Adsorption and Separation of the H2O/H2SO4 and H2O/C2H5OH Mixtures: A Simulated and Experimental Study

Abstract

Adsorption processes are characterized by their kinetics and equilibrium isotherms described by mathematical models. Nowadays, adsorption with molecular sieves is a method used to separate certain elements or molecules from a mixture and produce hydrogen, nitrogen, oxygen, ethanol, or water treatment. This study had two main objectives. The first one was focused on the use of different natural (Clinoptilolite-S.L. Potosi, Clinoptilolite-Puebla, and Heulandite-Sonora) and synthetic (Zeolite Type 3A) adsorbents to separate the mixtures H 2 O/H 2 SO 4 and H 2 O/C 2 H 5 OH. It was determined that both Zeolite Type-3A and Heulandite-Sonora have greater adsorption capacity in a shorter time compared with the Clinoptilolites at different temperatures. The second objective was the simulation of a pressure swing adsorption process to dehydrate ethanol using the parameters obtained from Zeolite Type 3A (with maximum adsorption capacity). Several configurations were considered to calculate the appropriate nominal values for the optimal process. The results illustrate that the purity of ethanol is increased when the following parameters are considered in the adsorption process: a high pressure, a constant temperature between 100 and 120 • C, a feed composition near the azeotropic point with lower water content, and a purge pressure near the vacuum. Finally, the results show that it is possible to take advantage of the length of the absorber bed in order to reduce the energy costs by increasing the ethanol production as well as complying with the international purity standards.

Review of the Pressure Swing Adsorption Process for the Production of Biofuels and Medical Oxygen: Separation and Purification Technology

“…Among the adsorbents that have been used to separate the ethanol-water mixture, natural zeolites are good candidates and have an advantage over some types of membranes or natural adsorbents because they remain stable in harsh chemical environments and high temperatures [14][15][16][17][18]. Dehydration of ethanol through adsorption with natural zeolites is acceptable and effective in adsorbing large amount of water, but the use of synthetic zeolites has recently been suggested as a promising alternative.…”

“…(3) Gas-solid heat transfer (4) Enthalpy of mixing is negligible (5) Include wall energy data (6) Heat of adsorption (7) Thermal conductivity of gas and thermal conductivity of solid (8) Compression (9) The system is fully mixed in the radial direction (10) Plug flow with axial dispersion occurs (11) The gas phase is ideal or nonideal (12) The driving force is based on a gas or solid film, and is either linear or quadratic (13) Gas phase pressure is either constant or the pressure varies according to a laminar or turbulent flow momentum balance (14) Mass transfer coefficients are either constant or vary with local conditions (15) Mass transfer is described using a lumped overall resistance, or by a model that accounts separately for micro-and macropore effects (16) Adsorption isotherms are either applicable for single or multicomponent adsorption…”

Extractive Distillation Approach to the Separation of Styrene from Pyrolysis Gasoline Feedstock Coupled with Deep Desulfurization

“…The implementation of ionic liquids and porous materials on a large-scale industrial basis is hindered by their high cost and extreme difficulties in recovery or regeneration [18][19][20][21][22][23]. Extractive distillation finds the most widely applications in this separation practice [24][25][26]. Specifically, such process is accomplished by changing the relative volatility of distillation components through the incorporation of auxiliary solvents, such as sulfolane, N-methylpyrrolidone, and N-formylmorpholine [27][28][29].…”