Catalytic cracking of fatty acid methyl esters (biodiesel) is an attractive alternative to petroleum processing to produce valuable and versatile aromatics over the Zn-modified HZSM-5(25) catalysts. The catalysts with a Zn loading amount of 0–2.6 wt % were prepared and characterized. The introduction of Zn species presented great effects on the textural property and acidity of the parent HZSM-5(25) zeolite, and the chemical state of Zn species was heavily dependent on the amount of Zn loading. The strong Brönsted acid sites on the 0.5% Zn/HZSM-5(25) catalyst were exchanged by Zn species and formed new Zn-Lewis acid sites, which were identified as [ZnOH]+ and Zn2+ species. These Zn species greatly enhanced the dehydrogenation activation of alkanes to form more alkenes. Besides, they also promoted the further dehydrogenation reactions during aromatization of alkenes, thus improving the formation of H2 (>4 wt %) and increasing the production of aromatics (>40 wt %). The dominant components in the organic liquid product were monocyclic aromatics including benzene, toluene, and xylenes. Moreover, the 0.5% Zn/HZSM-5(25) catalyst exhibited an excellent stability, adaptability, and regeneration.

Catalytic pyrolysis of triglycerides to aromatics over zeolites is an advanced technology for a high value-added utilization of renewable biomass resources. Therefore, in this research, the catalytic performance of M/HZSM-5 catalysts (M = Zn, Ga, In, Ni, and Mo) during the pyrolysis process of glycerol trioleate and the effect of the compositional difference of several woody oils and waste oils on aromatic formation were investigated. Results revealed that Zn/HZSM-5 with appropriate acidity and metal sites reached the maximum aromatics yield (56.13%) and significantly enhanced the catalytic stability. In addition, these renewable nonedible oils were effectively converted to aromatics over the Zn/HZSM-5 catalyst, the aromatic yield of jatropha oil reached up to 50.33%, and the unsaturation and double bond number of feedstocks were crucial for the production of aromatics. The utilization of biomass resources to produce high value-added aromatics can alleviate the problems caused by the shortage of fossil resources and achieve sustainable green development.

A novel Nb 2 O 5 −ZrO 2 support was synthesized and used to support Ni or Mo metal as a catalyst, and γ-Al 2 O 3 and SAPO-11 were selected as supports for comparison. The catalysts were then used for catalytic hydrodeoxidation of glycerol trioleate (GT) and jatropha curcas oil into jetfuel-range hydrocarbons in one step. The results showed that the reduced Ni metal could significantly promote hydrodeoxidation of GT and improve the selectivity of alkanes (57.1−73.0%). The support had significant inference on the catalysts. The prepared Nb 2 O 5 −ZrO 2 support, due to its properties of high surface area (34.1 m 2 g −1 ), suitable pore size (13.7 nm), and appropriate medium-strength acidic sites with proper density, made the Ni/Nb 2 O 5 −ZrO 2 catalyst beneficial for the high selectivity of jet fuel (54.5%) in liquid products (68.5%). Ni/Nb 2 O 5 −ZrO 2 could reduce the generation of coke and gas and increase the yield of liquid product compared with Ni/ γ-Al 2 O 3 . On the other hand, Ni/Nb 2 O 5 −ZrO 2 had higher catalytic efficiency upon hydrodeoxidation of GT and could inhibit the excessive production of aromatics in liquid products compared with Ni/SAPO-11. In the final product of catalytic hydrocracking of GT over Ni/Nb 2 O 5 −ZrO 2 , the specific composition of hydrocarbons in the C8−C16 range was 65.9% alkanes, 8.6% aromatics, 16.1% olefins, and 2.3% oxygenates, indicating that the direct catalytic cracking product of GT over Ni/Nb 2 O 5 −ZrO 2 almost meets the needs of jet fuel.