Alumina-supported nickel catalysts for catalytic partial oxidation of methane in short-contact time reactors

Abstract

The aim of this work was the development and performance evaluation of alumina supported nickel catalysts for partial oxidation of methane to syngas in a self-sustained short contact time fixed bed reactor using pure oxygen or air. It was also verified the attainment of relative constant temperatures in an appropriate range (750–1050 °C) along the catalytic fixed bed independently of the operative weight hourly space velocity (WHSV); thus sintering and coking problems and the consequent performance decay were avoided. The activity tests with a Ni load of 5% and 10% by weight were carried out increasing the WHSV from 150 to 1440 Nl h −1 g cat −1. The results obtained with 10% Ni/Al 2O 3 catalyst when working with pure O 2 showed an excellent performance towards CH 4 conversion (>90%) and H 2 selectivity (>95%), comparable to the best rhodium based catalysts tested at the same operating condition [29]. When working with air, 10% Ni/Al 2O 3 was able to maintain the reactor thermally self-sustained using air rather than pure oxygen until WHSV of 1440 Nl h −1 g cat −1 (GHSV ≈ 750,000 h −1) and gave a performance similar to that with pure O 2 (but producing a syngas diluted by N 2) till a WHSV value of about 600 Nl h −1 g cat −1.