WASTE HEAT RECOVERY IN A CHEMICAL PROCESS AND PLANT, PARTICULARLY FOR THE SYNTHESIS OF AMMONIA

摘要

A method for recovering waste heat in a process for the synthesis of a chemical product, particularly ammonia, where the product is used as the working fluid of a thermodynamic cycle; the waste heat is used to increase the enthalpy content of a high-pressure liquid stream of said product (11), delivered by a synthesis section (10), thus obtaining a vapour or supercritical product stream (20), and energy is recovered by expanding said vapour or supercritical stream across at least one suitable ex-pander (13); the method is particularly suited to recover the heat content of the syngas effluent after low-temperature shift.

主权项

1. A process for the synthesis of a chemical product, comprising the steps of:
obtaining at least one make-up reactant in a front-end section; reacting said least one make-up reactant in a synthesis section, obtaining said product in a high-pressure liquid state; heating at least a portion of the liquid product delivered by the synthesis section by heat exchange with a waste heat source made available by said process, obtaining an expandable stream of said product in a vapour state or supercritical state; expanding said expandable product stream to recover energy, obtaining an expanded product stream, and condensing said expanded product stream by heat exchange with a suitable cooling medium, obtaining a product condensate stream.