[Methyl palmitate supply and sales] Preparation method of methyl palmitate

Methyl palmitate is a colorless liquid or crystal. Easily soluble in alcohol, acetone, chloroform and benzene, soluble in ether but insoluble in water.

There are two preparation methods for methyl palmitate:

1. A method of extracting and purifying methyl palmitate from biodiesel, It is characterized by including the following steps:

1) Add polyvinyl alcohol to deionized water, heat and stir until the polyvinyl alcohol is completely dissolved, then lower to room temperature, add potassium nitrate solid, stir and dissolve, and obtain polyethylene. Alcohol-potassium nitrate solution is used as an extraction agent for later use;

2) Carry out a methyl esterification reaction between vegetable oil containing palmitic acid and methanol to obtain biodiesel, and add the extraction agent of step 1) to the biodiesel. Stir and extract, and the lower extraction phase is back-extracted with petroleum ether, left to separate and separate, and the upper petroleum ether phase is separated. After the petroleum ether is evaporated, the oily methyl palmitate is obtained.

2. Add 26g palmitic acid and 38.4g anhydrous methanol to the reaction kettle in sequence, add 2.34g cerium phosphotungstate as a catalyst, heat and reflux for 4 hours, after the reaction is completed, recover the unprocessed product by distillation under reduced pressure. The reaction methanol; the methyl palmitate and the solid cerium phosphotungstate catalyst in the reaction kettle are separated by centrifugation. The upper layer is methyl palmitate. After the methyl palmitate is separated, the methyl palmitate product is obtained. The conversion rate of palmitic acid is 96.61%, the lower layer is a solid cerium phosphotungstate catalyst. Use 3.5g of deionized water to dissolve the separated solid cerium phosphotungstate catalyst. Add hydrochloric acid to prepare the solution with a pH value <1. Filter to remove the suspended cerium phosphotungstate solution that is not easily dissolved. The carbon deposits were removed, and the obtained cerium phosphotungstate solution was concentrated and crystallized to obtain 2.34g of solid cerium phosphotungstate. The solid cerium phosphotungstate was directly used as a catalyst for the next esterification reaction.