Method 1: A process with a production capacity of 600t/a that is neutralized by propionic acid and calcium carbonate or calcium hydroxide. The reaction of propionic acid with calcium carbonate is completely similar to that of propionic acid with sodium carbonate. The reaction of propionic acid with calcium hydroxide and its production process are shown in the figure:

The main raw materials are propionic acid (food grade, content above 99.5%), quicklime (industrial grade, content of calcium chloride above 95%), deionized water (arsenic and heavy metals in the water must not be detected). Neutralization reaction conditions: the reaction temperature is 70-90°C, the reaction time is about 2-3 hours, and the pH value at the end of the reaction is 7-8. Concentration and crystallization process conditions The heat transfer oil inlet temperature is 170-180°C, the outlet temperature is 120-130°C, and the heat transfer oil flow rate is 6m3/h. Airflow drying process conditions The hot air temperature is 200°C, the drying temperature is 120-130°C, the material outlet temperature is 60°C, and the wind pressure is 4-5kPa.
Method 2: A membrane chemical reactor is used to prepare a high-purity calcium propionate. The preparation process roughly includes the following steps: (1) Put a certain amount of deionized water into the above membrane chemical reactor, and then heat it at 50-80°C At this time, the input amount of solid calcium hydroxide and propionic acid is alternately input into the membrane chemical reactor in 4-10 batches according to the mass ratio of 1:3.5-3.7, that is, a batch of propionic acid is added and then a batch of calcium hydroxide is added. , during the process of putting in the last batch of calcium hydroxide, test the pH value of the neutralizing solution several times, control the feeding speed and amount of the remaining calcium hydroxide according to the pH value, and stop feeding when the pH value reaches 6.4-8.0; (2 ) After feeding, keep the above reaction solution at 70-80°C for 30-40 minutes, and control the pH value of the reaction solution to 6.4-8.0; (3) After the reaction in the membrane chemical reactor, press filter, Crystallization, dehydration, and drying processes to obtain calcium propionate powder.