The 3 Types of Chlorine Dioxide Generators

Chlorine dioxide is an effective and efficient biocide for water treatment, biofilm, and bacteria control and elimination for hospitals, pulp & paper settings, cooling towers, and other large industrial facilities. In order to produce and treat large scale water systems, a facility needs to host and maintain a chlorine dioxide generator that feeds into the water system. Economically, it doesn’t make sense for the facility to haul in tanker-loads of chlorine dioxide aqueous liquid. This is primarily due to chlorine dioxide existing as a gas-infused liquid and can be prone to ‘gas off’, losing concentration and effectiveness.

Chlorine dioxide generators (equipment that generates chlorine dioxide) must be placed on-site to efficiently produce the biocide for treating water. But how does a business or facility manager know what type of chlorine dioxide generator is best for their water system? There are many different models available on the market, with different niches or focuses for each model, and different precursor chemicals that the generator uses to create chlorine dioxide on-site. We discuss the three most common types of chlorine dioxide generators, their commonalities, and main differences between them.


The Three-Chemical Chlorine Dioxide Generator

A three chemical chlorine dioxide generator utilizes Sodium Chlorite, an acid (such as Hydrochloric Acid), and Sodium Hypochlorite to produce chlorine dioxide at over 95% efficiency. Chlorite converts to chlorine dioxide in the final product for the generator. Below is the chemical reaction creating Chlorine Dioxide for a typical three-chem system:

NaClO2 + 2HCl + 2NaOCl –> H2O + 3NaCl + 2ClO2

Sodium Chlorite is typically used by smaller-scale generators as a precursor chemical due to an economic breakpoint. The economics point to a tons/day breakpoint of chlorine dioxide generated which would determine whether Sodium Chlorite OR Sodium Chlorate is used as a precursor. Given lower-to medium quantities of chlorine dioxide for the business or facility, Sodium Chlorite is typically used.

Three-chemical systems are typically used by small-to-medium sized industrial facilities and food processors for treating water systems. PureLine’s Pure 3 Series and DC3 Series Generators are options within


The Two-Chemical Chlorine Dioxide Generator

A two chemical chlorine dioxide generator utilizes Sodium Chlorate and a high strength sulfuric acid to create chlorine dioxide at over 95% efficiency. Chlorate converts to chlorine dioxide in the final product for the generator. The reaction chemistry utilizing Sodium Chlorate is as follows:

NaClO3 + ½ H2 SO4 + ½ H2O2 –> ClO2 + ½ Na2 SO4 + H2 0 + ½ O2

With larger chlorine dioxide needs, Sodium Chlorate is economically optimal when compared to sodium chlorite. While the reaction chemistry seen above looks to have three chemicals in the initial reaction, the sodium chlorate is often blended with reducing agents to be one aqueous liquid. So when utilized in a generator, only two chemical feeds are necessary to create this reaction for chlorine dioxide!

Two-chemical systems are typically used by medium-to-large sized industrial facilities treating cooling towers, the oilfield, commercial marine applications, and within municipal water systems.

PureLine offers a sodium chlorate blend, PureMax, which is utilized in typical two-chemical generator systems. While PureMax can be utilized as the sodium chlorate blend in non-PureLine generators, our CG series is designed as a 2-chemical system to create chlorine dioxide with PureMax precursor.


The Single-Chemical Chlorine Dioxide Generator

A single-liquid chlorine dioxide generator utilizes a highly concentrated precursor along with electricity to create a highly efficient, pH neutral chlorine dioxide solution. The chemistry is as follows, with electricity as an added variable within the reaction:

2NaClO2 + 2H2 O —> 2CIO2 + 2NaOH + H2

What is particularly great about the single-liquid precursor is that pure ClO2 is delivered on demand, safely, and efficiently without the need for an external storage tank. Single-chemical generators can come in different sizes, scaling from low to high daily chlorine dioxide needs.

Single-chemical systems are typically used by hospitals and even food & beverage companies that utilize chlorine dioxide as a large-scale fruit and vegetable wash.

PureLine’s HP Series utilizes a single-liquid precursor of PureCideE and our patented electrochemical cells to efficiently produce 99.5% pure, chlorine-free, Cl02. The system is capable of feeding multiple dosage points simultaneously, allowing several applications from a single generator. With multiple safety interlocks, available reporting and remote monitoring, the HP series is truly the benchmark in safe and reliable ClO2 generation.


What Type of Chlorine Dioxide Generator is Right For Your Business?

Different types of chlorine dioxide generators can feel complicated at first. But a conversation with a reputable vendor can easily turn complexity into simplicity. How much water does your business use on a given day? Do you need to treat your water for a hospital or food production, or is this for industrial water? The answer to these questions can lead you to a three-chemical, two-chemical, or single-chemical chlorine dioxide generator.

If you would like to learn what type of chlorine dioxide generator is right for your business, fill out the contact form below and a PureLine representative would be glad to talk through costs and which machine is the right fit for your business.