NEW ROUTES FOR THE PROCESSING OF OLEFINS AND AROMATICS

Duma, Viorel (Chemnitz University of Technology, Division of Industrial Chemistry, D-09107 Chemnitz, GERMANY) | Dietzsch, Enrico (Chemnitz University of Technology, Division of Industrial Chemistry, D-09107 Chemnitz, GERMANY) | Honicke, Dieter (Chemnitz University of Technology, Division of Industrial Chemistry, D-09107 Chemnitz, GERMANY)

OnePetro 

NEW ROUTES FOR THE PROCESSING OF OLEFINS AND AROMATICS NEW ROUTES FOR THE PROCESSING OF OLEFINS AND AROMATICS Viorel Duma, Enrico Dietzsch, Dieter Hönicke, Chemnitz University of Technology, Division of Industrial Chemistry, D-09107 Chemnitz, GERMANY

INTRODUCTION

Olefins and aromatics are two groups of the main products of steam cracking processes. as catalyst [2,3]. Nitrous oxide was adsorbed The conversion of these hydrocarbons into and activated in an appropriate manner on the more valuable chemicals is an important goal surface of the catalyst (Fig. I). The preparation of the petrochemical industry. Besides the of the catalysts was focused on obtaining well-known processes ideas exist for new and catalysts with different porosities as well as unusual routes of olefins and aromatics iron and sodium loadings. The reaction conversion. In the present study two parameters were varied to study the effect of heterogeneously catalyzed gas phase reactions, reactant composition, reaction temperature, gas viz. the direct epoxidation of propene and the hourly 'space velocity and time on stream on hydro- genation of benzene to cyclohexene activity and propene oxide selectivity. Further- were investigated. more, the possibility of regenerating the catalysts after a reaction experiment and the PROPENE EPOXIDATION distribution of products was also studied. Epoxides are important intermediates for The experimental results have shown the production of many chemicals. Aside from that the optimum catalyst have a mesoporous the manufacturing of ethene oxide, today the structure, an iron loading of 300 ppm and iron other epoxides like propene oxide are mostly oxide particles smaller than 2 nm. produced by means of indirect ways [I]. The Furthermore, the sodium impregnation reason for this is that alkenes which have improved the catalyst properties. Over this allylic hydrogen atoms react with oxygen over kind of catalyst high selectivities to propene the same catalysts used for the epoxidation of oxide of 40-60% were reached at economically ethene in both positions, vinyl and allyl. As a interesting propene conversions of 6-12%. The consequence, the reaction leads to the total iron catalyst offers two advantages, viz. low oxidation of C3+- alkenes. For the selective cost and an easy regeneration by air treatment. oxidation in the vinyl position, mild Further investigations have provided insights electrophilic oxygen species would be into the reaction mechanism and the nature of necessary. Our approach to solve this problem the active species. Related investigations by and direct the oxygen to the vinyl position was temperature- programmed de sorption and using nitrous oxide as oxidant and silica- reduction measurements have given valuable supported alkali-promoted iron oxide information [3,4]. BENZENE HYDROGENATION The surplus of aromatics especially benzene due to the expected substitution in gasoline by non-polluting components leads to the necessity to de