摘要:
Fischer-Tropsch synthesis is performed using a compact catalytic reactor unit (10) defining channels in which is a gas-permeable catalyst structure (16), the channels extending between headers (18). The synthesis occurs in at least two stages, as the reactor unit provides at least two successive channels (14, 14a) for the Fischer-Tropsch synthesis connected by a header, the gas flow velocity through the first channel being sufficiently high that no more than 65% of the carbon monoxide undergoes conversion. The gases are cooled (25) in the header between the two stages, so as to condense water vapour, and then pass through the second channel at a sufficiently high gas flow velocity that no more than 65% of the remaining carbon monoxide undergoes conversion. This lowers the partial pressure of water vapour and so suppresses oxidation of the catalyst.
摘要:
A catalytic reactor 10 comprises a plurality of fluid-impermeable elements (tubes or plates) 12 defining flow channels 15 between them. Tight fitting within each flow channel 15 is a sheet 16 of corrugated material whose surfaces are coated with catalytic material. At each end of the reactor 10 are headers 18 to supply gas mixtures to the flow channels 15, the headers communicating with adjacent channels being separate. The reactor 10 enables different gas mixtures to be supplied to adjacent channels 15, which may be at different pressures, and the corresponding chemical reactions are also different. Where one of the reactions is endothermic while the other reaction is exothermic, heat is transferred through the wall of the tube 12 separating the adjacent channels 15, from the exothermic reaction to the endothermic reaction. The reactor 10 may be used in a compact plant to perform steam/methane reforming, obtaining the necessary heat by catalytic methane combustion, and also for Fischer-Tropsh synthesis.
摘要:
A compact catalytic reactor (20) comprises a channel for a rapid reaction having an inlet (26) for a gas mixture to undergo the reaction. The channel is provided with two different catalyst structures (32, 34), a first catalyst structure (32) in the vicinity of the inlet (26) and a second catalyst structure (34) further from the inlet, such that a gas mixture supplied to the inlet flows past them both. The first catalyst structure (32) has little catalytic activity for the rapid reaction, whereas the second catalyst structure (34) has catalytic activity for the rapid reaction. This is applicable to combustion of gas mixtures containing hydrogen, for which the first catalyst structure (32) may comprise uncoated oxidised aluminium-containing ferritic steel, while the second catalyst structure (34) may incorporate Pt and/or Pd in an alumina support. Exhaust gases may also be recycled to the inlet (26) to inhibit combustion.
摘要:
A compact catalytic reactor (20) comprises a channel for a rapid reaction having an inlet (26) for a gas mixture to undergo the reaction. The channel is provided with two different catalyst structures (32, 34), a first catalyst structure (32) in the vicinity of the inlet (26) and a second catalyst structure (34) further from the inlet, such that a gas mixture supplied to the inlet flows past them both. The first catalyst structure (32) has little catalytic activity for the rapid reaction, whereas the second catalyst structure (34) has catalytic activity for the rapid reaction. This is applicable to combustion of gas mixtures containing hydrogen, for which the first catalyst structure (32) may comprise uncoated oxidised aluminium-containing terrific steel, while the second catalyst structure (34) may incorporate Pt and/or Pd in an alumina support. Exhaust gases may also be recycled to the inlet (26) to inhibit combustion.
摘要:
A method of operation of one or more chemical reactors (12), wherein each chemical reactor defines first flow channels (15) for a chemical reaction process in proximity to second flow channels (16) for heat transfer, and each chemical reactor is provided with fluid connections for bringing about flows of respective fluids through the first flow channels and the second flow channels, involves the steps of shutting down the flows of fluids through at least one of the first flow channels and the second flow channels, and then changing the fluid connections, and then reopening the fluid connections. There is no change in the chemical reaction process performed by the reactors. The change to the fluid connections is preferably such as to achieve a flow reversal. This may involve turning the reactor (12) itself around, or changing the arrangement of ducts connected to the reactor. This changes the thermal stress distribution within the reactor, and can consequently increase the reactor's operational lifetime.
摘要:
A compact catalytic reactor defines a multiplicity of first and second flow channels arranged alternately, the first flow channels being no more than 10 mm deep and providing flow paths for combustible reactants, and containing a catalyst structure (20) to catalyse combustion of the reactants, and having at least one inlet for at least one of the reactants. The fist flow channel also includes an insert (40 or 60) adjacent to each inlet, this insert not being catalytic to the combustion reaction: the insert may define gaps which are narrower than the maximum gap size for preventing flame propagation. This reactor is applicable in a steam methane reforming plant.
摘要:
A plant (10) for producing hydrogen from a feed gas comprising short chain hydrocarbons, the plant comprising reactor means (14) defining channels for treating the feed gas in three successive stages, the channels for treating the feed gas in each case being adjacent to respective heat transfer channels, and the successive treatment stages being as follows: (a) pre-heating the feed gas (16b); (b) subjecting a mixture of steam and the heated feed gas to reforming (18b) in the presence of a reforming catalyst, while providing heat from adjacent channels (18a) in which catalytic combustion occurs; and (c) subjecting the gases produced by reforming to the water gas shift reaction (20b) in the presence of a shift catalyst, whilst removing heat into adjacent channels (20a) to generate steam. Preferably the reactor means is a single integrated reactor (14) in which all three of the successive treatment stages (16, 18, 20) occur, so that the heat transfers between the various fluids are also integrated. Such a reactor may be formed by a stack of plates between which the treatment channels and heat transfer channels are defined alternately in the stack.
摘要:
Natural gas is processed to generate longer-chain hydrocarbons, the process comprising subjecting the gas to steam reforming to generate a mixture of carbon monoxide and hydrogen, and then subjecting this mixture to Fischer-Tropsch synthesis. The Fischer-Tropsch synthesis is performed at an elevated temperature above 230 °C and with a gas hourly space velocity greater than 10 000 hr-1 so as to achieve a selectivity to the production of C5+ hydrocarbons that is less than 65%. The resulting liquid product can be used as a vehicle fuel, while the tail gases may be used to generate electricity.
摘要:
A catalytic reactor 10 comprises a plurality of fluid-impermeable elements (tubes or plates) 12 defining flow channels 15 between them. Tight fitting within each flow channel 15 is a sheet 16 of corrugated material whose surfaces are coated with catalytic material. At each end of the reactor 10 are headers 18 to supply gas mixtures to the flow channels 15, the headers communicating with adjacent channels being separate. The reactor 10 enables different gas mixtures to be supplied to adjacent channels 15, which may be at different pressures, and the corresponding chemical reactions are also different. Where one of the reactions is endothermic while the other reaction is exothermic, heat is transferred through the wall of the tube 12 separating the adjacent channels 15, from the exothermic reaction to the endothermic reaction. The reactor 10 may be used in a compact plant to perform steam/methane reforming, obtaining the necessary heat by catalytic methane combustion, and also for Fischer-Tropsh synthesis.
摘要:
A plant is provided for processing natural gas. The plant comprises two or more modules connected in parallel. The plant is configured to convert the associated gas into a material with a higher density. In addition, a method of processing gas associated with one or more oil wells. The method comprises the steps of: providing a modular plant comprising two or more modules in parallel wherein at least one of the modules is a robust module and at least one of the modules is an economical module; turning down one or more of the modules when productivity drops; switching off one or more of the modules at least when productivity drops beyond the turndown limit. The natural gas is treated in a Fischer-Tropsch unit.