Hydrogen is produced at a large industrial scale primarily from natural gas for heavy- industrial applications (e.g., petrochemical). However, there is a growing global market for merchant hydrogen (relatively small-scale, analytical equipment, fuel cells, microelectronic fabrications, turbine cooling, etc). All together, these market niches provide excellent business opportunities for manufacturing small- and medium-scale electrochemical hydrogen compression (EHC) and separation systems using PGM and PEM technologies. EHC can be a part of a large market associated with infrastructure for fuel cell deployment. Other potentially large market also includes hydrogen separation and purification. The EHC system can operate as a very efficient hydrogen separation unit. Conventional membrane-based separations and purification of hydrogen mixtures typically involve the use of polymeric membranes that do not provide sufficient selectivity as well as are not chemically and thermally stable. High-selective separations can be achieved by using palladium membranes that are rather costly. Electrochemical hydrogen separation combines high selectivity of separations as well as provide relatively affordable costs in comparison of palladium-based membranes. The typical flux densities of the hydrogen achieved in the electrochemical separation process are much higher than in conventional membrane separations. This is due to the fact that the mechanism of the hydrogen transport is fundamentally different in the electrochemical separation systems. Hydrogen is transported in the form of charge carries, e.g. in the form as protons, and the flux is proportional to the current density applied, but not to the concentration gradients between the feed and the permeate side. Selectivity values of the electrochemical separation are also very large as only hydrogen is anodically oxidized to form protons over a catalyst, typically, Pt, and the other components of the gas mixture, such as permanent gases, such as helium etc., remain neutral charge. Therefore, a promising possibility to utilize platinum-group metals (PGM) as electro-catalysts is to electrochemically compress hydrogen to reduce hydrogen compression and storage costs. An electrochemical hydrogen compressor (Figure 1) typically consists of three functional components, i.e. a cathode, an anode and a membrane. The anode and cathode is connected to a DC power source that controls the current. Low pressure hydrogen is fed to the anode, where the hydrogen is oxidized to produce protons and electrons. The proton diffuses through the membrane to form discharged hydrogen and the electrons moves through the electric circuit. This process will continue until the supply of electricity or hydrogen is stopped. Some advantages of the EHC systems include: no moving parts, no energy losses due to friction, easer to eliminate product losses, low noise level, suitable for small scale, relative high efficiency, isothermal process, purifies hydrogen, hydrogen is not contaminated with oil. In this paper, experimental data will be discussed for both hydrogen compression and purification. Figure 1. Schematic of electrochemical H2 compressing across PEM [1]. The process design of the hydrogen/water feed subsystem, EHC cell stack, hydrogen vent subsystem and the hydrogen discharge subsystem is shown in Figure 2. Figure 2. Key elements of the EHC system. Figure 3 shows that there is a strong relation between the current density (0.2, 0.25, 0.3, 0.35, 0.4 A.cm-2 and the compression rate of the EHC. Figure 3. Discharge pressure (up to 100 Barg) vs. Time. This section reports on the separation results. The GEN2 EHC HySA unit was used. Gas analysis was conducted by using Bruker SCIONTM 456-GC. The experimental method included testing a sample of inlet gas as baseline; test a sample of the compressed gas and compare. The following feed gas mixtures we used: 77.4 % Hydrogen, Balance Argon ~50 % Hydrogen, Balance Helium. Separation resulted in complete purification of H2 as measured by GC on the permeate side of the electrochemical cell. References [1] P. Bouwman, “Fundamentals of Electrochemical Hydrogen Compression”, In: “PEM Electrolysis for Hydrogen Production: Principles and Applications”, Eds: Dmitri Bessarabov, Haijiang Wang, Hui Li, Nana Zhao, CRC Press (2016), https://doi.org/10.1201/b19096