Claude process

The operating conditions for the process were a pressure of 1000 bar and a temperature of 550°C. Under these conditions, a high conversion of around 40%, close to the theoretical equihbrium conversion, was achieved despite impurities that must have been present in the synthesis gas. The process was autothermal, and even required some form of cooling. The converter was small and weighed only 11 tonnes for a production of 20 tonnes ammonia per day. 

A useful procedure adopted by both Claude and BASF was the inclusion of a guard bed to absorb poisons, and to convert any residual carbon monoxide to methane. The guard bed usually contained spent catalyst that had been discharged from the main converters, and operated at a temperature of 400°C. A similar procedure was later used by many other operators to extend the life of the catalyst. 

The Claude Process was not very popular, and was developed further by Grande Paroisse to operate at a pressure of 600 bar, arrd to use pure rrrake-up gas from a nitrogen wash system. The catalyst used in this process appears to be one of the first reported to use calcium oxide as a catalyst promoter. 

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Claude process A process similar to the Linde process for the liquefaction of air, except that additional cooling is produced by allowing the expanding gas to do external work. 

The flow diagram for the Claude process, shown by Fig. 9.10, is the same as for the Linde process, except that an expansion engine or turbine replaces the... 

The former method is based on the principle that the sudden, adiabatic expansion of gases against an external pressure causes external work to be done by them, accompanied by a proportional diminution m their own internal energy manifested by a reduction in temperature.4 Although this method was introduced by Cailletet in 18775 and was successfully applied by him to the liquefaction of oxygen, nitrogen, and air, it was not until 1905 that it was successfully applied on a commercial scale, namely, in the Claude Process.6... 

Example 4.23 Analysis of the Claude process in liquefying natural gas We wish to partially liquefy natural gas in a Claude process shown in Figure 4.28. It is assumed that the natural gas is pure methane, which is compressed to 80 bar and precooled to 300 K. In the expander and throttle the methane is expanded to 1.325 bar. The methane after the first heat exchange at state 5 is at 80 bar and 250 K. Thirty percent of the first heat exchangers output is sent to the expander. Only 10% of the first heat exchange is liquefied. The expander efficiency is 0.8. Determine the work loss in the liquefaction section excluding compression and precooling. 

It is economic to cool the compressed methane for liquefaction by the gas that does not liquefy in the throttling process. In the Claude process, the gas at an intermediate temperature splits into two parts. One of them enters the expander and exhausts as a saturated or slightly superheated vapor, and produces work. The remaining gas is further cooled in the second heat exchanger and throttled to liquefy. The portion that is not liquefied is combined with the output vapor of the expander and recycled into the compressor. 

Figure 4.28. Schematic of the Claude process considered in Example 4.23.

Table 4.11 Distribution of exergy losses at each unit in the Claude process in Example 4.23...

A more efficient liquefaction process would replace the throttle valve by an expander, but operating such a device into the two-phase region is impractical. Flowever, the Claude process, shown in Fig. 9.7, is based in part on this idea. Gas at an intermediate temperature... 

Tims tlie Linde process is a limiting case of tlie Claude process, obtained when none of tlie high-pressure gas stream is sent to an expander. 

However, in the paths entered during wartime shortages—dyes and ammonia—Du Font s success in commercializing new products was much slower. A joint venture with Lazote, Inc. permitted the company to use the Claude process for high-pressure production of synthetic nitrates and ammonia (SIC 2873). By 1929 Du Font accounted for 40 percent of the syn-... 

Claude process for the fractionation of liquefied air. From this fraction, oxygen (B.P.-182.9), kryton (B.P -151.7) and xenon (B.P.-106.9) can be easily separated from one another by fractional evaporation and collected as gases, because their boiling points are sufficiently far apart. 

The Hikoshima plant started by importing technology for ammonia synthesis. A pilot plant having a daily production run of 5 tons was constructed utilizing the Claude process from France at a cost of 5,000,000 yen. The commercial process at Hikoshima started in 1924, but this system was new and needed many improvements. There were several accidents, causing explosions and casualties. Steady production was not reached until 1928. 

A conunonly applied method in large-scale liquefaction plants is the Claude process. The necessary refrigeration is provided in four principal steps leading to the liquefaction of hydrogen (Fig. 5-13) ... 

The first expansion process would be sufficient for liquefaction, however, Joule-Thomson expansion is applied for the final step (from approx. 26 K down) to avoid two-phase flow in the expander. Variations of the dual-pressure Claude process as a large-... 

Fig. 5-13 Schematic of the Claude process for hydrogen liquefaction, from [Messer Griesheim]... 

It was tested in several small 3 to 10 ton per day plants but was never operated intact on a large scale commercial basis. Instead the large commercial units became adaptations of the Haber process, the Cassale Process, or the Claude Process for ammonia synthesis. The American Process was originally described as using electrolytic hydrogen. This was much too expensive for commercial use in America at that time. Instead hydrogen was obtained from the reaction of steam with coal or later from the... 

Norsk Hydro. At this time six Italian factories used Fauser, one used Casale, and two used Claude processes. ... 

Problem 6.39 Natural gas, which you may take to be pure methane, is liquefied in the Claude process shown in Figure 6-22. The process operates between a high pressure of 30 bar and a low pressure of 1 bar. The inlet stream is at 1 bar, 20 °C, compression is to 30 bar, stream 14 is at 10 °C, the precooler uses water to cool the compressed gas to 30 °C, streams 5 and 6 are at 8 °C, and the mass flow rate in stream 2 is 10 times larger than The efficiency of the compressor and the turbine is 85%. Determine the mass, energy, and entropy balances on the basis of 1 kg of liquefied natural gas, and report the actual and ideal work. Discuss the features of this process compared to the Linde process. 

Claude process A process for Uquelying air on a commercial basis. Air under pressure is used as the working substance in a piston engine, where it does external work and cools adlabatically. This cool air Is fed to a counter-current heat exchanger, where it reduces the temperature of the next intake of high-pressure air. The same air is recom-press and used again, and after several cycles eventually liquefies. The process was perfected in 1902 by the French scientist Georges Claude (1870-1960). 

In the Ludwigshafen Ammonia Laboratory located in Building 35 Pier resumed his high-pressure research, working for a time with Mittasch on the synthesis of ammonia and of methanol. The purpose of the ammonia experiments was to test the effectiveness of different iron catalysts at extremely high pressures, up to 1,000 atm as in the Claude process. Upon... 

Fractination of liquid air by Claude process give rise to two main fractions, one containing mainly nitrogen and the other containing mainly oxygen. 

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