Free to use Process Simulators

[ben]

Are there any free-to-use & dependable process simulators available?
Please share if any.

[tuan]

DWSIM, go for that. I believe would be the best available in this free-to-use category.

[jeem]

There is another non-commercial use application, COCO Simulator:
There are plug and play models available.
It includes TEA (thermo), COFE (flowsheeting), COUSCOUS (dynamic).
Recommended for teaching, and basic design work.
You will be having some startup effort on this but still very good.