ATHEX Tubes for Biotechnology

Tubes for Algae bioreactors

In recent years microalgae have been considered as a fast growing raw material for the production of biomass (biofuel) in many countries. In the meantime, however, it has become apparent that from microalgae more valuable high quality components can be extracted for applications in food supplements (Omega 3 etc.) and other pharmaceutical and medical fields. For these type of products uncontaminated and highly quality consistent raw materials are mandatory. Open pond or trench systems do not provide ideal conditions which is why microalgae are more and more grown in closed systems of aquacultures.


Photosynthesis is the growth engine of the microalgae. To permit sufficient light and guarantee a sustainable quality, photo-bioreactors have proved to offer the microalgae an ideal growth-intensive environment.



Since microalgae live in water, photo-bioreactors are water-retaining containers whose walls are transparent. In most cases this is achieved with the physically best-suited geometry of a tube.


ATHEX offers tubes (PMMA) for photo-bioreactors.

Our highly transparent tubes offer many advantages both technically and economically:

  • PMMA tubes can be produced in many diameters from Ø 50 mm up to Ø 450 mm and in lengths up to 10 m
  • The specific weight of PMMA is by factor 1.9 less than that of glass (a tube with a diameter of 300 mm and a thickness of 5 mm
    weighs 10.33 kg/m, but made from PMMA only 5,53 kg/m)
  • PMMA has a high light transmission of approx. 92%
  • PMMA is UV-resistant without additional coatings
  • PMMA is approved for contact with foodstuffs
  • PMMA is resistant to many chemical cleansers and salt water
  • Experience shows that the surface of PMMA is little prone to biofouling
  • Tubes made of PMMA are cost-effective 
  • Up to a height of 10 m no coupling pieces are necessary 
Acryl-Rohren for Bioreaktors

Vertically installed bioreactors have a much lower space requirement and can generate large quantities of algae biomass with the energetically advantageous “airlift” method.


However, the increasing pressure onto the tube's wall caused by the rising water column, must be taken into account. ATHEX has developed a patented technical process which allows to adapt the wall thickness within a tube to the static loads deriving from the internal pressure. The highest load is located at the bottom of the water column and decreases linearly upward. The ATHEX method allows to adapt the thickness of the tube to this deceasing compressive load. As a result up to 25% material can be saved without loosing the required static integrity. In addition to a much better environmental balance this results in clear cost advantages due to reduced material input. Due to the tube's reduced weight, assembly is easier as well !


In recent years ATHEX has acquired extensive manufacturing know-how through the supply of acrylic tubes for bioreactors and has appropriate extrusion lines at its disposal to manufacture bioreactor tubes of a wide range of sizes.