Batch Neutralization of Acid/Alkaline Industrial Waste0 pages
CHEMICAL
FMC Biopolymer reduces operating expenses
more than 80% with PERpH-X™ sensors.
RESULTS
• 80% Reduced Maintenance Cost
• $200K Yearly OpEx Savings
• Measurement Deadtime reduced by 70%
APPLICATION
pH in a Chemical Processing Plant
CUSTOMER
FMC Biopolymers in Rockland, Maine, USA
CHALLENGE
FMC makes ingredients for consumer products such as toothpaste,
baking mixes, and other food products. The plant makes carrageenan
out of seaweed using a sequence of chemical processing steps that
starts with soaking the seaweed at 200°F. The processing tanks and
lines are regularly subjected to both acid and base clean in place (CIP)
solutions. pH measurement in the recirculation line of the modification
tank is used to control acid addition and keep the pH in the range of 7.5
to 8. pH values in this range minimize downstream buildup on filters.
Unfortunately, conventional pH electrodes were only lasting less than 1
week in this application, so FMC had installed a triple redundant system
to make sure the pH reading is continuously available.
The process in the modification tank is a thick brown gel that can be
difficult to remove completely from the pH sensor and tends to foul
the reference junction, causing the sensor to become nonresponsive.
Maintenance on the pH sensor included cleaning the sensor, replacing
the glass electrode every week, replacing the reference electrode
every 2 weeks, and replacing the pH assembly every 6 months. Every
time the sensor was rebuilt, the pH reading required recalibration,
which took an average of 30 minutes to complete.
Mike McNeil, E/I Planning Engineer at FMC had investigated several pH
vendors but was still looking for a more reliable measurement. He
For more information:
www.EmersonProcess.com/QBR
www.raihome.com
Rosemount Analytical’s PERpH-X™ model
3400HTVP sensor and loop powered
transmitter model XMT were installed in
May 2006 to run side by side with 3
sensors from another manufacturer to see
if they could provide better results.