Can cantera support photochemistry?

[Matt Tino]

Hello,

I am looking to use Cantera to model a water treatment photoreactor system with 50+ reactions. I have looked extensively into the documentation but have not found the answers for the following:

Questions:

1. Can cantera create radical species? I know I can make ionic species, but not sure if it can support, say, the hydroxyl radical HO*

2. Can cantera support photochemistry? Many of my equations involve photons of various wavelengths, particularly in hydroxyl generation. Is there any support for this?

3. Say I want to compute kinetics quantities for my liquid wastewater treatment system... the only options for kinetics models are gas, surface, and edge. Is there no support for liquids?

4. I'm confused on why there exists a thermodynamic and kinetics model for the phase, and then you can implement a separate thermo and kinetic model/equation of state for each specie? 

Thanks so much,
Undergraduate Research Student in Nano Engineering
University of Waterloo, Canada

[Ray Speth]

Hi,

1. Yes, representation of radicals is not a problem - Cantera doesn’t really care (or even know) whether a species is a radical or not.
2. There’s no specific handling for photochemical reactions. I think what you would need to do is build the photon flux at the wavelength relevant for each reaction into the rate constant. If this is a variable quantity within your system, you could treat it as a multiplier on each rate constant, which can varied as needed from the Kinetics object in Cantera.
3. That’s a good question. I don’t think there’s really anything specific to gas phases in the GasKinetics class. As long as the rate parameterizations you want to use are all among the ones available in Cantera already, I think you should be able to use it for liquids as well.
4. Could you provide a bit more detail, with a specific example? The additional equation-of-state data needed for species in some of the condensed phases is indeed a bit confusing, and I don’t know that I can provide a general answer that would be very helpful.

Regards,
Ray

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