Reactor internals


Includes all processes which involve chemical reactions, heat exchange, mass transfer and separation. The main chemical processes in which our reactor internals can be found are:

Ammonia conversion
Ammonia is one of the most important inorganic chemicals. In commercial processes, a mixture of hydrogen and nitrogen is firstly compressed to the desired pressure. The compressed mixture is then preheated by a heat exchanger, countercurrent to the final product, before entering the ammonia reactor (generally a radial flow reactor). The reaction typically occurs in radial flow reactors over a catalytic bed at a high temperature. The exit gas containing ammonia passes through a cooling chamber where ammonia is condensed, while unreacted hydrogen and nitrogen are recycled. The major end use of ammonia is in the fertiliser field for the production of urea, ammonium nitrate as well as ammonium phosphate and sulphate. Ammonia is the precursor for many other chemicals such as nitric acid, hydrazine, acrylonitrile and hexamethylenediamine.

Urea synthesis
Urea production is based on the reaction of ammonia with carbon dioxide, typically in a down flow reactor. The reaction occurs in two steps: ammonium carbamate is formed first, followed by a decomposition step of the carbamate to urea and water.
The urea solution resulting from the decomposition of carbamate is expanded and heated at a low pressure and the ammonia is recycled. The resulting solution is further concentrated (to a melt)and crystallised in a prilling tower where it is sprayed from above and passed through a countercurrent air stream.
The major use of urea is in the fertiliser field, which accounts for approximately 80% of its production. Approximately 10% of urea is used for the production of adhesives and plastics (urea formaldehyde and melamine formaldehyde resins).

Methanol synthesis
Methanol is produced by the catalytic reaction of carbon monoxide and hydrogen (synthesis gas). The synthesis reaction typically occurs in down flow reactors, over a heterogeneous catalyst arranged in either sequential adiabatic beds or placed within heat transfer tubes. The converter effluent is cooled to condense the product methanol and the unreacted gases are recycled. The crude methanol contains water and low levels of by-products, which are removed using a two-column distillation system.
Methanol has many important uses as a base chemical, a fuel and for producing other products.