Combined hydrogen combustion

For combined hydrogen production and C02 capture several novel technologies are in development, most of them for the application in a pre-combustion C02 capture combined cycle. The main focus is to reduce the efficiency penalties and other associated costs of CO2 capture. The most important technologies in the R D phase, membrane reactors and sorption-enhanced reactors, are described below, with special attention paid to the catalytic aspects. 

To improve the efficiency of combined hydrogen production and C02 capture, several technologies are in development that combine catalytic reactions and the separation of either hydrogen or C02. Major targeted areas of application are the production of bulk hydrogen as a transport fuel and electricity production with pre-combustion C02 capture. 

Catalytic Hydrogen Combustion 3 [CHC 3] Combined Mixer/Cross-flow Com-bustor/Heat Exchanger for Determination of the Kinetics of Hydrogen Oxidation... 

A combined methane steam reformer-catalytic hydrogen burner was developed by Ryi et id. [67] for a thermal power equivalent of 67 W. Rh/Mg/Al203 was applied as the steam reforming catalyst and Pt/Sn/Al203 served as the hydrogen combustion... 

Petrachi, GA, Negro, G, Specchia, S, Saracco, G, Maffetone, PL, Specchia, V. Combining catalytic combustion and steam reforming in a novel multifunctional reactor for on-board hydrogen production from middle distillates. Ind. Eng. Chem. Res. 2005 44 9422-9430. 

The steam reforming of hydrocarbons such as diesel has been demonstrated in MSRs whose mechanical stability has been proven at high temperature (750-850 °C). Most of the configurations consist of co-current flow diesel steam reforming combined with combustion of fuel cell anode and/or cathode off-gas surrogate. Full conversion was obtained in all cases. Power equivalent of these systems varied between 2-5 kW thermal energy of the hydrogen produced and 10 kW thermal input of the diesel feed [4,73]. However, the most advanced... 

It is seen that the obtained dependence is not a linear combination of known values. For 0 < Xh2 < 0.5 H2 added to CH4 has a weak effect on the flame velocity and the methane dominates the flame propagation. For hydrogen content 0.9 < Xh2 < 1 in the mixture, the CH4 additive noticeably slows down the hydrogen combustion. When the binary fuel is diluted with CH4 and in the range 0.5 < X 2 < 0.9 transient variations of hydrogen combustion with moderate difficulties for flame propagation, have been observed. 

Grasselli RK, Stem DL, Tsikoyiannis JG Catalytic dehydrogenation (DH) of light paraffins combined with selective hydrogen combustion (SHC)—I. DH ->SHC ->DH catalysts in series (co-fed process mode), Appl Catal A Gen 189(l) l-8, 1999a. 

Kaneko S, Arakawa T, Ohshima M, et al Dehydrogenation of propane combined with selective hydrogen combustion over Pt-Sn bimetallic catalysts, Appl Catal A Gen 356 (l) 80-87, 2009. 

Combustion. The primary reaction carried out in the gas turbine combustion chamber is oxidation of a fuel to release its heat content at constant pressure. Atomized fuel mixed with enough air to form a close-to-stoichiometric mixture is continuously fed into a primary zone. There its heat of formation is released at flame temperatures deterruined by the pressure. The heat content of the fuel is therefore a primary measure of the attainable efficiency of the overall system in terms of fuel consumed per unit of work output. Table 6 fists the net heat content of a number of typical gas turbine fuels. Net rather than gross heat content is a more significant measure because heat of vaporization of the water formed in combustion cannot be recovered in aircraft exhaust. The most desirable gas turbine fuels for use in aircraft, after hydrogen, are hydrocarbons. Fuels that are liquid at normal atmospheric pressure and temperature are the most practical and widely used aircraft fuels kerosene, with a distillation range from 150 to 300 °C, is the best compromise to combine maximum mass —heat content with other desirable properties. For ground turbines, a wide variety of gaseous and heavy fuels are acceptable. 

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