Sulfuric Acid Heat Exchangers

Hello

I have a sulfuric acid (H2SO4) heat exchanger application and I wanted to know the benefits of the tantalum surfaces over a PTFE or Hastelloy C276 (These are the two other materials we are considering). My application involves concentrated sulfuric acid at about 98% and we dilute to 25% and we are trying to cool the sulfuric acid down so it is not so reactive.

Thanks
James

Hello James,

Your sulfuric acid heat exchanger application is quite common since H2SO4 is exothermic when it is diluted. By removing the heat out of the H2SO4 with a heat exchanger (acid chiller), it will be a lot less corrosive downstream. Of course to answer your question specifically I would need to know the temperature however generally, in this type of application the Ultra-Metal tantalum surface in sulfuric acid has a nil corrosion rate in any concentration from 0-99% up to 150°C.

The main issue with PTFE heat exchangers is the fact that PTFE is a great insulator. While the PTFE would be corrosion resistant, the heat exchanger would have to be several times larger than an tantalum treated Ultra-Metal plate and frame heat exchanger. This then makes PTFE a costly solution due to the size and footprint required.

With regard to Hastelloy C276 heat exchangers with H2SO4 is that it generally will have a corrosion rate. Depending on the concentration and temperature of the H2SO4, the Hastelloy C276 heat exchanger will have a limited life.

Hopefully this answers your question
Ultramet CPT Corrosion Experts