Hydrodeoxygenation of Methyl Laurate over Ni Catalysts Supported on Hierarchical HZSM-5 Zeolite

Nana Li,Yadong Bi,Xiaoqiang Xia,Jianli Hu,Hui Chen

doi:10.3390/catal7120383

Abstract

The hierarchical HZSM-5 zeolite was prepared successfully by a simple NaOH treatment method. The concentration of NaOH solution was carefully tuned to optimal the zeolite acidity and pore structure. Under NaOH treatment conditions, a large number of mesopores, which interconnected with the retained micropores, were created to facilitate mass transfer performance. There are very good correlations between the decline of the relative zeolite crystallinity and the loss of micropores volume. The Ni nanoclusters were uniformly confined in the mesopores of hierarchical HZSM-5 by the excessive impregnation method. The direct deoxygenation in N2 and hydrodeoxygenation in H2 of the methyl laurate were compared respectively over the Ni/HZSM-5 catalysts. In the N2 atmosphere, the deoxygenation rate of the methyl laurate on the Ni/HZSM-5 catalyst is relatively slow. In the presence of H2, the synergistic effect between the hydrogenation function of the metal and the acid function of the zeolite supports can make the deoxygenation level more obvious. The yield of hydrocarbon products gradually reached the maximum with the appropriate treatment concentration of 1M NaOH, which could be attributed to the improved mass transfer in the hierarchical HZSM-5 supports.

Highlights

Non-edible lipids are green renewable biomass energy, mainly including algae oil [1], jatropha oil [2] and cooking waste oil
A high adsorption capacity was achieved on initial low relative pressure (p/p0 is less than 0.01), and the isotherm remained flat with the increase in relative pressure, indicating that the parent HZSM-5 is a microporous material with a uniform pore structure
Ni catalysts loaded on the hierarchical HZSM-5

Summary

Introduction

Non-edible lipids are green renewable biomass energy, mainly including algae oil [1], jatropha oil [2] and cooking waste oil. Transforming the lipid raw material into high quality fuel through catalytic technology is a hot research and development field [3,4,5,6]. The first generation technology of lipid catalysis transformation is the production of fatty acid methyl ester biodiesel via transesterification methods over homogeneous base catalyst, which is currently a mature industrial production technology. The restricted utilization of biodiesel is inevitable due to the shortcomings such as high oxygen content and poor anticoagulant performance. It is necessary to develop the second generation hydrocarbon fuel technology by further deoxygenation [7]. The different pathways for the deoxygenation of fatty acids include decarboxylation, decarbonylation, and hydrodeoxygenation

Results

Discussion

Conclusion