Theoretical Investigation of the Deactivation of Ni Supported Catalysts for the Catalytic Deoxygenation of Palm Oil for Green Diesel Production

Sanaa Hafeez,Sultan M Al-Salem,Nikolaos D Charisiou,Kyriakos N Papageridis,Maria A Goula,Achilleas Constantinou,George Manos

doi:10.3390/catal11060747

Abstract

For the first time, a fully comprehensive heterogeneous computational fluid dynamic (CFD) model has been developed to predict the selective catalytic deoxygenation of palm oil to produce green diesel over an Ni/ZrO2 catalyst. The modelling results were compared to experimental data, and a very good validation was obtained. It was found that for the Ni/ZrO2 catalyst, the paraffin conversion increased with temperature, reaching a maximum value (>95%) at 300 °C. However, temperatures greater than 300 °C resulted in a loss of conversion due to the fact of catalyst deactivation. In addition, at longer times, the model predicted that the catalyst activity would decline faster at temperatures higher than 250 °C. The CFD model was able to predict this deactivation by relating the catalytic activity with the reaction temperature.

Highlights

Green diesel as an environmentally friendly fuel has attracted considerable attention in recent years due to the fact of its high cetane number and high oxidative stability
In order to assess the validity of the computational fluid dynamic (CFD) model, a comparison with the experimental data was performed
The results show that the conversion of palm oil increased up to a maximum value of approximately 96%; it decreased significantly at temperatures greater than 300 ◦ C for the Ni/ZrO2 catalyst at t = 60 min

Summary

Introduction

Green diesel as an environmentally friendly fuel has attracted considerable attention in recent years due to the fact of its high cetane number and high oxidative stability. Green diesel is a non-oxygenated hydrocarbon fuel produced from plant-derived oils. It can be used as a transportation fuel because its physiochemical properties are like those of diesel [1]. Nickel-supported catalysts have attracted great attention in recent years for green diesel production [2,3,5,6,7,8,9,10,11,12,13,14,15,16]. Further reasons for the loss of catalytic activity may be sintering, poisoning or active metal leaching which reduces the number of active sites [17]

Methods

Results

Conclusion