Supported catalyst systems and method of making biodiesel products using such catalysts
A heterogeneous catalyst system, a method of preparing the catalyst system and a method of forming a biodiesel product via transesterification reactions using the catalyst system is disclosed. The catalyst system according to one aspect of the present disclosure represents a class of supported mixed metal oxides that include at least calcium oxide and another metal oxide deposited on a lanthanum oxide or cerium oxide support. Preferably, the catalysts include CaO—CeO 2 ZLa 2 O 3 or CaO—La 2 O 3 /CeO 2 . Optionally, the catalyst may further include additional metal oxides, such as CaO—La 2 O 3 —GdOxZLa 2 O 3 .
1. A supported, heterogeneous catalyst system used for the production of a biodiesel product from the transesterification of an oil, the supported catalyst system comprising:
a mixed metal oxide catalyst; the catalyst including calcium oxide and at least one additional metal oxide; and
a metal oxide support selected from the group consisting of CeO 2 and La 2 O 3 upon which the catalyst is deposited;
wherein the metal oxide support exhibits basic properties and provides a synergistic effect to the mixed metal oxide catalyst in catalyzing transesterification reactions; and
wherein the supported catalyst system exhibits a pH of at least about 10.0 when 0.1 grams of the supported catalyst system is added to 2 mL of methanol.
2. The supported catalyst system of claim 1 , wherein the additional metal oxide in the mixed metal oxide catalyst is at least one selected from the oxides in which the metal is Ce, La, Nd, Pr, Er, Gd, or Yb.
3. The supported catalyst system of claim 2 , wherein the mixed metal oxide catalyst is one selected from the group of CaO—CeO 2 and CaO—La 2 O 3 .
4. The supported metal catalyst system of claim 2 wherein the supported catalyst system is in a pelletized form.
5. The supported metal catalyst system of claim 2 , wherein the mixed metal oxide catalyst is one selected from the group of CaO—NdOx-La 2 O 3 , CaO—NdOx-La 2 O 3 —CeO 2 , CaO—YbOx-La 2 O 3 —CeO 2 , CaO—ErOx-La 2 O 3 —NdOx, CaO—CeO 2 —La 2 O 3 —PrOx, CaO—NdOx-CeO 2 , and CaO—GdOx-La 2 O 3 .
6. The supported metal catalyst system of claim 1 , wherein the amount of calcium in the supported catalyst system ranges from about 0.5 to 15 atomic % and the amount of the other metals that comprise the additional metal oxide in the supported catalyst system range from about 0 to 15 atomic %.
7. The supported metal catalyst system of claim 1 , wherein the metal oxide support exhibits a pH of at least about 8.0 when 0.1 grams of the support is added to 2 mL of methanol.
8. A biodiesel product formed by reacting an oil with an alcohol in the presence of the supported catalyst system of claim 1 .
9. The supported catalyst system of claim 1 , wherein the supported catalyst system exhibits a pH of at least about 12.0 when 0.1 grams of the supported catalyst system is added to 2 mL of methanol.