Selective Deoxygenation of Biomass‐Derived Bio‐oils within Hydrogen‐Modest Environments: A Review and New Insights

Rogers, Kyle; Zheng, Ying

doi:10.1002/cssc.201600144

Cited by 176 publications

(119 citation statements)

References 146 publications

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“…Although the conversion of stearic acid reaches 100 % at 60 min, the yield of octadecanol is higher over Mo/G compared to the promoted catalysts at this time due to the slower reaction rate in the presence of this catalyst. It is mainly believed that the alcohol intermediate is formed through the hydrogenation of the aldehyde . It is also possible that the aldehyde intermediate remains adsorbed on the surface of the catalyst after its conversion from the carboxylic acid to directly form the alcohol intermediate.…”

Section: Resultssupporting

confidence: 66%

Deoxygenation of stearic acid with a novel Ni(CO)‐MoS₂/Fe₃S₄ catalyst

Sharifvaghefi

Zheng

2017

Can J Chem Eng

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Magnetically recyclable Ni(Co)-promoted MoS 2 catalysts with greigite (G) core were synthesized and their activity and selectivity in hydrodeoxygenation of stearic acid were investigated. The activity of the catalysts tested at 320 8C and H 2 initial pressure of 3.5 MPa could be ranked as NiMo/G > CoMo/G > Mo/G. Two main products were detected, C18 (through HDO pathway) and C17 hydrocarbons (through DCO pathway). HDO was the dominant pathway for all of the catalysts. As for the C18/C17 ratio, the catalysts were found to be in the order: Mo/G > CoMo/G % NiMo/G. The Paraffin/Olefin ratio was over 1 for all of the catalysts with NiMo/G showing the highest ratio. Stearic acid was found to have an inhibiting effect on the adsorption of intermediates over the active sites. Moreover, the concentrations of intermediates decreased at high conversions of stearic acid. The formation of the intermediate aldehyde is through C-O hydrogenolysis of the fatty acid following the protonation, dehydrogenation, and hydride addition steps. The same steps were suggested to be involved in the transformation of the aldehyde to the alcohol. Formation of C n-1 hydrocarbons was found to be via decarbonylation route. The enhancement of the DCO pathway over the promoted catalysts was related to the electron transfer from the promoting atom to an adjacent sulphur atom and reduction in sulphur-metal bond strength.

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Section: Resultssupporting

confidence: 66%

Deoxygenation of stearic acid with a novel Ni(CO)‐MoS₂/Fe₃S₄ catalyst

Sharifvaghefi

Zheng

2017

Can J Chem Eng

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“…Several studies have been performed to gain some insights into the mechanism of deoxygenation under different atmospheres. Detailed discussions about mechanisms of deoxygenation are presented in recent reviews by Gosselink et al (2013) and Rogers and Zheng (2016).…”

Section: Upgrading Routesmentioning

confidence: 99%

“…Alumina and zeolite supports were conventionally used for hydrotreating petroleum fuels. Lewis acid sites on Al2O3 can activate oxygenated species and facilitate deoxygenation through DCO pathway (Rogers and Zheng, 2016). Nevertheless, the presence of water in bio-based feedstocks can reduce the specific surface area of γ-Al2O3 by crystallization to Boehmite (Laurent and Delmon, 1994).…”

Section: Role Of Supportmentioning

confidence: 99%

A comprehensive review on biodiesel purification and upgrading

2017

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HIGHLIGHTS Various biodiesel purification methods, i.e., equilibrium-based, affinity-based, and reaction-based separation techniques along with membrane technology and solid-liquid separation processes were reviewed.Deoxygenating process via hydrodeoxygenation and decarboxylation/decarbonylation pathways is a common way to upgrade bio-based oils to produce biorenewable diesel with excellent fuel properties. Catalysts and operating conditions, i.e., pressure, temperature, and contact time, are the most important variables in biodiesel upgrading discussed herein. Serious environmental concerns regarding the use of fossil-based fuels have raised awareness regarding the necessity of alternative clean fuels and energy carriers. Biodiesel is considered a clean, biodegradable, and non-toxic diesel substitute produced via the transesterification of triglycerides with an alcohol in the presence of a proper catalyst. After initial separation of the by-product (glycerol), the crude biodiesel needs to be purified to meet the standard specifications prior to marketing. The presence of impurities in the biodiesel not only significantly affects its engine performance but also complicates its handling and storage. Therefore, biodiesel purification is an essential step prior to marketing. Biodiesel purification methods can be classified based on the nature of the process into equilibrium-based, affinity-based, membrane-based, reaction-based, and solid-liquid separation processes. The main adverse properties of biodiesel -namely moisture absorption, corrosiveness, and high viscosity -primarily arise from the presence of oxygen. To address these issues, several upgrading techniques have been proposed, among which catalytic (hydro)deoxygenation using conventional hydrotreating catalysts, supported metallic materials, and most recently transition metals in various forms appear promising. Nevertheless, catalyst deactivation (via coking) and/or inadequacy of product yields necessitate further research. This paper provides a comprehensive overview on the techniques and methods used for biodiesel purification and upgrading. ABSTRACT

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“…The alarming predictions of the rapid depletion of fossil‐fuel resources have inspired researchers to develop alternative technologies that exploit renewable energy sources . Many studies have focused on the conversion of lignocellulosic biomass and triglycerides into various platforms of value‐added chemicals .…”

Section: Introductionmentioning

confidence: 99%