Bio-Oil Fuels Upgrading Through Hydrodeoxygenation Reaction

Abstract

Substitution of petroleum-derived liquid fuels with biodiesel is currently being explored to reduce dependency on unsustainable methods. Catalytic hydrodeoxygenation (HDO) is shown to be a promising route to upgrade first-generation biofuels to a functioning fuel source comparable to traditional fossil fuels. In this study, the aim is to design a bimetallic system using different approaches to tailor the surface basicity and modify the metal-support interfaces in a system Ni(Cu)/promoter/zeolite by adopting mechano-chemical principles (ball milling technique). In particular, the mechanochemical tool was used to tune the zeolite↔promoter interface (coded IF1) and the promoter↔metal (Ni,Cu) interface (coded IF2).

The prepared catalysts have been studied using variable characterization techniques so to probe different length scales, such as XRD, HR-TEM, N2-physisorption, XPS, chemisorption experiments, such as H2-TPR, CO2-TPD, NH3-TPD, and H2-TPD, and CO and NH3 DRIFTS studies. In brief, the XRD and physisorption results showed that the zeolite beta (support) remained crystalline post the mechanochemical treatment. The reducibility of NiO was enhanced with the addition of Cu and La2O3 and interface tuning (IF1, IF2) as evident in H2- TPR studies. The addition of La2O3 along with mechanochemical treatment also affected the acid/basic sites concentration on the surfaces, and this was evaluated employing NH3/CO2- TPD. Subsequently, HDO of oleic acid studies conducted at 250 °C showed that with each compositional addition (La2O3 promoter and Cu secondary metal) there is greater selectivity towards biodiesel (C15-C18) ranged products. 10Ni5Cu/10La-Beta(IF1) showed the best selectivity towards C18 alkanes meaning reduced extent of cracking.

Date of Award	28 Dec 2023
Original language	American English
Supervisor	Kyriaki Polychronopoulou (Supervisor)