ChemJunction | Reactor and Condenser Design

PROCESS INPUTS & DESIGN BASISEnter reactor, utility line sizes, and dual-condenser available areas.

01 | REACTOR & VAPOUR LOAD GENERATION

1. Equipment Identification

Equipment Number / Tag

2. Capacity, Distillation Volume & Agitator

Total Capacity (L)

Initial Liquid Volume (L)

Solvent to Distill (L)

Agitator Type

Agitator RPM

Reactor MOC

3. Binary Component Selection & Composition

Component 1

Component 2

Composition Basis

Component 1 Fraction

4. Operating Pressure & Binary VLE

Pressure Value (absolute)

Pressure Unit

VLE Model

NRTL α12 / α21 basis

NRTL τ12

NRTL τ21

Bubble Point

Dew Point

Vapour y₁

Vapour y₂

02 | HEATING MEDIUM & REACTOR THERMAL DESIGN

5. Heating Medium Selection

Heating Fluid

Hot Water Inlet (°C)

Hot Water Outlet (°C)

Pump Flow (m³/h)

Steam Pressure (bar abs)

Saturated Steam Temperature

6. Reactor Heat Transfer Coefficients

Initial hp

Jacket hj

Overall U

03 | DUAL-CONDENSER TRAIN DESIGN (PRIMARY & SECONDARY)

7. Primary Condenser (Main Duty)

Available Area (m²)

Utility Fluid

Utility Flow (m³/h)

Utility Inlet Temp (°C)

Utility Outlet Temp (°C)

Condenser MOC

Calculated U₁

Design U₁ (80%)

Primary Heat Capacity

Primary Condensation Split

8. Secondary / Vent Condenser (Slip Recovery)

Available Area (m²)

Utility Fluid

Utility Flow (m³/h)

Utility Inlet Temp (°C)

Utility Outlet Temp (°C)

Condenser MOC

Calculated U₂

Design U₂ (80%)

Secondary Heat Capacity

Secondary Condensation Split

8A. Primary Condenser Vent to Secondary Condenser Vapour Line Sizing

Vapour Line Internal Diameter (mm)

Service Condition

Design Vapour to Secondary

Vapour Density at Operating P/T

Volumetric Flow

Calculated Line Velocity

Allowable Velocity

Minimum Required ID

Velocity Check

Line-sizing basis: The design vapour flow is taken as the maximum simulated vapour flow entering the secondary condenser. Vapour density is calculated from the ideal-gas relation using molecular weight, operating absolute pressure and boiling/condensing temperature. Line velocity is then calculated from actual volumetric flow and the entered internal diameter.

Condenser U design basis: Calculated overall U includes condensation-side film resistance, utility-side film resistance, condenser wall resistance and fouling allowance. Design U = 80% × Calculated U. Design U is used for condenser heat-duty and capacity calculations.

04 | RESULTS & ENGINEERING SUMMARY

9. Distillation & Dual-Condenser Engineering Report

Initial Vapour Load

Vapour condensed in primary condenser

Vapour condensed in secondary condenser

Vapour Loss

Primary Heat Load

Secondary Heat Load

Reactor LMTD

Primary Condenser LMTD

Secondary Condenser LMTD

Distillation Time Cycle

Overall Condenser Recovery

Binary Bubble Point

Binary Dew Point

Initial Vapour y₁ / y₂

9A. Distillation & Condenser Area Requirement by Time

The table shows the simulated batch progression. Distilled quantity is normalized to L/h for each simulation step; condenser quantities and vapour loss are reported as kg/h.

Time	Distilled Quantity per Hr (L/h)	Vapour Condensed in Primary Condenser (kg/h)	% Quantity Condensed in Primary Condenser (% of vapour)	Vapour Condensed in Secondary Condenser (kg/h)	Vapour Loss (kg/h)
Run CALCULATE to generate the table.

9AA. Binary VLE Composition Progression

The table shows the liquid-phase composition and equilibrium vapour composition at each simulated batch step.

Time	Pressure Required at Initial Set Temperature (mmHg abs)	Bubble Point (°C)	Liquid x₁	Liquid x₂	Vapour y₁	Vapour y₂
Run CALCULATE to generate the binary VLE table.

Pressure column basis: the required absolute pressure is recalculated at each hourly liquid composition while holding the initial set bubble-point temperature constant. This shows the pressure that would be required to maintain the initial set temperature as composition changes. For a fixed-pressure operation, the actual operating pressure remains the SI No. 4 set pressure and the bubble point changes instead.

Technical Calculations & Engineering Methodology

9B. Batch Utility Consumption & Cost Summary

Utility consumption is estimated from the calculated batch duties and operating conditions. Enter the applicable utility tariff and, where required, utility conversion assumptions for the batch study.

Steam Cost (₹/kg)

Cooling Water Cost (₹/m³)

Chilled Water Cost (₹/m³)

Steam Latent Heat (kcal/kg)

Cooling Water ΔT (°C)

Chilled Water ΔT (°C)

Water Cp (kcal/kg·°C)

Utility	Calculated Duty	Estimated Consumption / Batch	Tariff	Estimated Cost / Batch
Steam / Equivalent Steam	—	—	—	—
Cooling Water	—	—	—	—
Chilled Water	—	—	—	—
Total Utility Cost				—

Utility Cost Incurred per kg of Solvent Evaporated

Based on total utility cost per batch ÷ solvent mass evaporated in the batch.

—

Calculation basis
Direct steam consumption = Heating duty ÷ Steam latent heat.
For hot-water heating: Equivalent steam = Heat transferred by hot water ÷ Steam latent heat.
Heat transferred by hot water is taken from the calculated reactor heating duty for the batch.
Cooling-water consumption = Cooling duty ÷ (Water Cp × Cooling-water ΔT).
Chilled-water consumption = Chilled-water duty ÷ (Water Cp × Chilled-water ΔT).
Utility cost = Consumption × Applicable tariff.
Solvent mass evaporated (kg) = Distilled solvent volume (L) × Solvent density (kg/m³) ÷ 1000.
Utility cost per kg solvent evaporated = Total utility cost per batch ÷ Solvent mass evaporated per batch.

Hot-water heating note: When Hot Water is selected, the reactor heating duty is treated as the heat transferred from the hot-water loop to the batch. The equivalent steam quantity is calculated as Q_{hot water} / λ_steam. Actual steam consumption at the hot-water generation system may be higher depending on heat-exchanger efficiency, distribution losses and hot-water return conditions.

9C. Condenser Adequacy & Design Margin

This section compares calculated condenser duty with available design capacity. Utilization is based on required duty divided by design capacity; the remaining percentage represents available design margin.

Parameter	Primary Condenser	Secondary Condenser
Required Heat Load (kcal/h)	—	—
Design Heat-Transfer Capacity (kcal/h)	—	—
Capacity Utilization (%)	—	—
Available Design Margin (%)	—	—
Thermal Adequacy	—	—

Calculation basis
Capacity utilization = Required heat load ÷ Design condenser capacity × 100.
Available design margin = (Design capacity − Required heat load) ÷ Design capacity × 100.
Interpretation: utilization ≤ 80% is shown as COMFORTABLE; >80% to 100% as REVIEW; >100% as INADEQUATE. These are screening indicators for the calculator and should be confirmed against the applicable project design basis.

1. Purpose of the study

This study combines reactor thermal performance, binary batch distillation vapour generation, vapour-liquid equilibrium and dual-condenser adequacy. Component selection, liquid composition, operating pressure, heating conditions and condenser utility conditions are used to estimate binary bubble point, vapour composition, heat duty, condenser split and overall recovery.

2. Binary vapour-liquid equilibrium

The binary liquid composition is entered as mole fraction or mass fraction. The calculator converts the selected basis to both mole and mass fractions and then calculates the equilibrium vapour composition.

P = x₁γ₁P₁°(T) + x₂γ₂P₂°(T)

yᵢ = xᵢγᵢPᵢ°(T) / P

For the default ideal model, γ₁ = γ₂ = 1 and the calculation reduces to Raoult's law. The optional NRTL mode uses the entered τ₁₂, τ₂₁ and α parameters.

3. Bubble-point temperature

At the selected absolute operating pressure, the bubble point is solved iteratively until the total equilibrium vapour pressure equals the operating pressure.

Σ xᵢγᵢPᵢ°(T_b) = P

The calculated bubble-point temperature is used as the local condensation-temperature basis for the reactor and condenser heat-transfer calculations.

4. Dew-point indication

A dew-point indication is calculated from the equilibrium vapour composition using the ideal binary dew-point relation. This provides a reference temperature for the vapour phase and should be checked against a validated thermodynamic package for strongly non-ideal systems.

Σ yᵢP / Pᵢ°(T_d) = 1

5. Reactor heat-transfer area, U and LMTD

The reactor wetted geometry is used to estimate the effective heat-transfer surface. The temperature driving force is represented by the logarithmic mean temperature difference.

A_R = πDH + 1.25(πD²/4)

LMTD_R = (ΔT₁ − ΔT₂) / ln(ΔT₁/ΔT₂)

Q_R = U_R × A_R × LMTD_R

6. Binary vapour generation

The reactor heat duty is converted to vapour generation using the composition-weighted latent heat of the current liquid mixture.

λ_mix = x₁λ₁ + x₂λ₂

ṁ_vapour = Q_R / λ_mix

The vapour composition is calculated from the binary VLE relation at each simulation step.

7. Batch composition change

As vapour is generated, the component inventories in the reactor are reduced according to the calculated vapour composition. The liquid x₁/x₂ therefore changes during the batch and a new bubble point is calculated at each simulation step.

ṅᵢ,vapour = ṁ_vapour × y_i / MW_i

This is a time-stepped engineering approximation of binary batch distillation behaviour.

8. Condenser overall heat-transfer coefficient

The condenser U is calculated from condensation-side resistance, utility-side resistance, wall resistance and fouling resistance.

1/U_calc = 1/h_cond + 1/h_util + R_wall + R_fouling

U_design = 0.80 × U_calc

9. Dual-condenser heat duty and vapour split

The primary condenser is evaluated first. Vapour not condensed by the primary condenser becomes the secondary condenser inlet load.

Q_cond = U_design × A_cond × LMTD

Vapour to Secondary = max(0, Vapour Generated − Vapour Condensed in Primary)

Vapour Loss = max(0, Vapour Generated − Primary Condensed − Secondary Condensed)

10. Overall binary recovery

Overall recovery represents the fraction of generated vapour condensed by both condenser stages over the complete simulated batch.

Recovery (%) = [(Total Primary Condensed + Total Secondary Condensed) / Total Vapour Generated] × 100

11. Primary-to-secondary vapour line sizing

The vapour transfer line is checked using the maximum simulated vapour flow entering the secondary condenser. Vapour density is calculated from operating absolute pressure, vapour molecular weight and the current condensation temperature.

ρ = P × MW / (R × T)

V = 4Q_v / (πD²)

The screening criteria retained from the single-component calculator are <30 m/s for atmospheric service and <60 m/s for vacuum service. Final piping design should also verify pressure drop, compressibility, fittings, line length, supports and the applicable project/company piping standard.

12. Engineering interpretation

A changing liquid composition causes the bubble point, vapour composition and mixture latent heat to change during the batch. The calculator therefore reports the initial binary VLE condition and uses the time-stepped composition for the distillation and condenser calculations.

Design note: Raoult's law is an ideal-mixture screening model. NRTL results depend directly on the entered binary interaction parameters. Final process design should use validated binary interaction data and, where required, a validated thermodynamic package or vendor/process simulation.

READY • Enter design inputs and run the calculation

05 | PROCESS & DISTILLATION CHARTS

Vapour Generation & Condenser Split

Primary vs Secondary Heat Load

Remaining Liquid Volume

Reactor Overall Heat Transfer Coefficient

STUDY OF REACTOR THERMAL, BINARY BATCH DISTILLATION AND CONDENSER ADEQUACY