Exergoeconomic Study Of Hydrogen Production From Steam Reforming Of Natural Gas

Steam Reforming of Natural Gas is, at the moment, the most economical process for producing hydrogen. This work performs an exergetic and exergoeconomic study of this process. The main steps in hydrogen production from steam reforming are the reforming reaction, the shift reaction and the hydrogen purification. The final hydrogen has purity of about 99,999% (wt) and can be used in fuel cells. Synthesis Gas containing H2, H2O, CO2, CO and residual CH4 is formed inside the reformer; its composition depends on the Steam-CH4 ratio and the temperature-pressure conditions. Equilibrium conditions in the synthesis gas components are considered at reformer exit. After reforming, shift reaction converts CO and H2O into CO2 and H2. Absorption in diethanolamine is used to separate CO2 from the gas stream. CO2 can be collected and sold as a by-product. Fixed adsorption beds are used to purify the hydrogen, eliminating H2O, CO2 and CO and CH4 residuals. An exergy analysis was performed in this process identifying the main sources of irreversibility. The exergy flows are disaggregated into chemical and physical exergies. The theory of exergetic cost is applied to analyse the internal cost distribution. The results are discussed.11231130Armor, J.N., The multiple roles for catalysis in the production of H2 (1999) Applied Catalysis A: General, 176, pp. 159-176Kothari, R., Buddhi, D., Sawhney, R.L., Sources and technology for hydrogen production: A review (2004) International Journal of Global Energy, 21 (1-2), pp. 154-178Choudhary, T.V., Goodman, D.W., CO-free production of hydrogen via stepwise steam reforming of methane (2000) Journal of Catalysis, 192, pp. 316-321Anderson, J.R., Boudart, M., (1981) Catalysis - Science and Technology, 1. , Edit. Springer-Verlag, BerlinRosen, M.A., (1986) The Development and Application of Process Analysis Methodology and Code Based on Exergy, Cost, Energy and Mass, , PhD. Diss. Dept. of Mechanical Engineering, Univ. of Toronto, TorontoRosen, M.A., Thermodynamic investigation of hydrogen production by steam-methane reforming (1991) International Journal of Hydrogen Energy, 16 (3), pp. 207-217Yang, R.T., Gas separation by adsorption process (1997) Series on Chemical Processes, , Imperial College PressKent, R., Eisenberg, B., Better data for amine treating (1976) Hydrocarbon Processing, 55, pp. 87-90. , fevPark, S.H., Lee, K.B., Hyun, J.C., Kim, S.H., Correlation and prediction of the solubility of carbon dioxide in aqueous alkanolamine and mixed alkanolamine solutions (2002) Industrial Engineer Chemical Research, 41, pp. 1658-1665Perry, R.H., Grenn, D.W., Perry's chemical engineers (1999) Handbook, , McGraw Hill CoRuthven, D.M., Principles of adsorption and adsorption processes (1984) A Wiley-interscience PublicationSircar, S., Waldron, W.E., Rao, M.B., Anand, M., Hydrogen production by hybrid SMR-PSA-SSF membrane system (1999) Separation and Purification Technology, 17, pp. 11-20Szargut, J., Morris, D.R., Steward, F.R., (1988) Exergy Analysis of Thermal, Chemical, and Metallurgical Processes, , Hemisphere Publishing CorporationKotas, T.J., The exergy method of thermal plant analysis (1985) Anchor Brandon LTD, Tiptree, , Essex. Great BritainAlves, L.G., Nebra, S.A., Thermoeconomic evaluation of a basic optimized chemically recuperated gas turbine cycle (2003) International Journal of Thermodynamics, 6 (1), pp. 13-22. , MarchLozano, M.A., Valero, A., Theory of the exergetic cost (1993) Energy, 18 (9), pp. 939-96