Zeolite Advances in the Chemical and Fuel Industries: A Technical Perspective

Whyte, T.E.; Betta, Ralph A. Dalla

doi:10.1080/03602458208079663

Cited by 36 publications

(10 citation statements)

References 65 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In particular, simultaneous TG-DTA measurements have supplied useful qualitative or semi-quantitative information about dehydration processes (mechanisms) or high-temperature stabilities of various zeolitic frameworks (McAdie, 1970;Breck, 1974;McDaniel & Maher, 1976;Shlyapkina, 1978; Haynes, 1978;Lechert, 1983). Besides their selective sorption, molecular sieving and cation-exchange characteristics, most of these natural zeolites have shown spectacular catalytic properties towards a variety of reactions in petroleum processing and, since the 1960s, rapid and dynamic progress has been achieved in zeolite catalysis (Breck, 1974;Rabo et al, 1978;Flanigen, 1980;Whyte & Dalla Betta, 1982). An important step in the study of zeolitic materials was reached in 1959 when the Linde Division of the Union Carbide Corporation reported for the first time the synthesis of an aluminium-rich zeolite, namely Zeolite A (Milton, 1959) and, up to 1983, more than 180 new synthetic zeolitic species have been described (see for example Barrer, 1981;Barrer, 1982;Lok et al, 1983, and references therein).…”

mentioning

confidence: 99%

“…Combined TG-DTA was mostly used to provide complementary information on the decomposition process of various organic host molecules (ions) occluded in the zeolitic framework during synthesis. Usually only qualitative information is desired on the temperature range in which the organics are removed from the precursor framework by oxidative degradation, and examples illustrating the fruitful use of DTA for this purpose are numerous: decomposition of tetra-methylammonium (TMA) ions occluded in various zeolites (Barrer & Denny, 1961;Aiello & Barrer, 1970;Wu et al, 1971;Colella et al, 1982;Whyte & Dalla Betta, 1982;Penchev et al, 1983;Sidamonidze et al, 1983;Occelli & Perrotta, 1983); decomposition of ZSM-5 containing either its classical structure-directing tetra-propylammonium (TPA) ions (Bibby et al, 1979;Chao, 1979;Bibby et al, 1980;Derouane et al, 1981b;Chao et al, 1981;Yun & Ruren, 1982;Penchev et al, 1983), or tetra-ethylammonium (TEA) ions (Parker et al, 1984), or containing various other (poly)alkylamines (Qingxia et al, 1982;Gabelica et al, 1983f;Parker et al, 1983); decomposition of ZSM-11 containing tetra-butylammonium (TBA) ions (Bibby et al, 1979;Gabelica et al, 1983f;Surin et al, 1983); decomposition of ZSM-5/11 mixed phases (intergrowths) containing tri-alkylamines (Gabelica et al, 1983f) and degradations of many other complex organic molecules incorporated in high-silica zeolites such as ZSM-39 (Bibby & Parker, 1983) or Eu-1 (Casci et al, 1983), or even decomposition of tetra-alkylammonium ions 'occluded' within amorphous silica-aluminas (Manton & Davidtz, 1979;Howden, 1982b).…”

mentioning

confidence: 99%

See 1 more Smart Citation

The use of combined thermal analysis to study crystallization, pore structure, catalytic activity and deactivation of synthetic zeolites

et al. 1984

View full text Add to dashboard Cite

Emphasis is placed on the advantages of combining simultaneous thermal analysis methods (TG-DTA-DTG) with other complementary physico-chemical techniques for investigating synthesis and various properties of zeolites belonging to the pentasil family. TG and DTA give quantitative information on the dehydration and decomposition of organic guest molecules that interact with intermediate phases obtained during hydrothermal transformation of amorphous aluminosilicate gels into crystalline zeolites. In particular, weight losses (TG) and heat effects (DTA) due to the oxidative decomposition of tetrapropylammonium ions occluded in an intermediate phase have been related to the amount of zeolite ZSM-5 present. As a result, very small particles of this zeolite, amorphous to X-rays, could be detected in the early stages of the crystallization process. Isothermal sorption of small hydrocarbon molecules (n-hexane, 3-methyl-pentane) is used to probe the intracrystalline pore volume of zeolite ZSM-5. The total hydrocarbon uptake (TG) and the shape of the corresponding DTA peak are sensitive to steric modifications of the ZSM-5 channel system by various chemicals, while the sorption rates are better correlated to the extent of zeolite surface poisoning by boron or carbon. TG-DTA data provide an easy means of describing the filling and packing of n-hexane in ZSM-5 pore structure. Various steps characterizing isothermal competitive sorptions (nitrogen, ethylene, water) or catalytic conversions at high temperature (ethylene, methanol) over H-ZSM-5 are described. Finally, the progressive formation (removal) of carbonaceous residues resulting from these transformations are related to the actual rate of de-activation (re-activation) of a zeolitic material. In this respect, three different synthetic zeolites, namely mordenite, offretite and H ZSM 5, which differ by their shape-selective properties and structure of their channel network, are investigated by TG.Combined thermal analysis methods have been used extensively to characterize natural minerals, including various zeolites and clays (Mackenzie, 1970;Smykatz-Kloss, 1974; Todor, 1978; Mackenzie & Caillere, 1979). In particular, simultaneous TG-DTA measurements have supplied useful qualitative or semi-quantitative information about dehydration processes (mechanisms) or high-temperature stabilities of various zeolitic

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

The use of combined thermal analysis to study crystallization, pore structure, catalytic activity and deactivation of synthetic zeolites

et al. 1984

View full text Add to dashboard Cite

show abstract

“…It has the same crystal structure as the ZSM-5 zeolite which has been applied as a catalyst in MTG and other petrochemical processes [2].…”

Section: Rende 87030 Rende (Cs) Italymentioning

confidence: 99%

Thermal behaviour of the tpa IONS in ZSM-5 zeolite: II. Effect of crystal size and grinding of silicalite-1

Crea

Giordano

Mostowicz

et al. 1990

Journal of Thermal Analysis

View full text Add to dashboard Cite

RENDE, 87030 RENDE (CS), ITALYThermal decomposition of Silicalite-1 crystals of various size was studied. The crystals were in as-made form and upon grinding. The DTA and DTG curves show differences in the temperature of thermal decomposition of TPA species occluded in the as-made crystals. These differences disappear upon grinding. The explanation of this phenomena is given.Silicalite-1, the Al-free analogue of ZSM-5 zeolite was first prepared by E. M. Flanigen et al. [1]. It has the same crystal structure as the ZSM-5 zeolite which has been applied as a catalyst in MTG and other petrochemical processes [2].Synthesis of the ZSM-5 zeolite and its aluminium deficient end-member silicalite has been the topic of a large number of investigations [3]. The parameters affecting the growth of large silicalite crystals and the effect of reactant concentration on crystal morphology have been reported by Hayhurst et aL [4,5].The organic compounds used as either structure-directing and/or space filling species in a high-silica zeolite synthesis are generally occluded in the zeolite channels and cavities either in an intact or in a modified state [3,6]. The state of tetrapropylammonium (TPA) ions, occluded in ZSM-5 channels has been most thoroughly investigated by thermal analysis combined with mass spectrometry [7] or 13C-NMR spectroscopy [8]. TPA ions decompose by the Hoffman reaction to give an olefin and trialkylamine [7].The three DTA peaks (B, C1 and C2) have been assigned [8] to decomposition of different TPA species occluded into the zeolitic channels. In the case of Al-free silicalite, the low temperature (ca 380 ~ peak B is attributed [9] to less strongly held or "outer shell" strained TPA ions. A peak C1 (ca. 425 ~ is assigned to inner ions neutralizing SiO-negative charges of John Wiley & Sons, Limited, Chichester Akadgrm'ai Kiad6, Budapest

show abstract

“…Selective gasoline synthesis from methanol had actually been developed many years before the work of Ishihara et al (48), thus the latter based on FTS should be seen as an alternative route. The methanol to gasoline (MTG) process, which was based on the catalytic properties of H-ZSM-5, was developed by Mobil Oil in the 1970s and tested in New Zealand in the early 1980's (49)(50)(51)(52). MTG later inspired the UOP/Hydro development of the methanol to olefins (MTO) process, which utilizes a SAPO-34 zeolite catalyst (53).…”

Section: Introductionmentioning

confidence: 99%