COMBINED WASTE GAS TREATMENT OF WASTE GAS STREAMS CONTAINING AMMONIA AND NITROGEN OXIDES IN INDUSTRIAL PLANTS

摘要

PROCESS FOR THE COMBINED REMOVAL OF BOTH AMMONIA IN ONE OR MORE AMMONIA-CONTAINING WASTE GAS FLOWS AND NITROGEN OXIDES IN ONE OR MORE ADDITIONAL NITROGEN OXIDE-CONTAINING WASTE GAS FLOWS IN A COMBINED AMMONIA/UREA SYNTHESIS PLANT ACCORDING TO THE SELECTIVE NON-CATALYTIC REDUCTION IN A TEMPERATURE RANGE FROM 850°C TO 1100°, BY WHICH NITROGEN OXIDE REDUCTION RATES OF UP TO 80% ARE ACHIEVED, OR ACCORDING TO THE SELECTIVE CATALYTIC REDUCTION IN A TEMPERATURE RANGE FROM 150°C TO 550°C, BY WHICH NITROGEN OXIDE REDUCTION RATES OF UP TO 99% ARE ACHIEVED, IN WHICH THE AMMONIA AND THE NITROGEN OXIDES REACT WITH ONE ANOTHER TO GIVE NITROGEN AND WATER, THE AMMONIA-CONTAINING WASTE GAS FLOW TO BE TREATED FROM A LOW-PRESSURE ABSORBER AND/OR AN ATMOSPHERIC ABSORBER OF THE UREA SYNTHESIS PLANT UNIT BEING MIXED WITH THE NITROGEN OXIDE-CONTAINING WASTE GAS FLOW TO BE TREATED OF A FLUE GAS DUCT OF A PRIMARY REFORMER OF THE AMMONIA SYNTHESIS PLANT UNIT OF THE COMBINED AMMONIA/UREA SYNTHESIS PLANT AND BEING SUBMITTED TO A SELECTIVE NON-CATALYTIC REDUCTION OR A SELECTIVE CATALYTIC REDUCTION DEPENDING ON THE TEMPERATURE OF THE MIXTURE AND DEPENDING ON THE NITROGEN OXIDE REDUCTION RATE TO BE REACHED, BOTH THE AMMONIA AND THE NITROGEN OXIDES OF THE MIXED WASTE GAS FLOWS BEING DEPLETED SIMULTANEOUSLY DURING THE SAME PROCESS STEP. FIGURE TO BE PUBLISHED WITH THE APPLICATION: FIG. 3