Counter-Current Packed Absorption Column
100 mm ID clear acrylic column packed to 1.50 m with 10 mm ceramic Raschig rings.
Chemical & Process Engineering / Gas Absorption in Packed Column
FREE TO EXPLORELABORATORY 18 · CHEMICAL & PROCESS ENGINEERING
Packed Column Gas Absorption & Volumetric Mass Transfer Coefficient K_G a
Operate a continuous counter-current packed absorption column absorbing carbon dioxide from air into water, measure inlet and outlet gas concentrations, and evaluate the volumetric overall mass transfer coefficient K_G a and Height of a Transfer Unit (HTU). Explore interactive transport phenomena, unit operations simulation, and chemical engineering telemetry.
TRANSPORT PHENOMENA · UNIT OPERATIONS · PROCESS CONTROL · REACTION ENGINEERING
Your virtual chemical and process engineering laboratory.
MASS TRANSFER FACTOR (K_G A)—
PROCESS & PILOT PLANT TELEMETRY
Ready to sample with Liquid Rate L = 30.0 L/(min·m^2).
Adjust Liquid Rate L, then execute chemical process trial.
Chemical and process engineering telemetry is evaluated rigorously using 64-bit IEEE 754 precision. Residuals reflect ordinary least-squares regression across successive observations. Continuous data structures support high-fidelity transport phenomena and unit operations modeling.
Process engineering assumptions and boundary condition limits
The transport and thermodynamic models apply within the specified calibrated operating window (10.0 to 60.0 L/(min·m^2)). Evaluated using a 100 mm ID acrylic column packed to 1.50 m with 10 mm ceramic Raschig rings (specific area a_p = 440 m^2/m^3). Gas feed contains 5.0 mol% CO_2 in air at constant flow G = 25.0 kg/(h·m^2). Linear regression models K_G a versus L^0.7.
Process apparatus & industrial sensors.
Multi-Point Liquid Spray Distributor
Provides uniform liquid irrigation over column cross-section without wall channeling.
Gas Mixing & Blending Manifold
Blends industrial compressed air with CO_2 from cylinder to maintain stable 5.0 mol% feed.
Non-Dispersive Infrared (NDIR) CO_2 Gas Analyzer
Measures inlet and outlet gas CO_2 volume concentrations from 0 to 10.0% with 0.01% precision.
Positive-Displacement Liquid Solvent Pump
Delivers deionized water solvent across liquid irrigation rates L = 10 to 60 L/(min·m^2).
U-Tube Water Manometer Array
Monitors gas-side pressure drop across the 1.5 m packed bed to verify operation below flooding.
FOLLOW THE METHOD
A reason behind every step.
Operate a continuous counter-current packed absorption column absorbing carbon dioxide from air into water, measure inlet and outlet gas concentrations, and evaluate the volumetric overall mass transfer coefficient K_G a and Height of a Transfer Unit (HTU). Standardized parameter settings: 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 L/(min·m^2).
01
Gas Blending & Baseline Calibration
Start air blower and open CO_2 cylinder; adjust rotameters to establish 5.00 mol% CO_2 in air at total gas flux G = 25.0 kg/(h·m^2); calibrate NDIR analyzer zero and span.
02
Liquid Distributor Priming
Start water pump at moderate flow to pre-wet the Raschig ring packing completely for 10 minutes to eliminate dry spots.
03
Initial Irrigation Rate Setting
Adjust water flow to establish liquid irrigation rate L = 10.0 L/(min·m^2); verify gas pressure drop across bed is stable.
04
Steady-State Concentration Logging
Allow 15 minutes to establish mass transfer steady state; sample column inlet gas y_in and top exit gas y_out via NDIR analyzer.
05
Liquid Rate Progression Protocol
Step liquid irrigation rate through 20.0, 30.0, 40.0, 50.0, and 60.0 L/(min·m^2), logging inlet and exit CO_2 concentrations at each plateau.
06
Mass Transfer & HTU Regression Analysis
Compute log mean concentration driving force, calculate K_G a for each run, plot K_G a versus L^0.7, and evaluate the scaling slope S.
YOUR NOTEBOOK · 0 OBSERVATIONS
Turn measurements into chemical process engineering insight.
Points are your recorded observations. The solid regression line validates Gas Absorption in Packed Column mathematical scaling.
LINEAR REGRESSION FIT · y = mx + b
K_G a = S · L^0.7 = 0.0820 · L^0.7
| # | Liquid Solvent Irrigation Rate L (L/(min·m^2)) | Mass Transfer Factor (K_G a) (kmol/(m^3·h·bar)) | Liquid irrigation factor L^0.7 ((L/(min·m^2))^0.7) | Volumetric mass transfer coefficient K_G a (kmol/(m^3·h·bar)) | Remove |
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No readings yet. Execute a process trial and record it.
Calculate it yourself.
CHECK YOUR UNDERSTANDING
Explain what the process engineering metrics mean.
For absorption of a sparingly soluble gas like CO_2 in water, the controlling mass transfer resistance lies in:
The total required packing height Z of an absorption column is calculated as:
In a packed tower operating below the loading point, increasing liquid irrigation rate L causes the effective interfacial area 'a' to:
The flooding point in a packed absorption tower represents:
THEORY AND UNIT OPERATIONS CONTEXT
Process engineering background & physical principles.
Gas absorption (scrubbing) is a fundamental mass transfer separation operation in chemical plants, environmental emissions control, and synthesis gas purification, responsible for removing acid gases (CO_2, H_2S, SO_2) from gas streams by dissolving them into a liquid solvent. In a counter-current packed tower, gas enters at the bottom and ascends through packing, while liquid solvent is distributed over the top and trickles downward over packing elements (such as Raschig rings or structured gauze). Interfacial mass transfer is described by the two-film theory of Whitman (1923), which posits stagnant gas and liquid films on either side of the phase interface. The volumetric mass transfer rate is N_A · a = K_G a · (P_A - P_A*), where K_G a is the overall volumetric gas-phase mass transfer coefficient, 'a' is the effective gas-liquid interfacial area per unit packed volume, P_A is solute partial pressure in the bulk gas, and P_A* is equilibrium partial pressure over the liquid. For physical absorption of sparingly soluble gases like carbon dioxide in water, liquid film resistance dominates overall transport: 1 / K_G a = 1 / (k_G a) + H / (k_L a), where H is Henry's law constant. According to Onda's classic packed bed mass transfer correlations, liquid-side mass transfer coefficient k_L and wetted specific area 'a' scale with liquid mass velocity as L^0.7. In this laboratory investigation, an instrumented 1.5-meter packed tower absorbing CO_2 into water is operated across liquid irrigation rates from 10.0 to 60.0 L/(min·m^2) to measure K_G a, verify L^0.7 scaling, and determine the Height of a Transfer Unit (HTU).
K_G a = S · L^0.7 = 0.0820 · L^0.7
Evaluated using a 100 mm ID acrylic column packed to 1.50 m with 10 mm ceramic Raschig rings (specific area a_p = 440 m^2/m^3). Gas feed contains 5.0 mol% CO_2 in air at constant flow G = 25.0 kg/(h·m^2). Linear regression models K_G a versus L^0.7.