Roles of monometallic catalysts in hydrodeoxygenation of palm oil to green diesel

Srifa, Atthapon; Faungnawakij, Kajornsak; Itthibenchapong, Vorranutch; Assabumrungrat, Suttichai

doi:10.1016/j.cej.2014.09.106

Cited by 202 publications

(119 citation statements)

References 57 publications

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“…Based on turnover frequencies calculated for deoxygenating oleic acid over four alumina supported monometallic catalysts, catalytic activities were found to be in the order: Co > Pd > Pt > Ni. It was also emphasized that DCO was more dominant in the case of Pd, Pt, and Ni catalysts, whereas the Co/Al2O3 catalyst deoxygenates palm oil through both DCO and HDO pathways (Srifa et al, 2015). Similar results were obtained for deoxygenation of spent coffee oil using Pd/C and NiMoS/γ-Al2O3 (Phimsen et al, 2016).…”

Section: Supported Metallic Catalystssupporting

confidence: 71%

“…This is advantageous from both environmental and energy efficiency viewpoints since less CO and CO2 are released in the product gas stream and more carbon ends up in the product liquid stream. Although it initially seems that more hydrogen is consumed in the HDO pathway as opposed to DCO, the successive methanation of CO and CO2 would increase the overall hydrogen consumption (Srifa et al, 2015). Saturation of double bonds also generally occurs during HDO processes.…”

Section: Upgrading Routesmentioning

confidence: 99%

“…However, it still suffers from moisture absorption, corrosiveness, high viscosity, poor cold-flow properties, and low power density mainly due to high oxygen content (Srifa et al, 2015).…”

Section: Biodiesel Upgradingmentioning

confidence: 99%

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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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Section: Supported Metallic Catalystssupporting

confidence: 71%

Section: Upgrading Routesmentioning

confidence: 99%

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A comprehensive review on biodiesel purification and upgrading

2017

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“…Table 3 shows a comparison of the n-C17 obtained during the hydrodeoxygenation of oleic acid with different catalysts. It clearly shows an increase in the yield of n-C17 with the catalyst NAL5, when it was compared to the yield obtained with a similar catalyst [15]. Additionally, the NAL7 catalyst showed a similar yield with that reported containing 10 wt % of Ni [34].…”

Section: Conversion Of Oleic Acid By Hydrodeoxygenationsupporting

confidence: 53%

“…Due to the fact that the same support was used, the specific surface areas (S BET ) and average pore volume (APV) of the Ni/γ-Al 2 O 3 catalysts have similar values. A slight reduction in the average pore diameter (APD) was observed when Ni loading was increased, which might be directly related to the partial blockage of support pores [15,21]. The elemental composition of the Ni/γ-Al 2 O 3 catalyst was determined using energy dispersive X-ray spectroscopy (EDS) and is shown in the same table.…”

Section: Physico-chemical Characterization Of the Catalystmentioning

confidence: 99%

Effect of Size and Distribution of Ni Nanoparticles on γ-Al2O3 in Oleic Acid Hydrodeoxygenation to Produce n-Alkanes

et al. 2016

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Abstract:To contribute to the search for an oxygen-free biodiesel from vegetable oil, a process based in the oleic acid hydrodeoxygenation over Ni/γ-Al 2 O 3 catalysts was performed. In this work different wt % of Ni nanoparticles were prepared by wetness impregnation and tested as catalytic phases. Oleic acid was used as a model molecule for biodiesel production due to its high proportion in vegetable oils used in food and agro-industrial processes. A theoretical model to optimize yield of n-C 17 was developed using size, distribution, and wt % of Ni nanoparticles (NPs) as additional factors besides operational conditions such as temperature and reaction time. These mathematical models related to response surfaces plots predict a higher yield of n-C 17 when physical parameters of Ni NPs are suitable. It can be of particular interest that the model components have a high interaction with operation conditions for the n-C 17 yields, with the size, distribution, and wt % of Ni NPs being the most significant. A combination of these factors statistically pointed out those conditions that create a maximum yield of alkanes; these proved to be affordable for producing biodiesel from this catalytic environmental process.

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