• About SEPAREL


  • SEPAREL modules can degasify water at any ppb level.
  • SEPAREL modules support inline degasification and aeration.
  • DIC’s proprietary internal structure allows for compact membrane modules that exhibit low pressure loss.

DIC'S Proprietary Hollow Fiber Membrane

Types of Hollow Fiber Membranes for Degasification

Hollow fiber membranes are classified as either porous or non-porous. DIC has developed a proprietary non-porous membrane which utilizes a Surface Skin membrane (SS membrane) for enhanced degasification.

SS Membrane : Surface Skin Membrane


DIC’s Proprietary Hollow Fiber Membrane and Surface Skin Layer

【Applicable for Highly Permeable Liquid】
DIC’s hollow fiber SS membrane consists of an inner porous layer and an outer non-porous layer called “skin layers.” This non-porous skin layer is also applicable with highly permeable liquid.

【High Gas Permeability】
The raw material of the hollow fiber, Poly(4-methyl-1-pentene) (PMP)”, possesses a very high permeability rate due to its molecular structure. Furthermore, as the SS layer is very thin (about 1 μm), SEPAREL features excellent degassing performance.

【Ultra-Fine Hollow Fiber Membrane】
The smallest outer diameter of DIC hollow fiber SS membranes is about 180 μm—the smallest possible diameter for degasification membranes. This structure enables the largest possible membrane surface area within a small space.


Two module structures of SEPAREL

Internal Perfusion (PF Series)

【Internal Structure】

  • Liquid flows inside the hollow fiber
  • Gas moves out of the hollow fiber

In case the hollow fibers get clogged with particles, they can be removed via liquid backflushing.


Movie of Internal Perfusion

External Perfusion (EF Series)

【Internal Structure】

  • Liquid flows over the hollow fibers
  • Gas flows into the hollow fibers

Because liquid randomly flows over the hollow fibers during external perfusion, dissolved gasses touch the membrane more frequently. Therefore, degasification performance is higher than in the Internal Perfusion Series (PF Series). Also, a lower pressure drop means that larger modules can be used.


Movie of External perfusion

Products lineup

Series Perfusion Type Materials Liquid Type
PF Series Internal Perfusion Poly
(4-methyl-1-pentene) (PMP)
PF-F Series PTFE
EF Series External Perfusion Poly
(4-methyl-1-pentene) (PMP)

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