Hydrogenation Calculator

Calculator Inputs

Substrate or feed name

Feed mass (g)

Substrate molecular weight (g/mol)

Reducible double bonds

Reducible triple bonds

Target conversion (%)

Product selectivity (%)

Feed purity (%)

Stoichiometric factor

Hydrogen excess (%)

Hydrogen utilization (%)

Expected product molecular weight (g/mol)

Catalyst loading (% w/w on pure feed)

Solvent ratio (g solvent / g pure feed)

Hydrogen uptake rate (mol/min)

Reactor pressure (bar)

Reactor temperature (°C)

Batch overhead time (min)

This tool estimates hydrogen demand, expected product, catalyst need, gas volume, and simple batch timing from hydrogenation stoichiometry and user-entered operating assumptions.

Scenario	Feed mass (g)	MW (g/mol)	Unsaturation	Conversion	Selectivity	Charged H₂ (mol)	Expected product (g)
Cyclohexene to cyclohexane	125	82.15	1 double bond	98%	96%	1.8182	121.3197
Styrene to ethylbenzene	150	104.15	1 double bond	95%	94%	1.6668	143.2498
Alkyne reduction case	90	80.00	1 triple bond	92%	91%	2.4710	85.7220

Formula Used

Pure Substrate Mass = Feed Mass × Feed Purity

Substrate Moles = Pure Substrate Mass ÷ Substrate Molecular Weight

Hydrogen Equivalents per Mole = (Double Bonds × 1) + (Triple Bonds × 2)

Theoretical H₂ (mol) = Substrate Moles × H₂ Equivalents × Stoichiometric Factor

Consumed H₂ (mol) = Theoretical H₂ × Conversion

Charged H₂ (mol) = [Theoretical H₂ × (1 + Excess %)] ÷ Utilization

Expected Product Moles = Converted Substrate Moles × Selectivity

Expected Product Mass = Product Moles × Product Molecular Weight

Catalyst Mass = Pure Substrate Mass × Catalyst Loading

Solvent Mass = Pure Substrate Mass × Solvent Ratio

Reaction Time = Consumed H₂ ÷ Hydrogen Uptake Rate

Gas Volume in Reactor = nRT ÷ P

Use this model for batch planning, rough sizing, and education. Real reaction performance can shift with catalyst type, transfer limits, impurities, solvent choice, mixing, and heat removal.

How to Use This Calculator

Enter the feed name, total feed mass, and substrate molecular weight.
Input the number of reducible double and triple bonds.
Set target conversion, expected selectivity, and feed purity.
Choose your stoichiometric factor and any extra hydrogen percentage.
Enter utilization, catalyst loading, solvent ratio, uptake rate, pressure, temperature, and overhead time.
Press Calculate Hydrogenation to show the result above the form.
Review hydrogen demand, product estimate, catalyst requirement, reactor gas volume, and timing.
Use the CSV or PDF buttons to export the current calculation.

FAQs

1. What does this hydrogenation calculator estimate?

It estimates hydrogen required for reduction, charged gas after utilization losses, expected product mass, catalyst loading, solvent mass, reaction time, and simple batch planning values.

2. How are double and triple bonds treated?

Each reducible double bond consumes one mole of hydrogen per mole of substrate. Each reducible triple bond consumes two moles of hydrogen per mole of substrate.

3. Why does charged hydrogen exceed theoretical hydrogen?

The charged amount includes your planned excess and corrects for utilization losses. This gives a more practical gas requirement for real batch charging and handling.

4. What is hydrogen utilization in this tool?

Hydrogen utilization reflects how much charged gas is effectively used by the reaction. Lower utilization means more hydrogen must be supplied to meet the target.

5. Does the calculator replace laboratory or plant validation?

No. It is a planning and educational calculator. Real results depend on catalyst behavior, pressure, agitation, impurities, solvent effects, mass transfer, and safety limits.

6. What does atom economy mean here?

Atom economy compares the product molecular weight with the total mass of reactants entering the ideal reaction. It gives a simple green chemistry efficiency indicator.

7. Can I use this for partial hydrogenation?

Yes. Adjust the number of reducible bonds, conversion, selectivity, and stoichiometric factor to reflect the partial reduction target and expected process behavior.

8. What pressure and temperature effects are included?

Pressure and temperature are used in the ideal gas estimate for reactor hydrogen volume. They do not model kinetics, equilibrium, safety margins, or heat release.