(135a) Granular Type of Supported CaO Catalyst for a Continuous Flow Reactor
Supported CaO catalysts showed a high heterogeneous catalytic activity for transesterification of triglycerides with methanol at relatively low temperature. However, the mechanical strength of a granular type of solid catalyst was not enough strong to be used in a continuous flow reactor for a long period. La2O3, CeO2, ZrO2, ã-Al2O3, and mixtures of them were chosen as supports. In order to make mechanically stronger granular type of catalyst, nitrates salts of Ca, Ce, and La were loaded on the various supports. In order to prepare granular type of supported catalyst, polyols such as polyethyleneglycol, Lycatab-PGS, and corn starch were added to the metal salts loaded solids in an aqueous solution. The starched solids were calcined 1000°C for 2 hrs. The attrition resistance was measured using ultrasonic fragmentation. The binding effects of supports and binding agents on the mechanical strength of the granular type catalyst were evaluated. Metal compositions and surface acidity of the supported catalysts were determined with SEM-EDS and pH indicators, respectively. The concentration of metals dissolved from the catalyst to the reaction medium was measured with inductively coupled plasma spectrometry. Catalytic activity and deactivation feature of supported CaO catalyst were measured in a continuous flow reactor where transesterification of triglyceride with methanol took place for a long period. The catalytic activity of the supported CaO was highly dependent on acidic or basic property of the supports. The leaching of Ca specie can be minimized by using combined metaloxides (CaO-La2O3, CaO-CeO2) loading on multi composition support.