Methyl Propanediol (MPD) is an important organic chemical raw material, widely used in coatings, inks, resins, plasticizers, pharmaceutical intermediates and other fields. In this paper, we will introduce the manufacturing method of Methyl Propanediol, including raw material preparation, reaction process, post-treatment and precautions.
I. Raw material preparation
1. Acrolein: Acrolein is the main raw material for the preparation of methyl propylene glycol, which can be obtained by propylene oxidation method.
2. Formaldehyde: formaldehyde as another raw material, and acrolein addition reaction.
3. catalyst: usually choose acidic catalyst, such as sulfuric acid, hydrochloric acid, etc..
2. Reaction process
1. addition reaction: under the action of catalyst, acrolein and formaldehyde undergo addition reaction to produce 3-hydroxypropionaldehyde.
2. Reduction reaction: 3-hydroxypropionaldehyde undergoes reduction reaction to produce methyl propylene glycol. Reduction method can choose chemical reduction method, such as using hydrogen and catalyst for reduction, or using metal hydride for reduction.
III. Post-treatment
1. Distillation: After the reaction is completed, the unreacted raw materials and by-products are separated by distillation to obtain crude methyl propylene glycol.
2. Refining: The crude methyl propylene glycol needs to be further refined to remove the impurities in it. Usually distillation, extraction, crystallization and other methods are used for refining.
4. Precautions
1. Selection and use of catalyst: The type and dosage of catalyst have an important influence on the reaction speed and selectivity, so it is necessary to select a suitable catalyst according to the actual situation.
2. Control of reaction temperature: The reaction temperature also has a great influence on the reaction speed and selectivity, so it is necessary to control the temperature according to the reaction.
3. Safety protection: During the production process, it is necessary to pay attention to safety protection, avoid contacting toxic and harmful substances to ensure production safety.
In short, the manufacturing method of methyl propylene glycol includes raw material preparation, reaction process, post-treatment and precautions. By mastering the appropriate manufacturing methods, high quality methyl propylene glycol can be produced, providing important raw materials for the field of chemical production.
