Hydrofining of heavy gas oil on zeolite-alumina supported nickel-molybdenum catalyst

Mann, R. S.; Sambi, Inderjit S.; Khulbe, K.C.

doi:10.1021/ie00082a009

Cited by 37 publications

(22 citation statements)

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“…In this case, the N-, S-, and O-compounds in the feed are more stable than are those in conventional feeds because they were already exposed to high temperatures. For every feed, the activation energy for HDS was greater than that for HDN, contrary to results obtained by Mann et al (496) for as oil of similar origin. The average boiling point and molecular weight of the fractions varied from 551 to 812 K and 187 to 425 MW respectively.…”

Section: E Furimsky and F E Massothcontrasting

confidence: 94%

Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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A high level of hydrodenitrogenation (HDN) is required to achieve a desirable conversion of other hydroprocessing reactions. This results from a strong adsorption of nitrogen-containing compounds on catalytic sites that slows down the hydrogen activation process and hinders the adsorption of other reactants. Studies on model compounds and real feeds indicate that less than 50 ppm of nitrogen in the feed can poison catalytic sites. Kinetic studies determined adsorption constants of various nitrogen-containing compounds and concluded that at least four different catalytic sites are required to interpret experimental observations in contrast with a dual site site ffi concept, which only considered two sites. The advancements in experimental techniques allowed identification of products formed during very early stages of hydrodenitrogenation. These results confirmed that the removal of the amino group from saturated amines, as the last step in hydrodenitrogenation, is governed by the type of carbon to which the amino group is attached rather than the number of hydrogen atoms attached to carbon in a and b position to nitrogen Performance of conventional Co(Ni)Mo(W)/Al 2 O 3 catalysts during hydrodenitrogenation was enhanced by combination with various additives and by replacing the traditionally used g-Al 2 O 3 support with novel supports. Catalytic functionalities could be modified by using different precursors of active metals and varying conditions during preparation. Progress has been made in the development of catalysts possessing a high selectivity for hydrodenitrogenation. In this case, the nonconventional catalysts based on the carbides and nitrides of transition metals exhibited high activity and selectivity. Noble metal sulfides alone or supported on different supports were active for HDN as well. Feedstocks used for catalyst evaluation included model compounds and mixtures of model compounds as well as real feeds. The challenges in the development of catalysts for hydrodenitrogenation of heavy feeds containing asphaltenes and metals have been identified.In general, compared to Q, conversions were little affected by a methyl (Me) on the aromatic ring, while being lower for Me on the N-ring, except for 2-MeQ. It is evident that Me substitution in the 2-position had little effect on HDN over the NiMoP/Al 2 O 3 catalyst, whereas it actually enhanced the HDN rate over the CoMo/Al 2 O 3 catalyst. For both catalysts the HDN rate was suppressed in 6-MeQ and particularly in 3-MeQ and 4-MeQ. The distribution of N-containing intermediates was influenced by the ring substitution and the type of catalyst. This suggests that several factors influence the overall HDN mechanism of Qs. This should be kept in mind while analyzing differences in the networks proposed by different authors.The preceding discussion on the HDN of Q mostly referred to conventional catalysts. A number of studies on the HDN of Q were conducted over unconventional catalysts. For example, 3-and 4-MeQs were more reactive than Q over the unsupported Zr,...

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Section: E Furimsky and F E Massothcontrasting

confidence: 94%

Hydrodenitrogenation of Petroleum

Furimsky¹,

2005

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“…The effects of pressure on hydrotreatment activity for the hydrotreated and hydrotreated‐pretreated feeds were also studied, and the results are shown in Tables and . Increase in pressure using NiMo/γ‐Al 2 O 3 catalyst is known to increase HDS and HDN reactions and has minimal effects on HDA . Similarly, while keeping other parameters such as temperature and LHSV constant for both the hydrotreated and hydrotreated‐pretreated feeds, the nitrogen, sulfur, and aromatics conversion were studied with respect to changes in pressure.…”

Section: Resultsmentioning

confidence: 99%

“…However, the increase was minimal compared with the nitrogen conversion. A reason for this might lie with the catalyst being used; NiMo/γ‐Al 2 O 3 through literature has been known to increase both HDS and HDN with increasing pressure; however, HDN improvements was more significant than HDS, as NiMo/γ‐Al 2 O 3 catalyst is more sensitive to pressure than temperature . This explains the increase in HDS that is observed with increase in pressure.…”

Section: Resultsmentioning

confidence: 99%

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Insights into the integrated effects of polymeric pretreatment and catalytic hydrotreatment of light gas oil

Olomola

Misra

Chitanda

et al. 2019

Asia-Pacific J Chem Eng

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A study has been carried out in detail to measure the effects of the removal of nitrogen compounds on the hydrotreatment of light gas oil (LGO) using a synthesized polymer consisting of a polymer support, copolymer of glycidyl methacrylate and ethylene glycol dimethacrylate (PGMA-co-EDGMA), a π-acceptor moiety (2,4,5,7-tetranitrofluorenone, TENF), and a three-carbon linker (diaminopropane, DAP (3)). The primary focus of this paper is first to study the effects of selectively removing nitrogen compounds on the hydrotreatment of LGOs. Removal of these catalyst inhibiting and poisoning compounds prior to hydrotreatment will help in improving the hydroprocessing efficiency as well as in reducing the chemical fouling, thus improving the catalyst life. Second, the effectiveness on the reusability of bulk polymer after regeneration was studied. To achieve this, nitrogen compounds from LGO were adsorbed on the synthesized polymer by mixing polymer and LGO. The polymer was regenerated by washing with toluene in a Soxhlet apparatus. Hydrotreating experiments were performed in a pilot scale trickle-bed reactor.To create a baseline for monitoring the hydrotreatment activity, untreated LGO (without polymer adsorption) was hydrotreated with a commercial NiMo/γ-Al 2 O 3 catalyst and analyzed for nitrogen, sulfur, and aromatics content. The pretreated feed (with polymer adsorption) was also hydrotreated, and the results were compared. The results show that prior selective removal of nitrogen compounds improved overall hydrotreatment activity and resulted in additional decrease of 18.7%, 8.3%, and 9.4% in total nitrogen, sulfur, and aromatics content, respectively.

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“…It is important especially in reducing polluting emissions from petroleum fuel and also for pretreating feed for downstream processes such as cracking and reforming (Sambi et al, 1982;Yui, 1994;Bej et al, 2001a;Yui and Ng, 1995;Diaz-Real et al, 1993;Mann et al, 1987Mann et al, & 1988and Sato et al, 1992). The effect of hydrogen sulfide on hydrotreating (the use of both model compounds and real feed) has been widely studied (Sie, 1999;Leglise et al, 1996;Sakanishi et al, 1991;Mochida et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation

Botchwey¹,

Dalai²,

Adjaye³

2006

International Journal of Chemical Reactor Engineering

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A two-stage, micro trickle-bed reactor (for studies of the effects of hydrogen sulfide on hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of Athabasca bitumen-derived heavy gas oil over commercial NiMo/Al 2 O 3 catalyst) has been simulated. One dimensional homogeneous mass transfer and a two dimensional heat transfer models were developed. The essence of the simulation was to enhance the understanding of the effects of hydrogen sulfide in the hydrotreating catalyst bed in a two-stage mode and also to predict the catalyst requirements for deep HDS and HDN processes. The kinetic model used in the simulation was based on the Langmuir-Hingshelwood method of rate determination. Adsorption constants were estimated by non-linear least squares method. The kinetic models were tested on independent set of data and found to predict the experimental data satisfactorily. The mass transfer simulation considered the effects of variables such as temperature and catalyst loading or liquid hourly space velocity (LHSV) on the trends of hydrogen sulfide generation and, sulfur and nitrogen conversions along the catalyst bed. The model was numerically solved using a fourth-order Runge-Kutta technique. The 1:3 wt/wt catalyst loading with inter-stage hydrogen sulfide removal was found to give the best HDN and HDS activities. Simulated results showed that doubling the present catalyst mass and operating at 653 • C with inter-stage hydrogen sulfide removal would give 6 and 179 ppm product sulfur and nitrogen, respectively. On the other hand, without hydrogen sulfide removal, only 49 and 302 ppm product sulfur and nitrogen could be attained, respectively. The heat transfer simulation compared temperature profiles in the two-stage process to a single stage process for the 1:3 wt/wt catalyst Brought to you by | University of Connecticut Authenticated Download Date | 5/29/15 7:09 AM loading at 653 K. The temperature regime in Stage II was found to be more uniform unlike Stage I and the single stage. Crank Nicholson algorithm was used to solve the 2-D partial differential equations.

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Hydrofining of heavy gas oil on zeolite-alumina supported nickel-molybdenum catalyst

Cited by 37 publications

References 1 publication

Hydrodenitrogenation of Petroleum

Hydrodenitrogenation of Petroleum

Insights into the integrated effects of polymeric pretreatment and catalytic hydrotreatment of light gas oil

Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation

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