Respected Members,
We are operating a cryogenic nitrogen generation unit with product specification as 2600 Nm3/hr gaseous nitrogen and 400 nm3/hr liquid nitrogen. For this the design air flowrate is 9750 Nm3/Hr at 7.6 Kg/Cm2(g) pressure at coldbox.
In front end , we are operating a TSA unit contains two adsorption bed (one online + one under regeneration).
The cycle time for adsorption/desorption is 4 hour ( 10 minute for depressurization from 7.75 kg/cm2(g) to 0.2 kg/cm2(g) pressure, 85 minute heating with 1350 nm3/hr regeneration gas flow at 190 Deg.C temperature, 130 minute cooling to bring back bed temperature to 35 Deg.C and lastly re-pressurization (15 min)).
For that, each bed contains 985 kg alumina+ 1350 kg 13X zeolite molecular sieve. Air inlet temperature is 20 Deg.C and pressure 7.8 kg/cm2G pressure with 100 % RH. Regeneration electric heater rating 90KW.
Although bed is operating at design condition (9700 nm3/hr air ,400 ppm CO2, 20 Deg air at 7.8kg/cm2G and 100% RH) but CO2 seepage is happening up to 10 PPM near the end of bed run time. We are thinking about increasing regeneration flow and temperature.
Sir, my requirement is I would like to know heat of desorption of CO2, Methane etc ,(which are commonly present in air) for 13X molecular sieves at 0.05 kg/cm2G . Also heat of desorption calculation for Water from alumina bed.
Also dynamic adsorption capacity of H20,CO2 in Alumina bed and molecular sieve bed respectively data would be highly helpful.
The regeneration gas is bone dry waste air which contains approx 67% nitrogen, 32.8% oxygen and rest is argon (in mole %). In datasheet of adsorbent materials not much data are given.
Thanks in advance