“Green” ammonia is an ideal energy carrier. Being free of carbon, it offers a highly interesting potential for the future. As a typical building block of the “power-to-X” principle, “green” ammonia contributes to driving decarbonisation – in particular as a means of transport for hydrogen. Since the launch of the advanced ammonia production process, WIKA has been supporting plant developers and operators with customised instrumentation solutions for the measurands pressure, temperature, level and flow.
Up to now, ammonia or NH3 has predominantly served as the basis for fertilisers. It is produced synthetically from hydrogen (H2) and nitrogen (N2) in a reactor. The conventional hydrogen production process mainly takes place in a steam methane reformer (SMR) and involves a high input of fossil raw materials and fossil fuels – especially natural gas – with corresponding CO2 emissions into the atmosphere.
Production using renewable electrical energy
However, the global push for alternative energy sources has now led to a change from “grey” to “green” ammonia. The change is based on the “power-to-X” strategy. This means that renewable electrical energy is used to obtain the required chemical molecules. In the case of ammonia, wind and solar energy is used to power the electrolysis plants for hydrogen production from water as well as the air separation units (ASU) for nitrogen extraction from the air.
“Green” ammonia offers more versatile uses than “grey” NH3
Compared to the “grey” product, “green” ammonia can be used in more ways: not only as an important fertiliser but also as fuel, for example, for the energy-intensive shipbuilding industry. Additionally, it plays an important role as a carrier medium for “green” hydrogen. This is because NH3 enables energy-efficient and space-saving ship transport from the regions where hydrogen is produced to regions worldwide with a high demand. At the destination, ammonia crackers split off the hydrogen again and make it available to all consumers.
“Green” ammonia: The diagram shows the value chain based on the “power-to-X” strategy.
Demand will triple by the year 2050
Given these opportunities, the ammonia demand will grow from previously 200 million tonnes per year to an estimated 690 million tonnes in 2050 according to the International Renewable Energy Agency (IRENA) and the Ammonia Energy Association (AEA). That is why the industry is investing heavily in production and logistics. Worldwide, there are 300 registered projects for the production of “green” NH3. WIKA offers a complete portfolio of solutions in this field.
Examples of tailor-made measuring systems along the value chain
Due to specific challenges, numerous process steps along the NH3 value chain require tailor-made measuring systems. Here are four examples:
For each step along the value chain, WIKA offers suitable measuring systems (clockwise from left), for example a level indicator with double-chamber system for ammonia separation and liquefaction, the model TC96-O Flex-O™ multipoint thermocouple for ammonia synthesis, the HHR FlowPak® flow meter for the air separation unit and the model TC59-E eTEFRACTO-PAD® tubeskin thermocouple assembly for ammonia cracking.
- Flow measurement in the air separation unit: The installation space in this unit is often limited. For such applications, WIKA has developed the HHR FlowPak® flow meter. The instrument, which is based on the differential pressure principle, does not require upstream and downstream pipes and can even be installed following two 90° pipe elbows. Nevertheless, it offers very high accuracy.
- Temperature monitoring during ammonia synthesis: Multipoint thermocouples with fast response times enable quick generation of a temperature profile in the catalyst beds of the reactors. With only one connection, up to 40 measuring points can be realised in this way. Characterised by their modularity, models TC95 and TC96-O Flex-O™ are specifically designed for such applications.
- Level monitoring during ammonia separation and liquefaction: For this task, WIKA offers a customisable level indicator with diverse redundant monitoring in a double-chamber system. The two-chamber solution features a reed chain or magnetostrictive sensor as well as a guided wave radar and a magnetic indication that can easily be read from a distance. It can withstand high pressures with ease. The smart design of the measuring system also ensures that a bubbling effect caused by “boiling” liquid ammonia does not cause the float to dance, thus guaranteeing a trouble-free signal.
- Monitoring the tubeskin temperature in ammonia crackers: The separation of hydrogen from ammonia takes place in numerous catalyst-filled cracker tubes. The thermal energy input required for the chemical reaction is provided by external firing. The exact continuous measurement of the tubeskin temperature is an important variable for controlling processes efficiently and preventing overheating. WIKA’s portfolio comprises different instrument models for this, including the patented TC59-E eTEFRACTO-PAD® which is mounted with just one weld seam and outputs the exact tubeskin temperature around the clock.
“Green” ammonia: Services for measuring instruments for the production
All process steps also require process and differential pressure transmitters and corresponding instrumentation valves, which are also used for hydrostatic level and flow monitoring. In addition, plant operators can draw on accompanying WIKA services, for example during installation, maintenance and calibration.
Note
On the WIKA website we provide you with an overview of instrumentation solutions for hydrogen applications as well as for conventional ammonia production. There you will also find further information on the mentioned instruments TC95, TC96-O Flex-O™, TC59-E eTEFRACTO-PAD®, HHR FlowPak® as well as the level indicator. We also present further measurement solutions for the chemical industry. Would you like to learn more about WIKA’s sustainability strategy? Then download a copy of the sustainability report. Should you have any further questions, your contact will gladly help you.
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