- Technology Introduction
Trimethylolpropane (TMP) is an important organic chemical intermediate and fine chemical product, and has been widely used in many fields. It is mainly used in the production of alkyd resin and polyurethane, and is also used in the production of surfactants, wetting agents, plasticizers, fiberglass, rosin esters, advanced aviation lubricants, fiber processing agents, printing inks, and polyurethane foams. It can also be used Used as chain extender for resin, textile auxiliary and heat stabilizer for polyvinyl chloride (PVC) resin.
Industrially, TMP mainly uses n-butyraldehyde and formaldehyde as the main raw materials, and undergoes a condensation reaction under the action of an alkaline catalyst to obtain the intermediate dimethylol butyraldehyde. The intermediate further reacts with formaldehyde to generate trimethylolpropane.
The main processes are: Canizzaro method and catalytic hydrogenation method.
- Connizzaro method
In the Canizzaro method, n-butyraldehyde and formaldehyde aqueous solution undergo an aldol condensation reaction under the action of an alkaline catalyst to generate 2,2-dihydroxymethylbutyraldehyde, which is then reacted with excess formaldehyde. Cross-Canizzaro reaction occurs under strong alkaline conditions to generate TMP, formaldehyde is oxidized to generate formic acid, formic acid neutralizes with calcium hydroxide to generate calcium formate, and the reaction mixture is desalted and refined to obtain qualified products.
The Cannizzaro method is a traditional TMP production method. The process technology is relatively mature, and the technical indicators and process operations are relatively easy to master. Currently, many large TMP manufacturers in the world use this process as their main production method.
- catalytic hydrogenation
The catalytic hydrogenation method was successfully researched and developed in the 1970s and achieved industrial production in the 1980s. n-Butyraldehyde and formaldehyde react under the catalysis of trialkylamine (such as triethylamine) to obtain the aldol condensation product 2,2-dihydroxymethylbutyraldehyde, and then in the presence of the catalyst, 2,2-dihydroxymethylbutyraldehyde is reacted Methylbutyraldehyde undergoes aqueous hydrogenation reduction to obtain TMP product.
The catalytic hydrogenation method is a new TMP production technology developed in recent years. This method not only shortens the production process, but also greatly reduces the dosage of formaldehyde and alkali, and has very few by-products, and the refining of the product is also relatively simplified. The product yield is relatively high. However, this method has high requirements on catalysts and hydrogenation equipment, and it is relatively difficult to control the process technical indicators during the production process. Currently, this process technology has not been used to produce TMP products.
Our company’s trimethylolpropane production technology is based on the Cannizzaro method-calcium method.
- Product indicators
1) Trimethylolpropane
Trimethylolpropane Product Specifications
| serial number | Test items | unit | Technical indicators |
| 1 | Exterior | / | white flake crystal |
| 2 | Trimethylolpropane content | %wt | ≥99.0 |
| 3 | Hydroxyl value (weight) | %wt | ≥37.5 |
| 4 | Acid value (calculated as formic acid) | %wt | ≤0.0025 |
| 5 | Ash content | %wt | ≤0.02 |
| 6 | Moisture | %wt | ≤0.1% |
| 7 | melting point | ºC | ≥58 |
| 8 | Chroma | Fri-Co | ≤20 |
2) Bistrimethylolpropane
Ditrimethylolpropane Product Specifications
| serial number | Test items | unit | Technical indicators |
| 1 | Exterior | / | white flake crystal |
| 2 | Ditrimethylolpropane content | %wt | ≥95 |
| 3 | Hydroxyl value (weight) | / | 810-910 |
| 4 | Ash content | %wt | ≤0.05 |
| 5 | Moisture | %wt | ≤0.5% |
| 6 | melting point | ºC | 106-115 |
| 7 | Color | Fri-Co | ≤50 |
3) Calcium formate (by-product)
Calcium Formate By-Product Specifications
| serial number | Test items | unit | Technical indicators |
| 1 | Calcium formate | %wt | ≥98 |
| 2 | Exterior | / | White crystals |
| 3 | Organic matter content | %wt | ≤1.0 |
| 4 | Moisture | %wt | ≤0.5 |
For more detailed trimethylolpropane technical information, please contact us. Hubei Sanli Liquidambar Technology Co., Ltd. specializes in providing complete sets of chemical technologies.