1. Definition of Sodium Methoxide
Sodium methoxide, also known as sodium methylate. Its molecular formula is CH3ONa, and its molecular weight is 54.02. Under normal temperature and pressure, it is a white amorphous powder with a density of 1.31 g/cm3. It is easily soluble in methanol and ethanol but insoluble in other organic solvents. Sodium methoxide is highly alkaline, extremely hygroscopic, and quickly decomposes into methanol and sodium hydroxide upon contact with water.
Sodium methoxide is an important chemical product with strong alkalinity and high activity. It can be used as a pharmaceutical intermediate for the production of vitamin A1, vitamin B2, sulfadiazine, etc. As the energy crisis attracts increasing attention, biodiesel, a green fuel, is favored by people. In the production process of biodiesel, solid sodium methoxide has high catalytic activity, is easy to separate and recycle, and causes less corrosion to equipment. It has more advantages than traditional homogeneous acid-base catalysts and has a good market prospect.
Sodium methoxide is a dangerous chemical product with corrosiveness and spontaneous combustibility. It is mainly used in the pharmaceutical industry and as a condensing agent, chemical reagent, and catalyst for the treatment of edible oils in organic synthesis. Sodium methoxide has a relatively wide range of uses. It is mainly used in the production of sulfonamide drugs. Sodium methoxide is also an organic synthesis catalyst and is used in pesticide production and the oil processing industry.
2. Industry classification of sodium methoxide
Sodium methoxide products mainly exist in two forms: solid and liquid. Solid sodium methoxide can be obtained from liquid sodium methoxide. The production methods of sodium methoxide mainly include the sodium metal method and the alkali method. The sodium metal method refers to the liquid sodium methoxide product obtained by the direct reaction of sodium metal with methanol. The purity of the product is relatively high, but sodium metal is expensive. Hydrogen is generated during the reaction process, increasing the risk of the operation. The alkali method refers to dissolving sodium hydroxide in methanol and reacting it with methanol to generate sodium methoxide. The raw materials are cheap and the operation is relatively safe. However, this reaction is reversible. The alkalinity of sodium methoxide is stronger than that of sodium hydroxide. Sodium methoxide is extremely prone to reverse reaction upon encountering water to regenerate sodium hydroxide and methanol. Sodium hydroxide often has side effects in pharmaceutical synthesis reactions, so the content of sodium hydroxide in liquid sodium methoxide products needs to be strictly controlled. In large-scale continuous industrial production, the alkali method is mostly used to produce sodium methoxide in a reaction stripper. A certain concentration of sodium hydroxide/methanol solution enters from the top of the tower, and a large amount of anhydrous methanol vapor is introduced from the bottom of the tower to contact the reaction liquid phase in countercurrent to remove the water generated in the liquid phase reaction and continuously promote the reaction in the direction of generating sodium methoxide. The traditional alkali method process recycles and reuses methanol through a methanol distillation tower to reduce methanol consumption. At present, the improvement and innovation of the alkali method process mainly involve adopting efficient methanol separation and recovery methods such as ion exchange resin method, molecular sieve method, and pervaporation, as well as improving the entire process flow, such as mechanical vapor recompression method. However, the main reaction process still takes place in the reaction stripper.
