Methanol synthesis converter design

Other gas-phase methanol synthesis converter designs are available from such designers as Haldor-T opsoe and Mitsubishi Gas Chemical Company. 

Quench Converter. The quench converter (Fig. 7a) was the basis for the initial ICl low pressure methanol flow sheet. A portion of the mixed synthesis and recycle gas bypasses the loop interchanger, which provides the quench fractions for the iatermediate catalyst beds. The remaining feed gas is heated to the inlet temperature of the first bed. Because the beds are adiabatic, the feed gas temperature increases as the exothermic synthesis reactions proceed. The injection of quench gas between the beds serves to cool the reacting mixture and add more reactants prior to entering the next catalyst bed. Quench converters typically contain three to six catalyst beds with a gas distributor in between each bed for injecting the quench gas. A variety of gas mixing and distribution devices are employed which characterize the proprietary converter designs. 

Tube collectors, 26 702 Tube-cooled converter, in methanol synthesis, 26 309 Tube furnaces, 12 739 Tube-in-orifice jet nozzle design,... 

The Mitsubishi Gas Chemical Low-Pressure Methanol Synthesis Process. A schematic flow diagram of the process developed by the Mitsubishi Gas Chemical Company [27] is shown in Figure 3.16. This process also uses a copper-based methanol-synthesis catalyst and is operated at temperatures of 200-280°C over a pressure range of 50-150 atm. The temperature in the catalyst bed is kept under control by using a quench-type converter design, as well as by recovering some of the reaction heat in an intermediate stage boiler. The process uses hydrocarbon feedstock. The feed is desulfurized and... 

Figure 3 [11] displays the classic ICI quench converter. A typical installation is shown in Figure 4. This design was the first to be used in low-pressure methanol synthesis plants and has been successfully applied in many instances. The loop that contains the ICI quench reactor is not very different from that given...

The various designs for gas-phase methanol synthesis have their own peculiarities along with associated advantages and disadvantages. Because of variations in approach to equilibrium and catalyst utilization, each of the systems previously described exhibits different yield factors with respect to the required volume of methanol synthesis catalyst. TraditionaUy, the isothermal converters have required the lowest catalyst volumes because of the more or less constant approach to equilibrium achieved as the gas passes downward through the catalyst-fiUed tubes. This reactor then exploits the maximum reaction rate by ap-... 

Key features are the high reforming pressure (up to 41 bar) to save compression energy, use of Uhde s proprietary reformer design [1084] with rigid connection of the reformer tubes to the outlet header, also well proven in many installations for hydrogen and methanol service. Steam to carbon ratio is around 3 and methane slip from the secondary reformer is about 0.6 mol % (dry basis). The temperature of the mixed feed was raised to 580 °C and that of the process air to 600 °C. Shift conversion and methanation have a standard configuration, and for C02 removal BASF s aMDEA process is preferred, with the possibility of other process options, too. Synthesis is performed at about 180 bar in Uhde s proprietary converter concept with two catalyst beds in the first pressure vessel and the third catalyst bed in the second vessel. 

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