Utilization of waste crude glycerol for hydrogen production via steam reforming over Ni-La-Zr catalysts

The biodiesel industry generates crude glycerol (CG) at the rate of 10% of the amount of biodiesel produced. With the production of this biofuel increasing, a large amount of CG is produced each year. This results in low price for it and its final disposal becomes a significant problem. Herein, steam reforming represents a viable route to valorize this biodiesel by-product into hydrogen. The performance of Ni-La-Zr catalysts (15 wt%) for steam reforming of a CG without any purification treatment has been investigated at atmospheric pressure and at 500 degrees C and 650 degrees C. These materials were prepared using a coprecipitation method with oxalic acid. At 650 degrees C, the catalyst calcined at 850 degrees C presents higher catalytic activity and stability and displays better resistance to deactivation by carbon formation than the catalyst calcined at 700 degrees C. This behavior can be attributed to several causes: higher surface nickel content, higher catalyst reducibility and the presence of oxygen vacancies formed as a consequence of the partial substitution of nickel atoms into the pyrochlore structure during the formation of the biphasic system, which is related to mechanisms that act in the removal of carbon deposits on the catalyst.