Company profile

CelSian is employee owned. Our well trained, multi-disciplinary team is based in Eindhoven, The Netherlands and works worldwide on customer projects.


Our products and services aim to deliver value to the glass manufacturing chain in the areas of:

  • Furnace support
  • Process optimization
  • Knowledge transfer


We have worked on more than 30% of active furnaces worldwide. Implementations of our models have proven to optimize glass properties, deliver savings in energy and/or increasing furnace lifetime. More than 1500 participants have joined our well known Glass Course training in Eindhoven, UK or USA.


We also run GlassTrend, a platform for operating companies and institutions active in the field of glass and glass manufacturing. This consortium aims to continuously improve the competitive strength of the glass industry by organizing knowledge sharing, network events and also managing pre-competitive projects.

CelSian is led by Harmen Kielstra (general/commercial) and Johan van der Dennen (operations).

Harmen Kielstra


Johan van der Dennen