The hydrogen production unit using the pressure swing adsorption (PSA) method is designed to make high-purity hydrogen from a mixed gas flow. It is particularly common at plants where hydrogen is generated as a primary product (such as steam methane reforming) or as a by-product that needs to be purified for reuse or sale.
Operational concept
Regeneration:
Once the sorbent becomes saturated with impurities, the pressure reduces (returning to atmospheric conditions or vacuum) to desorb and remove the impurities, thereby regenerating the sorbent for the next cycle.
Pressure change cycle:
At high pressure, impurities such as carbon monoxide, carbon dioxide and methane are adsorbed, while hydrogen passes through the system as a product gas due to its smaller molecular size and lower adsorption capacity.
Adsorption process:
PSA-H2 unit is based on the selective adsorption of impurities using porous materials (usually zeolites or activated carbon) at high pressures.
Main components
Adsorbent:
Selective absorbing material.
Valves and control system:
Control cyclical pressure increase and decrease phases.
Preparation of feed gas:
Pre-treatment systems designed to remove particles and moisture that may damage the sorbent.
Products
Hydrogen: 100–100,000 Nm³/h
Product purity
Hydrogen: 99.999%
Application
Production of hydrogen fuel:
For fuel cells used in transport and stationary power generation applications.
Petrochemical industry:
For hydrocracking and other catalytic processes.
Oil refineries:
For the removal of sulfur compounds and hydrogenation reactions.