Energy Savings in the System Pickling/Acid Recovery: The New ECOmode

by Frank Baerhold, Stefan Mitterecker, Gerhard Jauk, Arthur Stingl

Publisher - Andritz AG, Austria

Category - Engineering & IT

The recovery of hydrochloric acid from a pickling line via pyrohydrolysis in a spray roast reactor is state of the art. A major part of the energy consumption of this process results from the evaporation of water. Although the process uses an internal pre-concentration step to recover energy, the amount of water that has to be evaporated can still be reduced further. A new operating mode for the system pickling/acid recovery was implemented, that saves up to 25% fuel without any additional process steps. This new ECOmode enables the total system to more efficient operation level. The energy consumption of the ARP is mainly a result of water evaporation. The hot off-gas from the roaster is cooled down by direct contact with the waste acid, whereby the waste acid is pre-concentrated and then sprayed into the roaster. This pre-concentration is a very elegant way of process integrated heat recovery. Anyway, the concentration of the liquid sprayed into the roaster is far lower than it could be. This means, that more water is evaporated than necessary.

Please login to borrow the book.