Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-20FORMALDEHYDE FORMATION DURING NON-OXIDATIVEDEHYDROGENATION OF METHANOLV.F. Tretyakov, A.M. Ilolov, R.M. Talyshinskiy, T.N. Burdeynaya, A.S. LermontovA.V. Topchiev Institute of Petrochemical Synthesis RAS, Moscow, Leninsky pr. 29E-mail: tretjakov@ips.ac.ruFormaldehyde is one of important chemicals with annual production of 27 million tonnes,which are used for the synthesis of polymers, resins, paints and explosives. Currently, the mostwidely used technology for formaldehyde production is the partial oxidation of methanol (1):2 CH 3 OH + O 2 2 CH 2 =O + 2 H 2 O (1)The main drawback of this technology is water produced during synthesis leading to formalinproduction instead of pure formaldehyde. Production of pure formaldehyde from formalinneeds a complicated distillation procedure which increases its overall cost. The side reactionsleading to formic acid are also not favorable from process organization and equipment.Non-oxidative methanol dehydrogenation (2) gives a mixture of formaldehyde andhydrogen which is easy separable. Moreover, this method also produces hydrogen – clean fuelCH 3 OH CH 2 =O + H 2 (2)of XXI century, which could be used for heating the rector for formaldehyde productionpreventing toxic exhausts.The catalyst based on modified silica (K-1) was developed for this process and tested atvarious conditions for methanol dehydrogenation. The results are presented in Table 1.Table 1. Experimental data for formaldehyde production on K-1 catalyst at different reactionconditionsCatalystsCH Yield, %WHSV,CHh –1 T, C volume, N 2 , l/min 3 OH,3 OHCH 2 =Oconversion,selecti-vity,cm 3ml/minCH%2 O CO CH 4%0,141 900 0,326 0,35 85,4 1,8 83,6 ~ 2,130,315 7500,326 0,335 23,5 4,16 19,34 ~ 17,71,19 900 1,4 2,8 +5%H 2 O 45,4 12,6 32,8 ~ 27,72,02 900 0,7 2,8 50,5 21,3 29,2 ~ 42,3201,59 900 0,7 2,8 48,0 16,8 31,2 ~ 35,02,12 9001,4 5,6 40,6 11,2 25,9 3,5 27,7Thermodynamic calculation shows that the desired reaction (2) starts only from 500 °C,but the typical catalysts (sodium-containing solids) performance starts near 900 °C. Thecurrent opinion is that active centers of catalysts for non-oxidative methanol to formaldehydeconversion are sodium atoms evaporated from the surface of catalysts. Gaseous state of activeparticles and gas-phase catalysis leads to extremely high sensitivity of the reaction to large432