Poisoning of nickel‐based catalysts in fat hydrogenation

Irandoust, Said; Edvardsson, Jonas

doi:10.1007/bf02632158

Cited by 17 publications

(18 citation statements)

References 39 publications

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“…This resulted in a slightly slower deactivation. A similar effect has already been reported for Ni-catalysts [10]. The purification procedure probably needs to be optimized to remove all impurities (since the deactivation was not completely inhibited), but the result is a promising first step.…”

Section: Catalyst Deactivationsupporting

confidence: 70%

Hydrogenation of palm oil in near-critical and supercritical propane

Macher

Holmqvist

2001

Eur. J. Lipid Sci. Technol.

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Palm oil was hydrogenated in a single-phase mixture with propane and hydrogen. This was done in a small (0.5 ml), continuous fixed-bed reactor, using a 1% Pd/C catalyst. Temperature (65-135 o C), H 2 /TG ratio (4-50 mol/mol) and residence time (0.2-2.0 s) were varied systematically to assess the iodine value (IV) as a function of these three variables. The substrate concentration was 1 wt-%. The IV was dependent mainly on temperature and residence time. At 120 o C and a residence time of 2.0 s, full hydrogenation was achieved. The trends observed indicate that this is possible even at lower temperatures, if the residence time is increased further. Unexpectedly, the hydrogen concentration (i.e. the H 2 /TG ratio) was of minor importance, which can be a sign of either H 2 -saturation of the catalyst or a phase-split of the reaction mixture with resulting mass transport limitations for the hydrogen. Unfortunately, the catalyst showed strong signs of deactivation very early in the experiments, possibly due to impurities in the feedstock and/or to coke formation.

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Section: Catalyst Deactivationsupporting

confidence: 70%

Hydrogenation of palm oil in near-critical and supercritical propane

Macher

Holmqvist

2001

Eur. J. Lipid Sci. Technol.

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“…Under stress conditions such as drought, these levels can nearly double (Bouchereau et al, 1996;Jensen et al, 1996). Chlorophyll presents a problem for oil quality because it is capable of poisoning the hydrotreating catalysts (Irandoust and Edvardsson, 1993). Levels of chlorophyll in Brassica seeds have been reported from 3 to 64 mg/kg with higher values in immature green seeds (Daun et al, 1994;Khattab et al, 2010).…”

Section: Introductionmentioning

confidence: 99%

Development of near-infrared spectroscopy calibrations to measure quality characteristics in intact Brassicaceae germplasm

Oblath

Isbell

Berhow

et al. 2016

Industrial Crops and Products

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a b s t r a c tDetermining seed quality parameters is an integral part of cultivar improvement and germplasm screening. However, quality tests are often time consuming, seed destructive, and can require large seed samples. This study describes the development of near-infrared spectroscopy (NIRS) calibrations to measure moisture, oil, fatty acid profile, nitrogen, glucosinolate, and chlorophyll content in six species from the Brassicaceae family. Rapeseed and similar oilseeds are potential feedstocks for producing hydrotreated renewable jet fuel. Screening samples with NIRS would allow cultivars with desirable characteristics to be quickly identified. A total of 367 samples of six species (Brassica napus, Brassica carinata, Brassica juncea, Brassica rapa, Sinapis alba, and Camelina sativa) were scanned with NIRS. Global calibrations for all six species were developed using modified partial least squares regression with reference values obtained through wet chemistry techniques. Comparing predicted values to reference data, the coefficients of determination (r 2 ) and ratios of performance to deviation (RPD) varied, with some calibrations performing better than others. The calibration equations for seed oil content (r 2 = 0.98, RPD = 7.3) and nitrogen (r 2 = 0.98, RPD = 5.3) performed very well while the equations for seed moisture (r 2 = 0.93, RPD = 3.8) and total glucosinolate content (r 2 = 0.92, RPD = 2.3) were more qualitative. Large variation was observed for chlorophyll content (0-390 mg/kg) so two calibration equations were developed, one for the higher and one for the lower range of values. When combined, these calibrations also showed very good performance (r 2 = 0.99, RPD = 14). The performance of the calibrations for the fatty acids was more varied, with some performing very well, such as the calibration for C 18:3 (r 2 = 0.99, RPD = 9.9), and others, such as C 22:0 (r 2 = 0.69, RPD = 1.9), showing poor correlation. (E.A. Oblath), terry.isbell@ars.usda.gov (T.A. Isbell), mark.berhow@ars.usda.gov (M.A. Berhow), brett.allen@ars.usda.gov (B. Allen), david.archer@ars.usda.gov (D. Archer), jbrown@uidaho.edu (J. Brown), russ.gesch@ars.usda.gov (R.W. Gesch),

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“…The flange seals were maintained with either two silicone or Kalrez o-rings (ASA-223), depending on the substrate being used at the time. Spherical milling media (440C, d = 7.67 g/ cm 3 ) was added in the following quantities and sizes: (12) 19.1 mm balls, (53) 12.7 mm balls, and (86) 6.35 mm balls. Alumina.…”

Section: Acs Omegamentioning

confidence: 99%

“…The steel frits were replaced with glass filters. Spherical milling media (yttria-stabilized zirconia, d = 6 g/cm 3 , Inframat Advanced Materials LLC) was added in the following quantities and sizes: (5) 19.1 mm balls, (15) 12.7 mm balls, and (50) 6.35 mm balls. A duplicate of the steel reactor, with a high alumina content (99.8%) and 6 mm walls, was manufactured by CoorsTek, Inc. Titanium flanges with the same dimensions as those of the steel flanges, except that the Conflat knife edge was replaced by an o-ring groove, were machined.…”

Section: Acs Omegamentioning

confidence: 99%

Heterogeneous Metal-Free Hydrogenation over Defect-Laden Hexagonal Boron Nitride

Nash

Restrepo

Parra³

et al. 2016

ACS Omega

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Catalytic hydrogenation is an important process used for the production of everything from foods to fuels. Current heterogeneous implementations of this process utilize metals as the active species. Until recently, catalytic heterogeneous hydrogenation over a metal-free solid was unknown; implementation of such a system would eliminate the health, environmental, and economic concerns associated with metal-based catalysts. Here, we report good hydrogenation rates and yields for a metal-free heterogeneous hydrogenation catalyst as well as its unique hydrogenation mechanism. Catalytic hydrogenation of olefins was achieved over defect-laden h- BN ( dh -BN) in a reactor designed to maximize the defects in h- BN sheets. Good yields (>90%) and turnover frequencies (6 × 10 –5 –4 × 10 –3 ) were obtained for the hydrogenation of propene, cyclohexene, 1,1-diphenylethene, ( E )- and ( Z )-1,2-diphenylethene, octadecene, and benzylideneacetophenone. Temperature-programmed desorption of ethene over processed h -BN indicates the formation of a highly defective structure. Solid-state NMR (SSNMR) measurements of dh -BN with high and low propene surface coverages show four different binding modes. The introduction of defects into h- BN creates regions of electronic deficiency and excess. Density functional theory calculations show that both the alkene and hydrogen-bond order are reduced over four specific defects: boron substitution for nitrogen (B N ), vacancies (V B and V N ), and Stone–Wales defects. SSNMR and binding-energy calculations show that V N are most likely the catalytically active sites. This work shows that catalytic sites can be introduced into a material previously thought to be catalytically inactive through the production of defects.

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Poisoning of nickel‐based catalysts in fat hydrogenation

Cited by 17 publications

References 39 publications

Hydrogenation of palm oil in near-critical and supercritical propane

Hydrogenation of palm oil in near-critical and supercritical propane

Development of near-infrared spectroscopy calibrations to measure quality characteristics in intact Brassicaceae germplasm

Heterogeneous Metal-Free Hydrogenation over Defect-Laden Hexagonal Boron Nitride

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