ZnO nanoparticle catalysts for use in biodiesel production and method of making

摘要

A method of forming a biodiesel product and a heterogeneous catalyst system used to form said product that has a high tolerance for the presence of water and free fatty acids (FFA) in the oil feedstock is disclosed. This catalyst system may simultaneously catalyze both the esterification of FAA and the transesterification of triglycerides present in the oil feedstock. The catalyst system is comprised of a mixture of zinc oxide and a second metal oxide. The zinc oxide includes a mixture of amorphous zinc oxide and zinc oxide nanocrystals, the zinc nanocrystals having a mean grain size between about 20 and 80 nanometers with at least one of the nanocrystals including a mesopore having a diameter of about 5 to 15 nanometers. Preferably, the second metal oxide is a lanthanum oxide, the lanthanum oxide being selected as one from the group of La2CO5, LaOOH, and combinations or mixtures thereof.

主权项

1. A heterogeneous catalyst system comprising:
a mixture of amorphous zinc oxide and zinc oxide nanocrystals, the zinc nanocrystals having a mean grain size between about 20 and 80 nanometers with at least one of the nanocrystals having a crystal face that includes a mesopore having a diameter of about 5 to 15 nanometers; and a lanthanum oxide, wherein the combination of the zinc oxide mixture and the lanthanum oxide exhibits a Zn:La bulk molar ratio between about 9.0:1.0 and 1.0:1.0 and having a first surface site and a second surface site, the first surface site capable of catalyzing a transesterification reaction of triglyceride with an alcohol and the second surface site capable of catalyzing a esterification reaction of a fatty acid with an alcohol.