OP-II-3

PP-III-43METHANOL AND DIMETHYL ETHER SYNTHESIS INSUPERCRITICAL CONDITIONS OVER (Au, Ag) – Cu/ZnAl 2 O 4CATALYSTSPaweł Mierczyński, Tomasz P. Maniecki, Katarzyna Bawolak,Wojciech K. JozwiakTechnical University of Lodz, Institute of General and Ecological Chemistry90-924 Lodz, Zeromskiego 116, e-mail tmanieck@.p.lodz.plMethanol and DME synthesis in supercritical conditions is an interestingopportunity to the classical industrial process. During last years a few rapportsreferring to this method of oxygenate production can be found in the literature.Synthesis in supercritical conditions allows to achieve a mixture of CH 3 OH and(CH 3 ) 2 O. The product distribution depends strongly from catalysts and reactionconditions (pressure, temperature, kind of supercritical fluid). Such mixture can bedirectly used as a fuel for diesel engines (for DME cetane number – 55, petroleumachieves 53 only). Additionally European Union consider the possibility of use DMEas primary fuel for diesel engines in 2030. Above mentioned facts suggest that newways of methanol and DME synthesis are necessary. For both process a typicalmethanol synthesis catalysts can be used.In this work we studied the influence of catalyst composition and, reactionconditions on selectivity and yield of oxygenates synthesis.Catalysts were prepared by coprecipitation method from zinc, aluminum andcopper nitrates. Mixture of hydroxides were dried and finally calcined at 400C.Promoters (Au, Ag) were introduced by impregnation or precipitation method. Coppercontent was 10-60% wt , Promoters content was 1 or 5% of weight. Prior to reactioncatalysts were reduced in 5%H 2 -95%Ar mixture. Reaction were carried out in asystem built on the base of small autoclave, high pressure flow regulators and backpressure regulators. Liquid phase used as a supercritical solvent were introduced viahplc pump. Synthesis were carried out in a CO/CO 2 /H 2 feed with molar ratio 4:2:12.As a supercritical fluid we used n-pentane or n-octane. The reaction pressure had astrong influence on reaction way. In low pressure range DME as a main reactionproduct were observed. At higher pressure (above 100 bar) methanol was the mainproduct of reaction. The CO conversion achieve 50% for the most active catalyst.The most active was catalyst 20%Cu-1%Au/ZnAl 2 O 4 .519