Modular Dioxane Stripping System

Decatur, AL

A subsidiary of one of the world's leading producers in the intermediate petrochemicals industry (“the client”) came to Koch Modular for a complete modular 1,4-dioxane (“dioxane”) stripping system.

To provide some background, dioxane is classified by the EPA as a likely carcinogen, and can be released into the environment from industrial facilities where it is used. Dioxane does not readily biodegrade and can leach into the groundwater, ultimately contaminating drinking water supplies.

Motivated by health and environmental safety concerns, the client wanted to separate dioxane from the wastewater stream of a PET manufacturing facility and reduce the dioxane content below 1 ppm.


The goal was to reduce the dioxane content in wastewater from a PET manufacturing facility to below 1 ppm. As informed by the client, the low pressure process steam used in their process is corrosive due to the presence of organic carboxyl end groups. As a result, the materials of the contact equipment and pipes were carefully chosen. Additional challenges included the need to match the process module to the client’s existing stair tower, as well as the module’s large size and heavy weight.


These types of projects are typical for Koch Modular engineers. In fact, much of the process design was based on a project previously completed with the client’s sister company. The client’s existing stair tower was integrated into the design of the module. Due to weights, a hydraulic lift was used to get the heavy process module on the trailer for shipping.


Koch Modular provided a 82’ module stripper system designed to remove dioxane from waste water stream. The system was designed to utilize either live steam or process waste steam, and for organics to be vented to the client’s existing thermal oxidizer system.

Koch Modular also included the development programming for all control loops, discrete motor/valve control, alarms, interlock function and general operator interfaces (system overview, setpoint changes, tuning, alarms and histories).

Overall, the system reduces the dioxane content in the waste stream to below 1 ppm, which is sent off to POTW plants. The dioxane-rich stream is then fed to an off gas pipe going to burners for incineration.

The module process start-up proceeded successfully and the system has been running ever since with no issues.