Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-IV-1method is adiabatic or autothermal regeneration, meaning heating of the catalyst-sorbent bedby exothermic reaction performed directly inside the bed [7]. In this case CO 2 -sorbentregeneration is performed according to reaction (4) with supply of heat, necessary forregeneration, by oxidation of available combustible substances (say, the same feedstockmethane) in the air flow directly in the adiabatic sorbent-catalyst bed:CH 4 + 2O 2 ⇒ CO 2 + 2H 2 O (5)Both process stages may be performed in a periodical «traveling heat wave» regime andin this case it becomes possible to create at each process stage the axial profiles of catalysttemperature, optimal for performance of next stage. Especially efficient operation mode maybe realized by application of counter-current (or reverse flow) operation, when methane/steamand air/fuel mixtures are fed into processor bed in opposite directions.Notably, the co-current heat wave of combustion reaction (5) at the regeneration stage issuperadiabatic, i.e. the maximum temperature in such wave significantly exceeds the adiabaticone and, therefore, the high temperatures required for efficient sorbent regeneration may beobtained with air-methane mixtures with very low methane content.Such approach will provide fast and efficient sorbent regeneration with minimum heatlosses to environment. Application of low-cost and available within the process combustiblefuels (such as recycled unused hydrogen from fuel cell or methane from initial natural gas)will result in advantageous economic efficiency of the proposed technology in comparisonwith existing processes. Application of cheap and simple equipment (adiabatic reactors withfixed beds of sorbent-catalyst, absence of external furnaces and heat supply piping etc.) willmake the proposed hydrocarbon fuel processor inexpensive and simple in operation.The presentation discusses process modelling and pilot tests results, confirming thecapability and high efficiency of proposed technological concept.The research was performed under financial support from Russian Foundation ofFundamental Research, grants No.06-08-00258, 06-08-08089.References1. Tessie du Motay, M., Marechal, M.: Bull. Chim. France 9, 334 (1868).2. A.R. Brun-Tsehovoy. Doctor of Sciences Thesis. Moscow, 1990.3. J.R. Hufton, S. Mayorga, S. Sircar. AIChE J., v.45, N 2 (1999) 248–256.4. W.E. Waldron, J.R. Hufton, S. Sircar, AIChE J., v.47, N 6 (2001) 1477–1479.5. Y. Ding, E. Alpay. Chemical Engineering Science 55 (2000) 3929–3940.6. G. Xiu, P. Li, A.E. Rodrigues. Chemical Engineering Science, 57 (2002) 3893 –3908.7. A.N. Zagoruiko, A.G. Okunev. React.Kinet.Catal.Lett., Vol.91, No.2 (2007), p.315-324.398