Separation of methane and nitrogen by adsorption on carbon molecular sieve

• Type: Article in International Scientific Journal
• Date: 2005

Authors

Cavenati, S (Author) Other; Grande, CA (Author) Other; Alírio Rodrigues (Author) FEUP

Journal

Title: Separation Science and Technology

Vol. 40

Pages: 2721-2743

ISSN: 0149-6395

Publisher: Taylor & Francis

Indexing

ISI Proceedings

ISI Web of Knowledge - 28 Citations

Scopus - 39 Citations

Scientific classification

CORDIS: Technological sciences > Engineering > Thermal engineering

Other information

Authenticus ID: P-000-6R7

DOI: 10.1080/01496390500287846

Resumo (PT): Adsorption equilibrium of methane and nitrogen on CMS 3K from Takeda Corp. were gravimetrically measured at 298, 308, and 323 K and at pressures up to 2000 kPa. The most adsorbed gas is methane followed by nitrogen. The adsorption loading at 550 kPa and 308 K is 1.73 mol/kg for methane and 0.91 mol/kg for nitrogen. Experimental data were fitted with the multisite Langmuir model. Single component uptake of these gases at low pressures was used to determine the adsorption kinetics. Adsorption of nitrogen is much faster than methane, although this gas is preferentially adsorbed. The adsorption rate of both gases was controlled by a surface barrier resistance at the mouth of the micropore combined with micropore diffusion. Breakthrough curves of pure gases and their binary mixtures were measured at ambient temperature. A bi-LDF (Linear Driving Force) model was used to predict the fixed-bed behavior. Large differences in the adsorption kinetics were observed: at 308 K the LDF constant ratio was K-mu,K-N2/K-mu,K-CH4 = 133, although because of much higher adsorption of methane, the overall kinetic selectivity was 1.9 at 308 K. The data obtained in this work can be used for adsorption separation processes modeling for methane purification from nitrogen-contaminated streams.

Abstract (EN): Adsorption equilibrium of methane and nitrogen on CMS 3K from Takeda Corp. were gravimetrically measured at 298, 308, and 323 K and at pressures up to 2000 kPa. The most adsorbed gas is methane followed by nitrogen. The adsorption loading at 550 kPa and 308 K is 1.73 mol/kg for methane and 0.91 mol/kg for nitrogen. Experimental data were fitted with the multisite Langmuir model. Single component uptake of these gases at low pressures was used to determine the adsorption kinetics. Adsorption of nitrogen is much faster than methane, although this gas is preferentially adsorbed. The adsorption rate of both gases was controlled by a surface barrier resistance at the mouth of the micropore combined with micropore diffusion. Breakthrough curves of pure gases and their binary mixtures were measured at ambient temperature. A bi-LDF (Linear Driving Force) model was used to predict the fixed-bed behavior. Large differences in the adsorption kinetics were observed: at 308 K the LDF constant ratio was K-mu,K-N2/K-mu,K-CH4 = 133, although because of much higher adsorption of methane, the overall kinetic selectivity was 1.9 at 308 K. The data obtained in this work can be used for adsorption separation processes modeling for methane purification from nitrogen-contaminated streams.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 23