UHPC Corrosion Protection for Biogas production plants

In biogas production, corrosion problems can arise due to various factors inherent to the process and the environment. Some common corrosion issues encountered in biogas production include:

1. Acidic corrosion: Biogas production involves the fermentation of organic materials, which can generate acidic by-products such as acetic acid. These acids can corrode metals used in the construction of equipment and infrastructure within the biogas plant.

2. Hydrogen sulfide (H2S) corrosion: Biogas often contains hydrogen sulfide, which can be highly corrosive to metallic components. When H2S comes into contact with metal surfaces, it forms sulfuric acid, leading to corrosion. This can be particularly problematic in pipelines, tanks, and other metal structures.

3. Microbiologically influenced corrosion (MIC): Microorganisms present in biogas production facilities can accelerate corrosion processes by facilitating the formation of biofilms on metal surfaces. These biofilms create localized microenvironments where corrosion can occur more rapidly.

4. Stress corrosion cracking (SCC): Biogas environments, especially those containing hydrogen sulfide and other corrosive agents, can increase the susceptibility of metals to stress corrosion cracking. This type of corrosion occurs under tensile stress and in the presence of a corrosive environment.

5. Corrosion of concrete: While concrete itself is not susceptible to corrosion, the reinforcement steel within concrete structures can corrode due to the presence of corrosive agents like hydrogen sulfide or acidic by-products. Corrosion of reinforcement can lead to concrete deterioration and structural integrity issues.

For all the corrosion problems listed in biogas plants, UHPC concrete is a much better building material for on-site processing or for processing

into precast elements of concrete than a steel or standard concrete construction.

The extreme density of our UHPC binder/concrete compared to conventional cement/concrete generally extends the decomposition time for our UHPC. In general, our UHPC concrete offers about 5 to 15 times higher resistance, depending on the type of chemical attack. Some specific chemicals that normally attack ordinary concrete cannot harm UHPC concrete at all. Due to its enormous density, the reinforcing steel is completely protected against corrosion.

Our UHPC concretes can be processed as mortar, grouted concrete and shotcrete.

Here's how we can describe UHPC concrete:

1. Strength: UHPC exhibits exceptionally high compressive strength, typically exceeding 150 MPa (22,000 psi), and high flexural strength, which makes it significantly stronger than conventional concrete mixes.

2. Density: UHPC has a very dense microstructure due to its low water-to-

cement ratio and the use of fine particles, fibers, and additives. This dense matrix contributes to its high strength and durability

.

3. Durability: UHPC is highly durable and resistant to various environmental factors

such as freeze-thaw cycles, chemical attack, abrasion, and corrosion. Its dense matrix and low permeability help prevent the ingress of water, chloride ions, and other harmful substances, thus enhancing its long-term performance.

4. Workability: Despite its high strength and density, UHPC can exhibit excellent workability and flowability, allowing it to be cast into intricate shapes and forms using conventional or specialized casting techniques.

5. Fiber Reinforcement: UHPC often incorporates carbon fibers, platic firbers, stainless steel fibers or other types of reinforcing fibers to further enhance its tensile strength, toughness, and ductility. These fibers help control cracking and improve the overall performance of the concrete under various loading conditions.

6. Mix Design: The mix design of UHPC involves precise proportions of cement, fine and coarse aggregates, water, and sometimes supplementary

cementitious materials (SCMs) or chemical admixtures. The proportions are carefully optimized to achieve the desired mechanical properties and durability characteristics.

7. Applications: Due to its exceptional properties, UHPC is commonly used in demanding structural applications where high strength, durability, and resistance to harsh environments are required. It is used in bridge construction, architectural facades, precast elements, marine structures, and other infrastructure projects where performance is critical.

In summary, Ultra-High Performance Concrete (UHPC) is characterized by its exceptional strength, density, durability, workability, fiber reinforcement, precise mix design, and wide range of applications in demanding structural, architectural and industrial projects.