How Much Should a Boiler Feed Water Treatment System for a Thermal Power Plant Cost?

Home 9 Boiler Feedwater Treatment 9 How Much Should a Boiler Feed Water Treatment System for a Thermal Power Plant Cost?

When thermal power plants ask us “How Much Should a Boiler Feed Water Treatment System for a Thermal Power Plant Cost?” it’s often challenging—but not impossible—to estimate.

Since the process of maximizing water treatment options and generating an efficient system design is complex and based on several factors (the water treatment systems are integrated, multifaceted solutions that depend upon a thermal power plant’s available water source, process requirements, and effluent regulations), careful consideration goes into designing the best possible water treatment options at each phase.

In order to narrow down what you might be spending on a boiler feed water treatment system for your thermal power plant, here is what you should keep in mind:

The main factors that will determine the cost of a thermal power plant’s boiler feed water system

When it comes to treating a thermal power plant’s boiler feed water, it’s important to know the boiler feed water quality and makeup quantity needed so the proper treatment options can be used to avoid costly scaling, corrosion, and fouling of the boiler and downstream equipment. When these things occur, cost can significantly increase with frequent equipment repairs, energy loss, and an increased risk of plant downtime, so it’s critical to address these issue up front.

There are usually three steps to treat water for a thermal power plant’s boiler:

Raw water treatment
Primary demineralization
Polishing (depending upon the pressures in the boilers and the boiler manufacturer’s requirements)

Another stream that might require treatment is the condensate return. Once the steam is used for the turbines in many systems (such as combined cycle systems), the condensate that comes back from the various process requires polishing so it can be reused for the boilers.

Assuming the process is beginning with properly pretreated water (if you require more information about raw water treatment systems, see our article about how much a raw water treatment system costs here), these are the main factors that will determine the technologies you might need for your system, and therefore the cost:

Quality and quantity of water needed for your boiler

The quality of feed water needed for your individual boiler depends on many factors, but the primary element to consider is the pressure at which you need to run your boiler (which suggests the feed water quality needed) in relation to the amount of water you need to process per day and how fast (this is your required peak gallons per minute, or GPM).

What is the source of the raw water to your plant? Careful considerations should be made when selecting the source of your feed water. Are you sourcing your water from a publicly owned treatment works (POTWs)? Are you pumping from a well or surface water?

Each source has its advantages and disadvantages, but all in all, certain pressures limit the maximum level of contaminants you can feed into the boiler. As you increase the pressure in your boiler, it becomes more critical for thorough water treatment that yields higher quality water.

Also note that boiler/turbine manufacturers each have their own requirements for water quality, so be sure to check with your manufacturer what their recommendations are.

Boiler makeup and chemistry

Your boiler makeup/chemistry is a complex calculation, but knowing your internal boiler chemistry treatment program and the characterization of your feed water will help dictate the technology you need to treat it.

SAMCO has years of experience helping our customer’s understand this complex chemistry. If you have questions about how your boiler’s specific makeup might affect your treatment system, feel free to contact us and set up a call with one of our engineers.

What goes into a typical thermal power plant boiler feed water treatment system?

Thermal plant boiler feed water treatment and filtration

Assuming that the turbine pressure is fairly high and the requirements for treatment is demineralization (typically for power plants there is no need for softening, only demineralization), the primary treatment for surface water will use a two-step process of ultrafiltration (UF) followed by reverse osmosis (RO). In some cases, based on the raw water chemistry, ion exchange may be a better technology choice.

Thermal plant boiler feed water treatment and GPM

For surface waters, with colloidal silica, decayed vegetation, and other suspended material, typically UF is used ahead of RO to protect the RO unit. Raw water UF may not be needed if suspended and colloidal material is low enough. It’s critical to test for this with an SDI test kit to be sure about whether or not your plant requires the UF (it might not), but in general, the typical design would be a UF followed by single- or double-pass RO (one RO feeding a second RO) to lower the level of TDS enough to feed a polishing device (such as electrodeionization, or EDI).

Thermal plant boiler feed water treatment and polishing

The water coming out of an RO system is typically not high enough in terms of sodium and silica removal to feed the boilers, so polishing systems are often used.

Polishing systems can consist of a sandwich configuration (such as pack DOW UPCORE™ and AMBERPACK™) or a mixed bed system. With both of these systems, sodium and silica can be remove to low levels (to under 10 PPB levels). A technology commonly used is EDI. Typically it is used as a polisher to double-pass RO.

Other important factors to consider when pricing a boiler feed water treatment system

Feed water sourcing. Choosing your feed water source is a critical parameter to minimizing your capex and opex costs. While city water sources might reduce your system cost overall, keep in mind that the charge for incoming water can be high. SAMCO can help you evaluate the various sources available to your site and recommend the best options for your plant. These sources might include city water, city treated effluent, in-plant wastewater recycle (cooling tower blowdown recycle), well water, or any other surface water source.
Up-front planning. There are costs associated with developing the concepts, designs, and regulatory requirements for boiler feed system projects. Typically, the cost of engineering for a project like this will be about 10–15% of the entire project cost. This cost is usually phased in over the course of the project.
Installation rates. Installation rates for a boiler feed water treatment system will usually run you 15–25% of the project. In general they have a smaller footprint and don’t require as much civil work. Another thing to keep in mind is the installation rates in your area, which may fluctuate by location. Since the boiler feed water treatment systems are usually prepackaged, their footprint is typically smaller (about 100 x 100 feet is the average size). SAMCO specializes in these types of turnkey, prepackaged systems, and for more information about what we offer, you can visit our website here.
Shipping the system to your plant. When you are coordinating the shipping details of your system, you usually want to factor in about 5–10% of the cost of the equipment for freight. This can vary widely depending upon the time of year you are purchasing your system in addition to where your plant is located in relation to the manufacturing facility.

Off-site regeneration services. Many companies that need a polishing component in their boiler feed water treatment system outsource resin regeneration. This minimizes the amount of labor required and keeps your capital cost down. It also eliminates the need for you to keep certain chemicals on hand, such as acid and caustic, and therefore you won’t have to worry about discharge regulations. SAMCO is experienced in this type of resin regeneration, so if this is a service you might need, feel free to reach out to us for more information or visit our off-site regeneration page on our website here.

Other possible costs and fees. When purchasing a boiler feed water treatment system, you might also want to keep in mind what other hidden costs and fees might be. For example: Will there be any taxes on the system or additional purchasing fees? What are your possible utility costs to the installation area? Will there be any environmental regulatory fees and/or permits? Any ongoing analytical compliance testing you need to pay for? Also consider that there will be costs to treating the secondary waste produced by the system. With stringent environmental regulations, especially with the new Environmental Protection Agency effluent limitation guidelines, you will need to either treat the waste for discharge or solidify and transport to third party disposal firm. You can learn more about SAMCO’s wastewater treatment systems on our website here.

The bottom line

A typical system at a 100 GPM flow with an UF/double-pass RO primary system can run about $750,000 to $1.2 million depending upon the materials of construction, the layout and design, and conditions of the feed water. If a thermal power plant requires a polishing unit, this can add $250,000 to $1 million.

Although figuring out what your boiler feed water treatment system needs might be can seem complex, SAMCO has over 40 years’ experience custom-designing and manufacturing these types of systems, so please feel free to reach out to us with your questions. For more pricing information or to get in touch, contact us here to set up a consultation with an engineer or request a quote. We can walk you through the steps for developing the proper solution and realistic cost for your boiler feed water treatment system needs.

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