Reaction principle of hydrogen production from methanol reforming

Under certain temperature and pressure conditions, methanol and water vapor undergo methanol cracking reaction and carbon monoxide shift reaction under the action of a catalyst to generate hydrogen and carbon dioxide.

This is a multi-component, multi-reaction gas-solid catalytic reaction system. The first-stage reaction "methanol cracking reaction" of this reaction is an endothermic reaction, and the second-stage reaction "carbon monoxide shift reaction" is an exothermic reaction. However, the absorption and exotherm of these two reactions cannot be balanced, and the total reaction should be an endothermic reaction process.

The reaction equation is as follows:

CH3OH → CO+2H2 -90.7kJ/mol CO+H2O → CO2+H2 +41.2kJ/mol 

Total reaction CH3OH + H2O → CO2+3H2 -49.5kJ/mol 

The reforming reaction generates H2 and CO2, and the H2 and CO2 are separated after the subsequent processes of heat exchange condensation and pressure swing adsorption separation to obtain hydrogen with a purity of 99%-99.9995%.

Technical indicators of methanol reforming hydrogen production + pressure swing adsorption purification system

1. Raw material specifications

Methanol: Meet the first-class product requirements of GB338-2011 standard

Deionized water: C1-≤2mg/l 

Conductivity: ≤5μS/cm2

2. Installation scale

Hydrogen gas volume: 1 Nm3/h-30000 Nm3/h 

Hydrogen purity: 99%-99.9999% 

Hydrogen temperature: ≤40℃ (or ambient temperature)

3. Reformed gas index

H2: 73%-75% CO2: 23%-24%

CO: ≤1.5% CH4: ≤0.5%

4. Operating conditions and running time

Reaction temperature: 230℃-300℃ 

Reaction pressure: 0.8 MPa-3.0 Mpa 

Device operation: 8000 hours

Bird's-eye view of hydrogen production from methanol reforming