Preparation and Characterization of Malaysian Dolomites as a Tar Cracking Catalyst in Biomass Gasification Process

Abstract

Three types of local Malaysian dolomites were characterized to investigate their suitability for use as tar-cracking catalysts in the biomass gasification process. The dolomites were calcined to examine the effect of the calcination process on dolomite’s catalytic activity and properties. The modifications undergone by dolomites consequent to thermal treatment were investigated using various analytical methods. Thermogravimetric and differential thermal analyses indicated that the dolomites underwent two stages of decomposition during the calcination process. The X-ray diffraction and Fourier-transform infrared spectra analyses showed that thermal treatment of dolomite played a significant role in the disappearance of the CaMg(CO3)2phase, producing the MgO-CaO form of dolomite. The scanning electron microscopy microphotographs of dolomite indicated that the morphological properties were profoundly affected by the calcination process, which led to the formation of a highly porous surface with small spherical particles. In addition, the calcination of dolomite led to the elimination of carbon dioxide and increases in the values of the specific surface area and average pore diameter, as indicated by surface area analysis. The results showed that calcined Malaysian dolomites have great potential to be applied as tar-cracking catalysts in the biomass gasification process based on their favorable physical properties.

Green Biofuel Production via Catalytic Pyrolysis of Waste Cooking Oil using Malaysian Dolomite Catalyst

“…The composition of calcined Malaysian Dolomite in this study are similar with Malaysian Dolomite catalyst, P1 reported by Mohammed et al [15] in biomass gasification process. The main content of this Malaysian Dolomite are CaO (31.0 %), MgO (20.0 %), and small amount of undesirable impurities, such as: SiO2, MnO, K2O, Na2O, and Al2O3.…”

“…While, the small additional peaks of SiO2 (JCPDS 35-0063), TiO2 (JCPDS 76-0326) and Fe2O3 (JCPDS 89-0597) were also observed, occurring at 2θ of 28°, 72°, and 74°, respectively. All peaks were also observed in research work conducted by Mohammed et al [15].…”

“…The formation of CaO and MgO indicated that Malaysian Dolomite could convert triglycerides of WCO to long chain hydrocarbons in a gasoline and diesel range. Mohammed et al [15]…”

“…The surface area and pore volume of calcined Malaysian Dolomite (CMD900) has increased from 2.25 m²/g to 12.02 m²/g and 0.06 cm³/g to 0.24 cm³/g, respectively, due to thermal activation at 900 °C. Based on Mohammed et al [15], the increasing of surface area and pore volume are possibly due to the high formation CaO and MgO content and removing of undesirable impurities, such as: SiO2, MnO, K2O, Na2O, and Al2O3, in calcined Malaysian Dolo-mite. A reduction of 58 % in average pore diameter of calcined Malaysian Dolomite was observed due to decomposition of carbonates mineral and the release of CO2 as represented in Equations (2) and (3).…”

Utilização de resíduo de mármore e de óxido de boro em escórias sintéticas dessulfurantes para aços.

“…Primeiro há a decomposição do MgCO3 presente na dolomita, acima dos 600ºC. Na sequência, próximo aos 800ºC ocorre a decomposição da calcita (CaCO3) [66].…”