CASE STUDY
RO | NF | UF | MF

Whey Production
Germany

Toray Heat Sanitisable RO Membranes Demineralise NF Permeate forDiafiltration at a Whey Production Plant
CHALLENGE
In the food industry, heat sanitisation of membrane systems is acrucial aspect of preventing microbial growth. A leading producerof whey ingredients in Germany struggled with bacterial counts
in the RO permeate. As a result, the whey producer began to pilot
alternative membrane supplier models, including Toray's heatsanitisation membranes.
HEAT SANITISATION
For the pilot, two pressure vessels were each set up to containfive RO elements: one pressure vessel loaded with Toray's heatsanitisable membrane model TMRO8040HS, and the otherpressure vessel with the existing RO membrane. The goal wasto keep the germ content in the permeate as low as possible
while maintaining a comparable performance through periodic
sanitisation of the membrane elements.
The RO system has an average feed capacity of 35,000 litres perhour at 27 bar and 10 degrees Celsius. Since the pilot commenced,
the test modules have been sanitised three times with hot water.
Sanitisation conditions were 20 to 30 minutes at a maximum of85°C, with a baseline of 1 bar and 0.1–0.2 bar of differential pressure.

Figure 1: Heat sanitisable RO system. Image source
MMS AG Urdorf Switzerland

4500

Table 1 — Comparative average performance
Avg. flow (L/h)

COD (mg/L)

Heat sanitised TMRO8040HS

3,811

20–30

Existing RO

2,530

100–168

4,008

4000

RESULTS
Toray modules consistently outperformed the competitor
modules, measured by the permeate flow rate and COD (ChemicalOxygen Demand) levels (see Table 1). On average, the flux of theToray elements was 50% higher, and the permeate COD levelswere 82% lower than the competitor. Based on this performance,permeate flow, and the production time of 18 hours per day, theheat-sanitisable TMRO8040HS can reduce the COD content total
by 176 kilograms per production day.
The results, with significant flow improvement and bacterial countreduction, are of great interest in other membrane systems within
this plant.

Vessel Flow, L/hParameter

Figure 2: Comparative vessel flows*TMRO8040HS was sanitised weekly
3,876

3,731

TMRO8040HS

3,628

3500
3000

2,7472500

Existing RO

2000

02,5481Time (Weeks)

2,500

2

2,327

3"With Toray's membrane, we save 138 mg/L csb [COD}compared to the competing product." —Whey producer

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CASE STUDYToray Heat Sanitisable RO Membranes Demineralise NF Permeate for Diafiltration
at a Whey Production Plant

RO | NF | UF | MF

Figure 3: Design of NF/RO Diafiltration System

Storagetanks

TORAY HEAT SANITISABLE RO
Below are specifications for Toray's Heat Sanitisable RO elements.
Toray HSRO elements are sanitised with hot water as the preferred
method in food and pharmaceutical applications eliminating theneed for chemicals and other disposals.

Storagetank
NF retentate

New Toray HSRO elements must be pre-conditioned before
initial use by exposure to hot water. Conditioning water must behigh-quality chlorine and oxidant free, non-scaling, non-foulingwater. RO permeate is preferred, and from an RO that has been in
operation for at least 24 hours.

NF feedNF
RO permeate /Diafiltration water
for NF system

Storagetanks

NF permeate /RO feedRO

Toray's manufacturing facility in San Diego, California that produces
heat-sanitisable elements and other membranes in sanitary
design, is registered under ISO 9001:2015 and 14001:2015 toensure consistency in product and service quality and enhanceenvironmental performance.

RO retentate

Specifications for TMRO8040HS & TRO8038HS

TRO8038HS in Sanitary Design (no ATD)

Components conform to FDA Regulation CFR Title 21 andUSDA/3A Sanitary Standards
Flow direction

NaCl rejection%

Permeate
flow rate
GPD (m3/d)

Feed spacer
thicknessin. (mm)

Active area
ft² (m²)

99.5%

9,000 (34.1)

0.028 (0.71)

400 (37.2)

CAStandard dimensions in. (mm)
B

Size

A
Diameter

B
LengthC
Permeate tube ID

TMRO8040HS (w/ ATD)

80407.9 (201)40 (1,016)

1.125 (28.6)8038

7.9 (201)

38 (965)

1.125 (28.6)

Components conform to FDA Regulation CFR Title 21
Flow direction

CA
B

Test Conditions
Feed water pressure psi (bar)150 (10.3)

Feed water temperature °F (°C)

77 (25)

Feed water concentration mg/l as NaCl

2,000

Recovery rate %15

Feed water pH

7

TORAY MEMBRANE USA, INC. 13435 Danielson Street, Poway, CA 92064, U.S.A. Tel: +1 (858) 218 2360 innovation@toraymem.com
TORAY MEMBRANE EUROPE AG Grabenackerstrasse 8b, Muenchenstein 1 CH-4142, Switzerland Tel: +41-61-415-8710 info@toraywater.com

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Marks designated with a ™ or ® are trademarks of Toray Industries, Inc.
All information presented herein is believed reliable and in accordance with accepted engineering practices.
Toray makes no warranties as to the completeness of this information. Users are responsible for evaluating
individual product suitability for specific applications. Toray assumes no liability whatsoever for any special,
indirect or consequential damages arising from the sale, resale or misuse of its products. © 2020 TorayIndustries, Inc. Subject to change without notice.
MC-CS-MB3-HSRO-AC-2009

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