Removal of Carbon Dioxide from Natural Gas by Vacuum Pressure Swing Adsorption

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Simone Cavenati (Author) FEUP; Carlos Grande (Author) FEUP; Alírio Rodrigues (Author) FEUP

Journal

Title: Energy & Fuels

Vol. 20 No. 6

Pages: 2648-2659

ISSN: 0887-0624

Publisher: American Chemical Society

Indexing

ISI Proceedings

Scientific classification

CORDIS: Technological sciences > Engineering > Chemical engineering

Other information

Resumo (PT): A vacuum pressure swing adsorption (VSA-PSA) process is studied for the removal of carbon dioxide in a contaminated stream of natural gas to achieve fuel grade methane. The adsorbent used was zeolite 13X (CECA) where CO2 is strongly adsorbed. A Skarstrom-type cycle comprising pressurization with product, feed, countercurrent blowdown, and countercurrent purge was employed. A mixture having 60% CH4/20% CO2/ 20% N-2 was used, and two different temperatures were evaluated in a single-column VSA-PSA unit. Under the conditions tested, CO2 was removed to levels lower than 2% as required by fuel grade methane with methane recovery higher than 80% without recycle. This separation process also helps in the CH4-N-2 separation. A bidisperse (macropore-micropore) model also including distributed energy balances in gas, solid, and column wall considering heat and mass transfer resistance at the gas-solid interface was used to simulate the VSA-PSA behavior and compare with experiments. Also, some scale-up considerations are considered and evaluated by simulations of the process.

Abstract (EN): A vacuum pressure swing adsorption (VSA-PSA) process is studied for the removal of carbon dioxide in a contaminated stream of natural gas to achieve fuel grade methane. The adsorbent used was zeolite 13X (CECA) where CO2 is strongly adsorbed. A Skarstrom-type cycle comprising pressurization with product, feed, countercurrent blowdown, and countercurrent purge was employed. A mixture having 60% CH4/20% CO2/ 20% N-2 was used, and two different temperatures were evaluated in a single-column VSA-PSA unit. Under the conditions tested, CO2 was removed to levels lower than 2% as required by fuel grade methane with methane recovery higher than 80% without recycle. This separation process also helps in the CH4-N-2 separation. A bidisperse (macropore-micropore) model also including distributed energy balances in gas, solid, and column wall considering heat and mass transfer resistance at the gas-solid interface was used to simulate the VSA-PSA behavior and compare with experiments. Also, some scale-up considerations are considered and evaluated by simulations of the process.

Language: Portuguese

Type (Professor's evaluation): Scientific