Nitrogen separation

In case the nitrogen content of the natural gas falls below 25% by volume, the process described above is no longer suitable for the separation of nitrogen with the required volume and purity. In such cases, a process with pre-separation column (10) (see Fig. 7.23) is applied. Here, in the first heat exchanger the feed gas is 

In general combustible gases with a high calorific value are referred to as fuel gases (Table 8.1). 

Name of the gas Chemical formula Ignition range In air (% vol. fraction) Ignition temperature (°C) Specific calorific value (k) kg- ) 

Natural gas Mixtures esp. of CH4, CjHg, COj.Nj depending on composition depending on composition depending on composition 

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In the production of ammonia from hydrogen and nitrogen the conversion, based on either raw material, is limited to 15 per cent. The ammonia produced is condensed from the reactor (converter) product stream and the unreacted material recycled. If the feed contains 0.2 per cent argon (from the nitrogen separation process), calculate the purge rate required to hold the argon in the recycle stream below 5.0 per cent. Percentages are by volume. 

The macrocyclic ligands utilized for incorporation of copper generally contain four nitrogens separated by ethylene or propylene groups. The overall size of the macrocycle, thus, extends to fourteen atoms in the case of 4-[(l,4,8,ll-tetraazacyclotetradec-l-yl)methyl]benzoic acid (PCBA) (Figure 8).112... 

The equations developed for vacuum and pressure purging apply to the case of pure nitrogen only. Many of the nitrogen separation processes available today do not provide pure nitrogen they typically provide nitrogen in the 98%+ range. 

Cryogenic bearing lubrication, 75 254 Cryogenic distillation, nitrogen separation via, 77 274... 

Trimethoprim is a diaminopyrimidine derivative. It is reasonably basic (p/fa 7.2) and we should remember here that amino substituents are able to utilize their lone pairs and provide resonance stabilization to a conjugate acid. Consequently, aminopyrimidines protonate on a ring nitrogen. If we consider protonation of the two ring nitrogens separately, and then think about potential resonance stabilization, we can predict the site of protonation. 

The 4/(H-F) values are usually lower when atoms other than nitrogen separate the two nuclei <1985 8 1966,30 1968 45 t969 62and84) as for example in ... 

Attention has been drawn to the importance of the counter-ion.22-26 When first formed, the diazonium ion is, presumably, part of an ion-pair such as 1, which is then converted into an ion-pair (2) in which the ions are initially separated by the nitrogen molecule (see Scheme 1). This nitrogen-separated ion-pair has been described as a vibra-... 

Carrier Facilitated Transport Oxygen/Nitrogen Separations... 

A 10% solution of the imino-thiocarbonate of resorcinol in 10% hydrochloric acid is heated for 15 min on the steam bath. The 6-hydroxy-l,3-benzoxathiol-2-one (thiocarbonate free from) nitrogen separates, on cooling, in the form of fine crystals melting at 158°C. 

FIGURE 4 Nitrogen separation by pressure swing adsorption. 

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