Global demand for small volumes of hydrogen (<1000 Nm³/h) is rising. Until now, much of this hydrogen was delivered to customers by truck – which is neither cost effective nor good for the environment. In most cases, on-site production is a much more viable option.
However, non-linear economies of scale mean that conventional steam reformer technology cannot simply be downsized. Which is why Linde Engineering teamed up with Plansee SE and support of Karlsruhe Institute of Technology (KIT) to develop a new small-scale reformer process based on palladium membrane tubes that can produce pure hydrogen without a separate purification unit.
This innovative process uses thin palladium layers, which are exclusively hydrogen selective, to produce pure hydrogen. The composite palladium membranes comprise a porous metal support, a ceramic diffusion barrier layer and the final selective, thin and defect-free palladium layer.
The new membrane tubes are highly permeable, have good H2/N2 selectivity and remain stable under production conditions. They deliver consistent results on an industrial scale.
In addition, the chemical equilibrium of the reforming reaction shifts towards the products and the whole process can be operated at lower temperatures of 600-650°C while delivering higher conversion rates.
The new process also consumes less natural gas. The compact unit is easy to operate and cuts investment costs.