The reaction mechanism of the selective oxidation of butane on (VO)2P2O7 catalysts: The role of oxygen in the reaction chain to maleic anhydride

Rodemerck, Uwe; Kubias, B.; Zanthoff, H.‐W.; Baerns, M.

doi:10.1016/s0926-860x(96)00330-4

Cited by 48 publications

(27 citation statements)

References 15 publications

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“…The importance of having a defined amount of V 5+ in order to obtain better selectivity has been pointed out by Volta and co-workers, the optimal V 5+ /V 4+ ratio being equal to 0.25 [93][94][95][96][97]. Evidences for the role of V 5+ have also been reported by other authors [98][99][100][101]. Isolated V 5+ sites in strong interaction with the VPP are those responsible for the activation of the alkane and for O-insertion, while the formation of bulk VOPO 4 is detrimental for selectivity.…”

Section: Reactivity Under N-butane-rich Conditions and The Role Of Tmentioning

confidence: 72%

VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge?

et al. 2006

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A Partner of Concorde CA and of Idecat NoE, 6FP of the EU) b Lonza SpA, via E. Fermi 51, 24020 Scanzorosciate (BG), ItalyThis review describes recent findings in the oxidation of n-butane to maleic anhydride. The process is commercial since the 80's, but yet the yield is far from being optimised. Therefore, it represents an emblematic example of how several scientific disciplines, from solid-state science to reactor technology, can contribute to the improvement of the process performance.KEY WORDS: Vanadyl pyrophosphate; n-butane; selective oxidation; maleic anhydride 1. The oxidation of n-butane catalysed by VPO: How to improve process performance?The activation of light alkanes by high-temperature contact with a redox catalyst represents one way to transform these hydrocarbons to valuable chemicals (a few reviews and books dealing with this topic, published after 1998, are refs [1-18]). The most successful example is the oxidation of n-butane to maleic anhydride (MA), catalysed by a V/P/O-based catalyst (VPO), which starting from the 80's has been replacing in part the commercial synthesis from benzene. This reaction, and the unique chemical-physical properties of the vanadyl pyrophosphate (VO) 2 P 2 O 7 (VPP), the active and selective phase for this reaction, are amongst the most studied topics in catalysis during the latest decades, initially with the aim of understanding which catalyst peculiarities make this complex transformation possible, and later on with the aim of improving the process performance.MA finds its major use in the production of unsaturated polyesters and of butanediol. The yearly world consumption exceeds 1.3 · 10 6 metric tons [19]. Approximately 70% is produced by n-butane oxidation, the remaining still being obtained from benzene. There are several reactor technologies available, including fixed-bed (Scientific Design, Huntsman, BASF, Pantochim), fluidised-bed (Lonza, BP, Mitsubishi), and transported-bed (DuPont). Best process performances reported in patent literature range from 53 to 65% molar yield to MA [20][21][22][23][24][25], with a conversion of the hydrocarbon not higher than 85-86%. An excellent result of more than 70% yield is reported [26], which however refers to a recycle process. In lab reactors best yields reported are lower than 50%.The best performance for a fixed-bed reactor does not exceed 65% per-pass yield, while that in a fluidised-bed is typically somewhat lower; in fact, back-mixing phenomena are responsible for the consecutive combustion of MA. Moreover, with fluidised-bed operation n-butane-richer conditions can be used (up to 5 molar % in feed); under the latter conditions, a worsening of selectivity is expected, which however is compensated by a considerable improvement in MA productivity. In the fluidised-bed process developed by Lonza and Lummus (shown in figure 1), the loss of selectivity is also compensated by the higher amount of high-pressure steam produced, due to the more efficient removal of the reaction heat and to the more CO x produced.The maximu...

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Section: Reactivity Under N-butane-rich Conditions and The Role Of Tmentioning

confidence: 72%

VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge?

et al. 2006

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“…On the other hand, Barteau (2002, 2003) concluded that both lattice oxygen and adsorbed oxygen on VPO catalysts can selectively oxidize butane to MA. The role of the different oxygen species is still under discussion and other authors using TAP experiments (Rodemerck et al, 1997) concluded that conversion of butane to MA happens only with lattice oxygen and no adsorbed oxygen is involved. However, the low partial pressure used in TAP could hinder the existence of weakly adsorbed oxygen.…”

Section: Resultsmentioning

confidence: 99%

A generalized kinetic model for the partial oxidation of n-butane to maleic anhydride under aerobic and anaerobic conditions

Gascón

Valenciano

Téllez

et al. 2006

Chemical Engineering Science

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“…However, it has been shown that n-butane could be activated in the absence of gas phase oxygen and that lattice oxygen was involved [27]; this proposal was confirmed by TAP experiments indicating that nearly all the oxygen incorporated into the oxygenated products came from the lattice [28]. Several mechanisms involving different sites have been proposed for the first step of the reaction (figure 1).…”

Section: Vpo Catalyst For N-butane Oxidation To Maleic Anhydridementioning

confidence: 89%

Mechanism of first hydrogen abstraction from light alkanes on oxide catalysts

Millet

2006

Top Catal

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The activation mechanism of light alkanes is discussed in view of the catalytic properties, and both, bulk and surface properties of active phases. Among the most efficient catalytic systems, four are examined: VPO, Ti(Zr)PO, VSbO and MoVTeNbO. Different activation processes are proposed depending upon the catalyst used but all have the same H abstracting sites corresponding to O ) . The formation of these relatively strong bound species may be related to structure defects (cationic vacancies, excess oxygen) or they might be created through thermally activated electron transfer. Particular emphasis is given to electrical conductivity measurements to evidence the presence of these active oxygen species.

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The reaction mechanism of the selective oxidation of butane on (VO)2P2O7 catalysts: The role of oxygen in the reaction chain to maleic anhydride

Cited by 48 publications

References 15 publications

VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge?

VPO catalyst for n-butane oxidation to maleic anhydride: A goal achieved, or a still open challenge?

A generalized kinetic model for the partial oxidation of n-butane to maleic anhydride under aerobic and anaerobic conditions

Mechanism of first hydrogen abstraction from light alkanes on oxide catalysts

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