Conversion of light alcohols to hydrocarbons over ZSM-5 zeolite and asbestos-derived zeolite catalysts

Mao, R. Le Van; McLaughlin, G.

doi:10.1021/ef00017a016

Cited by 10 publications

(6 citation statements)

References 1 publication

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“…Essentially, the acidity profile of the H-ZSM-5 zeolites showed two well separated peaks (which normally were overlapped [9,11,14]), the one recorded at higher desorption temperature corresponding to the stronger acid sites (figure 1). As the SiO 2 /Al 2 O 3 ratio increased, these two peaks slightly shifted to higher temperatures, meaning that the fewer the acid sites, the slightly stronger they were (table 5 and figure 1).…”

Section: Resultsmentioning

confidence: 99%

“…In particular, with zeolites and related materials, ammonia adsorption and desorption (NH 3 -TPD) method can be used to measure the density of acid sites and to determine their distribution in terms of acid strength [9,10]. Most of the time, a gas chromatograph equipped with a thermoconductivity detector (GC-TCD) is used to record the amount of the ammonia desorbed as a function of the heating temperature, thus allowing the assessment of the distribution of the acidity strength in a ZSM-5 zeolite [9].…”

Section: Introductionmentioning

confidence: 99%

“…Most of the time, a gas chromatograph equipped with a thermoconductivity detector (GC-TCD) is used to record the amount of the ammonia desorbed as a function of the heating temperature, thus allowing the assessment of the distribution of the acidity strength in a ZSM-5 zeolite [9]. However, it is extremely difficult to obtain an accurate analysis because the quite slow response of the TCD combined with the gas backmixing effect in the outlet tubing as well as in the detector volume infers a serious peak overlapping.…”

Section: Introductionmentioning

confidence: 99%

“…However, it is extremely difficult to obtain an accurate analysis because the quite slow response of the TCD combined with the gas backmixing effect in the outlet tubing as well as in the detector volume infers a serious peak overlapping. This problem cannot be solved even by using deconvolution techniques or stepwise heating programs [9]. A ''water'' purging technique used to eliminate the weakly adsorbed ammonia has been recently developed [11].…”

Section: Introductionmentioning

confidence: 99%

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New method for the study of surface acidity of zeolites by NH3-TPD, using a pH-meter equipped with an ion selective electrode

Mao

Al-Yassir

et al. 2006

Catal Lett

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Desorbed ammonia is captured by an acetic acid solution whose concentration of ammonium ions formed by neutralization, is continuously recorded by a pH-meter equipped with an ion-selective electrode (ISE). This technique allows the study of both the acidity density and the distribution of acid site strengths. Such ''strength profile'' was obtained by plotting the relative rate of desorbed NH 3 versus the temperature. Results obtained can be fairly well correlated with those already published. It is shown that by investigating several H-ZSM-5 zeolites with different SiO 2 =Al 2 O 3 ratios, the data of acid density obtained by the ISE method are very close to those calculated from the Al content. The slight shift of the desorption peaks towards higher temperature suggests a slightly higher strength for more isolated acid sites. Zeolite structures, which are richer in Al, contain weaker acid sites, as evidenced by the H-Y when compared to the H-mordenite, while the acid sites density of the former is much higher. The ultra-stabilized Y zeolite (H-USY) shows a lower acidity density than the parent H-Y owing to the removal of some of the tetrahedral Al atoms from the framework during the preparation. The strength profile of the H-USY is also quite different from that of the H-Y. The new technique appears to be much simpler, more rapid, more informative and quite accurate when compared to the technique using a gas chromatograph equipped with a thermal conductivity detector (GC-TCD).

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

New method for the study of surface acidity of zeolites by NH3-TPD, using a pH-meter equipped with an ion selective electrode

Mao

Al-Yassir

et al. 2006

Catal Lett

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“…Conversion of butanol to gasoline-range hydrocarbons has been studied by various research groups [35,[61][62][63]; however, research on this issue seems to be limited. The reaction sequence includes dehydration of butanol as the first step of alcohol-gasoline conversion over solid acids.…”

Section: Upgrading Of Butanol To Fuelsmentioning

confidence: 99%

8. Conversion of lignocellulosic biomass-derived intermediates to hydrocarbon fuels

Heracleous,

Vasiliadou,

Iliopoulou

et al. 2015

Biorefineries

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Biofuels -liquid and gaseous fuels derived from organic matter -can play an important role in reducing CO 2 emissions in the transport sector and enhancing energy security. Although lignocellulosic biomass presents the highest potential as feedstock, its conversion faces physical, chemical, and technical limitations due to the complex structure of biomass. Moreover, biofuels produced from primary processing of lignocelluloses require further upgrading to hydrocarbons, in order to be able to be used as drop-in fuels, i.e., fuels that are fully compatible with the existing fuel infrastructure and can run in today's engines without modifications. In this chapter, we present an overview on the secondary processing of lignocellulosic biomass-derived intermediates (namely pyrolysis bio-oil, sugars, and butanol) to hydrocarbon fuels.

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Conversion of ethanol over metal‐exchanged zeolites

Schulz¹,

Bandermann²

1993

Chem Eng & Technol

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The effects of metal exchange between zeolites and alkali metals (Li, Na, K; zeolite Y, ZSM-5, T), alkaline earths (Mg, Ca, Sr, Ba; ZSM-5), transition metals (La, Ce, Cr, Mn, Fe, Co, Ni, Pd, Cu, Zn; ZSM-5) and aluminium (ZSM-5) on the conversion of ethanol were studied, Activities of the catalysts and selectivities for ethene, C3 + olefins, paraffins and arenes strongly depended on the cation, chosen for the modification. Only ethene was formed by alkali exchanged zeolites, the most active being Li-Y. This could be confirmed by a long-term ageing test with Li-Y pellets under semi-industrial conditions. The exchange of ZSM-5 with alkaline earths or transition metals permitted the formation of a wide variety of products, ranging from high ethene to high aromatic yields. A correlation between certain product selectivities and electronegativity was only possible in a rough approximation.

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Conversion of light alcohols to hydrocarbons over ZSM-5 zeolite and asbestos-derived zeolite catalysts

Cited by 10 publications

References 1 publication

New method for the study of surface acidity of zeolites by NH3-TPD, using a pH-meter equipped with an ion selective electrode

New method for the study of surface acidity of zeolites by NH3-TPD, using a pH-meter equipped with an ion selective electrode

8. Conversion of lignocellulosic biomass-derived intermediates to hydrocarbon fuels

Conversion of ethanol over metal‐exchanged zeolites

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