STATISTICAL-ANALYSIS OF OLEFINS YIELD IN FIXED-BED CONVERSION OF DIMETHYL ETHER

Selective conversion of dimethyl ether to lower olefins is a process o f commercial significance. Lower olefins are intermediates in the conv ersion of dimethyl ether to higher hydrocarbons. Conversion of dimethy l ether to hydrocarbons has significant advantages over its counterpar t methanol conversion process in the areas of heat duties, hydrocarbon selectivities, product yield, and reactor size. The present work exam ines the effect of key process variables on the dimethyl ether convers ion to lower olefins in a fixed bed reactor system. The effect of proc ess variables, namely reactor temperature, reactor pressure, feed dilu tion with nitrogen, and the weight hourly space velocity of dimethyl e ther has been investigated using a 2(4) full factorial experimental de sign, with three replicates of the center point of the design. The est imates of significant main and interactive effects have been quantifie d using the Yates algorithm and conducting F-tests. A computational mo del has been formulated to predict the olefin yield at different value s of process variables. Normal probability plots have been obtained to test model adequacy. The predictive capability of the developed model has been proved as illustrated by parity plots.