Braun process

The equipment of deep cooling brings a series of convenience for operation sequences before and after the purification and excellent comprehensive effects on the whole plant. For example, due to the deep cooling purification, the requirements for the secondary steam reformer are decreased remarkably, and there are no strict requirements for the ratio of H2 to N2 and the content of CH4. The outlet temperature of the secondary steam reformer can be lower than the conventional operation 

Recovered ventgas goes to the primary steam reforming of natural gas 

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The Braun process is a variation on the Haber-Bosch process ammonia synthesis process in which the synthesis gas is purified cryogenically1. It has been widely used since the mid-1960 s18. (Synthesis gas is a mixture of hydrogen, carbon monoxide and carbon dioxide - see Table 5.9 for more details). 

It is well known that the conversion of hydrogen and nitrogen per pass is only 20%-30% for the present catalytic ammonia synthesis technology (Table 1.4). Most synthesis gases need to be returned to the reaction system, which increases power consumption. In order to increase conversion per pass, it must increase the outlet ammonia concentration of reactor. Accordingly, it can be seen from Table 1.4 that it is necessary to increase reaction pressure for small and medimn scale aimnonia plants and Topspe process, or to reduce the content of inert gas in sjmthesis gas for Topspe and Braun processes, or to reduce ammonia concentration in the inlet of converter for small and medium scale ammonia plants and Kellogg process. But all of these operations will add the power consumption or unit gas consumption. 

For the improvement of synthetic quotient per pass, it is also an effective approach to increase volume of catalyst in order to reduce space velocity such as ICI-AMV and Braun processes. 

In the C. F. Braun process for ammonia manufacture, excess air is added in the second reformer. The excess nitrogen thus introduced must be removed prior to the synthesis step to avoid excessive loss of hydrogen and excessive compression costs. At the same time that the excess nitrogen is condensed and removed, the remaining traces of carbon monoxide, the methane, and most of the argon are removed, leaving a gas comparable to that produced by the nitrogen wash operation. 

As in the Braun process, the size of the primary reformer is reduced and the size of the air compressor increased in the AMV process compared to more conventional process schemes. This is due to the operation with excess process air and with high methane leakage. Power consumption in the synthetic gas compressor is low because of the low synthesis pressure and the low suction temperature (gas direct from the low temperature Selexol CO2 removal unit), but this is compensated by increased power consumption for the compression of excess nitrogen and high power consumption in the refrigeration section. 

Case d shows that stoichiometric carbon dioxide production can also be achieved by using an excess of process air. However, in this case it becomes necessary to introduce an extra gas separation process step in order to remove the excess nitrogen which is introduced with the excess air. As explained in Sect. 6.5.3.2.3, several process schemes exist where excess process air is used, and the excess nitrogen is removed in dedicated units. Processes using excess process air are the Braun process, the ICI processes, and several process schemes of minor importance. 

Braun, H., Hauck, A. Tomographic reconstruction of vector fields. IEEE Trans, on Signal Processing, 1991, 39(2) fOf-fll. 

W. K. Lam, W. J. Stupin and G. Christensen, "Recover Valuable Off-Gases by the Braun ROE Process," paper presented atMJOE National Meeting, New Orleans, La., Apr. 6—10, 1986. 

Braun, S. S., Power Recovery Cuts Energy Costs, Hydrocarbon Processing, p. 81, May (1973). 

The batch experiment had neither incoming fresh media nor any product stream leaving the fermentation vessel. A complete experimental set up with a B. Braun Biostat, is shown in the above laboratory experimental set up. The continuous flow of media requires a feed tank and product reservoir. The batch process has many disadvantages such as substrate and product inhibition, whereas in the continuous process the fresh nutrients may remove any toxic by-product formed. 

Braun, S.S. Power Recovery Pays off at Shell Oil, Oil and Gas Journal, May 21, 1973, p. 129. Abadie, V.H. Turboexpanders Recover Energy, Hydrocarbon Processing, July 1973, p. 93. Casto, L.V. Practical Tips on Designing Turbine-Mixer Systems, Chemical Engineering, Jan. 10,... 

Jackson HL, Nadolski GT, Braun C, and Lockwood SF. 2005. Efficient total synthesis of lycophyll (v /, /-carotene-16,16 -diol). Organic Process Research Development 9(6) 830-836. 

Braun and Scott (1987) used two-photon ionization of benzene and azulene in n-hexane and followed the e-ion recombination process by monitoring the transient absorption of the electron. The results are not very different from those obtained by the IR stimulation technique. A mean thermalization length of 5.0 nm was inferred at 223 K using a two-photon excitation at 266 nm. Hong and Noolandi s theory was used for the analysis. The absorption technique was... 

Rogers, J. Bao, Z. Makhija, A. Braun, P. 1999. Printing process suitable for reel-to-reel production of high-performance organic transistors and circuits. Adv. Mater 11 741-745. 

Braun A variation on the classic ammonia synthesis process in which the synthesis gas is purified cryogenically. Widely used since the mid 1960s. 

NoTICE [No Tie In Claus Expansion] A process for oxidizing sulfur for the manufacture of sulfuric acid. Oxygen is introduced below the surface of a pool of molten sulfur. This permits easy temperature control. Developed by Brown Root Braun and first used at Port Newches, TX, in 1989. 

Purifier An ammonia synthesis process, developed and sold by C. F. Braun, CA. 

Seward, W.H. "Process Alternatives for Sulfur Management Overview Report," C.F. Braun Co., Alhambra, CA, FE-2240-41, January 1978. 

A. Rehorek, K. Urbig, R. Meurer, C. Schafer, A. Plum and G. Braun, Monitoring of azo dye degradation processes in a bioreactor by on-line high-performance liquid chromatography. J. Chromatogr.A, 949 (2002) 263-268. 

A. Plum, G. Braun and A. Rehorek, Process monitoring of anaerobic azo dye degradation by high-performance hquid chromatography-diode array detection continuously coupled to membrane filtration sampling modules. J. ChmmatogrA, 987 (2003) 395-402. 

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