09-09-2014, 03:09 PM
Since methane is an inert gas in the ammonia synthesis process. It is desirable to reduce the methane content of the synthesis gas to the lowest possible level in order to keep the level of inert gases low. The methane content in the synthesis gas is governed by the equilibrium of reforming reaction (2) at the outlet temperature and on the catalyst activity. According to reaction (2), lower methane content can be obtained by increasing the temperature, lowering the pressure, or adding more steam. On the other hand, a relatively high reforming pressure results in considerable savings in the power necessary for the subsequent synthesis gas compression. An operating pressure of approximately 34.0 kg/cm^2g at the inlet of the primary reformer provides a reasonable economic compromise.