Case story

AGC aims forsustainable caustic
soda concentration
system throughprocess optimization
AGC, one of the world’s largest glass
manufacturers, has gone through a technology
conversion from shell and tubes to gasketed plate
heat exchangers, including use of HeatSealTM
gaskets, at its Chiba Plant in Japan, to improvethe efficiency of manufacturing processes and toreduce environmental impact.
AGC has replaced a one evaporator and four heatexchangers (economizers) in the caustic soda
concentration process at its Chiba Plant with
Alfa Laval plate heat exchangers and a speciallydesigned evaporator. The result is a 10% reduction
in steam consumption. Additionally, downsizing thepumps has resulted in a lowered electricity consumption
and reduced euipment space required. Also, with the
reduced frequency of gasket replacement due toimproved quality, the time and cost of maintenance will
be reduced.

AGC has developed its chemicals business domainfrom the manufacturing of soda ash, one of the raw
materials for glass. The manufacturing process forcaustic soda, one of its main products, has been
adapted to meet current needs for improved quality,reduced environmental impact, and cost reduction.

“We believe it is important for us to provide
a stable supply of caustic soda to theworld by building a more sustainable
and safer manufacturing process under
AGC Chemicals’ vision; Creating a safe,secure, comfortable and environmentallyfriendly world with chemical technology.
To this end, it is important to increase theplant’s operating rate and minimize problems.”
Shunsuke Okada, lead process designer at AGC

The challenge of chemical manufacturing toward
decarbonization
New energy and material solutions attract attention in theefforts to work toward the realization of a decarbonizedsociety. However, a major challenge for chemicals,
which play a fundamental role in many industries, is how
to improve the efficiency of manufacturing processes toreduce environmental impact.

UptimeTechnology shift

Lesser frequency of gasket
replacement reducing downtime
and maintenance costs.

From shell-and-tubes
to gasketed plate heatexchangers with HeatsealTM .

Energy savings

Cost savings

10% reduction in steam
consumption as well as
electricity consumption
reductions.

Reduced energy cost by
hundreds of thousandsof euros.

Inside Chiba plant

AGC’s sister plants outside of Japan already haveexperience with Alfa Laval’s plate heat exchangers using
HeatSealTM gaskets. Takuya Yoshikawa, responsible
for the equipment at AGC, says, “When we introduced
the gasket, we were of course expecting improved
gasket durability, smaller equipment, and easierinstallation and maintenance. We were able to reduce
the size of the pump by more than 5% compared to theconventional pump, and the reduction in the electricity
cost for the pump alone has had a great effect. Inaddition, Alfa Laval’s evaporation and concentration
process specialist Tomas Kovacs was able to help us
from the beginning with knowledge we didn’t have,on how to rethink the process to make it more energy
efficient. We are very pleased with the results.”

Yuu Kang explains that “The caustic soda concentration
process had three major challenges. First, the aging
shell-and-tube evaporators were costly to maintain.
Second, the caustic soda electrolysis plant consumed
a large amount of energy, so we had to review theprocess design to reduce energy consumption tomeet our sustainability goals. Third, the gaskets ofthe existing plate heat exchangers installed in theconcentration process had to be replaced more
frequently than scheduled due to the risk of leakage.”
Because the concentration process involves the handlingof dangerous materials, a leak could lead to a major
accident, which would further prolong plant shutdown.
Caustic soda is one of the main products produced in
the plant, and the other main product is chlorine gas
which is used for other processes inside the plant, so a
shutdown would have far-reaching consequences.
Energy efficiency through process improvement
As the solution to the problems listed, AGC choose
Alfa Laval’s gasketed plate heat exchanger and thenewly developed HeatSealTM gasket. The gaskets
use Aflas 600X, a fluoroelastomer developed
by AGC, which has significantly improved heat
resistance and oxidation resistance compared
to conventional gaskets, and can be used forcontinuous operation at temperatures up to 210°C.
“This material has properties like an intermediate
between resin and rubber, and is characterized byits resistance to strong acids, alkalis, and heat. Thus,
it can be used in gasketed plate heat exchangers
where amine resistance is required, which is a majoradvantage over conventional fluoroelastomers. It is
used for semiconductors, electric cables, and offshore
for special parts used in resource drilling,” said
Mr. Kawai of the Chemicals Development Department.
How to contact Alfa Laval
Up-to-date Alfa Laval contact details for all countries arealways available on our website at www.alfalaval.com.

Models•1 x AlfaVap 650 (nickel)•

2 x TL10P (nickel with HeatSealTM gaskets)•2 x TL10B (nickel with HeatSealTM gaskets)

Further possibilities“In our efforts to save energy in the electrolysis process,we were able to reduce energy cost by hundreds ofthousands of euros. Information on this initiative isbeing shared with our other facilities around the world
who I believe will consider to introduce this technology.
At the Chiba plant, we are planning to replace the restof the existing shell-and-tube heat exchangers with Alfa
Laval’s plate heat exchangers to increase efficiency,
save space, and reduce maintenance costs.” says Mr
Yuu Kang, Manager, Production Department who is also
looking forward to future developments. “In addition toenergy efficiency, we expect to reduce maintenancecosts significantly. We are looking forward to Alfa
Laval’s efficient service to complete the inspection andreplacement on a tight schedule.”

Outside Chiba plant

Yuu KangManager,
Production Dept.

Shunsuke Okada
Process Engineer,Electrolysis Dept.

Alfa Laval reserves the right to change specifications without prior notification.

100005104-1-EN-2201

Takuya Yoshikawa
Mechanical Engineer,
Mechanical First Dept.

Akinobu Kunimoto
Manager, Polymer,
Processing Group

Tsuyoshi Kawai
Group Manager, Polymer,
Processing Group