Secondary Reforming Catalysts

A secondary reformer is an auto-thermic unit located directly after a steam reformer
in a typical ammonia plant. In a secondary reformer, reformed gas from steam
reforming unit is initially mixed with air. Such mixing causes rapid reaction of the
process gas with oxygen provides the heat required for additional reforming. The
reforming reaction on that temperature lowered the methane content down to 0.2-
0.5. The main problems in the operation of a secondary reformer are associated with
the high temperatures generated by the combustion reactions where the temperature
at the point of mixing oxygen and tubular reformer effluent may reach 1200 ®C
or more. The gas distributor must be well designed so that the process gas and air
are mixed as rapidly and thoroughly as possible. This extremely high temperature
needs a refractory type catalyst to withstand this temperature without encountering
catalyst fusion. The catalyst bed itself is protected from the very high temperatures
generated by the homogeneous combustion of air, by a layer of refractory material
that is placed on top of the large, temperature-resistant catalyst particles. The rest
of the bed is filled with secondary reforming catalyst