A method for esterifying high-acid value oils with vaporized methanol

Abstract

The invention discloses a method for esterifying high-acid value grease by utilizing vaporized methanol. The method comprises the steps: adding the high-acid value grease into a reaction kettle having the bottom with a circulation pipeline, and heating to a preset reaction temperature; then allowing the grease to be continuously circulated in the circulation pipeline, carrying out reverse contact and mixing with the continuously-introduced vaporized methanol in the circulation pipeline, and then sending into the reaction kettle until an acid value of the materials in the reaction kettle is less than or equal to 1 mg KOH / g; and adding an acid catalyst into the reaction kettle to catalyze an esterification reaction. The vaporized methanol and the grease are in inverse contact in the circulation pipeline, so that the two materials can be fully mixed and the esterification reaction is brought forward to the circulation pipeline for rapid performing, the reaction time is shortened, the grease is only required to be heated for one time before the reaction, the temperature in the reaction kettle is not required to be controlled in the reaction process, and an external heater is more not required to be used for continuously heating the reaction materials; and the method has the advantages of easy manipulation, fast speed, less energy consumption and the like.

Description

technical field [0001] The invention belongs to the technical field of biodiesel production, and in particular relates to a method for esterifying high-acid-value oil with vaporized methanol. Background technique [0002] Biodiesel is a renewable clean energy. The existing biodiesel acid-catalyzed esterification process mainly involves adding grease, catalyst and liquid phase methanol into a reactor, heating to a certain temperature and then maintaining a constant temperature for esterification. When the reaction temperature exceeds 65°C, the methanol is evaporated before the esterification reaction, which increases the pressure in the kettle. At the same time, due to the continuous phase change of liquid phase methanol during the heating process and the reaction process, it absorbs a large amount of heat, resulting in a slow heating process. , the reaction temperature is difficult to control, the reaction time of the reaction section is 6 hours, which takes a long time, and...

AI Technical Summary

Problems solved by technology

When the reaction temperature exceeds 65°C, the methanol is evaporated before the esterification reaction, which increases the pressure in the kettle. At the same time, due to the continuous phase change of liquid phase methanol during the heating process and the reaction process, it absorbs a large amount of heat, resulting in a slow heating process. , the reaction temperature is difficult to control, the reaction time of the reaction section is 6 hours, which takes a long time, and more water is produced during the esterification reaction, which prevents the reaction from proceeding forward

When an external heater is used to heat the grease, since the grease needs to pass through the heater during the whole reaction process, it is easy to cause blockage of the heater