Survey of potential chlorine production processes. Final report Page: 98 of 199

                                
dioxide frcsn chlorine is not discussed in detail in the patent, it is known
from other processes (i.e. , the Vicksburg process) that these materials may
be successfully separated by a fractional distillation operation. The
separated nitrogen dioxide may then be returned to the initial process step.
Process kinetics have not been developed; however, thermodynamic
calculations show that, at room temperature, the process is strongly
exothermic, liberating 47.5 Kcal/mole of nitrosyl chloride generated in
the initial process step. The secondary reaction step (i.e., 2N0C1 +
O2 -*■ 2NO2 + CI2) is also exothermic, liberating 7.0 Kcal/mole. Process
energy needs would be minimal, if use can be made of the considerable volumes
of heat rclcaocd by the initial reaction.
4.10.1.3    Engineering
The process of producing chlorine from anmonium chloride and nitrogen
dioxide consists of the following operations and is shown in Figure 18.
1.    Reaction at rocm temperature of nitrogen dioxide with moist
ammonium chloride in an agitated system to produce ammonium
nitrate and nitrosyl chloride (N0C1).
2.    Recovery of the ammonium nitrate co-product (NH4NO3) from the
reactor and drying it to remove moisture.
3.    Oxidation uf the nilxosyl cl deride product with oxygen at
temperatures below 200°C to yield nitrogen dioxide and chlorine.
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4.    Separation of nitrogen dioxide and chlorine in liquid phase by
fractional distillation at -20°C.
5.    Compression of the chlorine product and recycle of the nitrogen
dioxide to the initial process step.
For this process, corrosion resistant materials such as titanium or
stainless steel will be required for all system units in contact with
either chlorine or nitrogen dioxide.
4.10.1.4    Economic Considerations
This process consumes ammonium chloride, nitrogen dioxide and oxygen
and produces ammonium nitrate and chlorine. According to 1977 figures,
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