Case Study: Duke Energy Selects HERO™ Membrane Process For ZLD Application
•Case Study: Duke Energy Selects HERO™ Membrane Process For ZLD Application
The Arlington Valley Power station being developed by DENA is a large combined cycle power plant located in Arlington, Arizona.
Duke/Fluor Daniel (DFD) of Houston, Texas are owner engineers and contractors. DFD were instrumental in selecting the HERO™ route for its economy, ease of operation and reduced operating costs. DFD obtained their permitting based on consideration of RO system followed by an evaporation pond.
The Problem
The cooling tower blow down volume is
about 1675 gpm saturated with silica, high
hardness and other constituents. A thermal brine
concentrator for this capacity will be a costly affair in
addition to high power and operating costs. A
conventional membrane process can not function
under these conditions due to silica and other organic
limitation. The permitting of the power plant
was based on evaporation pond. Customer actively
considered the HERO™ process from the very beginning
of design conceptualization with a small evaporation
pond. Notice should be taken of the fact that
the cooling tower circulating water chemistry was
based on 10500 PPM TDS.
The Solution
HERO™ is a Patented process which addresses the
treatment of high silica, organic and bio
active feed water and hence treatment of
cooling tower blow down enabling recovery
and reuse of the blow down water. The
HEROTM process is limited only by the system
osmotic pressure. HERO™ is a membrane
process with modified pre treatment scheme
to accommodate high silica concentrations.
HEROTM has been successfully tested with
silica level of 2000 PPM in the reject. Wastewater
recovery with HERO™ process is limited
only by osmotic pressure. Due to high TDS of
10500 PPM in the circulating water the
HEROTM system was designed for a recovery
of 88 %. A second pass R.O. treats a small
portion of the HERO™ product followed by a
mixed bed exchanger to produce DM water
for boiler feed purpose. Bulk of the HERO™
product water is returned to the cooling
tower cold well thus increasing the cycles of
concentration.
•Case Study: Duke Energy Selects HERO™ Membrane Process For ZLD Application