Ni/Co-Natural Clay as Green Catalysts for Microalgae Oil to Diesel-Grade Hydrocarbons Conversion

Abstract

The Ni/Co-natural clay catalysts have been prepared for the conversion of algae oil into diesel-grade hydrocarbons. Methyl oleate was used as a model compound for the present study. Ni/clay catalyst promotes decarboxylation/decarbonylation, whereas remarkable selectivity in hydrodeoxygenation (HDO) is achieved with Co/clay catalysts. Powder XRD and DRS studies of substrate mixed catalysts reveal a more prominent adsorption of substrate molecules over the Ni surface, which results in low HDO selectivity of nickel catalysts by surpassing the essential contribution of acidic sites. The HDO process provides higher carbon atom economy and energy value over decarboxylation/decarbonylation, while further reducing the formation of greenhouse gases such as CO2 and CH4. Total yield of saturated hydrocarbons from algae oil was 84–86 wt % with similar selectivity. The HDO rates of different fatty acids present in algae oil were independent of the fatty acid chain length. The catalysts are cost-effective and recyclable, and metal leaching during hydroprocessing is less than 1 ppm in all cases. This process is advantageous in terms of metal-to-substrate ratio, use of solvents and their concentration, and comparable HDO selectivity over the previously reported catalysts. A hydroprocessing reaction was also performed under solvent free conditions, which could be useful in industrial applications of this approach.

Fe/Indonesian Natural Zeolite as Hydrodeoxygenation Catalyst in Green Diesel Production from Palm Oil

“…The results showed 93.34% conversion of renewable diesel, with a selectivity and yield of the C13-C19 fraction of 42.72% and 34.87%, respectively. Soni et al [8] employed natural clay modified with a Ni/Co metal carrier metal as a catalyst for the conversion of methyl oleate/microalgae into green diesel. The result gave a total yield for the C12-C22 alkane hydrocarbon chain of 84-86 wt.%.…”

Insights into the Nature of the Active Sites of Tin‐Montmorillonite for the Synthesis of Polyoxymethylene Dimethyl Ethers (OME)

“…Na‐MMT was identified with the (00 l ) reflection at 7.0°, 14.2° and 28.6° as well as with the (020,110) and (200,130) reflections with maxima located at 19.9° and 34.9°, respectively . The (001), (002) and (004) reflections of Sn‐MMT almost disappeared showing a complete loss of the layered structure (confirming delamination) as well as a shift to lower diffraction angle, implying an increase in the mean interlayer distance from 1.24 nm to 1.31 nm (calculated using Bragg's law) . A broad (001) basal reflection is observed for AT‐MMT which hence only suffered from partial layer stacking loss and an increase in the mean interlayer distance to 1.45 nm.…”

“…[35,36] The (001), (002) and (004) reflections of Sn-MMT almost disappeared showing a complete loss of the layered structure (confirming delamination) as well as a shift to lower diffraction angle, implying an increase in the mean interlayer distance from 1.24 nm to 1.31 nm (calculated using Bragg's law). [23,37] A broad (001) basal reflection is observed for AT-MMT which hence only suffered from partial layer stacking loss and an increase in the mean interlayer distance to 1.45 nm. Retention of the (020,110) and (200,130) reflections intensity suggested preservation of the two-dimensional structure (i. e. the clay sheets) for both Sn-MMT and AT-MMT.…”

Catalytic Hydrogenation of Hydrocarbons for Gasoline Production

“…93 Total yield of saturated hydrocarbons from algae oil valorisation was 84-86 wt% with similar selectivity. The HDO rates of different fatty acids present in the algae oil were independent of the fatty acid chain length.…”