Process and zeolitic materials for the separation of gases
AssigneeENI S.p.A.
InventorsAngela Carati, Caterina Rizzo, Marco Tagliabue, Luciano Cosimo Carluccio, Cristina Flego, Liberato Giampaolo Ciccarelli
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Abstract
The present invention relates to a process for the separation of gases which comprises putting a mixture of gases in contact with a zeolite of the ESV type to obtain the selective adsorption of at least one of the gases forming the gaseous mixture. The present invention also relates to particular zeolitic compositions suitable as adsorbents.
Claims31
A process for the separation of gases which comprises putting a mixture of gases in contact with a zeolite for selectively adsorbing at least one of the gases forming the mixture, wherein the zeolite is a zeolite of the ESV type.
Zeolites of the ERS-7 type having in the calcined and anhydrous form the following general formula (I):
- M2/nO.Al2O3.xSiO2
- wherein M is at least a cation having a valence n selected from Li, Mg, Ca, Sr, Ba, optionally mixed with one or more cations selected from H+ and Na+, n=1 or 2, and x has a value ranging from 15 to 30.
A process for preparing zeolites of the ERS-7 type having in the calcined and anhydrous form the following general formula (I):
- M2/nO.Al2O3.xSiO2
- wherein M is a cation having a valence n selected from H+, metallic cations of the IA group, metallic cations of the IIA group and their mixtures, n=1 or 2, and x has a value ranging from 15 to 30, which comprises:
- a) reacting sodium silicate, aluminum sulfate, N,N-dimethylpiperidinium halide or hydroxide, under hydrothermal conditions, so that there are the following molar ratios in the reagent mixture:
- SiO2/Al2O3
- 15-30
- R/SiO2
- 0.2-0.4
- H2O/SiO2
- 30-50
- Na/Al2O3
- 10-30
- OH−/SiO2
- 0.3-0.6
- wherein R is N,N-dimethylpiperidinium, at a temperature ranging from 150 to 200° C. for a period of time varying from 5 to 15 days;
- b) discharging the resulting mixture from which a solid is separated, by means of filtration, which, after washing with demineralized water and drying at a temperature ranging from 120 to 150° C. has the following composition (II):
- yR20.mM2O.Al2O3.xSiO2 (II)
- wherein 0<y≦1, 0<m≦1, R is N,N-dimethylpiperidinium, M is sodium, x has a value ranging from 15 to 30;
- c) calcining at a temperature ranging from 500° to 700° C. for 5-18 hours, in a stream of air;
- d) optionally partially or totally exchanging with an aqueous solution containing at least one reagent selected from an acid, an organic ammonium salt, a salt of a cation selected from metallic cations of group IA, metallic cations of group IIA, and their mixtures, drying and optionally calcining.
Dependencies are inferred from the claim text.