Large Volume Inorganic Chemicals - Ammonia ... - ammk-rks.net

Chapter 4Energy input/outputNumber of catalyst bedsand inlet SO 2 level2+2 / 11 %2+2 / 11 %+ LP steam option3+2 / 11 % 2+2 / 5 %4 / 5 %(single contact)Process step GJ/tonne H 2 SO 4Inlet gas heating + 0.992 + 0.992 + 0.992 + 2.119 + 2.119Cooling of bed 1 - 0.471 - 0.471 - 0.471 - 0.704 - 0.704Cooling of bed 2 - 1.018 - 1.018 - 0.278 - 1.766 - 0.199Intermediate absorption - 1.190 - 0.673 - 1.380 - 1.609Reheating after intermediate absorption + 0.847 + 0.610 + 0.815 + 1.959no intermediateabsorptionCooling of bed 3 - 0.195 - 0.195 - 0.888 - 0.061 - 0.046Cooling of bed 4 - 0.629 - 0.629 - 0.066 - 1.413 - 1.574Cooling of the 5 th bed no 5 th bed no 5 th bed - 0.589 no 5 th bed no 5 th bedFinal absorption - 0.635 - 0.901 - 0.452 - 0.777 - 0.777Cooling of product H 2 SO 4 to 25 ºC - 0.096 - 0.096 - 0.096 - 0.096 - 0.096Potential export of HP and LP steam - 0.475 - 1.384 - 0.486 Import: 0.133 - 0.404Loss by cooling with water or air - 1.921 - 0.997 - 1.928 - 2.482 - 0.873(+) energy input by heat exchange (-) heat recoverable for HP steam production (-) heat recoverable for LP steam production, 180 ºC (-) loss to cooling water/airTable 4.18: Energy considerations of double contact plants with different plant setup in comparison with a single contact plant[58, TAK-S, 2003]Large Volume Inorganic Chemicals – Ammonia, Acids and Fertilisers 197