How to produce Potassium hydrogencarbonate?

Potassium hydrogencarbonate(CAS.NO:298-14-6)  is a colorless, odorless, slightly basic, salty substance. Soluble in water , insoluble in alcohol. Potassium hydrogencarbonate is "generally recognized as safe".There is no evidence of human carcinogenicity, no adverse effects of overexposure, and an undetermined LD50. Physically, Potassium hydrogencarbonate occurs as a crystal or a soft white granular powder. Potassium hydrogencarbonate is very rarely found in its natural form, the mineral called kalicinite.

1. Purposes

1) For the production of potassium carbonate, potassium acetate , potassium arsenite and other raw materials , it also used in medicine, food, fire extinguishing agent industry;

2) It can be  used as analytical reagent;

3) As acidity regulator and chemical leavening agents ,which can be used for all kinds of requirements which need to add leavening agent in food , according to production needs in moderation;

4) The production of potassium carbonate, potassium acetate , potassium arsenite materials. Petroleum and chemicals can be used for the extinguishing agent. it can also be used in medicine, baking powder.

2.Production methods

1) Carbonation
Potassium carbonate raw materials available three products. As a raw material,it can be an alkali earth , containing 40% to 60% of potassium carbonate , 10% to 15% potassium sulfate , potassium chloride 3.5% , before feeding to be calcined to remove organics , by the different solubility of potassium sulfate and potassium chloride was removed , milk of lime or magnesium can be removed by pressure filtration of silicon, aluminum , phosphorus and other impurities , and the filtrate was evaporated , the preparation of potassium carbonate solution , the total alkali concentration of 750 ~ 800 g / L ( total potassium carbonate ) , into the carbonation tower . At a temperature above 50 ℃ , reaction pressure 0.4MPa , the pass carbon dioxide ( 30% concentration ) for carbonization , with the concentration of Potassium hydrogencarbonate and continuous precipitation . 5 ~ 6h carbonation crystallization mother liquor after separation, washing , centrifugation , dried at 80 ℃ , Potassium hydrogencarbonate to obtain the finished product . Its

K2CO3 + CO2 + H2O → 2KHCO3


2) Ion exchange method

Potassium chloride solution by the addition of calcium, magnesium Walter countercurrent ion exchange column , so that sodium resin (R-Na) becomes potassium type (RK), washed with soft water chlorine ions, ammonium bicarbonate solution downstream through the resin exchange column , to obtain a mixture of Potassium hydrogencarbonate and ammonium bicarbonate dilute solution by evaporation decomposition of most of the decomposition of potassium carbonate , and the solution generated by carbonization send carbonation tower Potassium hydrogencarbonate , and then by crystallization, separation , washing and drying to obtain a Potassium hydrogencarbonate product. Its

R-Na + KCl → R-K + NaCl

R-K + NH4HCO3 → R-NH4 + KHCO3

2KHCO3 → K2CO3 + CO2 ↑ + H2O

K2CO3 + CO2 + H2O → 2KHCO3

3) Solution reaction


By potassium hydroxide in 80% ethanol solution or saturated solution of potassium carbonate to absorb carbon dioxide prepared products.
K2CO3 + CO2 + H2O → 2KHCO3