Corrosion Resistant FRP in Sulphuric Acid Processing Plants

Recently, Ashland Performance Materials put out an interesting white paper about the use of FRP in Sulphuric Acid (H2SO4) processing plants. G. Bruce Garret, John Recar, and Don Kelley’s “Fiberglass Reinforced Plastics Applications in Gas Cleaning Systems of Sulfuric Acid Plants” looks at the benefits of using FRP in sulphuric acid processing plants, rather than other materials like lead-lined steel or brick.

‘The development and application of fiberglass reinforced plastics construction over the last 20 years have made lead and brick-lined equipment a thing of the past for sulphuric acid plant gas cleaning systems.” The low cost of FRP, when compared with other traditional materials, also makes FRP an attractive and cost effective solution.

The two most common types of H2SO4 processing plants are sulfur burning (hot gas design) and metallurgical/spent acid regeneration (cold gas design). In the second type of plant, metallurgical/spent acid regeneration, “by-product SO2 gas from smelter processing sulfides of iron, copper, zinc, lead, nickel, molybdenum, or other metal is used.” This gas contains a number of contaminates and, “If not removed, the contaminants will reduce product acid quality, foul the mist eliminators and catalyst beds, and accelerate corrosion of equipment in the acid plant.” This is where FRP comes in.

Purifying the gas from these plants is a corrosive job and, in the past, the equipment designed to handle these jobs was created from “lead-lined steel with acid-proof or carbon brick added for protection.” However, this material solution left a lot to be desired. In addition to be requiring long construction times, plant down time, and intensive on-going maintenance this solution also posed health hazards.

The introduction and continuing improvements to FRP technology over the last 20 years has made FRP the preferred material solution for gas purifying equipment in H2SO4 processing plants. In addition to natural corrosion resistance, FRP allows for easier maintenance, repairs, and is a lower cost material solution.

The clear advantages of FRP have made FRP the standard material solution for all types of storage and handling equipment in the H2SO4 processing industry.

Reducing Material Costs with Corrosion Resistant FRP Solutions

reducing material costs with frpAcross a wide range of industries, material and metal costs are rising. Added to the increase in materials cost is the cost of damage caused by corrosion. A recent Owens Corning whitepaper, “How to Use FRP Material to Lower Corrosion Costs” by Mathew Lieser, discusses the application of fiberglass reinforced polymer (FRP) across industries to help curtail these rising costs.


What is corrosion? “During the process of corrosion, an engineered material actually disintegrates into its constituent atoms as a result of chemical reactions with its surrounding environment. Corrosion can be concentrated locally to form a pit or crack or it can extend across a wide area, almost uniformly corroding the surface.”

The damage caused by corrosion adds up to billions of dollars in repair costs worldwide. Since the installation of most of these corroding materials, FRP materials have been designed that have the ability to withstand corrosion. While there are other options for fighting corrosion, like surface treatments or coatings, FRP offers by far the most economical corrosion resistant solution. FRP solutions have also had over 50 years of tested service experience, “FRP is now a proven material technology.”

The 5 Steps

Although FRP material solutions used to have a higher upfront cost than other materials, like steel, the recent rise in metal costs have made even upfront FRP material costs less. The long service life and lower maintenance costs of FRP, coupled with lower upfront costs, make FRP ideal for lowering overall building costs.  To fully utilize the corrosion and money saving properties of FRP Lieser offers up a five step system.

  1. Identify suitable applications for FRP material
  2. Implement company FRP material standards
  3. Use existing governing standards to have FRP equipment made for use in corrosive environments (ASME, ISO, ASTM, etc)
  4. Specify proper materials (glass fiber, resin, corrosion barrier) to construct the FRP application
  5. Implement proper inspection protocols

To learn more about the five step and download the full Owens Corning whitepaper, click here.

Chemical Handling: Corrosion Resistant Tanks and Vessels

corrosion resistant tanksFRP are utilized worldwide for applications in chlorine, sulphuric acid, hydrochloric acid, biological transformation, fertilizer, petrochemical, and mining and mineral plants. In general terms they have been employed successfully in many chemical processes such as separation, filtration, settling (sedimentation), extraction or leaching, distillation, recrystallization or precipitation, drying, and adsorption.

In the Chemical Processing Industry (CPI) FRP are utilized to fabricate a full spectrum of products including pipes, ductwork, chemical storage tanks, absorption towers, drying towers, solvent extraction vessels, gas scrubbers, packed reaction columns, pressure vessels, process reaction vessels, stacks, process containment equipment, packing support systems, packed bed distributors, bed limiters, and distributor feed headers- to list some examples.

Each service environment is unique and requires special attention to engineering considerations. Special considerations such as concentration, temperature, pressure, vacuum will need to be addressed to ensure that the product being fabricated is optimized to enhance its performance and meet your specifications. To a large degree your service environment and specifications will influence many important design elements such as resin selection, laminate schedule and corrosion barrier.

A Short List of Some FRP Chemical Applications:

  • Diammonium Phosphates
  • Ammonia
  • Potassium Hydroxide
  • Phosphoric Acid
  • Hydrochloric Acid
  • Chlorine
  • Sodium Hypochlorite

The corrosion barrier is typically fabricated with a resin-rich liner or corrosion barrier, followed by a glass-rich structural wall. The corrosion barrier is one component of the entire laminates schedule; it is a critical layer that must be designed properly in order to ensure effectiveness, safety and performance of your FRP product. You should always discuss resin selection with a resin manufacturer or your engineering team.

Although the corrosion liner does not provide much in terms of mechanical properties it’s extremely important to the overall design of your composite product.

Among the many products that can be fabricated from FRP are corrosion resistant tanks and vessels.  Corrosion resistant FRP tanks and vessels are well known for their cost-effectiveness, long-life cycles, electrical insulation properties, high strength-to-weight ratio, dimensional stability, and their design flexibility. Furthermore, the corrosion resistance performance of FRP is exceptional when compared with traditional or common metal alloys such as stainless steel 2205 and alloy C-2706. This holds true in common chemical processing service environments—FRP performs well in hydrochloric acid and sulfuric acids—among many others.

FRP Corrosion Resistant Tank and Vessels Chemical Processing Applications


  • Batching
  • Electrowinning
  • Fuel
  • Plating
  • Pickling
  • Processing
  • Recovery
  • Remediation
  • Storage
  • Transfer
  • Waste
  • Effluent


  • Solvent Extraction Vessels
  • Process Reaction Vessels
  • Pressure Vessels

When designed properly FRP can provide excellent high-temperature capabilities and solvent resistance.  Depending on resin selection and other design factors unique characteristics may be enhanced.  In general, FRP withstand many acids, alkalis and oxidizing chemicals.

The constructability and design flexibility make FRP ideal for a multitude of CPI opportunities such as plant construction, process expansions, unit and equipment additions, upgrades, conversions, modernizations, rebuilds, renovations, retrofits, debottlenecks, and major maintenance turnarounds.

Lime Slurry Piping Reduces Westar Plant Downtime

limestone slurry pipingOne of the many advantages of working with fiberglass is its versatility. Fiberglass can be used in abrasive and corrosive applications, but it can also be used to create custom parts to fit almost any need. Which is why we were so excited to help Westar Energy, the largest electrical power producer in Kansas, develop a fiberglass pipe solution in one of their coal-fired centers.

Three years ago Westar Energy refurbished a Flue Gas Desulfurization (FGD) system. Designed to remove sulfur dioxide, the system makes use of an abrasive limestone slurry. The limestone slurry caused areas of the system to experience high wear. When high wear areas needed to be replaced the system had to be shut down, resulting in costly downtime. We worked with Westar Energy to identify problem areas throughout the system and made design changes the reduced downtime and repair costs.

To find out how we helped the largest electrical power producer in Kansas design an abrasive resistant solution that helped reduce plant downtime, read the Westar FRP case study here.

FRP Applications for Common Fracking Chemicals

Within the Fracking Industry there are many opportunities for FRP applications.  For example, chemical storage, containment, handling, transport, and batching—to name a few.  Whether you are working with breakers, clay stabilizers, acids, corrosion inhibitors, acids, biocides, crosslinkers, friction reducers, scale inhibitors, pH adjusting agents or gelling agents—chances are FRP products (i.e. tanks, vessels, pipe etc.) can be designed to meet your service requirements and job specifications. 

Here is a short list of common fracking chemicals, all of which FRP can be employed.

FRP Applications for Common Fracking Chemicals

Chemical Name CAS Chemical Purpose Product Function
Hydrochloric Acid 007647-01-0 Helps dissolve minerals and initiate cracks in the rock Acid
Calcium Chloride 010043-52-4 Product Stabilizer Breaker
Ammonium Persulfate 007727-54-0 Allows a delayed break down of the gel Breaker
Sodium Chloride 007647-14-5 Prevents clays from swelling or shifting Clay Stabilizer
Isopropyl Alcohol 000067-63-0 Product stabilizer and / or winterizing agent Surfactant
Formic Acid 000064-18-6 Prevents the corrosion of the pipe Corrosion Inhibitor
Boric Acid 001333-73-9 Maintains fluid viscosity as temperature increases Crosslinker
Ethylene Glycol 000107-21-1 Product stabilizer and / or winterizing agent Gelling Agent
Acetic Acid 000064-19-7 Prevents precipitation of metal oxides Iron Control
Potassium Hydroxide 001310-58-3 Adjusts the pH of fluid to maintains the
effectiveness of other components, such as crosslinkers
pH Adjusting Agent
Potassium Carbonate 000584-08-7 Adjusts the pH of fluid to maintains the effectiveness of other components, such as crosslinkers pH Adjusting Agent
Naphthalene 000091-20-3 Carrier fluid for the active surfactant ingredients Surfactant

Of course the type of resin you choose as well as other design considerations such as operating temperature, pressure, vacuum, concentration of chemicals will need to be considered before engineering your product. 

In general, isophthalic and vinyl ester resins are suitable for a wide range of conventional and custom FRP applications.  Their ability to withstand a multitude of chemical applications and their unique properties are directly related to their chemistry.

Isophthalic resins have a high- molecular weight, thermosetting resins offer superior physical and corrosion resistance properties in stringent harsh environments.  Similarly, vinyl ester resins are versatile and are able to retain many of the qualities epoxies typically posses, such as tensile strength, elongation, fatigue resistance, and good alkali and oxidizing chemical resistance.

Beyond the twelve chemical applications listed above there are more—literally thousands more.  There are opportunities everywhere and FRP offers many benefits including cost-effectiveness and corrosion/abrasion resistance.  Additional chemical applications can be found in many resin manufacturer guides.

Because each job has unique requirements please contact Beetle Plastics or a resin manufacturer regarding specific design specifications. We will work with you to ensure that our products meet your expectations in terms of both quality and service. Our custom FRP products are high quality, easy to install and have long life cycles.