About “Hydrogen Oil” or LOHC


Green hydrogen is the only known pure energy molecule that can be produced to any extent and in almost any place on earth.

Green hydrogen offers almost every community, company, and society the potential to produce its own fuel.

LOHC – “hydrogen oil” – is an inexpensive way of storing and transporting bulk (gaseous) hydrogen. Molecular hydrogen is connected in “hydrogen oil” to the carrier, benziltoluen (BT), into a non-toxic and non-flammable liquid. With this combination, hydrogen becomes suitable and safe for transport and distribution under normal ambient conditions.

The filling of “hydrogen oil” looks so that in LOHC- imprints molecular H2 under a pressure of 20 to 70 bar by hydrogenation process whereby up to 180 °C of heat is released and thus OBTAINED LOHC+.

When emptying full “hydrogen oil”, LOHC+, at a temperature of approximately 300 °C and a pressure of 2 bar, molecular hydrogen H2 is released, and LOHC+ passes into LOHC-.  LOHC- is ready for new filling, and H2 for direct use by standardized methods.But for the whole story of hydrogen and decarbonization, the cheapest possible source of electricity, from renewable sources or from waste, especially unsorted waste plastics, is first needed.

Oil and gas became what they are – a “global energy carrier” when a global system of transmission from the point of origin/production to the place of consumption/use of the “energy carrier” was designed and established. It is undeniable that hydrogen is a superior carrier of energy than oil and gas, due to little or no harmful impact on the environment. Disputed and questionable was the transport and distribution of hydrogen from the place of production to the place of consumption. LOHC – “hydrogen oil” is the answer chosen by the world as the solution to the problem of transporting and distributing a new environmentally friendly and energy-superior energy carrier – hydrogen.

Today, it is not a problem to produce hydrogen. Modes of transportation have required large investments and adjustments. The choice of LOHC as a hydrogen carrier considers all the usual methods for the transport and trading of hydrogen.

It is essential and primary to invest in LOHC storage and distribution infrastructure because other points are clearly defined and accessible.

It is not disputed that it is the most environmentally friendly “green hydrogen”, but its production is relatively expensive due to the energy needed for electrolysis. The production price for 1 kg of green hydrogen today, with the use of electricity from waste plastics, is approximately 1.7 EUR, whereby it should be counted that the ubiquitous problem of waste plastics should be solved permanently and environmentally friendly. The production of hydrogen of other colors is a widely established and common process. The price of non-green hydrogen ranges from 1.8 to 2.4 EUR per kg of hydrogen.

Greenhouse gases emitted in the production of non-green hydrogen can be “captured” and stored with SPRS technology. The greenhouse gases emitted by classic means of transport can be drastically reduced by combining AGFM technology and SPRS technology. The solutions are there, on the table.Investing in LOHC hydrogen distribution and investing in AGFM and SPRS technology or in PWED technology for waste plastic treatment is promising, sustainable and cost-effective.

What is “hydrogen oil”?

LOHC – Liquid Organic Hydrogen Carrier, liquid carrier medium for hydrogen – “hydrogen oil” is an oil-like liquid, hence the name “hydrogen oil”, which has been used for years as a heat transfer oil in various applications and industries. Recently, its ability to chemically bind hydrogen was discovered. By chemically binding hydrogen, it can be stored under normal conditions (pressure and temperature), contrary to current practice.

This makes handling hydrogen not only safer, but also cheaper. With LOHC, volatile hydrogen gas no longer needs to be cooled or compressed in an expensive and energy-intensive manner to enable cost-effective transportation.

One m³ LOHC allows safe storage of 57 kg H2.

With LOHC, we can compensate for time fluctuations as well as local differences between energy production and demand. This makes hydrogen easy to transport. For example, from North Macedonia and/or Croatia or anywhere in the world where there is an abundance of water, hydrogen can be produced using wind energy, photovoltaic energy, and energy from the depolymerization of plastics, to the heart of industrial Europe, hydrogen in the form of “hydrogen oil” can be transported in the usual and well-known ways.

Use at gas stations or marine plants is as conceivable as use in the glass and cement industry. All areas where hydrogen can be used also benefit from LOHC as a hydrogen storage facility.

How does LOHC work?

With pressures between 30-50 bar and catalysts developed for this application, LOHC is hydrogenated (enriched with hydrogen), i.e., hydrogen is chemically bonded to LOHC. The resulting hydrogenated LOHC+ is then handled using known infrastructure for fuels such as petrol and diesel. The hydrogenation process is exothermic[1]. Thus, developed waste heat can be used in other processes and thus increases the overall efficiency of the system.

If hydrogen is again needed, for example in chemical treatment plants, the steel industry or to supply fuel cells for the use of electricity, it can be re-extracted from LOHC+.

How to dehydrogenate LOHC+, i.e., releasing hydrogen, LOHC+ passes through the dehydrogenation reactor, which contains the catalyst necessary for this process. In contrast to hydrogenation, dehydrogenation is an endothermic[2] reaction. The required energy must be added, and this can be achieved by using hydrogen itself or other, external heat sources, say from PWED waste heat.

Dehydrogenated LOHC- can now be returned to the hydrogenation site and refilled with hydrogen. The cycle is closed. LOHC itself is not wasted but is reused many times. The service life is also increased by the possibility of purification as soon as it becomes necessary after different dehydrogenation cycles.

LOHC is a heat-resistant oil with a capacity of 57 kg of hydrogen per 1 m3. Hydrogen is chemically bound to LOHC and released from it in a chemical reaction at the catalyst.

Some features of LOHC

  1. Safe heat transfer oil, in commercial use for decades.
  2. Globally produced in refineries.
  3. Safe storage/release, transport, and handling under pressure/temperature versus liquid hydrogen at -252°C (-487 °F) or toxic ammonia.
  4. 50x more cost-effective than lithium-ion batteries.
  5. Compatible with existing infrastructure.
  6. Endless lifespan.
  7. The LOHC cleaning cycle is 7 years.

LOHC converts hydrogen into secure energy storage technology

LOHC makes the use of hydrogen as an energy source simple, safe, and efficient, enabling the storage, transport and discharge of large amounts of electricity in an environmentally friendly and harmless manner.

Hydrogen is an ideal source of energy. It is easily produced using renewable energy sources and is available in large quantities. There are no pollutants from H2-industrial processes. Nothing was burned. Nothing is contaminated. Nothing was damaged.

The LOHC solution is revolutionary and enables great progress in the electricity market. Hydrogen with LOHC becomes a safe source of energy from generation, storage, and transportation to discharge.

LOHC technology is based on liquid carriers that chemically bind hydrogen. Within the H2 process, stored hydrogen is non-volatile and cannot discharge on its own. LOHC can only be charged and discharged in combination with a catalyst, injection, and release of hydrogen, as often as necessary, making it extremely cost-effective.

Charging and discharging LOHC

Hydrogen storage or LOHC (hydrogenation) filling and the use of hydrogen release/discharge (dehydrogenation) LOHC are two independent processes. Of particular importance is the catalyst technology.

Filling or hydrogenation LOHC

The chemical process used to store hydrogen in LOHC is carried out under pressure. The electrolyzers can directly supply hydrogen to the LOHC charging process, making additional energy-intensive compression unnecessary. The chemical reaction by which hydrogen binds in LOHC takes place in a hydrogenation unit with a layer of porous, precious metal catalysts and dosed LOHC. During this exothermic reaction, heat is released, which can be further used in various processes. Hydrogen-laden LOHC+ (perhydro-dibenziltoluen) is eventually pumped into the tank.

Discharge or dehydrogenation of LOHC

Recovery of hydrogen from LOHC+ charged takes place at a temperature of 250 to 300 degrees Celsius. This endothermic reaction requires heat, which is obtained within the reaction process. The release process takes place in a dehydrogenation unit with a catalyst. Here, the chemical link between energy sources and hydrogen is again broken. Hydrogen is taken from the reactor in gaseous form and converted directly into electricity in the fuel cell. Released LOHC (dibenziltoluen) is stored in the container until it is needed again. The LOHC cycle is closed.

One liter of LOHC stores one kilowatt hour of electricity and one kilowatt-hour of thermal energy in the form of hydrogen. When a fuel cell is converted back into electricity, electricity becomes available again. The benefits of LOHC technology are impressive. It is safe and environmentally friendly, has unlimited storage capacity, is also rechargeable and is stable over long periods of time. In connection with wind or solar energy systems, LOHC technology makes the energy transition safe as renewable energies are now capable of a basic load.

LOHC in practice

Base stations for supplying LOHC in Germany

LOHC, thanks to its similarity to the handling method, which is close in society to the usual use of oil, has become widely accepted in Germany. The map above shows the points and integrators of the use of LOHC in Germany.

Germany and Europe are targeting carbon-free energy imports in the form of green hydrogen. LOHC enables the realization of high demand in a safe and cost-effective way.

Liquefied hydrogen transport vs hydrogen transport as LOHC

Discharging hydrogen from LOHC at pumping stations

Example of the use of LOHC in urban centers

Filling factory LOHC

MAN Energy Solutions has designed a modular LOHC storage plant for filling LOHC with molecular hydrogen storage capacity of 5 tonnes of hydrogen per day. Typically, 5 tons of hydrogen can drive half a million kilometers of hydrogen-powered vehicles.

In the LOHC storage plant, hydrogen is chemically bonded to LOHC material benzyl toluene, thermal oil. This oil carrier can be transported under environmental conditions in conventional and existing logistics infrastructures comparable to the delivery of oil or diesel. LOHC filled with hydrogen is loaded into a road transport truck to LOHC hydrogen discharge stations.

[1] An exothermic reaction or exothermic process in thermodynamics describes a process or reaction that releases energy from a system into the environment. Simply put, after an exothermic reaction, more energy was released into the environment than was absorbed to initiate and maintain the reaction.

[2] An endothermic reaction or endothermic process is a process that occurs due to the addition of energy to a system.

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