The production of hydrogen by steam reforming of trap grease - Progress in catalyst performance

Most hydrogen is currently produced via the steam reforming of natural gas. An environmentally preferable option is to produce hydrogen from renewable materials. Waste vegetable oil from food processing ("trap grease") is a low-cost, widely available renewable material that currently has no commercial use. In this work, we produced hydrogen via the fluidized-bed catalytic steam reforming of trap grease using commercial and experimental Ni/Al2O3 catalysts under conditions similar to those of commercial natural gas reforming operations-temperatures in excess of 800 degreesC, molar steam-to-carbon ratio of five, and a methane-equivalent volumetric space velocity of similar to1000 h(-1). During operation for 150 h, yields of 25 g of hydrogen per 100 g of trap grease were obtained. The process performance decreased with time, because of catalyst attrition and deactivation. We succeeded in extending the catalyst time-on-stream through the use of a laboratory-prepared attrition-resistant catalyst. Another strategy used was a two-step process where the thermal decomposition of grease preceded the catalytic fluidized-bed reforming and pyrolysis vapors instead of the liquid trap grease were fed to the reformer.