Conversion Of Eugenol Research Articles

Effect of nickel loading approaches on the structure and hydrodeoxygenation performance of Ni/Al-SBA-15

Lignocellulosic biomass-derived bio-oil is considered as a promising renewable biofuel. In this paper, incipient wetness impregnation method, ammonia grafting method and direct synthesis method were employed as nickel loading methods for the preparation of Ni/Al-SBA-15 catalysts. The effects of these nickel loading approaches on the structure and hydrodeoxygenation performance of Ni/Al-SBA-15 were studied. The structure of Ni/Al-SBA-15 was significantly influenced by the nickel loading methods, including the specific surface area, the pore volume, the wall thickness and so on. Nickel loading methods also affected the actual nickel content of nickel-based catalysts. Unsuccessful loading of nickel species was observed during the preparation of Ni/Al-SBA-15 using direct synthesis method. The conversion of eugenol and selectivity of products after hydrodeoxygenation in n-dodecane over Ni/Al-SBA-15 catalysts were investigated. Results showed that the conversion of eugenol nearly reached 100% for all the reaction, but the composition of product was significantly different when using different Ni/Al-SBA-15 as hydrodeoxygenation catalyst. The reaction pathway of eugenol hydrodeoxygenation in n-dodecane was also speculated in this paper. Effects of nickel loading approaches on the structure and hydrodeoxygenation performance of Ni/Al-SBA-15 were investigated. For the liquid phase hydrodeoxygenation of eugenol to hydrocarbon, catalysts prepared by ammonia grafting method exhibited the highest catalytic activity.

Upgrading of Lignin-Derived Compounds: Reactions of Eugenol Catalyzed by HY Zeolite and by Pt/γ-Al2O3

The conversion of eugenol (4-allyl-2-methoxyphenol), a compound derived from the lignin in woody biomass, was catalyzed by HY zeolite at 573 K and atmospheric pressure. The main products were isoeugenol and guaiacol, formed by isomerization and by deallylation, respectively. Substituted guaiacols with saturated side-chains (4-methylguaiacol, 4-ethylguaiacol, and 4-propylguaiacol) were also formed, by hydrogen transfer and alkylation reactions. The pseudo-first-order rate constant for the overall disappearance of eugenol was found to be 12.4 L (g of catalyst)/h. When the catalyst was Pt/γ-Al2O3 used in the presence of H2, significant hydrogenation of the propenyl side-chain took place, accompanied by isomerization, and hydrodeoxygenation. Under similar operating conditions, the reaction catalyzed by Pt/γ-Al2O3 in the presence of H2 gave a higher eugenol conversion (X = 0.70) than the reaction catalyzed by HY zeolite (X = 0.11), primarily because of the dominant hydrogenation observed with the former catalyst. In the absence of H2 as a co-reactant, the acidic γ-Al2O3 support in Pt/γ-Al2O3 evidently catalyzed all the classes of reactions catalyzed by HY zeolite. .

Influence of Copper on the Isomerization of Eugenol for as-Synthesized NiCuAl Ternary Hydrotalcites: An Understanding Through Physicochemical Study

Catalysts with the hydrotalcite-like structure and general formula NiCuAlyz-HT having (Ni + Cu)/Al atomic ratio of 3.0 with varying Ni:Cu atomic compositions (100:0–50:50) were synthesized, characterized and tested for isomerization of eugenol to isoeugenol. The decrease in the activity upon addition of copper to NiAl lattice is investigated through temperature programmed reduction and phenol adsorption. Conversion of eugenol over active NiAl hydrotalcite significantly decreased upon incorporation of Cu2+ in the NiAl binary lattice wherein substitution of 25 at% of Ni2+ by Cu2+ annihilated the isomerization activity. The decrease in the activity upon addition of copper to NiAl lattice is investigated through physiochemical studies.

Purification and characterization of eugenol dehydrogenase from pseudomonas fluorescens E118

Pseudomonas fluorescens E118 was isolated from soil as an effective eugenol-degrading organism by a screening using eugenol as enrichment substrate. The first enzyme involved in the degradation of eugenol in this organism, eugenol dehydrogenase, was purified after induction by eugenol, and the purity of the enzyme was shown by SDS-PAGE and gel-permeation HLPC. The enzyme is a heterodimer that consists of a 10-kDa cytochrome c and a 58-kDa subunit. The larger subunit presumably contains flavin, suggesting a flavocytochrome c structure and an electron transfer via flavin and cytochrome c during dehydrogenation. The activity of the purified enzyme depended on the addition of a final electron acceptor such as phenazine methosulfate, 2,6-dichlorophenol-indophenol, cytochrome c, or potassium ferricyanide. The enzyme catalyzed the dehydrogenation of three different 4-hydroxybenzylic structures including the conversion of eugenol to coniferyl alcohol, 4-alkylphenols to 1-(4-hydroxyphenyl)alcohols, and 4-hydroxybenzylalcohols to the corresponding aldehydes. The catalytic and structural similarity between this enzyme and a Penicillium vanillyl-alcohol oxidase and 4-alkylphenol methylhydroxylases from several Pseudomonas species is discussed.