United States Patent to 11 4,010,243 Thomas 45 Mar. 1, 1977

54 PREPARATION FOR POTASSIUM 532,301 1/1941 United Kingdom ...... 423/422 BICARBONATE FROM POTASSIUM 487,087 6/1938 United Kingdom ...... 423/422 HALIDE Primary Examiner-Oscar R. Vertiz 75) Inventor: Ian M. Thomas, Temperance, Mich. Assistant Examiner-Gary P. Straub 73) Assignee: Owens-Illinois, Inc., Toledo, Ohio Attorney, Agent, or Firm-Robert F. Rywalski; Edward J. Holler 22 Filed: Nov. 28, 1975 (21) Appl. No.: 638,225 57 ABSTRACT 52 U.S. Cl...... 423/424; 423/422 A process is provided for converting potassium chlor (51) Int. Cl...... C01D 7/16 ide to potassium bicarbonate with desirable conver 58) Field of Search ...... 423/419-429, sions which bicarbonate can then be calcined to potas 423/186, 187, 189, 190 sium carbonate. In one embodiment the potassium bicarbonate is formed in a reaction medium which is an 56 References Cited admixture of water and a water miscible alcohol with UNITED STATES PATENTS the other reactants employed being carbon dioxide and 2,752,222 6/1956 Birman ...... 423/422 an alkylamine. In a more preferred embodiment an 2,768,060 10/1956 Follows ...... 423/422 alcoholic solution of an alkylamine which solution is 2,782,093 2/1957 Hulot et al...... 423/422 saturated with carbon dioxide will be prepared and 2,913,310 1 1/1959 Sandborn et al...... 423f422 then an aqueous solution of a potassium halide, prefer 3,122,173 1/1963 Wolstein ...... 423f422 ably potassium chloride, will be added to the alcoholic 3,347,623 10/1967 Schmid ...... 423f422 solution so as to form potassium bicarbonate. FOREIGN PATENTS OR APPLICATIONS 1924,267 9/1970 Germany ...... 523,422 17 Claims, No Drawings 4,010,243 1. 2 be mentioned as primary, secondary and tertiary me PREPARATION FOR POTASSIUM BECARBONATE thylamines, primary, secondary and tertiary ethyla FROM POTASSUM HALIDE mines, primary and secondary normal or isopropyla The present invention is directed to the art of form mines, tertiary normal propylamine, primary (normal ing potassium bicarbonate and more specifically is or iso or secondary or tertiary) butylamines, secondary directed to a process for forming potassium bicarbon (normal or iso or secondary) butylamines, tertiary ate from a potassium halide; even yet more particularly (normal or iso) butylamines. In passing it should be the present invention is directed to forming potassium mentioned that mixtures of amines and mixtures of bicarbonate from potassium chloride employing car alcohols may likewise be employed. Additionally in bon dioxide and an amine and water as reactants. 10 order to obtain desired conversions at least stoichio For many years sodium carbonate, i.e., soda ash, has metric amounts of the reactants notably potassium been commercially manufactured from sodium bicar halide for example, potassium chloride, alkylamine, bonate which sodium bicarbonate is formed from so carbon dioxide, and water will be employed, i.e., each dium chloride. In this method of forming the bicarbon of the constituents relative to one mole of potassium ate sodium chloride has been reacted with carbon diox 15 chloride will be present in an amount of at least about ide and ammonia in excess water and is generally re 1 mole. Quite desirable results will be obtained by ferred to in the art as the Solvay Process or the Ammo employing a molar ratio of the amine to the potassium nia Soda Process. The latter process is not suitable halide of between about 1.5:1 to about 2:1. Addition however for the production of potassium bicarbonate ally, desirably the volume ratio of alcohol to water in from a potassium halide for example, potassium chlor 20 the miscible aqueous alcoholic medium will be at least ide. Thus, in order to obtain potassium carbonate from about 0.5:1 and preferably at least about 1:1. Conve potassium chloride the process which is comercially niently, ratios of about 0.5:1 or 1:1 to about 4:1 will be employed is a two-step process involving the electroly employed. Additionally, conveniently the total volume sis of potassium chloride to potassium hydroxide fol of alcohol and water employed per mole of the potas lowed by treatment of this product with CO, to give the 25 sium halide will be between about 300 to about 1000 carbonate. This obviously is an expensive and high ml. Thus as will be seen from the foregoing the ingredi energy consuming process and is accordingly undesir ents in performing the process consists essentially of an able. alkylamine, potassium halide, carbon dioxide, water, Thorpes Dictionary of Applied Chemistry, 4th Edition, and a water miscible alcohol. In passing it should be (1950), page 150 indicates that the ammonia soda 30 mentioned that while reference is made to amines or process was attempted by working in alcoholic solu alkylamines and carbon dioxide as reactants it will of tions in an attempt to obtain potassium bicarbonate but course be apparent that since it is probable that these that such attempts were not successful. Work has also two materials first react to form an alkylamine bicar been done using various amines and amine salts in bonate which then reacts further with the other re water but these likewise are not entirely satisfactory for 35 agents to form the potassium bicarbonate that this producing potassium bicarbonate from potassium terminology likewise contemplates such a reaction. chloride and these processes need improvement. While the present method will be found to produce in accordance with the present invention there is quite desirable results using various orders of addition provided an improvement in methods of manufacturing of the ingredients, in a highly preferred embodiment a potassium bicarbonates which methods of the prior art 40 prescribed order of addition will be followed. Thus, in involve reactively combining a potassium halide, for accordance with this preferred embodiment of the example potassium chloride, carbon dioxide, and an invention an alcoholic solution of an alkylamine will be alkylamine in the presence of water to form the bicar prepared which is saturated with carbon dioxide, such bonate. The improvement of the present invention solution for example being formed by simply bubbling essentially resides in employing, in addition to the 45 carbon dioxide into an alcoholic solution of the alkyla water which is present both as a diluent and a reactant, mine, and then an aqueous solution of a potassium a water miscible alcohol, i.e., instead of employing halide is added to that solution. The addition of the water itself the present invention contemplates per aqueous solution of potassium chloride to the alcoholic forming the reactive combination of the ingredients in solution of the alkylamine which has been saturated the presence of an admixture of water and a water 50 with carbon dioxide will desirably be done at a rate miscible alcohol. It will be found that when practicing sufficient to substantially preclude the occurrence of the present invention conversions of potassium chlor localized high concentrations of potassium halide upon ide to potassium bicarbonate, for example in terms of contact with the alcoholic solution. This can be accom product quality and conversion, will be quite desirable plished in various ways and is generally dependent on when contrasted to performing the same reaction 55 the manner of the addition of the potassium halide under substantially identical conditions in the absence solution and on the degree of agitation in the reactor. of the included water miscible alcohol. The amount of For example, the rate can be high if the agitation in the the water miscible alcohol employed in combination reactor is very violent and turbulent. If on the other with the water will be so selected such that the potas hand the agitation is mild then the rate of addition will sium bicarbonate product has lesser solubility in the 60 be slower. Dropwise addition, for example, can be done water-alcohol medium than in water perse. Exemplary with mild agitation of the reactor. Quite conveniently of the water miscible alcohols contemplated herein are one manner of adding the aqueous potassium halide methanol, ethanol, normal propanol, isopropanol, and solution to the alcoholic solution is to finely atomize tertiary butanol, or mixtures thereof. Since methanol the solution, for example with spray nozzles which are functions as a partial solvent for the product it will 65 disposed above the alcoholic solution whereby the generally be found most desirable to employ a C alco aqueous solution contacts the surface in a highly atom hol or higher. Exemplary of the alkylamines are those ized small particle state. By following this embodiment having 1 to 12 carbon atoms therein. Thus these may of the invention it will be found that residual potassium 4,010,243 3 4. chloride in the final potassium bicarbonate product will amine the reaction mixture was stirred vigorously and be decreased and accordingly conversions will be carbon dioxide gas was introduced slowly, but continu highly beneficial. Generally it will be desirable to add ously. At the completion of the potassium chloride the KCl solution over a period of at least five minutes. addition and cooling to about 20 C, the precipitated The process of this invention may be performed in reaction product was filtered with suction and washed conventional equipment using a propellor type stirrer with 100 ml of methanol. The solid product of potas operating at about 150-600 RPM and may be per sium bicarbonate was dried at 125 C. for 4 hours and formed over a wide range of temperatures and pres calcined at 250 C. for 1 hour. The weight of the cal sures and times. The reaction may be performed at cined solid was 30.6 g. It was analyzed for potassium atmospheric pressure with increased yields being real 10 carbonate, KCO, by titration with 1.0N hydrochloric ized by employing superatmospheric pressure e.g. pres acid and found to have a purity of 95%. The percent sure up to 50 psig, Convenient temperatures for per conversion was calculated as the weight of the solid forming the process are for example between about 25° product times the purity divided by the theoretical or 30°C. up to 60 or 70° C. or even higher with a range yield for complete conversion of potassium chloride to of about 30° C. to about 50 or 60° C. being quite satis 15 potassium carbonate. The conversion was found to be factory. In a convenient mode of practicing the present 84.6%. invention a potassium halide solution, suitably about 250 ml of water per mole of halide down to the water EXAMPLES 2-9 needed for a saturated solution, will be added to the These examples indicate the effect of certain reac reactor and the appropriate amount of water miscible tion parameters on yield and product purity when car organic alcohol then added thereto with stirring. The rying out the reaction of potassium chloride with dieth amine is added in any convenient manner. For exam ylamine and carbon dioxide in a methanol/water mix ple, it can be bubbled in or it can be dissolved in the ture to produce potassium bicarbonate. water miscible alcohol and added in that fashion. Sub The reactions were carried out in a one gallon stain sequently carbon dioxide gas is then added into the 25 less steel reactor fitted with a stirrer, thermometer and reaction flask. When doing this at atmospheric pressure gas inlet and outlet tubes. The vessel was jacketed in it will, of course, be most convenient to bubble the gas order to permit heating a cooling of the reaction mix in under the surface of the reactants in the reactor and ture. A bottom outlet permitted convenient removal of if Superatmospheric pressure (i.e., pressure above at the reactor contents. mospheric) is to be utilized as the mode by which the In the examples that follow, potassium chloride was process is practiced the carbon dioxide gas can simi dissolved in water and added to the reactor followed by larly be bubbled into the reactants below the surface the appropriate amount of methanol and diethylamine. thereof to build up the appropriate pressure in the head After heating to about 50 C. carbon dioxide gas was space of the reactor which is maintained during the bubbled into the reaction mixture at a rate sufficient to reaction; if desired the carbon dioxide can be directly 35 maintain the reactor at approximately 5 psig. The reac dispensed into the reactor into its head space and the tion mixture was heated or cooled as necessary in order appropriate maintained for operation at superatmos to keep the temperature as near as possible to 50 C. A pheric pressure. The reaction is exothermic and usually reaction time of two hours was selected and was re a reaction time on the order of about 1-3 hours will be corded as that time during which carbon dioxide was quite sufficient to obtain desired results. Generally the 40 being introduced into the reaction mixture. Example 9 completion of the reaction can be monitored by ob differed only in that a reaction time of three hours was serving that carbon dioxide is no longer being utilized employed. Stirring was maintained throughout the re in the reaction as evidenced for example by its no action. At the end of the reaction period the reaction longer being absorbed in the reaction medium. Upon mixture was cooled to about 20° C. and filtered. Fil completion of the reaction the reacted mixture is sim 45 trate was used to wash any residual solid product from ply cooled and the solid potassium bicarbonate then the reactor and this mixture was then filtered by adding separated from the liquid medium by filtration. Potas it to the original filter cake still on the filter funnel. Two sium carbonate is then obtained by calcination of the liters of methanol were used to further wash out the potassium bicarbonate. reactor. This methanol was then used to form a slurry While the foregoing describes the present invention 50 of the filter cake which was refiltered. Finally the solid so as to enable those skilled in the art to make and use product was washed with two 1.0 liter portions of fresh same and describes the best modes contemplated in methanol. The washed product was dried at 70 C. for practicing the present invention a few examples none about 1 hour and calcined at 250 C. overnight. theless follow for purposes of further exemplification. The analysis of the precipitated and calcined product 55 obtained at the end of the experimental runs included a EXAMPLE determination of the amount of potassium bicarbonate, A solution of diethylamine was prepared by dissolv KHCO, present as well as potassium carbonate, ing 66 g (0.9 mole) of this reagent in 300 ml of metha KCOa. Potassium bicarbonate was sometimes present nol in a 1000 ml flask fitted with a stirrer and gas inlet in small amounts when calcination was not complete. and outlet tubes. Carbon dioxide gas was bubbled into 60 Approximately 0.2 g of reaction product was dissolved the solution and the resulting exothermic reaction was in 75 ml of distilled water and titrated with 0.1 NHCl moderated by cooling the reaction flask. After the using phenolphthalein (pH range 8.2-10.0). The vol solution was saturated with carbon dioxide, as evi ume of hydrochloric acid required was noted and used denced by gas evolution in an exit bubbler, a solution of to calculate the percent composition of KCOs in the 37.3 g (0.5 mole) of potassium chloride in 100 ml of 65 sample. About four drops of methyl orange indicator water was added over a period of approximately ten (pH range 3.1-4.4) was then added to the titration minutes. During this addition which was at a rate less flask and the titration was continued to the endpoint of than about 0.06 moles of KCl per minute per mole of this acid base indicator. The additional amount of hy 4,010,243 5 6 drochloric acid required is due to the presence of po- calcined at 250 C. overnight. The weight of the cal tassium bicarbonate. The amount of potassium carbon- cined product was 215 g. with a purity corresponding ate equivalent to this amount of potassium bicarbonate to 97.5% KCO, determined as previously described. was calculated and this figure added to the value from The conversion of potassium chloride to potassium the first titration to give a total potassium carbonate 5 carbonate was 75.8%. assay. The weight of the dried and calcined solid from In Example 11 the reactor and quantities of reagents the reactor times the total potassium carbonate assay were the same as in Example 10. Diethylamine was divided by theoretical weight is taken as the percent introduced into the reactor followed by methanol. The conversion of potassium chloride to potassium carbon- temperature of this solution rose to about 32 C. and ate product. 10 was cooled to about 18 C. before the addition of car Additional reaction parameters as well as the results bon dioxide which was bubbled into the mixture at a of the experiments are reported in Table 1. rate sufficient to maintain a pressure of one atmo Table 1 CHOH Total HO Volume Assay, Moles Moles Volume CH-OH + % Example KCl (CH)NH Ratio HO KCOs Conversion 2 5 7.5 2 2700 ml 90.1 % 81.3% 3 5 7.5 1800 95.8 92.5 4. 4 6 0.5 1400 97.6 72.0 5 4 6 1 1920 97.6 81.0 6 4 6 2 2880 95.0 80.6 7 3 4.5 3 2880 88.8 69.2 8 4.4 4. 1 1920 72. 53.7 9+ 4. 6 l 1920 98.8 77.6 Reaction time 3 hours. When potassium chloride is used in excess, Example sphere in the reactor. After about one hour the mixture 8, the assay and conversion are poor. Best results are had become saturated with carbon dioxide as evi indicated by using at least stoichiometric amounts of denced by the increase in the rate of gas evolution in amines and a CHOH:HO volume ratio of 0.5:1 to 3:1. 30 the exit bubbler. Carbon dioxide was continuously bubbled in throughout the reaction. The temperature EXAMPLES 10 and 11 at this point was about 20 C. The aqueous potassium In these two examples the effect of the order of addi- chloride solution was then added over a period of 20 tion of reagents on the production of potassium bicar- minutes. At the end of this addition the temperature of bonate is illustrated. 35 the reaction mixture was increased by external heating The reactor was the same as that described in Exam- to about 50 C. in 15 minutes and held at this tempera ples 2-9. In Example 10 an aqueous potassium chloride ture for 1 hour before cooling to 21 and removing the solution was prepared by dissolving 298.2 g (4.0 mole) product. The mixture was stirred continuously through of reagent in 960 ml of distilled water. This solution out the reaction period. was introduced into the reactor and 1920 ml of metha- 40 The product was filtered and washed as described nol was added to it. Diethylamine, 438.8 g (6.0 mole) above in Example 10. It was dried at 60° C. for 1 hour was then added and the resulting mixture was heated to and calcined at 250 C. overnight. The weight of the about 38 C. Carbon dioxide was bubbled into the solid product was 225.1 g and analyzed as 98.2% reaction mixture at a rate sufficient to keep the reactor KCO. The conversion was therefore 80.0% pressure at one atmosphere. The temperature rose to 45 The results of these experiments indicate that the 50 C. within 10 minutes and was maintained at this addition of aqueous potassium chloride solution as the temperature for one hour and fifty minutes to give a last reagent in the reaction mixture is desirable. total reaction time of 2 hours. The mixture was stirred continuously throughout the reaction period. After EXAMPLES 12-14 cooling to about 20° C. the solid product was removed 50 In these examples the experimental procedures were from the reactor and filtered. The filtrate was used to essentially the same as those in Examples 2-9 except wash out the reactor and the additional product was that ethanol was substituted for methanol. The results combined with the initial material. Two liters of metha- are reported in Table 2. Table 2 CHOH Total HO Volume Assay, Moles Volume of CHOH % Example KCl (CHS)NH Ratio - HO KCO Conversion 12 4. 6 0.5 1440 98.7 86.7 13 4. 6 .0 1920 98.1 87.9 14 4 6 1.0 1920 98.6 87.4 nol was used to further wash the reactor and the filter cake was slurried with it also before refiltering. Finally 65 A higher degree of purity and percent conversion as the solid product on the filter funnel was washed with obtained here as compared to those reactions using two one liter portions of fresh methanol. The solid methanol. Examples 13 and 14 were run in an identical product was dried for one hour at 100° C. and then manner except that the former used denatured ethanol 4,010,243 7 8 while the latter used distilled ethanol free of the addi- propanol) to give a solution of known concentration tives present in the denatured alcohol. and appropriate aliquots were then added to the reac tion flask to give the desired amount of amine. After EXAMPLE 1.5 addition of the amine solution to the reaction flask The procedures followed in this example are substan- 5 additional alcohol was added. Carbon dioxide gas was tially the same as those described for Examples 2-9 bubbled into the solution while stirring and cooling. except that the alcohol used was isopropanol. Four After saturation with carbon dioxide and cooling to 20 moles of potassium chloride and six moles of diethyl- C. an aqueous solution of potassium chloride was amine were used with 960 ml of water and 960 ml of added dropwise to the mixture in the reaction flask. isopropanol. The purity of the product, obtained, cal- 10 Stirring was continued throughout the reaction and culated as carbonate was 98.3% and the conversion carbon dioxide was introduced slowly. The reaction was 89.6%. was carried out at atmospheric pressure. When addi tion of potassium chloride was complete and the reac EXAMPLES 16-19 tion mixture had cooled to 20 C., approximately 15 In this series of examples isopropanol was the alcohol 15 minutes, the solid product was filtered with suction and and diethylamine was the amine. Reactions 16 and 17 washed once with 100 ml of the alcohol used in the were carried out by adding carbon dioxide gas to a reaction, i.e., methanol or isopropanol. After drying at water-isopropanol solution of potassium chloride and 125 C. for 4 hours the product was calcined at 250 C. diethylamine. The reactions were at atmospheric pres- for 1 hour. The product was analyzed for potassium sure with carbon dioxide gas bubbled into the stirred 20 carbonate by titration with 1.0 N hydrochloric acid. reaction mixture continuously. Over a period of 20-30 The quantities of reagent used, degree of conversion minutes the temperature rose to about 50° C. and then of potassium chloride to potassium carbonate, and decreased. After cooling to about 20° C. the product purity of the product obtained are reported in Table 4. was filtered. Table 3 summarizes the results. TABLE 4 Ratio of Moles Moles of Volume Alcohol: Total Volume of Assay, Example KC Amine Volume Water Alcohol and Water %KCO Conversion Methanol and Dimethylamine 20 1.0 1.55 2.2:1 450 ml 65% 58% 21 1.0 1.75 2.0: 450 ml 77% 68% Isopropanol and Dimethylamine 22 1.0 1.50 2.0:1 450 m 99% 93% Isopropanol and Monomethylamine 23 1.0 1.60 2.0:1 450 ml 9% 82%

In Examples 18 and 19 an isopropanol solution of EXAMPLE 24 diethylamine was first saturated with carbon dioxide gas and an aqueous solution of potassium chloride In this example diethylamine is used in a pure aque Subsequently added, in one case all at once and in the ao ous solution with potassium chloride and carbon diox other dropwise. The reactor pressure was atmospheric ide. There is no alcohol present. and Table 3 summarizes these two examples. A solution of potassium chloride was prepared by TABLE 3 Her-to-real-e-la-e-elle-le i-CHOH Total HO Volume of Moles Moles Volume i-CHOH Assay, Example KCl (CH),NH Ratio and HO %. KCO Conversion . Comments 6 5 .75 3.5 450 m. 85% 84% CO, added to solution of KCl (CH),NH HO, i-CHOH 17 5 3.5 450 ml. 82% 81% CO added to solution of KCl (CH),NH HO, i-CHOH 8 5 .75 3.5 450 ml. 89% 87% KCl (HO) added at one time to (CH)NH, CO, i-CHOH 19 5 .9 3.0 400 ml. 100% 96% KCl (HO) added dropwise over ten minutes to (CH)NH, CO, i-CHOH also showed 0.3% chloride dissolving 74.6 g (1 mole) of this reagent in 250 ml of EXAMPLES 20-23 Water. g this solution was then added 146 g (2 mole) In Examples 20-22 the amine used is dimethylamine 65 of diethylamine to give a 2:1 molar ratio of amine to and in Example 23 the amine is monomethylamine. potassium chloride. Carbon dioxide gas was then bub Because these amines are gases at room temperature bled into the solution at a rate sufficient to maintain a they were first dissolved in alcohol (methanol or iso- pressure of one atmosphere in the reactor. The temper 4,010,243 9 1O ature slowly rose to about 58 C. and then fell to 40°C. carbonate and wherein said alkylamine contains from 1 indicating the reaction was substantially complete. The to 12 carbon atoms and wherein at least a stoichiomet total reaction time was about 90 minutes. The reaction ric amount of said alkylamine is employed relative to mixture was cooled to 8 C. filtered with suction but said halide and further wherein said aqueous solution not washed. After drying and calcination the solid of potassium halide is added at a rate sufficient to sub product was analyzed and found to have a potassium stantially preclude localized high concentrations of carbonate content of 47%. The degree of conversion of potassium halide upon contact with said alcoholic solu potassium chloride to potassium carbonate was 24%. tion. 2. The method of claim 1 wherein said aqueous solu EXAMPLE 25 10 tion is added over a period of time which is in excess of This example is a control experiment wherein the about 5 minutes. reaction of potassium chloride, diethylamine, and car 3. The method of claim 1 wherein said aqueous solu bon dioxide is carried out in water alone. The proce tion is added by being atomized over the surface of the dures followed and reagents used were essentially the alcoholic solution. same as those described in Example 3. The only differ 15 4. The method of claim 1 wherein said amine is an ence was the use of 1800 ml of water in this reaction amine having 1 to 6 carbon atoms. instead of 900 ml of water and 900 ml of methanol used 5. The method of claim 1 wherein the volume ratio of in Example 3. At the end of the reaction the solid prod alcohol in said alcoholic solution to water in said aque uct was filtered with suction and was washed with ous solution is about at least 0.5:1. methanol, dried, and calcined. The weight of the prod 6. The method of claim 1 wherein said alcohol is a uct was 174.5 g. Analysis by titration as described in C-C alkyl alcohol, or tertiary butanol, or mixtures Examples 2-9 gave a potassium carbonate content of thereof. 98.4% and a conversion of 49.7%. The benefits of the 7. The method of claim 1 wherein said alcohol is present invention will be readily apparent. isopropanol or ethanol. 25 8. The method of claim 1 wherein said halide is the EXAMPLE 26 chloride. 9. A method of manufacturing potassium bicarbon Example 1 of U.S. Pat. No. 3,189,409 was duplicated ate comprising reactively combining a potassium ha except the amounts of all materials were doubled, e.g. lide, an alkylamine and carbon dioxide in the presence 300 grams of triethylamine, 150 grams of KCl and 350 of a miscible aqueous alcoholic medium, and wherein grams of water were used. After the 4 hour period the 30 said alkylamine is employed in at least stoichiometric solid was filtered and washed with about 100 ml of amounts relative to said halide, so as to form said bicar methanol. There was obtained, after calcination, about bonate, said medium being so selected that said bicar 118.9 grams of material which assayed 92.2% KCO bonate is more insoluble therein than in water alone, and showed a strong chloride test. The conversion was 35 and separating said bicarbonate and wherein said 78.9 percent. 4. amine contains from 1 to 12 carbon atoms. EXAMPLE 27 10. The method of claim 9 wherein the volume ratio of alcohol to water in said medium is at least about The procedure of Example 26 was substantially du 0.5:1. plicated in which, in addition to the other materials, 40 11. The method of claim 10 wherin said ratio is be there was employed about 350 ml of isopropanol (vol tween about 0.5:1 to about 4:1. ume ratio of alcohol to water of about 1:1). The tem 12. The method of claim 1 wherein the mole ratio of perature rose to about 50 C and after about 30 min said amine to said halide is about 1.5:1 to about 2:1 and utes began to drop off. After an additional period of wherein the total volume of water and alcohol of said about 30 minutes the temperature was about 45° C. medium is between about 300-1000 ml per mole of The reacted system was then cooled over a period of 45 said halide. about 1 hour to about 15° C. After filtering, washing 13. The method of claim 9 wherein said reactive and calcination there was obtained about 135.6 grams combining is done at superatmospheric pressure up to of material which assayed 100% KCO, and which 50 psig, showed a trace of chloride, for a conversion of nearly 14. The method of claim 9 wherein said alcohol is a 97%. SO C, or higher alkyl alcohol or mixtures thereof. I claim: 15. The method of claim 9 wherein said alcohol is 1. A method of manufacturing potassium bicarbon ethanol. ate comprising adding an aqueous solution of a potas 16. The method of claim 9 wherein said alcohol is sium halide to an alcoholic solution of an alkylamine normal propanol or isopropanol. which latter solution is saturated with carbn dioxide so 55 17. The method of claim 9 wherein said alcohol is as to form potassium bicarbonate, said alcohol of said tertiary butanol. sk k is is sk solution being water miscible, and separating said bi

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65 UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION PATENT NO. : 4,010, 243 DATED : March l, 1977 NVENTOR(S) : Ian M. Thomas It is certified that error appears in the above-identified patent and that said Letters Patent are hereby Corrected as shown below: O Column 3, line 37 after the word "appropriate" insert -- pressure --. Column 6 line 65 delete "as" and substitute therefor -- was --. Column lO, line 42 in Claim l2, line l, change the dependency from "l" to -- ll --. Column 9, line 55 in claim l, line 4 delete "carbn" and substitute therefor -- carbon --. U eigned and gealed this Thirty-first Day of May 1977 SEAL Attest: O

RUTH C. MASON C, MARSHALL D ANN At testing Officer Commissioner of Patents and Trademarks O

O

O