What if hydrogen purification didn’t need extra heat? A new membrane can cut cost, energy use, and system size by working at lower temperature.
Hydrogen purification system developers face a problem. Conventional hydrogen permeable metal membranes require temperatures around 400°C to operate even though hydrogen is produced at about 300°C. This forces the use of extra heating equipment which increases cost, raises energy use, causes gas impurities due to heating, and speeds up equipment oxidation. It also prevents hydrogen purification systems from being small.
To solve this, TANAKA PRECIOUS METAL TECHNOLOGIES developed a palladium (Pd) alloy hydrogen permeable membrane that operates around 300°C while achieving higher hydrogen permeation performance compared to conventional products. This removes the need for extra heating equipment, reduces equipment oxidation, lowers energy use including electricity and CO₂ emissions, and allows smaller hydrogen purification systems.
Among PdCu alloy membranes, PdCu40 with 60 percent palladium and 40 percent copper is known for high hydrogen permeation performance but it required high temperature operation around 400°C. TANAKA focused on the palladium-to-copper ratio and improved the performance of PdCu-based membranes by developing PdCu39 with 61 percent palladium and 39 percent copper.
Until now, the high hydrogen permeation of PdCu39 was not known because even a small presence of the face-centered cubic fcc phase reduced performance, and achieving a full body-centered cubic bcc phase was difficult. By applying heat treatment methods developed through years of research in precious metal materials, TANAKA achieved a full bcc phase, allowing the product to be sold.
Recent advances in hydrogen purification technologies increased demand for metal membranes that can operate at lower temperatures. The common method for producing high-purity hydrogen involves generating hydrogen gas from methanol-water mixtures using modules with hydrogen permeable membranes. However, while hydrogen is produced at about 300°C, conventional membranes require 400°C or higher to work. This creates the need for extra heating equipment increasing cost and causing gas impurities due to heating.
The company claims that this product purifies hydrogen at about 300°C removing the need for extra heating equipment. It also reduces equipment oxidation compared to conventional products and lowers energy use including electricity and CO₂ emissions.
