Converting COD Values into % Solvent for Stripper Column Design

Chemical and pharmaceutical industries routinely measure COD (Chemical Oxygen Demand) and BOD values in effluents. COD represents the amount of oxygen required to completely oxidize organic solvents into CO₂ and H₂O.

Typical COD values range between 40,000 mg/L to 150,000 mg/L.

While COD is useful for environmental compliance, stripper column design and simulation require solvent concentration expressed as percentage, not COD alone. Therefore, converting COD values into % solvent becomes a critical engineering step.

Why COD to % Solvent Conversion Is Required

Stripper columns are widely used to:

• Reduce COD in effluents

• Recover valuable solvents

• Improve downstream biological treatment efficiency

For accurate hydraulic design, tray/packing selection, and simulation, solvent concentration must be known in weight percentage.

Example: Methanol COD Conversion

Solvent: Methanol (CH₃OH)
COD: 60,000 mg/L

Chemical Oxygen Demand represents oxygen required for complete oxidation:

2CH₃OH + 3O₂ → 2CO₂ + 4H₂O

This indicates:

• 1 mole of Methanol requires 1.5 moles of Oxygen

• Molecular weight of Methanol = 32

• Oxygen required = 48

Since 1% = 10,000 ppm,
60,000 mg/L COD = 6% COD

\text{% Methanol} = 6 \times \frac{32}{48} = 4\%

Result:

6% COD corresponds to 4% Methanol concentration

Applicability to Other Solvents

This stoichiometric approach can be applied to:

• Acetone

• Methanol

• Ethanol

• DMF / DMAC

• Other oxygen-demanding organic solvents

How S-Cube Mass Transfer Adds Value

At S-Cube Mass Transfer, we specialize in:

• Stripper column design & simulation

• Structured & random packing selection

• Solvent recovery systems

• Effluent COD reduction solutions

• Basic & detailed process engineering

Our engineering approach ensures that COD data is correctly translated into design-ready solvent concentrations, leading to efficient, compliant, and cost-effective effluent treatment systems.

Talk to Our Process Engineering Team

Call / WhatsApp: +91 9860253100 | +91 8956481799

Email: project@s3dist.in | marketing@s3dist.in

Website: www.s3dist.in

S-Cube Mass Transfer – Precision-driven engineering for solvent recovery and mass transfer solutions.