Properties of Sulphamic Acid

Advances in Sulphonation Techniques, SpringerBriefs in Applied Sciences and Technology, DOI 10.1007/978-3-319-22641-5 7 

A block diagram in Fig. 7.2 is attached herewith to descrihe the new process applied on liquid SO2 and liquid SO3. For comparison, a block diagram for the current process is also given in block diagram Fig. 7.1. The details of the current process are given below  

Urea and 23-25 % Oleum are fed at controlled rates to series of Reactors, which are cooled by chilled water/brine and cooling water. The reaction products are diluted by mixing with recycled mother liquor (available after separation of crystals of Sulphamic Acid). Temperature is controlled during mixing by chilled water/brine. Dilute acid stream (70 % Sulphuric Acid) is separated after the mixing operation and is sold to SSP/Alum manufacturers. 

Following suggestions of Baumgartner, equimolar quantities of urea, sulphur trioxide, and sulphuric acid are reacted directly with Sulphamic acid - 

This is a strongly exothermic reaction. The process is carried out in two stages, based on the following reactions  

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