CaO Supported on Porous Carbon as Highly Efficient Heterogeneous Catalysts for Transesterification of Triacetin with Methanol

Abstract

A series of carbon-supported CaO materials, prepared using different porous carbon materials as supports, were tested as basic catalysts for the transesterification of triacetin with methanol and characterized by means of X-ray diffraction (XRD), N 2 adsorption, temperature-programmed desorption (TPD), and X-ray photoelectron spectroscopy (XPS). It was found that all of the carbon-supported CaO catalysts are active for the transesterification reaction, and their catalytic performance can be influenced by a variety of factors, such as the types of carbon supports, the concentration of impregnated CaO, the heattreated temperatures of the catalysts, and the reaction temperatures. Particularly, the supported CaO catalyst, which is prepared using a kind of porous carbon (NC-2) as a support, exhibits very high activity, stability, and recyclability. We suppose that the main characteristics of this porous carbon, such as the presence of relatively abundant surface oxygen-containing functional groups and well-developed porosity, may be beneficial to build a suitable interaction between CaO particles and the carbon support, thus resulting in the formation of an active and stable catalyst system.

Biodiesel production from wet microalgae feedstock using sequential wet extraction/transesterification and direct transesterification processes

“…Although it was found in this study that the effects of the reaction temperature, oil-to-methanol ratio, and reaction time on the efficiency of the transesterification of microalgal oil were similar to those reported in related studies (Dang et al, 2013;Zu et al, 2010), the efficiency obtained in this work was higher than that in the related literature when the reaction was conducted at a low temperature (e.g., 35°C). It is thought that the presence of hexane as a co-solvent played a major role in improving the transesterification efficiency.…”

Preparation and catalytic behavior of biomorphic calcium oxide/carbon solid base materials

“…53 Zu et al 54 have reported two types of "CaO" phases in nanoporous carbon-supported CaO catalysts: the type-I phase has a strong interaction with surface oxygen-containing functional groups of the carbon supports Moreover, some oxygen-containing functional groups exist on the surfaces of carbon support, which would result in surface acidity.…”

Biodiesel production from crude Jatropha Curcas oil using calcium based mixed oxide catalysts

“…The active centers in mixed oxides could be either oxygen atoms or the dopants itself. Several research groups were reported that the interaction between CaO and supported [4,22,23] or the formation of binary complex oxide [9,24] improved the catalytic stability. Modification the cation shift in the Ca 2+ -O 2À system enhanced the transesterification processes [3].…”