Binary adsorption behaviour of methane and nitrogen gases

Abstract

Separation of methane and nitrogen gases is critical in the upgrading of LFG (Landfill gas), natural gas and coal bed gas in order to have a commercial heating value for methane. From an environmental point of view, methane capture from landfill gas is essential to prevent greenhouse gas emissions. Adsorption could be a beneficial process to capture low purity methane from a landfill site that is nearing the end of its lifecycle and produce high purity methane. In this work, Ceca 13X zeolite and Alcan Activated Alumina AA 320-AP have been studied for their potential for this separation and compared with Silicalite in literature. Pure and mixture adsorption isotherms were determined at 40 and 100°C for these adsorbents by constant volume method and concentration pulse chromatographic technique, respectively. Mixture adsorption isotherms for the binary system of methane and nitrogen gases at 40 and 100°C and 1 atmosphere total pressure have been determined by VV-CPM (Van der Vlist and Van der Meijden Concentration Pulse Method). The application of Extended Langmuir model for this binary system have also been discussed and compared to the experimental results. Results show that equilibrium separation factor for silicalite is larger than zeolite Ceca 13X and Alcan activated alumina AA320-AP. Both Silicalite and Ceca 13X find application in the bulk separation of methane from nitrogen when y CH4 [ 0.4, especially in LFG, coal bed gas and natural gas.

Adsorption equilibria and kinetics of CH4 and N2 on commercial zeolites and carbons

“…Adsorption based processes are well-established technologies for the separation of gas mixtures in, for example, the air separation industry [1], the hydrogen production industry [2][3][4], and the capture of carbon dioxide from flue gases [5][6][7][8][9]. In the past several decades, adsorption based processes for separating nitrogen and methane have attracted significant attention in areas such as natural gas production [8,10], landfill gas upgrading [11,12], coalbed methane enrichment [13], and coal mine methane/ventilation air methane purification [14].…”

Preparation and Gas Separation Properties of Metal‐Organic Framework Membranes

“…Among these efforts, the gas separation of CO 2 and N 2 is an important aspect 3. Meanwhile, CH 4 has stronger effects than CO 2 as greenhouse agents for per unit mass, and its separation from N 2 is necessary for both utilizing coal‐bed methane and purifying natural gases 4–6. Therefore, the design and synthesis of novel materials which are capable of performing gas separation with high efficiency and low cost are essential to prevent the global warming.…”

Mixed‐cation LiCa‐LSX zeolite with minimum lithium for air separation

“…The extended Langmuir model is one of the simplest and most practical models for the prediction of binary gas adsorption behavior from pure component isotherms . Using the extended Langmuir‐Freundlich model for binary mixtures, similar to the use of the extended Langmuir model, is also a simple yet reasonably good way of fitting binary experimental data, as shown by Mulgundmath et al…”