If you’re exploring options for industrial demineralization, you might be asking “How much does a water demineralization system cost for your plant?”
The following article offers a simple explanation of what’s included in an average demineralization system, what those systems typically cost, and the factors that drive these costs up and down, focusing on ion exchange in particular.
What’s included in a basic water demineralization system?
Demineralization is a type of water purification referring to the removal of dissolved solids from feed water, process, and waste streams. Demineralization systems can refer to any treatment process or technology that removes minerals from these streams. Typically done with ion exchange (IX) or reverse osmosis (RO), depending on the facility’s needs, demineralization can provide near-total removal of ionic mineral contaminants.
When discussing demineralization by ion exchange, there are a wide variety of technologies that exchange one ion for another and use a variety of regeneration chemicals to achieve a required level of purity. When figuring out what will go into a facility’s system, it’s important to also consider what ancillary equipment will be needed to support the ion exchange system. The footprint of ion exchange is relatively small compared to other treatment technologies, but many systems will require additional feed pumps and tanks.
IX demineralization utilizes both cation and anion exchange resins, sometimes even in the same column or bed. Following demineralization, the treated water will be of a high level of purity comparable to distilled water, but typically at a much lower cost.
Determining which technologies should make up the system will be affected by several factors:
Preceding ion exchange, when used on raw feed or waste water, there is usually some type of pretreatment required, such as microfiltration or conventional clarification; what that pretreatment is will depend on the contaminants in the facility’s water source. Pretreatment needs to be considered carefully because, in some cases, it can add about 30% to 50% to the total job cost and double or triple the size of the footprint (especially if the project site requires clarification). Also keep in mind that sludge from the pretreatment system may need to be treated with filter presses, which, if needed, will need to be incorporated in the system plan.
Chemicals and resins
If chemicals are needed, a chemical handling system to store the chemicals and feed them to the ion exchange system is typically required. For a robust industrial chemical handling system with storage tanks, metering pumps, and forwarding pumps, cost can be around $100,000 to $500,000 or more, depending on the size.
When using ion exchange as a polishing technology, a facility can opt for offsite regenerable ion exchange. This is a service provided by an outside contractor, and typically, depending on flow rates and how often you change out the resin, they can add cost anywhere from $30 to $100 per cubic foot for offsite services. These resin services are usually reserved for polishing applications because if the resin is changed frequently, the cost for the offsite regeneration can be more than installing a polishing technology to regenerate onsite. Also keep in mind a typical rule of thumb is that resins will need to be replaced every three to five years.
On the posttreatment end, the water coming out of the ion exchange system will usually go directly to process or to a big holding tank (as required for refineries and big power plants, who typically store one to two days’ worth of water to avoid downtime), so the cost of that tank and any associated pumps will need to be factored in. This is often determined by the facility’s discharge agreements, such as the local maximum and average monthly discharge limits to the environment or POTW.
The main factors of demineralization system system cost
All in all, there are four main factors that drive fluctuation in the cost of an ion exchange demineralization system:
- What are the system’s flow-rate requirementsgoing to be, or what amount of water do you need to process per day and how fast?
- What is the quality of the watercoming into the facility and what level of contamination?
- What is the required ion (and general) chemistryof the stream after it’s treated for use?
- What construction materialsare required?
If you can answer these questions, it will help you narrow down what your needs might be and provide a better sense of the budget you might be looking at.
In general, if your plant runs consistently at a lower flow rate, you’re usually looking at a lower capital cost for your ion exchange demineralization system. If your plant generally runs a greater flow in a shorter amount of time, your capital cost is usually higher for equipment.
Flow rates are always factored into the system cost, so be sure you measure this as efficiently as possible prior to requesting a quote in order to get an accurate cost estimate for your system.
How many solids need to be removed
The number of dissolved solids the facility needs to take out per gallon of water (usually measured in parts per million) is an important factor that goes into planning an ion exchange system, because the higher the amount of contamination, the bigger the ion exchange vessels have to be to handle them.
Water and ion chemistry
Along with the volume of ions that need to be removed, it’s important to know the chemistry of the ions:
- What ions are there and in what ratios?
- How many suspended solids and total dissolved solids (TDS) are there?
- What is the makeup of that TDS?
- How much hardness, chloride, sodium, silica?
- What are the other ions in the water?
This will affect the type of equipment you have and how many vessels and what is in those vessels in terms of resin. For example, ion exchange is sometimes used to separate valuable minerals, such as gold, silver, uranium, etc., and how the resins are charged will affect how efficient they will be in removing these minerals.
Some facilities will do just fine using PVC pipe and FRP tanks for lower flows with very simple controls. Others, such as those processing thousands of gallons a minute, will require and stainless-steel construction and design. Prices for these materials range from inexpensive plastics to high-end rubber-lined or stainless-steel vessels and/or piping.
Other important factors to consider when pricing an ion exchange demineralization system
- Up-front planning. Developing the concepts, designs, and regulatory requirements for your project is the first step to planning your ion exchange demineralization system. The cost of engineering for this type of project can typically run 10–15% of the cost of the entire project and is usually phased in over the course of the project, with most of your investment being allocated to the facility’s general arrangement, mechanical, electrical, and civil design.
- Space requirements. When planning for an ion exchange demineralization system, the size of your system will affect your cost, and the footprint is usually reasonable depending on what other ancillary equipment needs to be included, so keep in mind that sometimes your plant location can affect the cost of your system. For example, if your plant is located in a place that is very expensive when it comes to space, you might want to aim for a smaller footprint, if possible.
- Installation rates. Another thing to keep in mind is the installation rates in your area. These sometimes also fluctuate by location, so be sure you’re aware of the cost to install the system and factor this into your budget. In areas where installation costs are high you may want to consider prepackaged modules versus build-in-place facilities.
- Level of system automation needed. When it comes to the level of automation you need for your ion exchange demineralization system, there are two options. The first is a higher level of automation where you won’t need an operator present for much of the time. With type of automation, you can eliminate much of the human error associated with running the plant, and although this option is costlier up front (an initial investment in more sophisticated PLC controls and instrumentation), the ongoing labor costs are less. The second option is a lower level of automation with less capital cost, but with added labor, this can end up costing you more in the long run. When deciding whether or not to invest in more costly controls, you need to consider what works for your company and staffing availabilities.
- Turnkey and prepackaged systems. If you are able to order your ion exchange demineralization system prepackaged, this will typically save you about two – three months in construction time at about the same cost or less. A benefit to having your system prepackaged is that the production facilities and fabrication shops that assemble your system are, more often than not, highly knowledgeable about the type of system they are manufacturing. This results in a quick and efficient fabrication versus build-in-place facilities. Sometimes when you hire a field crew, there is a bit of a learning curve that can add extra time and/or cost to a project. SAMCO specializes in these types of turnkey, prepackaged systems, and for more information about what we offer, you can visit our website here. Installation costs will vary, but typically range between 15–40% of the project cost, depending on the specifics of prepackaging and amount of site civil work needed.
- Shipping the system to your plant. When having your ion exchange demineralization system shipped to the plant, 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.
- Operation costs. For operational cost when it comes to ion exchange, the big cost can mostly be found in the chemicals used and the power to run the system, so careful consideration has to be done to ensure you calculate what the operational cost and chemical consumption will be. Part of that is the waste coming out of the ion exchange has to be neutralized because it’s high pH and lower pH…you have to neutralize that for discharge. It may have to go to a chemical waste treatment facility either on site or just plain neutralization discharged to a POTW sewer for treatment by someone else. This needs to be carefully considered…what the costs are and what that post treatment technology is going to be. Also keep in mind that particular technology packages cost a certain amount to purchase up-front, but you need to also factor in system operating costs over time. For decisions like these, you need to weigh the pros and cons of initial versus long-term cost investment in addition to what works for your company and staff. You will likely want to look into having someone develop an operating cost analysis so your company can plan ahead for the operating cost over your ion exchange plant’s life cycle. This might help you consider whether or not you want to spend more on your system initially or over time.
- Other possible costs and fees. When purchasing an ion exchange system for demineralization, 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?
It is important to understand and look into any extra costs or hidden fees you might incur. For example, does your area have connection fees for discharging treated ion exchange? For more information about the possible connection fees in your area, check with local regulators. Many times, the fee is based on the volume of water your plant requires and varies based on whether you are discharging to the local municipal facility or into the environment. Regulations are typically stringent and are becoming more so every day. There is also consistent monitoring over time required. You will need to acquire some sort of permit to discharge and you’re your plant approved before releasing any waste, and failing to comply to your local restrictions can result in heavy fines so it’s worth making sure you’re on top of the current requirements in your area.
Also consider that there will be costs to treating the secondary waste produced by the system. With stringent environmental regulations, you will need to either treat the waste for hauling away or solidify with a filter press/evaporator and transport to third party disposal firm. You can learn more about SAMCO’s ion exchange systems on our website here.
Also, be sure to ask your system manufacturer about options that might be cheaper to install. They might be able to shed some light on the more installation-friendly systems with suggestions on how to keep your costs to a minimum.
The bottom line
Since ion exchange can be very complex, as can be the cost, let’s take a very simple system to start: a 20 gallon per minute system with two vessels (cation/anion), all FRP and PVC piping, using eductors instead of chemical feed pumps, with a simple control panel and minimal instruments might run $50,000 to $100,000. For the same system in rubber-lined steel vessels with stainless-steel piping, high-end valves, a PLC control panel with instrumentation, and chemical feed pumps, the project might be $200,000 to $400,000.
If you need higher quality water, you might be adding on a polishing mixed bed and that might add another $100,000 to the higher end system.
For larger systems at about 2,000 gallons per minute using a proprietary packed bed technology, such as DOW’s ADVANCED AMBERPACK™ or UPCORE™ Ion Exchange technology with two trains and a polisher to get low silica and low sodium, it would be a counter-current design with a sandwich pack polisher to get to less than 5 ppb silica and sodium might be $5 million to $10 million. A system like this would be for big petrochemical plant, refinery, or power plant where high-quality water well over 1 megaohm and sodium and silica down to 5 to 10 ppb range would be required.
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 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 demineralization/ion exchange system needs.