Are there any open-source software for making a process flow diagram?

I am trying to design the process flow of a waste-to-energy conversion plant, like the one below:

A sample diagram taken from internet

I know about Aspen Plus, but problem is it is not open-source and is not available in our University lab.

  • You want a program that does the mass balance calculation for you, with the drawing software coupled into it?
    – mart
    Feb 1, 2017 at 7:55
  • Yes, that is the requirement. Since I am a Mechanical Engineering student, aspects other than mass balance is not much importance. @mart
    – Rahul Ramesh
    Feb 1, 2017 at 8:14
  • I don't know enough about this to post an answer. But, perhaps alternativeto.net/software/aspen-plus might be of help?
    – Mawg
    Sep 25, 2023 at 20:25

1 Answer 1


At a previous job, I did a lot of PFDs with mass balance. We simply used Excel for the calcs and it's inbuilt drawing tools for the diagrams we displayed lots of numbers in the diagrams and went through many design iterations with multiple stakeholders, so it was important for us to have the numbers always coupled with the diagram.

If you use Excel for mass balances with circular flows, the solver plugin is important & I don't know if this is available in the OS alternatives.

If you don't need to couple the calculation to the graphics, try MS Visio (is often used professionally for PFD and P&ID) or Diag (OS clone of visio, has ASME complient P&ID symbols but not).

I've heard of application specific tools for proces imulation and mass balancing (e.g. SIMBA for wastewater treatment), I've never heard of one for mechanicl waste treatment.

While my suggestions certainly work, I would advise you to wait a bit with accepting this answer, there may be far better tools and you don't want to discourage other answers too fast!

  • Ohh, I am actually designing a municipal solid waste-to-energy conversion plant. So there are no software specific to this solid waste treatment purpose?
    – Rahul Ramesh
    Feb 1, 2017 at 8:56
  • Don't think so, we'll see if someone else has a better idea.
    – mart
    Feb 1, 2017 at 9:31
  • 2
    OhMiGod NO. Never ever EVER use Excel mixed with pasted images. It's unmanageable, unexportable, and nonverifiable. Since the OP appears to be starting from scratch, this is a chance for him to learn R and easily paste images and data into the charts that R generates. Feb 1, 2017 at 13:42

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