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ENERGIX-Stort program energi

PALLAMONIA

Alternative title: High purity hydrogen recovery from ammonia with palladium-membrane technology

Awarded: NOK 6.3 mill.

Project Manager:

Project Number:

332357

Project Period:

2022 - 2025

Funding received from:

Hydrogen carriers are a manner to store and transport hydrogen in a form which is easier to handle than H2. Ammonia (NH3) is a promising hydrogen carrier since it has a high amount of hydrogen per mass basis (over 17%), and is carbon-free. The hydrogen is retrieved from NH3 through decomposition of the molecule. This is performed over a catalyst, and at high temperature (700-900°C) in a process referred to as “cracking”. It is possible to enhance this process by continuously removing one of the products in the reaction, such as H2. Hydrogen Mem-Tech (HMT) wants to apply palladium-based membrane technology to enhance this process and produce high purity hydrogen. The goal is to design a separator with integrated ammonia cracking, in collaboration with SINTEF Industry. Palladium-based membranes have the innate quality that only hydrogen can pass through the membrane. HMT is commercializing such membranes, produced after a method originally developed by SINTEF Industry. The membranes are used in separators designed by HMT to recover hydrogen from gas mixtures. These membranes are very thin (<5µm), which is important to ensure a high amount of hydrogen passing through and to use a low amount of palladium. Detailed investigations into the behavior and performance of the membranes under exposure to industrial conditions and levels of NH3 will be carried out. This will aid in determining the optimal operational conditions and design parameters for the integrated separator and cracker. Identification and elimination of possible leakage points is required to obtain a hydrogen purity which fulfills the requirements of a proton exchange membrane fuel cell. The fuel cells convert H2 and oxygen to electricity, and are highly sensitive to trace amounts of NH3. The finished separators may facilitate the use of NH3 in industries aiming to reduce emissions. In particular the marine industry which has an increased focus on hydrogen fuel cell technology.

Palladium (Pd) based membranes are of great interest in the industry and academia because of their innate capability to selectively separate hydrogen from gas streams. The possibility to simultaneously capture CO2 in this process has led to the membranes being considered as Key Enabling Technology (KET) for the transition towards a low-emission economy. Hydrogen Mem-Tech (HMT) is currently commercializing such Pd-membranes. Ammonia, with a high hydrogen content, is regarded as a promising hydrogen carrier due to the comparative ease of liquefaction and low cost of transport and storage. There has been an increasing focus on the role of Pd-based membranes in the recovery of hydrogen from NH3, as well as facilitating higher conversions. The use of separators that can be used in combination with a cracker, or membrane reactors that combine cracking of NH3 with separation of hydrogen, may aid the use of hydrogen as fuel in marine and land transport. However, certain challenges must be addressed. Fuel cells require levels of NH3 < 0.1 ppm in the hydrogen, necessitating investigations into sealing technology. The effect of NH3 on the membranes is debated in the literature, with diverging reports of flux inhibition. Investigations of long-term exposure to amounts of NH3 comparable with post-cracker industrial levels is necessary to develop optimal process conditions to ensure stability and long life-time of the membranes. To secure the capability of the membrane technology commercialized by HMT to handle NH3 and produce hydrogen of fuel cell quality the approach will be as follows: 1.A technological approach in two parts, where the aim is a) a separator which can be applied downstream of a NH3 cracker and which can provide fuel cell standard hydrogen, and b) integration of NH3 cracking to the current separator technology. 2.A process approach, where the aim is to establish the optimal procedure to ensure long-term stability under exposure to NH3.

Funding scheme:

ENERGIX-Stort program energi