METHOD FOR REMOVING NITROGEN OXIDES FROM COMBUSTION FUMES WITH ON-SITE GENERATION OF AMMONIA

摘要

A method for the control of nitrogen oxides content in the combustion fumes of a thermal power plant is disclosed; the method comprises the on-site production of ammonia by the steps of: electrolysis of water as a source of hydrogen; separation of air as a source of nitrogen, formation of a make-up gas and synthesis of ammonia in a suitable synthesis loop; said on-site produced ammonia, or a solution thereof, is used for a process of reduction of nitrogen oxides in the combustion fumes.

主权项

1. A method for the control of nitrogen oxides content in the combustion fumes (G) of a power plant for the production of electric energy where said combustion takes place, the method comprising the steps of:
producing ammonia in the site of said installation, with a process including: producing a hydrogen current by means of electrolysis of water; producing a nitrogen current by means of separation of nitrogen from air; forming an ammonia make up gas containing hydrogen and nitrogen from said hydrogen current and nitrogen current respectively, and reacting said make up gas at a suitable ammonia synthesis pressure; and reducing nitrogen oxides contained in said combustion fumes using said produced ammonia; wherein the production rate of ammonia is regulated according to the cost and/or availability of electric energy, and/or according to the load of said power plant and/or according to the demand of electric energy, such that the production of ammonia is increased during electricity off-peak hours when the demand for electricity is low, and is reduced or stopped, thus maximizing the net output of said plant, during electricity peak hours when the demand for electric energy is higher.