Handling Hydrogen

Körting has been synonymous with jet ejectors for over 150 years. It also offers waste gas scrubbing and environmental technology solutions.

Handling hydrogen with jet ejectorsIn hydrogen systems, gas tightness is a must.

  • Körting jet ejectors convey hydrogen reliably and also come in controllable designs.
  • They are ideal for use in explosive environments because the jet ejector has no sources of ignition.
  • Hydrogen can be the propellant and suction medium (H2-ready)
  • Low maintenance (no moving parts)
  • Materials as desired (as long as these are suitable, HIC compliant etc.)
  • Körting Hannover has longstanding experience across a wide pressure range (vacuum to high pressure), which means its jet ejectors are very versatile.

Hydrogen blending into natural gas grid solution

Conveying hydrogen in natural gas pipelines

Due to the rising global demand for hydrogen, the supply chain presents lots of challenges when it comes to getting hydrogen to consumers. One option is to add some of the hydrogen to the existing pipeline infrastructure.

What is hydrogen blended with and why?

Hydrogen is mostly blended with natural gas such as biomethane. The quantity of hydrogen in the gas can be between less than 1% and 30%, depending on the application and what the existing gas infrastructure looks like. Due to its vastly higher combustion efficiency, hydrogen produced from renewable energy can be fed into natural gas pipelines. The resulting blends can be used to generate heat and electricity and emissions are lower than if only natural gas had been used.

How does the blending process work?

Natural gas is extracted from the ground and refined for use as a fuel. Afterwards, it’s usually fed into a grid of huge pipelines that take it to towns and industrial plants in a specific area. Hydrogen can then be fed into natural gas pipelines via injection systems at virtually any point along the grid or downstream along smaller pipelines belonging to particular towns that supply commercial and private consumers.

What challenges does blending present?
  • What challenges does blending present?
  • Hydrogen is extremely flammable over a wide blending range with air/oxygen.
  • Hydrogen causes material to become brittle, which poses a high leakage risk and safety hazard.

Catalytic fat hardening with hydrogen (hydrogenation of fatty acids)

Natural solid fats, such as butter or lard, are popular with consumers. However, they are also costly and have disadvantages, such as low smoke points, limited shelf lives and are not very spreadable.

Catalytic fat hardening can be used to convert comparatively inexpensive and standard vegetable oils into solid fats. Compared with butter or lard, these have even better product properties.

During catalytic fat hardening, the double bonds of the unsaturated fatty acid residues are saturated with hydrogen via a suitable catalyst (nickel). During this process, glycerol esters of saturated fatty acids are formed from the (poly)unsaturated fatty acid glycerol esters (e.g. in vegetable oils).

Hydrogen as a process gas (chemical industry)
Conveying process gas with gas jet compressors

Gas jet compressors are used in the chemicals industry to enrich or dilute process gases. In recirculation processes, the reaction gas to be fed in is expanded as a propellant gas via a nozzle inside a gas jet compressor to ensure conveying of the recirculated gas.

Fuel cells

Recirculation of unused hydrogen or oxygen with one or more liquid jet gas compressors or gas jet compressors connected in parallel (anode gas recirculation)

Basic principle

  • The tank pressure is gradually relieved via medium pressure of 30 bar to operating pressure of 1.5 - 4 bar.
  • The hydrogen is fed to the fuel cell stack superstoichiometrically.
  • After emerging from the fuel cell stack, the gas blend still contains large quantities of unused hydrogen.
  • The gas blend is refed into the fuel cell stack with fresh hydrogen from the tank (recirculated).
  • An electric blower is used during active recirculation to convey the gas blend. The advantage: volume flow is then easy to control.
  • In passive recirculation, the gas blend is conveyed using the ejector principle.
  • The ejector principle means the fresh hydrogen is injected through a jet ejector, creating a vacuum that suctions in the gas blend. The advantage: no extra energy consumption and installation space and weight are saved.
  • Recirculation also circulates water and inert gases (nitrogen) through the circuit at the same time.
  • Inert gases reduce efficiency and must be purged regularly.
  • Water also has a negative impact and must also be drained off regularly.

Product selection for fuel cell recirculation system

Jet ejectors are a good alternative to electrical circulation blowers. Jet ejectors function on the Venturi principle and use the hydrogen’s operating pressure downstream of the hydrogen tank as motive pressure to suck in and recirculate the unused hydrogen. In contrast to circulation blowers, jet ejectors have no moving parts or extra power supply. As a result, service lives are longer and maintenance, repair and energy costs minimised.

Nuclear power

Pumping and blending hydrogen into cooling water using liquid jet gas compressors to reduce oxygen reduction in the circuit.

  • Used as part of an advanced hydrogenation device for reactor coolant (RC) of pressure water reactor (PWR).
  • Ejector usage reduces total hydrogen volume to small amounts compared to the conventional hydrogenation concept.
  • Usage of ejector eliminates risk of fire and explosions.
  • Well established and reliable function as part of PWR´s (proven design).
  • Usage of ejector lowers consumption of total H2 in PWR´s.

Syngas treatment

High-pressure Venturi scrubbers for clean hydrogen

Cooling – scrubbing – dedusting – humidifying – mixing

Alongside Venturi scrubbers’ conventional usages, there’s rising demand (especially by some high-pressure processes) for them to perform and make improvements to cleaning, dedusting, humidifying, and mixing tasks. Examples can be found in syngas treatment and production, coal gasification and conversion to industrial alcohol/ether.

A Venturi scrubber’s design

Syngas production, i.e. the industrial production of gas mixtures and H2, are just two examples of the wide range of potential applications. The composition of the primary gases varies depending on the application, but mostly consists of H2, CO, CO2, N2, and H2O which virtually always contain a certain amount of process-related soot. Water is used as the scrubbing medium. High-pressure, Körting Venturi scrubbers are used in numerous processes.

Steam methane reforming (SMR)

Steam methane reforming is one of the most important processes involved in making syngas and hydrogen. To do so, natural gas (or higher hydrocarbons) is converted using a catalyst. SMR technology is based on an endothermic reaction where the temperature and energy required need to be supplied externally. The process is run at temperatures >700 to approx. 950°C and at pressures of up to 50 bar.

Multi-purpose gasification (MPG®)

MPG (partial oxidation of hydrocarbons) involves gasifying a range of feedstock containing hydrocarbons, even types that can’t be mixed. As a result, heavy refinery residues, chemical waste or sludge can be converted into useful and reusable syngas (primarily CO and H2).

Over 40 years of experience

The first projects with high-pressure Venturi scrubbers were carried out back in 1978. Körting Hannover GmbH draws on decades of experience with jet ejector technology and gas scrubbers to design this sophisticated process-engineering equipment. To come up with the best customised solutions, we collaborate with our in-house development department to conduct CFD or computational fluid dynamics simulations and trials on our own test rig.

CFD simulation of a high-pressure Venturi scrubber
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To ensure long service lives and minimal maintenance, high-pressure Venturi scrubbers are often made of, or clad with special materials or special material combinations, such as stainless steel or duplex stainless steel and subjected to stringent quality assurance inspections.

Special technical features

  • Pressure: 1 - 80 bar
  • Material: wall thicknesses from 10 - 60 mm
  • Flanges: 600 - 900 lbs.
  • Temperatures: 200 – 400 °C
  • Nominal widths: DN 200 – 1200
  • Gas inlet: axial (alternatively lateral at 90°)

Due to high-precision manufacturing, predominantly at the Hanover site in Germany, Körting ensures that high-pressure Venturi scrubbers are designed and made based on the requirements of the customer and processes, as well as the necessary specifications and codes. The appropriate process-engineering and mechanical design calculations are also carried out.

Film spray tests on the in-house test rig
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