Studies on the adsorption behavior of CO2-CH4 mixtures using activated carbon

Abstract

-Separation of CO 2 from CO 2 -CH 4 mixtures is an important issue in natural gas and biogas purification. The design of such separation processes depends on the knowledge of the behavior of multicomponent adsorption, particularly that of CO 2 -CH 4 mixtures. In this study, we present a series of experimental binary equilibrium isotherms for CO 2 -CH 4 mixtures on an activated carbon at 293 K and compare them with predicted values using the Ideal Adsorption Solution Theory (IAST) and the Extended Langmuir (EL) model. Even at concentrations of ca. 20% for all binary isotherms, CO 2 already presents higher adsorbed amounts with respect to CH 4 . A maximum selectivity of around 8.7 was observed for a nearly equimolar mixture at 0.1 MPa. The IAST in conjunction with the Toth equation showed slightly better results than IAST using the Langmuir equation and both showed better results than the EL model.

Life Cycle Analysis of Energy Production from Food Waste through Anaerobic Digestion, Pyrolysis and Integrated Energy System

“…Life cycle assessment [17] is an established technique for environmental analysis wherein system inputs (materials, energy, and others) are adequately correlated with the outputs (product, waste, and emissions) using standard methodologies with the aim of improving the system. However, LCA of waste treatments are often based on a single treatment technique coupled with uncertainties, which make them case specific with data unconnected to specific plant or functional scenarios [18,19].…”

New insights into the ideal adsorbed solution theory

“…33 The IAS predictions strongly depend on the choice of the isotherm model applied for the description of single component adsorption isotherms. 7,12,[33][34][35][36][37][38] To avoid this Chen and Sholl 39 developed the transition matrix Monte Carlo (TMMC) approach but it can be applied only for simulated and not for experimental adsorption data.…”

Biogas Purification using Coconut Shell Based Granular Activated Carbon by Pressure Swing Adsorption

“…Minimum and maximum CO 2 adsorption found to be 11% and 45% at 1 bar and 8 bar respectively. Low reduction of CO 2 may due to the fact that both CO 2 and CH 4 were absorbed by the material (Rios et al, 2013) and when the pressure increases, the material showed slight increase in adsorption of CO 2 than CH 4 . There is an initial and preferential filling of high-energy sites for which the more strongly adsorbed component (CO 2 ) is even more preferred in the competition for the sites than when competing for energetically weaker adsorption sites (Rios et al, 2013).…”