01/18/2012

www.gupta-verlag.de/polyurethanes

BMS commissions new hydrogenation technical center

"All global research activities related to the production of aromatic isocyanates have now been pooled in the new hydrogenation technical centre,” said Dr. Joachim Wolff, head of the polyurethanes business and member of the Executive Committee of Bayer MaterialScience, on the occasion of the commissioning. "The associated efficiency gains in the research and optimisation of the production processes will help to further expand our global technological leadership.”[image_0]The facility is focused on hydrogenation technology for the production of precursors to MDI and TDI. MDI is based on benzene, which is first nitrated into nitrobenzene and then hydrogenated to produce aniline. An additional step then converts the aniline to diphenylmethane diamine, the direct precursor to MDI. A catalyst is used to produce aniline from nitrobenzene and hydrogen gas. With the conventional isothermic process, which is performed at a constant temperature, the substantial heat generated during the reaction must be dissipated using heat transfer oils. The reaction takes place inside a reactor block, in which many thousands of tubes containing the catalyst have been welded together. Finally, the aniline must be painstakingly purified of byproducts before it can be used further.

According to BMS, the adiabatic variant developed by the company is a current example of innovative process development in the area of hydrogenation. The technology eliminates the need for heat transfer and enables a substantial gain in efficiency. Here the reaction takes place in a large steel vessel, in which the catalyst is placed on a grating. The heat of reaction is dissipated together with the gas flow, eliminating the need for the circulating oil loop. In addition, the product is also of significantly higher purity.

"The technology is already proving to be extremely successful in our world-scale facility in Shanghai, China, with an annual production capacity of 350,000 metric tons. The conventional process would have been too complex and too expensive for a facility of this size,” said Dr. Thorsten Dreier, who heads the isocyanate research department at polyurethane production.

The researchers plan to concentrate on the further optimisation of both process variants at the new technical centre. Other focal points will be researching and improving the hydrogenation of dinitrotoluene to obtain toluene diamine, the direct precursor to TDI, and also the Deacon process for the oxidation of hydrogen chloride.

BMS says it is not just the efficiency of the production processes that plays a central role at the new technical centre. The building itself is state-of-the-art and was designed for sustainability using innovative materials from the EcoCommercial Building network.



www.gupta-verlag.de/polyurethanes