A review of thermal homogeneous catalytic deoxygenation reactions for valuable products

Abstract

To remove high oxygen content is important to make high quality oil and valuable products. In this paper, the research on homogeneous catalytic deoxygenation reactions, including decarboxylation (DCX)/decarbonylation (DCN), hydrodeoxygenation (HDO) is reviewed. Based on DCX/DCN, the classic radical reactions such as the Barton decarboxylation, Henkel, Hunsdiecker and Kochi reactions were introduced, the practice and overall performance are also discussed. In addition, the different reaction pathways and mechanisms were demonstrated and the key chemical processes have been selected from the literature as examples to elaborate the critical emphasis on the mechanistic understanding. The applications of the catalytic deoxygenation reactions for highvalue products have also been highlighted. Overall, this review provides insight discussions on the DO issues and progresses in homogeneous catalytic aspects.

Transition Metal Catalysts for the Glycerol Reduction: Recent Advances

“…Thermal processes are widely diffused, often assisted by homogeneous or heterogeneous catalysts. [4] Liquid biomasses like vegetable oils, as such or after a hydrolytic step to free fatty acids, were successfully deoxygenated to form hydrocarbons by using, for example, a γ-alumina supported Ni/Mo catalyst, at 300-400 °C, in H 2 atmosphere. [5,6] More recently even biomass of different nature, like lignocellulosic materials, were subjected to controlled oxygen removal to obtain a series of functional highvalue low-oxygenated olefins or hydrocarbons.…”

“…To reach this goal, several strategies were applied. Thermal processes are widely diffused, often assisted by homogeneous or heterogeneous catalysts [4] . Liquid biomasses like vegetable oils, as such or after a hydrolytic step to free fatty acids, were successfully deoxygenated to form hydrocarbons by using, for example, a γ‐alumina supported Ni/Mo catalyst, at 300–400 °C, in H 2 atmosphere [5,6] .…”

Simulation of a catalytic deoxygenation reaction of fatty acids to produce biohydrocarbons and evaluation of the influence of reaction parameters on the conversion and selectivity of products

“…Em estudos focados na cinética, para levantamento de leis de velocidade, é comum o uso de um composto modelo constituído por ácidos graxos livres isolados, como o ácido esteárico (Arora et al, 2019;Castagnari Willimann Pimenta et al, 2021;Jeništová et al, 2017;Kumar et al, 2014), ácido graxo saturado contendo 18 átomos de carbono (Cheah et al, 2022). Além da matéria-prima, o tipo de catalisador e as condições de reação são amplamente estudados (Arend et al, 2011;Castagnari Willimann Pimenta et al, 2021;Cheah et al, 2022;Jeništová et al, 2017;Kay Lup et al, 2017;Kong et al, 2020;Kubička & Kaluža, 2010;Kumar et al, 2014;Lin et al, 2023;Snåre et al, 2008).…”

Recent advances in the catalytic deoxygenation of plant oils and prototypical fatty acid models compounds: Catalysis, process, and kinetics

“…On the contrary, heterogeneous catalysts are more susceptible to metal leaching and causing product fouling or sintering of oxide supports such as TiO 2 , Al 2 O 3 , PtO 2 due to condensation of the polar-polar substrate and catalyst surface cascades. Despite the homogenous catalysts are fully exempted from the typical limitations encountered by the heterogeneous catalysts, the separation of homogeneous catalysts from the product stream is rather cumbersome and usually incurs additional operational costs [6,9,10].…”