# Technical Integration

# Outputs

# Hydrogen Production

# What is the purity of hydrogen at the outlet?

The hydrogen outlet contains more than 99,9% pure hydrogen (H2). There are small amounts of water (H2O) and oxygen (O2). Those amounts can be further decreased with a hydrogen dryer to reach up to 99,999% pure hydrogen. Please see the datasheet for more information. The electrolyser itself does not have any sensors to measure the amounts of oxygen or water contamination.

# Is the hydrogen pressure at the outlet constant?

Yes. The hydrogen is produced at adjustable constant pressure and will flow into an external tank or pipeline until the pressure at the outlet reaches the threshold. Please see the datasheet for details.

# Is it possible to produce oxyhydrogen gas?

Hydrogen and oxygen should always be kept separately to avoid explosions and fire! It is not possible to directly produce a combined gas without cleaning the oxygen and equalize pressures first.

# How much hydrogen is consumed by the electrolyser and the dryer which cannot be stored?

The electrolyser purges about 20 NL/h for each ramp down and twice a day if is running continuously. The dryer uses about 15 NL/h of hydrogen to drag away the humidity.

# Oxygen Outlet

# What are the contents of the oxygen outlet?

The oxygen outlet primarily contains oxygen (O2) and a little amount of water steam. As it is not meant for further usage, there might be small amounts of H2 and traces of KOH/K2CO2. For safety reasons, the H2 concentration at the oxygen vent is always kept below a safe limit of 4% (at around 2%). A water trap is recommended to separate the water from the oxygen at the vent outlet. Ensure that the oxygen vent and hydrogen purge line outlets are led to safe areas and not close to each other.

# Can the oxygen be used?

Yes. But it is neither pressurized nor purified.

# Other Outlets

# Are there any other substances, gases or liquids that need to be considered?

No. There are no other substances released beside H2, O2, H2O (steam) and KOH (when drained). During each purge 1-10ml of water (mostly liquid) is released.

# Setup

# General

# What needs to be considered when storing an Enapter product?

Enapter products may contain small amounts of liquids when they leave Enapter. Therefore, Enapter products shall always be stored between +1°C and +45°C.

# Can I mount the electrolyser in an inclined position?

Unfortunately, the electrolyser must be mounted in a horizontal position and as described in the product documentation. Please check the product manual for further information.

# How can the electrolyser be started and stopped?

The electrolyser can be easily started and stopped via the Energy Management System (EMS) in standby-mode, via Modbus TCP or the front panel button. Please see the software chapter for more information.

# Does the electrolyser need an uninterruptible power supply?

No. But it is recommended to keep the power supply as stable as possible to preserve the internal components.

# Dry safe

# How quick is the dry safe shutting down the system?

An interruption at the dry safe will immediately shut down the system, similar to a power cut at the power supply. The electrolyser will then go into error mode, and the hydrogen production will stop. The Power Supply Unit (PSU) will also cut the power, and the valve at the purge line will open.

# Additional components and external devices

# Is a buffer tank needed at the hydrogen outlet?

No. A buffer tank is not needed but recommended for all setups where the hydrogen outlet is not directly connected to a storage tank. In those cases, a 50 L buffer tank will keep the pressure at the output stable.

# Is an oxygen concentration sensor needed at the hydrogen outlet?

No. The pressure difference between the oxygen and hydrogen sides ensures that no significant oxygen concentration can arise at the hydrogen outlet.

# Is it possible to add manual regulators to change the stack current, voltage and circulation pump flow control?

These functions are automatically controlled by the electrolyser. The production rate can be set via the Energy Management System (EMS). Manual regulators cannot be added.

# Maintenance and Lifetime

# Does varying the production rate of the electrolyser affect the overall lifetime?

No. Changing the production rate does not influence the lifetime.

# Does switching on and off the electrolyser affect the overall lifetime?

The electrolyser has been designed for continuous usage. Still, it is possible to switch it on and off for a few times. But for efficiency reasons and to increase the lifetime, continuous usage is preferred.

# What maintenance is required for the AEM Electrolyser?

Almost none. The main regular maintenance needed is draining and refilling electrolyte once a year. The used electrolyte needs to be disposed according to the local regulations. It should be checked that the ventilation ports are free of dust and obstacles and that there are no leakages. Please see the user manual for more information.

# What maintenance is required for the dryer?

Almost none. But it should be checked that the ventilation ports are free of dust and obstacles and that there are no leakages.

# What maintenance is required for the Water Tank?

None. The Water Tank does not need any maintenance if the water inside meets the electrolyser’s purity requirements. However, it should be checked for leakages.

# How is it possible to detect the electrolyser’s end of life?

The power consumption may increase, which will eventually end in a decreased efficiency.

# How is it possible to detect the dryer’s end-of-life?

The amount of absorbed water might shrink, and therefore the hydrogen will be wetter. The electrolyser or the dryer does not measure the hydrogen’s purity.

# Can the electrolyser be recycled?

Yes. Enapter will take back old hardware and recycle it.