Scientists from Boreskov Institute of Catalysis Developed Innovative Method for Synthesis of TMOS

Scientists from Boreskov Institute of Catalysis have developed a new, cost-effective and environmentally friendly method for synthesis of tetramethyl orthosilicates (TMOS), one of the crucially important chemical substances necessary for manufacturing a wide range of products within chemical and petrochemical complexes. The results of the study are published in the top-rated Chemical Engineering Journal (impact factor 13.273).

TMOS, tetramethyl ether of orthosilicic acid, is used in production of the advanced catalysts, efficient silicate sorbents, strong technical coatings and protective films, new composite materials, etc. However, there is still no cost-effective, environmentally friendly and power-saving industrial methods of TMOS production. The technologies engaged today produce a large amount of wastes, including hydrochloric acid that can adversely affect the environment, and this takes a lot of efforts to neutralize the impact.

To develop the new method for synthesis of TMOS the researchers used the reaction of silica with methanol in the presence of catalyst. The main obstacle for the efficiency of the synthesis was the problem of removing the isolating water, while the removal of water from alcohol is quite consuming in terms of energy and materials.

“The main problem of interaction of silica with alcohol is that water is produced as a result. Since the forming TMOS easily decays under the influence of water (i.e. the reaction is reversible), the main technical and scientific problem we faced at this stage was to timely remove water”, comments Dr. Ivan Kozhevnikov, researcher of BIC.

The reaction of SiO₂ with supercritical methanol was realized in one-pot flow reactor at a temperature of 270°C. Traditional sorption technologies of water adsorption usually do not work at elevated temperatures, especially when it is necessary to separate the mixtures of water and alcohol. This problem was solved with the help of cascade interchange of reactor zones of elevated heating, in which the reaction occurs, and cold parts of the flow reactor, in which the desiccant was placed for adsorbing the isolating water. The suggested construction allows obtaining the product of required purity with high TMOS concentration, which dramatically increases the cost-efficiency of the process.

Another important feature of the developed solution is the possibility to use various natural materials containing silica as the source feedstock. This helps to better tailor the industrial process for the customer’s needs.

“The demand for tetraalkyl orthosilicates, including TMOS, is very high at the global scale. They are used, in particular, in the manufacturing of various sorbents and supports, waterproof coatings, various composite materials, and even in dentistry, where certain additives are used”, says Dr. Andrey Chibiryaev, senior researcher of BIC. “The present market limitation of TMOS supply is determined by the flaws of the existing production of orthosilicates, which is expensive and dirty in terms of ecology. The new method of manufacturing based on our solution would allow a significant growth of TMOS production for satisfy the high demand at the market for these materials as well as support the ecological safety of the process”.