Brief description of potassium formate production process:
Due to different raw materials and routes, potassium formate production mainly includes the following types.
(1) Formic acid method
Formic acid and potassium hydroxide are used as raw materials to produce potassium formate and water.
KOH+HC00H-- HC00K+H20
Formic acid and potassium carbonate are used as raw materials to produce potassium formate and water.
K2C03+2HC002一一HC00K+C02+H20
Potassium formate is prepared by direct reaction of formic acid and potassium hydroxide or potassium carbonate under certain conditions. The process is to add methanol and potassium hydroxide or potassium carbonate into the reactor, stir, and control the reading of English to prepare potassium formate. Then, the prepared potassium formate is sent to the vaporizer to evaporate the water generated by the reaction in potassium formate, and make the potassium formate in a compatible state to prepare the product. Then
It can be used by users. Therefore, it has the characteristics of simple process, easy operation, standardized model production, low cost and no "three wastes" emission. However, to obtain potassium formate with high purity, a relatively complex purification process is required, with high cost and low quality.
(2) High pressure synthesis of C0 and KOH
Using C0 and potassium hydroxide as raw materials, potassium formate is produced without by-products.
C0+K0H- - - HC00K
At present, CO method is mainly used to produce potassium formate in China. This method can use the waste gas containing C0 to reduce environmental pollution, but the cost of potassium hydroxide is high, and a large amount of energy is required to produce the temperature and pressure conditions required for the reaction, which belongs to a high energy consumption method. The process includes pressure swing adsorption of synthesis gas, synthesis reaction, evaporation and concentration, crystallization, centrifugal separation, drying and packaging.
(3) Acid base method
The neutralization method includes potassium hydroxide and formic acid neutralization method, potassium carbonate and formic acid neutralization method, and potassium bicarbonate and formic acid neutralization method. These three methods have the advantages of simple process and easy operation. However, the above methods all use formic acid with volatile corrosivity as raw material, resulting in the disadvantages of high production cost, serious pollution, high equipment cost and easy injury to workers.
(4) Anion exchange resin method
This method solves the problem of high cost and high energy consumption in the process of preparing potassium formate existing in the prior art. The steps include: using the cation exchange resin as the reaction carrier, exchanging the KCl solution with a concentration of 15% - 30% with the cation exchange resin for a reaction time of 2-12 hours; then washing the cation exchange resin, and then continuing to react with the cation exchange resin with 20-60% sodium formate solution to finally obtain the potassium formate solution, which is crystallized after concentration and sedimentation treatment to obtain qualified products. The energy consumption is greatly reduced, which indirectly reduces the product cost. After the reaction, no harmful substances are produced and no environmental pollution is caused. Since the potassium formate solution produced has almost no harmful impurities, it has high purity and excellent quality after crystallization. However, the raw material used is 15% - 30% KCl solution, and the raw material price is high, resulting in an increase in product cost.
(5) Reaction of formaldehyde, potassium hydroxide and isobutyraldehyde in water
This method uses formaldehyde, potassium hydroxide and isobutyraldehyde in a molar ratio of 1:1:1 to 3:2:1 at 0-100'c, preferably 30-70 C in water. The resulting reaction solution was neutralized to a pH of 4-6 and evaporated in the first step, thereby obtaining two phases, an organic phase and an aqueous phase, the latter comprising the main part of potassium formate, and subsequently the organic phase and water
Phase separation, after final evaporation under the pressure of water phase bar and at the temperature of 160250c, a melt of potassium formate is obtained, water is added and then filtered to obtain a solution with a potassium formate content of more than 99 wt%, which is calculated on an anhydrous basis. In this way
The purity of the product is high, but due to the use of organic solvents formaldehyde and isobutyraldehyde, it is easy to cause environmental pollution.
(6) Seawater adsorption method
This method uses seawater, bittern or other potassium - containing brine as raw materials and natural clinoptilolite as inorganic ion adsorbent To achieve potassium enrichment, the raw materials in the adsorbent after adsorption saturation are ejected with water, and then the adsorbent is eluted with sodium formate solution to prepare a potassium rich solution. Then, the potassium rich solution is separated by two evaporation, concentration and centrifugation to prepare 75% liquid potassium formate for industrial use, or the liquid potassium formate is separated by evaporation, concentration and centrifugation to obtain a solid potassium formate product. The natural clinoptilolite can be recycled after elution and regeneration. The waste water and wet sodium formate produced in the reaction process can be recycled. Compared with the prior art, the method has wide sources, low cost and environmental protection, but it is suitable for coastal and inland areas with rich brine resources.
(7) The waste liquid produced by preparing pentaerythritol is used to produce pentaerythritol and produce potassium formate and sodium sulfide
The waste liquid produced in the preparation of pentaerythritol is subjected to vacuum distillation to obtain pentaerythritol crystal and sodium formate. Then, after the reaction of sodium formate and potassium sulfate, further deep processing is carried out to obtain potassium formate and sodium sulfide products respectively.
This method can digest waste liquid and reduce the environmental pollution caused by waste residue; It can also produce valuable potassium formate and sodium sulfate products with limited social benefits and economic benefits. It is a practical treatment and utilization method with simple production process and equipment. But the problem with this method is that the production of potassium formate is a by-product.