AROMATIZATION OF PROPANE OVER A ZEOLITE CATALYST IN BOTH A MICROREACTOR AND PILOT-PLANT

The conversion of propane to aromatics over a gallium-loaded ZSM-5 catalyst was studied at temperatures from 480-degrees-C to 550-degrees-C in two systems; a microreactor (3.0 g catalyst) at atmospheric pressure, and a pilot plant (430 g catalyst) at pressures from 180-800 kPa absolute. Comprehensive product composition was determined from separate gas and liquid product measurements involving two on-line gas chromatographs capable of measuring from hydrogen and methane through to BTX and C-12+. aromatics. Conversion and selectivity to aromatics were examined at each temperature for various values of the catalyst contact parameter, W/V0. The kinetics of the conversion of propane was modeled as a first-order reaction taking account of volume change with reaction. The kinetic results for the two reactors were similar, the specific rate constants following Arrhenius relationships with temperature with an activation energy of 81 410 J/mol (microreactor) and 86 850 J/mol (pilot plant). Maximum selectivity to aromatics in both the microreactor and pilot plant on carbon basis was 68.7 C% at 520-degrees-C. Increased pressure resulted in lower selectivity to aromatics and increased proportion of higher molecular weight, non-BTX, aromatics in the product.