Page 167 - CW E-Magazine (10-6-2025)

Special Report Special Report

High-tech rubber in the service of the energy transition plate-type shape such as layered are encapsulated in two layers of
silicates or graphites can help to addi-
this material; when the fi lm melts it
in Düsseldorf is the world’s DR. STEFAN ALBUS tionally reduce gas permeation. perfectly envelops the cells. EVA is
most relevant trade fair for extremely translucent and weatherproof
K not only the plastics but also Freelance trade journalist To ease hydrogen transport, alter- and boasts a wide processing window;
the rubber industry. Sustainability and phide and ammonia. This is why such native carrier media have also been under it is not a classical elastomer but can –
saving resources, however, are also materials as EPDM (Ethylene-Propy- discussion as of late, such a gaseous depending on its EVA content – be con-
burning issues here that nobody can lene-Diene-Rubber) membranes are ammonia (NH ) at room temperature) sidered an “elastomer-similar” material
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ignore. One more reason to shed some used in biogas production plants, along- which is easier to liquify and store. This by all means. There are also approaches
light on just how important rubber is in side their rivals like double membranes application also requires low-tempera- of its problematic resistance to weather- to replace EVA fi lms from fossil sources
“green” applications in the run-up to from polyvinyl chloride (PVC)-coated ture and especially alkaline-resistant ing and ozone. Instead, NBR is the with alternatives that contain a percent-
K 2025. Our society is faced with gas is also still considered an interim polyester wovens. Both materials have high-performance rubbers. preferred option for full-rubber rotary age of bio-based “sugarcane ethylene”.
completely new challenges due to climate fuel for comparatively carbon dioxide their pros and cons in this application; shafts. In radial shaft gaskets you will
change. Does the material that is (CO )-low energy production. At pre- but EPDM rubber is a little more Needless to say, hydrogen already also often fi nd ozone-resistant HNBR, To make sure the solar panels stay
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rubber, invented over 180 years ago, sent, Germany sources plenty of natural fl exible, and easy to recycle. serves its purpose in fuel cells very which, in addition, also withstands in place on today’s stylish fl at roofs,
still play a role here? gas from the USA where around 88% of reliably. But there is no such thing as a temperatures as high as 170°C for short installers like to use EPDM mats. These
this energy carrier are obtained through While the tasks described for highly “one-fi ts-all” sealing material for fuel periods. With the corresponding rein- provide additional support on slippery
Of course! Often it is precisely fracking. The components needed for advanced rubber materials so far might cells: for instance, there are alkaline forcement HNBR can also be used for ground and prevent the modules from
those materials made of particularly this application also include extremely be addressed with half-way “traditional” and phosphoric acid, polymer electro- large-diameter bearings, and thanks to shifting over time. Speaking of build-
advanced synthetic rubbers that come high-performance hoses that can also approaches, things get really tricky lyte and high-temperature fuel cells. its oil-resistance even in grease-lubri- ings: needless to say, heat pumps can
to the fore here. withstand contact with aggressive with hydrogen. Hydrogen only liqui- Here, too, elastomer-bonded sealing cated main bearings. hardly do without rubber either. How-
liquids, which are injected into the rock to fi es under normal pressure at extremely materials with a high content of special ever, this application calls for (weather-
Geothermal release the gas trapped there. For these, low temperatures. Which is why the fi llers are already used for sealing tasks. The cables transmitting power resistant) sealing gaskets and hoses,
One such application for rubber of multi-layered products are preferred sealing materials for a future hydrogen from offshore wind parks can become which are also suffi ciently fl exible at
this kind is heat recovery from deeper because their inner layers consist of an economy should be designed to cover Wind power very hot. This is why rubber materials lower temperatures; but also for vibra-
layers of the earth. After all, geothermal acid-resistant synthetic rubber; for the a wide temperature range (-40 to over Wind turbines are growing to ever with a higher temperature resistance tion-dampening rubber mats that reduce
drilling can reach depths of 1,000 to outer layer rubber grades with excellent +80°C). In addition, high pressures are greater heights. Today, they can achieve are required, like EPDM in addition to undesired pump vibration.
even 3,000 metres. In the process wear and ageing resistance are used. to be withstood. nominal outputs of over 10-MW with HNBR.
so-called packers are deployed – roughly rotor diameters of 150-m to 220-m. So, rubber is anything but an
1-metre-long downhole devices used One feared hazard in natural gas The problem here is that non-polar In this application, offshore locations, And let’s not forget, rubber is not “obsolete” material. Without extremely
to seal the space between the wellbore extraction are uncontrolled, violent H molecules can permeate and thereby UV radiation, ozone (not rarely pre- only in demand for operating these sys- performance rubber grades the energy
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casing and the drilling tubing; these releases of gas from deposits, known as impair conventional sealing materials. sent in the surroundings of electrical tems – it is also already required for the transition and fi ght against climate
consist, amongst others, of heat-resistant “blowouts”. These are prevented with If hydrogen gradually deposits in the equipment), salt water and strongly manufacturing of the rotors from glass- change would not work.
rubber. In the spaces isolated by these packers, the help of so-called blowout preventers sealing material explosive decompres- fl uctuating temperatures all make high fi bre reinforced elements with sections
temperature or pressure measurements can (BOPs), i.e., extremely hard-wearing sions can occur that destroy the seal- demands on the elastic materials of silicon, butyl or EPDM rubber. At K 2025 Rubberstreet will again
be taken for example. Incidentally, in such rubber seals – which also survive con- ing gasket. And these sealing gaskets deployed. On top of this, ultimate fl ame- serve as the showcase for the innovative
deep drilling – in geothermal projects tact with hydrogen sulphide and both are urgently needed in the hydrogen proofness is required because nacelles Solar systems power and operational excellence of the
but also in the crude oil sector – engines corrosive and abrasive media. These economy: for electrolysis, in valves or that have caught fi re can practically not Photovoltaic (PV) systems, of elastomer industry. It has already been
with a spiral rotor in a stator housing are seals are very expensive and therefore membranes, for transport in tanks and be extinguished. These nacelles include course, also need sealing gaskets, that the fi rst point of contact and orientation
used that are clad with rubber inside. The expected to last accordingly. This is pipelines and, of course, in fuel cells. components for the vibration isolation keep the modules aligned and prevent for all those seeking information about
rubber components used here are virtually why HNBR is a preferred solution. and elastic bearing of the generator: water ingress. Vertical sealing gaskets, elastomers (rubber and TPE) at K since
a Who’s Who of advanced rubber In actual fact, truly effective H - rubber buffers can be found at the con- for example, that keep the offset bet- 1983. The patronage of Rubber Street
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applications technology: Nitrile Butadiene Biogas and hydrogen tight rubber sealings are still the sub- nections between the rotor blades and ween several PV modules, are made comes care of the Trade Association of
Rubber (NBR), NBR-HR (High-Resistance In 2021, about 9% of Germany’s ject of current research; probably some the hub where they absorb forces, help of silicon rubber or weather-resistant the German Rubber Industry, wdk.
NBR), Hydrogenated Nitrile Butadiene total agricultural land was used for progress can be made by a smart combi- minimize vibrations and also dampen EPDM. However, the pivotal sealing ABOUT THE AUTHOR
Rubber (HNBR) and even extremely producing renewable raw materials for nation of gas-tight rubber grades and noise. tasks are mostly performed by another Dr. Stefan Albus is a Doctor of
chemical-resistant fl uorelastomers – depen- biogas production. fi llers that obstruct hydrogen swelling material. Chemistry and freelance trade jour-
ding on the temperature profi le and and permeation. Qualifying here as Among the several hundreds of nalist. His focal themes include
aggressiveness of the fl ushing liquids. Biogas, however, contains not only basic elastomers are butyl rubber – kilos of elastomer materials built into Solar modules are often encapsu- polymer chemistry as well as plastic
the fuel that is methane but also corro- already relatively gas-tight by defi nition – wind turbines, you will hardly fi nd lated in ethylene-vinyl-acetate fi lms and rubber applications technology.
Speaking of deep drilling: natural sive ingredients such as hydrogen sul- or also fl uor rubber; additives with a any natural rubber, not least because (EVA). In the process the solar modules

166 Chemical Weekly June 10, 2025 Chemical Weekly June 10, 2025 167

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