SYNTHESIS OF TARGETED CATALYST FOR THE OXIDATIVE DEHYDRATION OF SEC-BUTANOL AND STUDY OF THE KINETICS AND MECHANISM OF THE PROCESS

F.A Agayev

doi:10.32737/2221-8688-2020-4-477-484

Abstract

The catalytic activity of CaA zeolite modified with metal cations (Cu, Zn, Pd) by means of ion exchange in the reaction of partial oxidation of sec-butanol to methyl ethyl ketone was studied at atmospheric pressure in the temperature range of 240-3500 C, space velocities 1500-4000 h-1 and partial pressures of butanol-2 PB−2 = 0.12-0.36 atm, oxygen O2 P = 0.12-0.24 atm. It found that the metal zeolite catalyst CuZnPdCaA containing 3.0 wt% Cu2+ , 2.0 wt% Zn2+ and 0.1 wt% Pd2+ exhibited the highest activity and selectivity in the reaction under consideration. Also, kinetic regularities of the reaction on the indicated catalyst were studied. On the basis of experimental data, a probable stepwise mechanism of the reaction was proposed and a theoretically substantiated kinetic model of the process developed.

Highlights

Methyl ethyl ketone (MEK) is used as solvent and extractant, in some cases superior to acetone, it proved not so volatile and safer in terms of fire
Methyl ethyl ketone is produced by oxidation of butylenes on PdCl2 a two-stage method which consists of hydration of n-butylene into butanol-2 with the participation of sulfuric acid as a catalyst and oxidative dehydrogenation of sec-butanol in MEK on mixed oxide catalysts [1,2]
In works [6,7,8,9,10,11,12], we found that zeolites modified with metal cations by ion exchange exhibit high catalytic activity and selectivity in the reactions of oxidative dehydrogenation of aliphatic alcohols at relatively low temperatures (250-3500C)

Summary

Introduction

Methyl ethyl ketone (MEK) is used as solvent and extractant, in some cases superior to acetone, it proved not so volatile and safer in terms of fire. Disadvantages of the process of oxidative dehydrogenation of sec-butanol in MEK are a relatively high temperature (400–5000C) and a low selectivity for methyl ethyl ketone [3,4,5]. For the production of methyl ethyl ketone, the method of oxidative dehydrogenation of secbutyl alcohol is used more [1] Due to these disadvantages, this method is characterized by low economic efficiency. The aim of this work is to select an active and selective catalyst for the reaction of partial oxidation of butanol-2 into one of the most important products of the chemical industry, methyl ethyl ketone, as well as to study the kinetics and mechanism of the reaction with the participation of active metal zeolite catalyst

Experimental part

Results and discussion

No Zeolite