Abstract
In this work, the ethanol dehydration production process is carried out using the Mathematical Modeling Pressure Adsorption Process. A new model is suggested, it has two equalization steps, and is compared with the Industrial Pressure Swing Process operating cycle. An analysis of the effects of introducing the pressure equalization step is performed on four main response variables: purity, production, recovery and energy consumption and it is compared with the current cycle configuration operating in the industry. We used Aspen Adsorption for the valuation and simulation of the cyclic PSA process. We analyzed and processed the simulation results in Statgraphics Centurion to obtain optimum operating conditions for the process. This evaluation shows that purity decreases slightly, whereas recovery and production increase. The most important thing is that the energy consumption is reduced. These results clearly show that by modifying the operating cycle schema, optimum operating conditions also change. The optimization of the new cycle was executed considering as variables bed pressure, adsorption time and purging flow. We found that a smaller column is more productive for the equalization cycle than that of a 14m bed, which is optimal in the industrial cycle with a consequent reduction in adsorbent material.
References
[1] Okewale A.O., Etuk B.R., Igbokwe P.K., Comparative studies on some starchy adsorbents for the uptake of water from ethanolwater mixtures, IJET-IJENS, 2011, 11, 21-31 Search in Google Scholar
[2] Frolkova A.K., Raeva V.M., Bioethanol dehydration: state of the art, Theor. Found. Chem. Eng., 2010, 44, 545–556 10.1134/S0040579510040342Search in Google Scholar
[3] Carmo M., Adeodato M., Moreira A., Parente Jr, E. Vieira R., Kinetic and thermodynamic study on the liquid phase adsorption by starchy materials in the alcohol-water system, Adsorption, 2004, 10, 211–218 10.1023/B:ADSO.0000046357.86218.16Search in Google Scholar
[4] Carmo M.J., Gubulin J.C., Ethanol-water separation in the PSA process, Adsorption, 2002, 8, 235–248 10.1023/A:1021264601910Search in Google Scholar
[5] Guan J., Hu X., Simulation and analysis of pressure swing adsorption: ethanol drying process by the electrical analogue, Sep. Purif. Technol., 2003, 31, 31–35 10.1016/S1383-5866(02)00151-XSearch in Google Scholar
[6] Skarstrom C.W., Method and apparatus for fractionating gaseous mixtures by adsorption, U.S. Patent 2,944,627 (July 12, 1960) Search in Google Scholar
[7] Yavary M., Ale-Ebrahim H., Falamaki C., The effect of reliable prediction of final pressure during pressure equalization steps on the performance of PSA cycles, Chem. Eng. Sci., 2011, 66(12), 2587–2595 10.1016/j.ces.2011.03.005Search in Google Scholar
[8] Seader J.D., Henley E.J., Roper D.K., Separation process principles: chemical and biochemical operations. 3rd ed. John Wiley & Sons, Inc.: USA; 2011 Search in Google Scholar
[9] Chahbani M.H., Tondeur D., Predicting the final pressure in the equalization step of PSA cycles, Sep. Purif. Technol., 2010, 71, 225–232 10.1016/j.seppur.2009.11.027Search in Google Scholar
[10] Simo M., Brown C.J., Hlavacek V., Simulation of pressure swing adsorption in fuel ethanol production process, Comput. Chem. Eng., 2008, 32, 1635–1649 10.1016/j.compchemeng.2007.07.011Search in Google Scholar
[11] Simo M., Sivashanmugam S., Brown C.J., Hlavacek V., Adsorption/desorption of water and ethanol on 3A zeolite in near-adiabatic fixed bed, Ind. Eng. Chem. Res., 2009, 48, 9247–9260 10.1021/ie900446vSearch in Google Scholar
[12] Jeong J.S., Jang B.U., Kim Y.R., Chung B.W., Choi G.W., Production of dehydrated fuel ethanol by pressure swing adsorption process in the pilot plant, Korean J. Chem. Eng., 2009, 26, 1308–1312 10.1007/s11814-009-0226-3Search in Google Scholar
[13] Jeong J.S., Jeon H., Ko K.M., Chung B., Choi G.W., Production of anhydrous ethanol using various PSA (Pressure Swing Adsorption) processes in pilot plant, Renew. Energ., 2012, 42, 41-45 10.1016/j.renene.2011.09.027Search in Google Scholar
[14] Humbird D., Davis R., Tao L., Kinchin C., Hsu D., Aden H., et al., Process design and economics for biochemical conversion of lignocellulosic biomass to ethanol, Contract 303(NREL/ TP-510047764), 275–3000. 1617 Cole Boulevard Golden, Colorado 80401 Search in Google Scholar
[15] Ritter J.A., Wu F., Ebner A.D., New approach for modeling hybrid pressure swing adsorption-distillation processes, 2012, Ind. Eng. Chem. Res., 51, 9343-9355 10.1021/ie300744nSearch in Google Scholar
[16] Leo D.M., Adsorption of water and ethanol vapors on 3A and 4A molecular sieve zeolites, MS Thesis, State University of New York at Buffalo, 2007 Search in Google Scholar
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