Marine Clays - Passing AC currents

[wildwildwest]

I am working on a project involving electrically heating clayey soils (having 55% moisture content and 0.5 M salt (nacl/KCl) solutions in the pore space.

Does anybody know if electrolysis of water/electrolyte is a concern with AC currents (230 V, 60 Hz frequencies)?

Thanks,
WWW

 

[Gokul43201]

I'm not sure what you mean by "is a concern". Yes, the water will be electrolysed, but as long as you don't stick your fingers in the clay, you should be okay. Unless your concerned about shorting the power line, which is a valid concern. I'd use a rheostat in series with the clay and start with a high load resistance and keep turning it down in each successive try.

PS : Standard conductivity measurements of water are done using AC, and counts on the conductivity from the ions.

 

[wildwildwest]

clays - electrical heating

Thanks for the reply,

Yes, my concern was with the shorting of the power line. Does anyone know of 'rule of thumb'/'back of envelope' calculations for determining how much of power energy put in goes into heating the clay and how much is lost in electrolysis?


Thanks,
WWW

 

[pack_rat2]

When a chloride is electrolyzed, Cl2 gas will be produced. That's in addition to the H2, of course. Also, the Cl2 reacts further, which ends up with the generation of chlorate. Would any of these products cause a problem?

 

[Gokul43201]

Does anyone know of 'rule of thumb'/'back of envelope' calculations for determining how much of power energy put in goes into heating the clay and how much is lost in electrolysis?

You can calculate the energy going into ionization (actually deposition, since most salt are ionized by the polarity of water) if you know what salts are dissolved in the clay, and what their concentrations are. The rest goes into heating the clay.

I'd be surprised if more than 20% went into ionization/deposition.