The gas-phase load of the tower, and the acid gas flow rate?
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Dear seniors: How can the gas-phase load of the sulfur absorption tower be calculated based on the feed material balance? What about the flow rate of the regenerated acid gas in the regeneration tower? Material name: Process gas at the inlet of the absorber, liquid-rich stream leaving the absorber, exhaust gas at the outlet of the absorber, acidic gas at the top of the regeneration tower. Material number: 306309310311. Temperature: °C – 40, 44, 41, 43. Pressure: MPa – 0.016, 0.01, 0.004, 0.09. Enthalpy: KJ/Kg – 1484.3, 0, -12051.000, -1446.700, -3935.800. Liquid-phase parameters: Mass flow rate: Kg/h – 432, 45.4; Volume flow rate: m3/h – 42.6; Standard volume flow rate: Nm3/h – 42.9; Density: kg/m3 – 1015; Molar mass: kg/kmol – 24.29; Viscosity: cP – 1.855; Specific heat: kj/kg·°C – 3.59; Surface tension: N/m – 0.061. Gas-phase parameters: Mass flow rate: Kg/h – 15072, 14609.95, 24.3; Volume flow rate: m3/h – 12018, 13188, 198; Standard volume flow rate: m3/h – 12139, 11894, 323; Density: kg/m3 – 1.254, 1.108, 2.654; Molar mass: g/mol – 27.83, 27.53, 36.38; Viscosity: cP – 0.017, 0.017, 0.009; Specific heat: kj/kg·°C – 1.08, 1.09, 0.97, 0.994, 0.9887. Composition: kmol/h – H2S: 9.428, 321.3, 1.089, 360.9, 0.085; 2.99, 0.343, 318.4; SO2: ; H2: 15.176, 30.6, 15.175, 30.6; H2O: 36.004, 648.6, 1657.4, 29858.5, 37.005, 666.7, 0.651, 1.7; N2: 445.895, 12491.1, 0.016, 0.444, 5.881, 2490.7, 0.016, 0.4; CO: 0.781, 21.9; CO2: 36.142, 1590.6, 4.542, 199.9, 31.739, 1396.8, 4.402, 193.7; COS: 0.007, 0.4; CS2:
It’s quite troublesome to do the calculations by hand; it is recommended to use some calculation software for this purpose.
The volumetric flow rate of the acidic gas at the top of the regeneration tower = number of moles * 22.4. For example: The volumetric flow rate of hydrogen sulfide = 9.43*22.4 = 209.2832 cubic meters/h. The mass flow rate of hydrogen sulfide = 209.2832*34 (the molecular weight of hydrogen sulfide) / 29 (the molecular weight of air) * 1.29 (the specific gravity of air) = 316.5 kg/m3. The flow rates of other gases such as H2O, N2, and CO2 can be calculated in the same way, and the results will be consistent.
The gas load at the bottom of the regeneration tower is equivalent to the steam flow rate of the reboiler; the actual volumetric flow rate is calculated by taking into account the temperature and pressure at the bottom of the tower. The gas load at the top of the tower is equivalent to the sum of the acid water return flow rate and the acidic gas flow rate.
Mass flow rate = number of moles * molar mass = 9.13 * 34 = 310 kg/h. Is that correct? What is the difference between the two methods? Thank you!