METHOD FOR MODERNIZATION OF AMMONIA PLANTS USING NATURAL GAS Russian patent published in 2017 - IPC C01B3/02 

FIELD: chemistry.

SUBSTANCE: for plant comprising a head section for natural gas conversion to the boost gas for ammonia synthesis, consisting of primary and secondary reformers. Tthe primary reformer includes a radiant section and a convection section. In the radiant section process gas catalytic conversion is performed and heat is transferred to this gas, which is called the reformer heat load, an to the secondary reformer air is supplied to support combustion with partly converted process gas exiting the primary reformer. The total amount of natural gas supplied to the plant is divided into the process portion used for catalytic conversion of methane to hydrogen, and fuel portion, the following changes are introduced: the thermal load of the primary reformer is reduced relative to the amount of produced ammonia, and as a consequence, the output temperature of the partially converted gas leaving the primary reformer is reduced, a feed line is added for substantially pure oxygen directed to the secondary reformer for at least partial replacement of combustion supporting air, a discharge line is added for nitrogen in an amount necessary to obtain makeup gas for ammonia synthesis, the fuel portion is reduced, and, consequently, the process portion is increased, at the given total amount of natural gas.

EFFECT: increased productivity of existing ammonia producing plants.

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