Upgrade of Methane from Landfill Gas by Pressure Swing Adsorption

Abstract

This work focuses on the production of pipeline grade methane from landfill gas (LFG). Vacuum pressure swing adsorption technology using a kinetic adsorbent, Carbon Molecular Sieve 3K (Takeda), was employed for the separation of methane−carbon dioxide mixture. Adsorption equilibrium and kinetics of methane and carbon dioxide are reported at 298, 308, and 323 to model the adsorption-based process. A four-step Skarstrom-type cycle was employed comprising pressurization, feed, counter-current blowdown, and counter-current purge with product. Co-current pressurization with feed stream and counter-current pressurization with product were evaluated. The separation of a mixture of CH4 (55%)−CO2 (45%) was tested using two different four-step cycles: pressurization with feed stream, feed, blowdown, and purge with product and pressurization with product, feed, blowdown, and purge with product. The results indicate that purity of methane higher than 96% can be obtained with recovery higher than 75%. The difference of the performance in the non-adiabatic and adiabatic cases was also studied. It was observed that the temperature in the column increases allowing a faster and more important desorption of carbon dioxide in the blowdown step, retaining more CO2 in the column and improving methane purity and recovery.

Cation Control of Molecular Sieving by Flexible Li-Containing Zeolite Rho

“…The selective adsorption of CO 2 is important for a range of separation technologies, including purification of air, 1 natural gas and biogas upgrading [2][3][4][5] and carbon capture from pre-and post-combustion gas streams. 6 Small pore zeolites are promising sorbents for this purpose, 7,8 because their performance can be adjusted through control of their polarity, cage and window size, pore capacity and extra-framework cation content.…”

Sorption and kinetics of CO2 and CH4 in binderless beads of 13X zeolite

“…Among the zeolites one of the most interesting is zeolite 13X due to its large cages that can accommodate a large amount of mass and at the same time the presence of cations that produce electric field that interacts with strong quadropole moment molecules such as CO 2 . This gives rise to an increased selectivity between CH 4 (apolar) and CO 2 that has been exploited in cyclic processes [18][19][20][21].…”

Desorption characteristics and kinetic parameters determination of molecular sieve by thermogravimetric analysis/differential thermogravimetric analysis technique

“…CO 2 is considered to be the main greenhouse gas responsible for global warming, formed primarily through combustion processes in power plants and through burning of flammable gases, such as methane, in gas flares in crude oil extractions sites (Cavenati et al, 2005a(Cavenati et al, , 2005bChen et al, 2014). Carbon capture and storage (CCS) technologies are increasingly viewed as a potential solution for carbon sequestration (Ordorica-Garcia et al, 2010).…”