Maleic anhydride from C-4 feedstocks using fluidized bed reactors

Contractor, R.M.; Sleight, A.W.

doi:10.1016/0920-5861(87)85006-x

Cited by 68 publications

(26 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The predicted concentration profiles indicate that due to the very high activity of the La 2 O 3 /CaO catalyst significantly shorter risers will be necessary for OCM compared to reactors applied for Fisher-Tropsch synthesis [34], catalytic cracking [28,35], selective oxidation of n-butane to MSA [30] or for the oxidation of propene to acrolein [29]. The results showed that at a reaction temperature of 740 C and a gas velocity of 18 m/s a height of approximately 8 m would be sufficient to achieve complete conversion of oxygen.…”

Section: Concentration Profilesmentioning

confidence: 99%

Reaction Engineering Simulations of Oxidative Coupling of Methane in a Circulating Fluidized-Bed Reactor

Pannek

Mleczko

1998

Chem. Eng. Technol.

View full text Add to dashboard Cite

Oxidative coupling of methane in a circulating fluidized bed (ID = 1 m, H = 20 m) was investigated by means of reaction engineering modeling and simulations. The hydrodynamics of the catalytic bed was described applying a two-phase (core and annulus) and two-zone (acceleration and fully developed flow) model. Chemical reactions were described by two separate networks for the heterogeneous and homogeneous reactions. The one for the heterogeneous steps was developed for a La 2 O 3 / CaO catalyst. Concentration profiles revealed that due to the high activity of the catalyst, almost complete conversion of oxygen was already obtained in the acceleration zone. Reactor performance was found to be strongly influenced by mass transport limitation between the core and annulus and by gas-phase reactions. The maximum C 2+ yield of 13% (T = 800 C, X CH4 = 34.5%, S C2+ = 37.5%) was obtained at a high solids circulation rate (G s = 800 kg/m 2 s) and a low methane-to-oxygen ratio (CH 4 /O 2 = 3).The C 2+ yields in the CFB are comparable to the ones predicted for an industrial-scale bubbling-bed reactor.

show abstract

Section: Concentration Profilesmentioning

confidence: 99%

Reaction Engineering Simulations of Oxidative Coupling of Methane in a Circulating Fluidized-Bed Reactor

Pannek

Mleczko

1998

Chem. Eng. Technol.

View full text Add to dashboard Cite

show abstract

“…Rapid increase in the price of benzene and strict pollution control norms in the next few decades necessitated commercialization of n-butane process and the first commercial plant was commissioned operational in 1974 by Monsanto. In subsequent decades, a variety of reactors such as multitubular fixed bed reactor, 6,7 fluidized bed reactor 8 and circulating fluidized bed reactor 8,9 have been used for n-butane oxidation process. Multitubular fixed bed reactors suffered from hot spot formation owing to the highly exothermic nature of this reaction.…”

Section: Introductionmentioning

confidence: 99%

Modeling of partial oxidation in gas–solids downer reactors

2009

View full text Add to dashboard Cite

Selective partial oxidations represent an important class of reactions in the process industry. Of particular interest is the partial oxidation of n-butane to maleic anhydride (MAN), which is arguably the largest commercialized alkane partial oxidation process. Partial oxidation of n-butane, which uses vanadium phosphorous oxide (VPO) as a heterogeneous catalyst, is believed to operate through a unique mechanism in which lattice oxygen oxidizes n-butane selectively to MAN. Past work has shown that performing partial oxidation reactions in gas-solids riser configuration is realizable and commercially viable, which has lead to commercialization of this technology in the last decade. Though the riser configuration allows optimal and independent control of the oxidation and reduction steps, the riser unit suffers from solid backmixing at walls, which in turn result into lower conversion, nonoptimal selectivity and diminished overall yield of desired product. In recent years, there has been growing interest in downers involving cocurrent downflow of both solids and gas phases, hence offering relatively uniform flow characteristics. In this contribution, we explore through modeling the implications of effecting partial oxidation reactions in a downer (gas-solids cocurrent downflow) compared to that in a conventional riser reactor (gas-solids cocurrent up flow) operated under equivalent operating conditions. Further, we explore the operational space of downers for these reactions, suggesting ways for improving the productivity of downer for partial oxidation applications. V

show abstract

“…The development of non-coproduct technologies (propylene oxide, phenol), and the monooxygenation of various reactants (methane to methanol, butane to tetrahydrofuran, propylene to propylene oxide, benzene to phenol). feedstocks new fluidized-bed technology offers advantages in the areas of heat generation and removal over fixed-bed operation (14). Molten nitrate salts have been reported as novel media for the selective epoxidation of propylene and other higher olefins without the generation of co-products (15,16).…”

Section: Homogeneousmentioning

confidence: 99%