Base Catalysts Derived from Hydrocalumite for the Transesterification of Sunflower Oil

Abstract

This work investigates the use of a layered Ca-Al double hydroxide (hydrocalumite) as precursor, after its thermal activation, of base catalysts for the methanolysis of sunflower oil. Above 750 °C, hydrocalumite is transformed into a mixture of CaO and mayenite (Ca 12 Al 14 O 33 ). Another Ca-Al material obtained under similar experimental conditions was also studied, but using the Ca/Al molar ratio of the mayenite, 12:14. A sunflower oil conversion of 97% has been reached with a methanol/oil molar ratio of 12:1, a reaction temperature of 60 °C, and 1 wt % of the CaAl-2:1 catalyst. This catalyst needs to be previously activated at 500 °C in helium atmosphere, which is an activation temperature at least 200 °C lower than that required to revert the CO 2 poisoning in bulk and supported CaO catalysts.

Calcium oxide as a promising heterogeneous catalyst for biodiesel production: Current state and perspectives

“…In the methanolysis of palm kernel oil over this catalyst the FAME yield of 98% was achieved within 2 h. Despite a loss of activity because of methanol leaching (110 ppm of Ca þMg), the FAME yield higher than 90% was maintained within seven repeated cycles. Also, hydrotalcite-like materials are good precursors for the preparation of heterogeneous transesterification catalysts [64,[110][111][112]. Metal oxides with a high surface area and with strong Lewis base sites are derived from these materials by thermal decomposition.…”

Innovative method for hydrocalumite-like compounds' preparation and their evaluation in the transesterification reaction

“…In recent years, these compounds have been applied successfully as hardening accelerator in concrete (Xu et al, 2009) and other distinct applications which include: aldol condensation (Cota et al, 2010), transesterification (Campos-Molina et al, 2010;Kuwahara et al, 2012;Sankaranarayanan et al, 2012), cycloaddition (Kuwahara and Yamashita, 2013), isomerization (López-Salinas et al, 1996), Meerwein-Ponndorf-Verley reaction (Aramendía et al, 2001;Mora et al, 2010), in situ polymerization of interleaved monomers (Vieille et al, 2004) and intercalation (Plank et al, 2008) reactions. Additionally, HC and HLC materials have been employed in environmental remediation for chloride, nitrate and carbonate (Phillips and Vandeperre, 2011), borate, sulfate, and arsenate (Reardon and Valle, 1997), chromate and phosphate (Qian et al, 2012), Cd 2+ , B, Cr, Mo, and Se (Hang and Reardon, 2003), Zn 2+ (Liu et al, 2011), perchlorate (Kim et al, 2011), dye (Pereira de Sá et al, 2013); (Zhang et al, 2012a) and organic pollutant (Zhang et al, 2012b) removal.…”

Evaluation of calcined hydrocalumite-type materials as supports of CoMo and NiMo for thiophene hydrodesulfuration reaction

“…They are due to metal-oxygen bonds 9 . By examining the results of Vieille et al 6 , López-Salinas et al 7 and Campos-Molina et al 12 , it can be concluded that the transformation of hydrocalumite during the calcination occurs in three steps: in the first one (25-200°C), the physisorbed water is lost from the hydrocalumite structure. The second (200-400°C) and third steps (400-800°C) correspond to dehydroxylation and expulsion of anions.…”

“…The second (200-400°C) and third steps (400-800°C) correspond to dehydroxylation and expulsion of anions. An exact sequence has not been established, however, it was reported that the material still losses water from dehydroxilation at temperatures above 600°C 12 . This could explain water molecule bands of the material observed on HC 420 (Figure 1b).…”