Improve Corrosion Resistance, Reliability, and Quality.
The benefits of an inert and corrosion resistant surface include:
Get more information about the benefits of SilcoTek coatings for renewable and alternative energy applications.
SilcoTek coatings, like Dursan® and SilcoNert®, are used to improve detection of contaminants found in natural gas feedstock used in gray and blue hydrogen production. Our coatings prevent loss of contaminants in the detection flow path system, assuring accurate and very low level detection limits. Accurate testing is vital in protecting process catalysts from contamination during production.
Our coatings are also used in product testing to assure hydrogen purity for use in fuel cells. Inert flow path surfaces enhance testing by preventing adsorption, reactivity, and by improving surface corrosion resistance. An inert flow path is a critical factor in achieving consistent low level detection of reactive compounds like hydrogen sulfide as well as maintaining a reliable corrosion resistant and fouling resistant surface. SilcoTek CVD coatings achieve the lowest detection limits for many industry standards relating to refinery and petrochemical testing.
Applications include:
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SilcoTek corrosion resistant barrier coatings prevent interaction with corrosives, significantly extending critical component life. Our corrosion resistant coatings, Silcolloy®, and Dursan®, are particularly useful for fighting corrosion in challenging environments found in offshore wind energy production and in sensitive processes found in hydrogen production, transport and use.
In addition to extending the usable life of precision stainless steel parts, SilcoTek coatings prevent nano-scale corrosive reactions that can cause metal ion leaching and contamination, ultimately increasing process yield and reducing failure rates.
Applications include
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SilcoTek coatings help to reduce maintenance and increase equipment uptime. Use SilcoTek coatings wherever corrosion or contamination is a problem. Coat components like:
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Reactive compounds like hydrogen sulfide (H2S) can poison hydrogen catalysts. Sampling for trace sulfur contamination is critical to efficient hydrogen production and quality testing. Unfortunately sulfur compounds are reactive and can get adsorbed or "stuck" in stainless steel analytical system flow paths, causing significant delays in response time and potential process contamination.
SilcoNert® and Dursan® coated surfaces allow compounds to travel through critical flow paths unimpeded, offering near-real-time response and improving productivity and product quality. Comparative data from CONCOA (below) show a nearly 10x improvement in response time for a SilcoNert coated flow path (blue line) compared to an uncoated stainless steel system when sampling part-per-million and part-per-billion level hydrogen sulfide.
As noted earlier, some gases may not physically harm production, transport, or use but can reduce the energy density of hydrogen fuels. Reliable detection of nitrogen, N2, or other contaminants assures hydrogen powered systems run at peak efficiency.
Advances in instrumentation and test procedures help, but inert surfaces like SilcoNert® and Dursan® enable testing agencies to repeatably detect part-per-million and part-per-billion levels of NOx and sulfurs and other emissions.
The California Energy Commission conducted a study comparing SilcoNert® (noted as Silcosteel® in the study) to other materials commonly used in sampling systems. The results show the SilcoNert coated surface reduces surface reactivity with NOx, sulfurs and other common emissions, enabling more reliable testing of trace emissions.
Prevent adsorption of active compounds
A SilcoNert® coated flow path will reduce signal loss and chemical adsorption while improving analytical test quality. The SilcoNert coated surface reduces ammonia adsorption by 95% compared to uncoated stainless steel, improving detection of catalyst contaminants.
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Corrosion is a continuing and major issue in all fields of energy and particularly renewable energy. Newly engineered systems are designed for up to 30 years of service but exposure to environmental corrosion, UV, extreme temperatures and salt corrosion can challenge component durability. Excessive component failures can lead to high maintenance cost and overall under performance of energy output.
Preventing corrosion in solar and wind applications.
Fittings, solar cell support structures, wind generators and heat exchangers are exposed to pollution related corrosion and extreme environmental conditions. Additionally, systems located in coastal environments are exposed to high salt levels which can lead to component corrosion and failure. Get our corrosion presentation to learn about all our corrosion resistant coatings for stainless steel and other metals.
Typical polymeric coatings are degraded by UV and acid rain exposure, limiting their ability to achieve the target 30 year life. Metallic coatings can extend service life but cannot achieve the target 30 year lifespan. That leaves corrosion resistant alloys which will certainly achieve the performance goal but will add cost and lead time. Semi metallic coatings like silicon offer a favorable mix of corrosion resistance, UV resistance, and durability that can help solar and wind fields achieve their target 30 year life. Here are some examples of how silicon coatings can improve component and system life.
Salt Exposure
EIS (Electrochemical Impedance Spectroscopy) data show Dursan remains pinhole free after over 250 days of salt spray exposure. In the experiment below, test coupons were subjected to salt spray for 247 days.
Figure 1: Test coupons in salt spray chamber
The test samples were periodically tested by introducing a voltage between 5 to 50 mV in a range of frequencies. If the resulting data points do not diverge or curve as the voltage and frequencies change, that indicates no voltage breakthrough and no additional pin holes in the surface were produced during the salt spray exposure. For example the uncoated stainless steel test coupon began to show pinholes after just 15 days of exposure. Note the divergent EIS lines below.
After 61 days of salt spray exposure, the Dursan coated stainless steel test coupon exhibited minimal pin-holing and EIS divergence.
We continued the salt spray test for 247 days. On day 247 we tested the Dursan coupon again and found minimal divergence, indicating little pitting corrosion.
Chloride Exposure
Industrial acid pollution is common, especially in urban environments. Acid exposure can significantly reduce the life of solar and wind systems, making improved acid corrosion essential to sustaining energy production over the projected 30 year lifespan. We conducted a series of comparative ATSM G31 immersion tests of various alloys to see how they performed after exposure to concentrated hydrochloric acid. We found the Dursan® and Silcolloy® coated samples performed comparably to Hastelloy® and other super alloys. All at a fraction of the cost of exotic alloys.
Environmental Pollution and Sulfuric Acid Corrosion
Solar and wind farms are often exposed to industrial pollution, one of the most common pollutants being sulfur species or sulfuric acid. When combined with water in the atmosphere, acid rain is formed. Over time exposure to acid rain will degrade fittings and structural components of wind and solar farms. Silicon coatings can improve the durability of surfaces exposed to acid rain.
ASTM G31 immersion comparison of uncoated stainless steel vs. silicon coated (Dursan and Silcolloy) surfaces shows an order of magnitude reduction of sulfuric acid corrosion rate (see graph below). Making silicon coatings an option to consider when increasing the life of renewable energy systems.
Galvanic Corrosion
Comparative galvanic corrosion was measured by immersing uncoated and coated aluminum test coupons into a salt solution. Galvanic potential was measured in a cathodic/anodic flat cell at a separation distance of 14 cm. The artificial seawater electrolyte conformed to ASTM D1141. The silicon coated (Dursan and Silcolloy) coupons exhibited significantly higher potential indicating fewer pinholes in the surface.
Read the entire galvanic corrosion comparison by clicking the report below.
A Unique Problem for CSP Plants.
Concentrated Solar Power plants (CSP) face one additional challenge. Temperatures on some CSP surfaces can reach 550 to 750c. Making it impossible to consider common coatings when selecting corrosion resistant materials. Silicon coatings can withstand exposure to extreme temperatures, making coatings like Silcolloy and Dursan an attractive option when improving corrosion resistance in high temperature applications like CSP plants. Watch our video and see how our high temperature corrosion resistant coatings perform.
Get the Spec.
Interested in learning more about coatings for renewable energy? Go to our Coating Properties Page and then contact a Technical Service Team Expert to discuss your application.
Hydrophobic coatings, like Notak®, repel water and ice to help to maintain a water free surface. This helps to control moisture contamination in hydrogen production, fuel delivery, and use. Notak prevents moisture carryover by preventing trace water from attaching to hydrogen flow path surfaces and hydrogen sampling flow paths. This allows the user to detect moisture before it becomes a problem in hydrogen manufacturing and transport flow paths.
Goniometer water contact evaluation (below) compares hydrophobicity data of various SilcoTek coatings. The water repelling properties of Notak, evident in the water droplet and 143 degree contact angle, prevent wetting and water retention of the stainless steel substrate. For reference, an uncoated stainless steel water droplet surface contact angle ranges from 30 to 40 degrees, making stainless steel a wettable surface that can retain water in tubing, valves, filters and other flow path surfaces.
Ice formation and removal is also a problem in hydrogen storage and transport. Surfaces with ice repelling or icephobic properties help operators to manage the accumulation and removal of ice. The ice repelling and removal properties of Notak® coated stainless steel are compared in the photo and table below. The frozen Notak droplet has the highest contact angle when compared to other coated and uncoated surfaces, indicating an icephobic surface.
Notak also made ice removal easier. After freezing coated and uncoated metal coupon samples, a metal pick was inserted at the point of ice attachment to the coupon. Gradual increasing force was applied laterally to the ice sample until the ice dislodged from the surface. The effort required (1 = easy, 10 = difficult) to remove the ice and associated observations are listed in the table below.
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316 SS Coupon Surface |
Effort (1-10) |
Observations |
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Notak® |
2 |
complete removal with little effort |
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Dursan® |
6 |
partial removal from surface with effort |
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Silcolloy® 1000 |
7 |
partial removal from surface with greater effort |
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Dursox® |
8 |
difficult, bulk chipped with minimal surface separation |
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Uncoated |
8 |
difficult, bulk chipped with minimal surface separation |
The ice and water repelling property tests demonstrate how SilcoTek coatings can improve the moisture detection, reduce the accumulation of water in flow paths and help to make ice removal from surfaces easier.
Related methods for hydrogen testing and use:
Watch our inert coating video to see how our coating technology improves performance.
If you have a technical question about how our coating technologies will perform in your application, contact our Technical Service Team and ask the experts.
If you would like to buy a coated product directly from the manufacturer, go to our Buy Coated Products page.
To get the most out of your process and product, coat all flow path components and systems. This includes:
Calibration and spec gas delivery systems
Process Flow Paths
Want to test our coating before you buy? Get a free test coupon or arrange for a free test evaluation.
