The CAMPFIRE alliance is developing technologies for the future ammonia-based energy system. The seasonal and regional production of green ammonia plays an important role in this. A new technology for the direct production of ammonia from air, water and renewable energy is solid-state ammonia synthesis (SSAS). A test bench is required to elucidate the performance and long-term stability as well as material improvement of membrane electrode units (MEA) for ammonia synthesis based on electroceramic membranes. As part of the establishment of the Power-to-Ammonia test site in the CAMPFIRE Open Innovation Lab (COIL) at the Poppendorf site, this will be available to campfire partners in the region for the investigation of MEAs and 3-cell stacks for SSAS.

The test rig to be designed and implemented by the contractor is to be used for the electrochemical synthesis of ammonia by means of the SSAS from hydrogen or water vapour and nitrogen or atmospheric nitrogen. For this purpose, single MEAs or short stacks of three MEAs (triple MEA) are measured in the test stand at pressures of 50 to 100 bar operating pressure at temperatures from 450 to 550 °C with regard to their electrochemical performance. The single MEAs and triple MEA stacks consist of tubes with an outer diameter of 8 mm, inner diameter of 5-6 mm and a length of 150 mm. They have components for media connections (inlets: H2/H2O/Ar and N2/syn. air/Ar, clamping ring fittings with ID 8 mm, outlets: NH3/N2/Luft/Ar and H2/H2O/Argon) as well as electrical contacting for the power supply (anode Pt-Wire 1 mm, cathode Pt-Wire 1 mm).

The contractor must provide the following services in total:

- Concept and implementation of the high-pressure high-temperature infrastructure

- Concept and implementation of reactant feed streams

- Concept and implementation of the pressure vessel

- Concept and implementation of analytics

- Concept and implementation of automation

- Concept and implementation of the safety device and HAZOP

- Commissioning at the contractor's premises

- Installation and final acceptance at the client's premises

- Provision of detailed plant documentation

The following requirements apply to the services to be provided:

The feed currents of the reactants H2/H2O/Ar and N2/Luft/Ar for the MEAs are to be realized over the highest possible minimum range greater than 100 Nml/min up to 1000 Nml/min with the lowest possible pressure and temperature dependence.

The contractor shall construct and implement a pressure vessel that is suitable for the integration of single MEAs and short stacks and has connections and supply for their electrochemical and analytical characterization. The contractor must also carry out a suitable heating concept for the pressure vessel against the background of the specific application.

In the test stand, the product gas must be fed to a suitable analytical module for online investigations of the composition of the product gas. It must be possible to determine ammonia concentrations over the widest possible range up to 1% in a matrix of N2, air/Ar, but at least with a minimum concentration value of 1 ppm. The analysis must be optimized by suitable apparatus measures for the specific application (online trace analysis of NH3).

For the electrochemical investigations of the single MEA and triple MEA stacks, an electrical power supply must be integrated into the test bench that realizes a power of 1500 W with a zero-volt option.

The test bench must have automation for monitoring and controlling feed currents, regulated electrical power supply, pressure and temperature based on a Siemens S7-1500 platform and WinCC Professional user interface with PLC software.

When operating the test stand, ergonomic handling by a laboratory employee must be possible.

A CE declaration of conformity must be submitted for the entire test stand during the final acceptance by the contractor. The contractor must create and implement a suitable concept for this.

In the offer, providers must provide proof of the execution of the services for the evaluation by the client. The offer must have the highest possible level of detail of the technical concretization of the concept in order to enable the client to evaluate the binding nature of the specification of the essential plant components.