrogen released at the vantages of both aforesaid processes, thereby reducing cathode as in instant invention is not disclosed. These capital and operating costs. patents only disclose the formation of an acid anolyte This electrolytic carbonate system may also be used and a basic catholyte with unreacted salt in the center for stack gas scrubbing of CO2. However, in this case compartment. where CO2 gas compositions up to 15% are available Similarly, although the prior art discloses the extrac compared to 0.035% in the atmosphere, adoption of a tion of CO2 from the atmosphere with a sodium hydrox conventional absorption/stripping technique may be ide solution whereby sodium carbonate is formed, and more economical. the regeneration of the sodium hydroxide in an electro The FIGURE shows by way of example a flow sheet chemical cell, the simultaneous liberation of CO2 and 10 of the process according to this invention with a dia hydrogen as in instant invention is not disclosed. grammatic representation of the three compartment Furthermore, there is no recognition in the prior art electrolytic cell. that CO2 from the atmosphere can be utilized in the A gas stream containing atmospheric CO2 is fed to a formation of a sodium carbonate electrolyte for a three caustic air scrubber 10 containing an aqueous NaOH compartment electrolytic cell capable of producing a 15 solution containing about 5 to 25% NaOH and at ambi substantially pure synthesis gas for the production of ent temperatures of about 10-25 C., wherein Na2CO3 synthetic fuel.