Impact of Zeolites on the Petroleum and Petrochemical Industry

Vermeiren, Walter; Gilson, Jean‐Pierre

doi:10.1007/s11244-009-9271-8

Cited by 831 publications

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“…[1][2][3] Within the field of heterogeneous catalysis, the conversion of methanol to hydrocarbons (MTH) or olefins (MTO) over acidic zeolites received a lot of attention during the last decades, due to its relevance in the search for alternative processes to produce hydrocarbon products. [4][5][6][7] The MTO process has experimentally been developed in the past 3-4 decades and is currently being industrialized.…”

Section: Introductionmentioning

confidence: 99%

Complex Reaction Environments and Competing Reaction Mechanisms in Zeolite Catalysis: Insights from Advanced Molecular Dynamics

Wispelaere

Ensing

Ghysels

et al. 2015

Chemistry A European J

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The methanol to olefins process is a show case example of complex zeolite-catalyzed chemistry. At real operating conditions, many factors such as framework flexibility, adsorption of various guest molecules and competitive reaction pathways, affect reactivity. In this paper we show the strength of first principle molecular dynamics techniques to capture this complexity by means of two case studies. Firstly, the adsorption behavior of methanol and water in H-SAPO-34 at 350 °C is investigated. Hereby we observed an important degree of framework flexibility and proton mobility. Secondly, we studied the methylation of benzene by methanol via a competitive direct and stepwise pathway in the AFI topology. Both case studies clearly show that a first principle molecular dynamics approach enables to obtain unprecedented insights into zeolite-catalyzed reactions at the nanometer scale.Keywords: ab initio calculations, molecular dynamics, proton mobility, methylation, zeolites 3 IntroductionChemical conversions in zeolites play an essential role in today's industrial catalysis. [1][2][3] Within the field of heterogeneous catalysis, the conversion of methanol to hydrocarbons (MTH) or olefins (MTO) over acidic zeolites received a lot of attention during the last decades, due to its relevance in the search for alternative processes to produce hydrocarbon products. [4][5][6][7] The MTO process has experimentally been developed in the past 3-4 decades and is currently being industrialized. [5] Methanol can be obtained from coal, natural gas or biomass and is in turn converted into ethene, propene or other hydrocarbons. The process proved extremely difficult to unravel at the nanoscale level due to various factors such as pressure, temperature and the occurrence of competing reaction mechanisms, which highly influence the catalytic performance of the system. Due to its complexity, it is a very challenging case study for theoretical modeling studies. [8] Currently, there is a consensus that a hydrocarbon pool (HP) mechanism operates during the methanol conversion process. Herein, an organic center is trapped in the zeolite pores and acts as co-catalyst. [9][10][11] The HP may be of aromatic or aliphatic nature and the two corresponding types of catalytic cycles are in close connection with each other, a concept that is called the dual cycle. [12] Depending on the catalyst topology and operating conditions either one or both cycles may be responsible for olefin formation during the methanol conversion process. [12][13][14] Theoretical contributions have proven to be indispensable within MTO research.Methodological developments and a steady increase in computer power, contributed to the fact that many properties, in particular rate coefficients of well-defined elementary reactions, are now routinely calculated with high accuracy. [8,[15][16][17] However, theoretical chemists are still confronted with paramount challenges to thoroughly explain experimental observations. The true challenge lies in linking the model system wit...

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Section: Introductionmentioning

confidence: 99%

Complex Reaction Environments and Competing Reaction Mechanisms in Zeolite Catalysis: Insights from Advanced Molecular Dynamics

Wispelaere

Ensing

Ghysels

et al. 2015

Chemistry A European J

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“…Zeólitas com estrutura do tipo FAU tem sido extensivamente estudada devido as suas aplicações em escala industrial no craqueamento de diversos hidrocarbonetos [25]. São utilizadas em mais de 95% dos casos no mercado de catálise; possuem um custo bastante elevado e as refinarias de petróleo consomem uma grande quantidade deste tipo de material para a fabricação da gasolina a partir de óleo cru nos processos de craqueamento catalítico em leito fluidizado [26]. São conhecidas por possuírem alta estabilidade térmica, grande diâmetro de poros com uma estrutura rígida e por apresentarem elevado teor de sódio [10].…”

Section: Introductionunclassified

Síntese de zeólita do tipo faujasita a partir de um rejeito de caulim

Hildebrando¹,

Angélica²,

Neves³

et al. 2012

Cerâmica

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ResumoMateriais zeolíticos foram sintetizados utilizando como fonte principal de silício e alumínio um rejeito industrial gerado durante o beneficiamento do caulim para cobertura de papel; o material de partida e as fases formadas como produtos de reação foram caracterizados por difração de raios X, microscopia eletrônica de varredura e espectroscopia de refletância difusa no infravermelho com transformada de Fourier. O processo de síntese ocorreu em condições hidrotermais através de autoclavagem estática e os efeitos tempo-temperatura, assim como também as relações Si/Al e Na/Al foram considerados. Os resultados mostram que na metodologia desenvolvida com o rejeito de caulim, inicialmente calcinado a 700 °C por 2 h, submetido em seguida à reação em meio alcalino a 90 ºC por 48 h na presença de uma fonte adicional de sílica foi obtida zeólita do tipo faujasita com boa cristalinidade como fase predominante no produto de síntese. Palavras-chave: zeólita, faujasita, caulim. AbstractZeolitic materials were synthesized using as main source of silicon and aluminum an industrial waste generated during the processing of kaolin for paper coating, the starting material and formed phases as reaction products were characterized by XRD

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“…The results reveal the formation of coke in agglomerates that span length scales from tens of nanometers to atomic clusters with amedian size of 30-60 13 Ca toms.T hese clusters correlate with local increases in Brønsted acid site density,demonstrating that the formation of the first deactivating coke precursor molecules occurs in nanoscopic regions enriched in aluminum. This nanoscale correlation underscores the importance of carefully engineering materials to suppress detrimental coke formation.Zeolites are crystalline,m icroporous materials that exhibit robust hydrothermal stability,allowing them to be used under demanding process conditions,s uch as oil refinery operations [1,2] and automotive emissions treatments. [3,4] Commercially,one of the most important zeolites is ZSM-5 with MFI framework topology,w hich has become ubiquitous in petroleum refining and chemical manufacturing.…”

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confidence: 99%

“…[3,4] Commercially,one of the most important zeolites is ZSM-5 with MFI framework topology,w hich has become ubiquitous in petroleum refining and chemical manufacturing. [2] Thee normous quantities at which this material is utilized at the global scale continue to drive research targeting improved performance. Thed etrimental formation of coke is one of the factors limiting zeolite materials,p articularly ZSM-5, in highdemand catalytic processes,s uch as fluid catalytic cracking (FCC) and the methanol-to-hydrocarbons (MTH) reaction.…”

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confidence: 99%

Coke Formation in a Zeolite Crystal During the Methanol‐to‐Hydrocarbons Reaction as Studied with Atom Probe Tomography

et al. 2016

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Understanding the formation of carbon deposits in zeolites is vital to developing new,s uperior materials for various applications,i ncluding oil and gas conversion processes.H erein, atom probe tomography (APT) has been used to spatially resolve the 3D compositional changes at the subnm length scale in as ingle zeolite ZSM-5 crystal, whichh as been partially deactivated by the methanol-to-hydrocarbons reaction using 13 C-labeled methanol. The results reveal the formation of coke in agglomerates that span length scales from tens of nanometers to atomic clusters with amedian size of 30-60 13 Ca toms.T hese clusters correlate with local increases in Brønsted acid site density,demonstrating that the formation of the first deactivating coke precursor molecules occurs in nanoscopic regions enriched in aluminum. This nanoscale correlation underscores the importance of carefully engineering materials to suppress detrimental coke formation.Zeolites are crystalline,m icroporous materials that exhibit robust hydrothermal stability,allowing them to be used under demanding process conditions,s uch as oil refinery operations [1,2] and automotive emissions treatments. [3,4] Commercially,one of the most important zeolites is ZSM-5 with MFI framework topology,w hich has become ubiquitous in petroleum refining and chemical manufacturing.[2] Thee normous quantities at which this material is utilized at the global scale continue to drive research targeting improved performance. Thed etrimental formation of coke is one of the factors limiting zeolite materials,p articularly ZSM-5, in highdemand catalytic processes,s uch as fluid catalytic cracking (FCC) and the methanol-to-hydrocarbons (MTH) reaction. ZSM-5 coking in the MTH reaction has long been studied, with ar ange of conclusions regarding the nature and mechanism of coke formation. [5,6] Despite ongoing investigations and debates,there is aconsensus that coking occurs due to the formation of alkylated mono-and polycyclic aromatics near internal channel intersections,followed by an increase in surface coke from polycyclica renes near pore openings, which finally form agraphitic layer and block pore access. [7][8][9][10][11][12][13] In order to more fully elucidate the material properties that promote the detrimental formation of coke during the MTH reaction on ZSM-5, it would be beneficial to study the carbon deposits on the sub-nm length scale.P revious coking studies on ZSM-5 in the MTH reaction have concentrated on the bulk, [7][8][9]13] or on micrometer length scales, [10,11,14,15] to gain some spatial insight, but none have been capable of delivering sub-nm resolution.Theo nly characterization method currently capable of spatially resolving 3D element distributions at the sub-nm scale is atom probe tomography (APT), which was first envisioned in the 1930s,b ut has recently experienced rapid growth due to improvements in instrumentation. [16][17][18][19][20] APT is able to create atom-by-atom 3D compositional reconstructions of materials within afabricated needle-...

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Impact of Zeolites on the Petroleum and Petrochemical Industry

Cited by 831 publications

References 95 publications

Complex Reaction Environments and Competing Reaction Mechanisms in Zeolite Catalysis: Insights from Advanced Molecular Dynamics

Complex Reaction Environments and Competing Reaction Mechanisms in Zeolite Catalysis: Insights from Advanced Molecular Dynamics

Síntese de zeólita do tipo faujasita a partir de um rejeito de caulim

Coke Formation in a Zeolite Crystal During the Methanol‐to‐Hydrocarbons Reaction as Studied with Atom Probe Tomography

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