Modular Solvent Recovery and Purification System 2 km Underground

Ontario, CN
Koch Modular worked with a Canadian world-class science facility to complete one of its most interesting projects to date.

The client engaged Koch Modular for the manufacture of a modular system designed to purify linear alkylbenzene (LAB) and to be installed nearly 2 kilometers underground. This solvent would get used in a liquid scintillator in their experiment observing neutrinoless double beta decay.

The client trusted Koch Modular’s process design experience in solvent recovery and impurity removal, as well as overall expertise in detailed modular engineering and project management to provide this unconventional recovery and purification system.


The client’s research facility is located nearly 2 kilometers underground, making it the world’s deepest operational clean room facility. Although the depth and required cleanliness allows for the study of highly sensitive and weak physical processes and interactions, it simultaneously poses difficulties for the modular construction of a solvent purification system. Although the unit operations were standard, the module height restriction of 20-25 feet required Koch Modular engineers to create a system that would usually be much taller to fit within a constrained space. This also required the process to be limited to fewer steps to avoid enlarging the system.


Koch Modular designed for the purification of the LAB to be performed in three steps: distillation, liquid extraction, and nitrogen stripping. Distillation is used to extract high boiling components, and liquid extraction is used to remove metallic species, including potassium, rhadon, and thorium. Nitrogen stripping is then used to remove additional trace impurities. These operations produce an ultra-pure LAB solvent that is then reused for subsequent experiments.

Koch Modular provided the complete engineering for this modular system, and prepared piping isometric and electrical drawings for instrumentation.

One cargo elevator was used to get the equipment underground. Koch Modular did not complete final fabrication, though provided appropriate instructions for a private contractor to assemble the system.


Koch Modular’s modular solvent recovery and purification system allows for the LAB solvent to be reused in additional experiments, ultimately reducing waste generation, operations costs, and the risk for contamination of the clean room facility.

The system is still in use today and has been successfully running with no reported issues since startup.