Fouling & Cleaning Science: Direct Detection of Biofilms and CIP-Related Problems in

Liquid Process Systems

Mark Fornalik Industrial Biofouling Science, LLC

www.industrialbiofouling.com

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Introduction: Process Cleaning Science

There is a science around determining if your industrial process is truly clean, and the tools for this determination include microscopy as well as FTIR. Both are complimentary to the traditional microbiology methods.

This talk introduces fouling cell technology and how to understand the sequence, chemistry and kinetics of fouling events on the interior surfaces of pipes, tanks and liquid-handling processes.

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Process Contamination:Impact to The Bottom Line

• Poor product quality• Random quality incidents• Time spent sorting good product from bad• Wasted materials (raw and finished)• Sub-optimized process cleaning = process

downtime• Erosion of customer base

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Cost of Process Contamination

• In a Fortune 500 chemicals company, the fouling cell approach:– Found and eliminated the root causes for $20M in

product waste (note: most of this was biofilm related)– Identified manufacturing sites with best cleaning

practices– Reduced the cost of commercialization, by identifying

cleaning problems – and proper cleaning procedures - in the product development cycle

– Enabled more robust process health

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Transfer Line Contamination

Manufacturing Problems:• Cross contamination between

product types• Physical waste – spots,

streaks, particles, filter plugging, viscosity changes

• Chemical waste – chemical contamination of final product

• Increased brand change time• Loss of product flow• Increased production runs to

allow for waste

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Insoluble Wall Fouling• Fouling: The unwanted formation of insoluble

residues on engineering materials in contact with flowing solutions

• Fouling is what is left on wall surface after even a proper water flush clean

• Chemical cleaning must be designed to address water-insoluble wall fouling

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• Organic • Inorganic• Biological (bacteria, fungi, algae - BIOFILMS)• Particulate (corrosion)• Crystallization/Scale (boilers, heat exchangers)• Combination (any two or more of the above)

Insoluble Wall Fouling Types*

* T.R. Bott, * T.R. Bott, Fouling of Heat ExchangersFouling of Heat Exchangers, Elsevier (1995), Elsevier (1995)

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The goal of cleaning is to return the system to the induction periodlevel of fouling

Fouling Rate

time

foul

ing

mas

s physicalproblems

chemicalproblems

induction period

secondary fouling

steady state

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Fouling Cell Technology:• Analyze fouling film while in place on substrate• FTIR for non-destructive chemical characterization (organics)• Epifluorescence microscopy determines if organics are biofilm

Fouling Cell Technology: Direct Detection of Biofilms & CIP Efficacy

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Process Cleaning: A Structured Approach

System Design

Water Flush Optimization

Chemical Clean Optimization

Biofilm Control

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Insufficient water flush leaves product behind in pipe; optimized water flush reaches “plateau” more quickly for

faster cleaning times

Water Flush Cleaning

0 .0 0 0 1

0 .0 0 1

0 .0 1

0 .1

1

1 0

1 0 0

1 0 0 0

0 5 1 0 1 5 2 0 2 5 3 0 3 5

T im e (m in u te s )

Per

cent

of D

ye in

the

Flus

h S

olut

ion

M a g e n ta Y e llo wC y a n

Old process water flush end point

Water flush “plateau “

Water Flush Cleaning: A Two-Step Process

1. Product displacement – governed by hydrodynamics

2. Wall cleaning – governed by kinetics

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Powerflush (Two-Phase Flow)Cleaning

Cleaning efficiency varies as a function of the ratio of air flow to water flow

Efficient flow ratio Water-rich flow ratio

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Direct Measure of Powerflush Cleaning Efficiency

-0.0010-0.0005

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

0.0045

0.0050

0.0055

0.0060

0.0065

0.0070

0.0075 0.0080

Abs

orba

nce

1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)

-0.0010-0.0005

0.0000

0.0005

0.0010

0.0015

0.0020

0.0025

0.0030

0.0035

0.0040

0.0045

0.0050

0.0055

0.0060

0.0065

0.0070

0.0075 0.0080

Abs

orba

nce

1000 1500 2000 2500 3000 3500 Wavenumbers (cm-1)

Peak height data correlate to effectiveness of cleaning: the smaller the peak, the more effective the cleaning

Before powerflush

After powerflush

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Chemical Cleaning Variables

Chemical cleaner formulationConcentrationTemperatureOrder of addition

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Measuring Chemical Cleaning Efficiency

0%

20%

40%

60%

80%

100%

TSP NaOCl TSP/NaOCl NaOH Citric acid

clea

ning

effi

cien

cy

FTIR peak height before & after cleaning provides an estimate of

cleaning efficiency

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Studying Chemical Cleaning Parameters

0%10%20%30%40%50%60%70%80%90%

100%

25 C 45 C 65 C5% NaOH

clea

ning

effi

cien

cy

Impact of temperature

0%10%20%30%40%50%60%70%80%90%

100%

0.2% 1.0% 5.0%NaOH wt% @ 60 C

clea

ning

effi

cien

cy

Impact of concentration

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Biofilm Chemistry Over Time*Subtraction Result:ir1848, 610 NRX disc #26, 3-month exposure, no clean*Subtraction Result:ir1896, 610 NRX, 14 batches (4 days), disc #7 (1/30 - 2/2/98)*Subtraction Result:ir2288, 610, NRX, #10, 24 hours, 5 batches, 2/26 - 2/27/98*Subtraction Result:ir1974, disc 10, 610 NRX, 1 batch, 4 hrs, without santoprene gasket

-0.008

-0.007

-0.006

-0.005

-0.004

-0.003

-0.002

-0.001

0.000

0.001

0.002

0.003

0.004

0.005

0.006

0.007

0.008

0.009

0.010

0.011

0.012

0.013

0.014

0.015

0.016

0.017

0.018

0.019

0.020

Abs

orba

nce

600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800 3000 3200 3400 3600 3800 4000

Wavenumbers (cm-1)

Biofilm exopolymer becomes more cleaning resistant upon aging

2 hrs

8 hrs

24 hrs

6 mo

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Case Study: Comparing Cleaning in Two Winery Product Lines

Fermentation cellar line

Fouling cells

Bottling line

Filler lines

Cellar & bottling lines cleaned daily with hot water & iodophor before & after each use

Filler line cleaned daily with 140F water, caustic/bleach, peracetic acid, 190F water

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Winery Line A 10 WeeksFermentation cellar line

Bottling line

Filler line

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Winery Line B 10 WeeksFermentation cellar line

Bottling line

Filler line

21bottling A

Cellar A

surge tank10002000

10002000

10002000

cellar

bottling

filler

Winery Line A 10 Weeks

protein

carbohydrate

22bottling B

Cellar B

surge tank

10002000

10002000

10002000

Winery Line B 10 Weekscellar

bottling

filler

protein

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Winery FTIR Peak Height Comparison

82 Line/Line 4

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

cellar bottling filler 1st

fouling cell location

peak

hei

ght

amidecarbo

Cribari Line/Line 5

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

cellar bottling filler A side filler B side

fouling cell location

peak

hei

ght

amidecarbo

Line BLine A

Conclusions:

• Fillers from both lines were clean

• Both lines A and B exhibit biofilms in cellar and bottling lines

• Line A has thicker fouling layer

• Line A exopolymer is carbohydrate & protein; Line B exopolymer is protein

• Both biofilms resist daily chemical cleaning: hot water, caustic, peracetic acid, iodophore

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Case Study: Mapping Process Cleaning in Bioproducts Plant

Fermentation reactor

Centrifuge

Process filters

Recovery

Fouling cells

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Fermentation Fouling Cells2-day exposure before CIP

2-day exposure after CIP

4-week exposure after CIP

CIP: 5% NaOH, 65°C, 30 min daily

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Recovery Fouling Cells2-day exposure before CIP

2-day exposure after CIP

4-week exposure after CIP

CIP: 5% NaOH, 65°C, 30 min daily

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Fermentation vs. Recovery

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Conclusions• Microscopy provides a valuable tool in industrial biofilm detection

and characterization• Fouling cells provide an ideal way to acquire biofilms in full-scale

manufacturing processes• Fouling cell technology is complimentary to existing microbiology

methods for biofilm analysis, enabling analysis of exopolymer and biofilm morphology while still in place on the fouled surface

• FTIR analysis targets exopolymer and residual chemicals fouling from product

• This approach can be used to “map” the cleaning effectiveness within a process or compare cleanliness over different production lines or sites, and determine whether product fouling or biofilms are the root cause of process and product contamination issues

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WineryFood dye

Food dye

Bioproducts

Industrial salt system

Gelatin

AgNO3

Ultrapure water

Brewery

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With Thanks to Kodak’s Former Systems Cleaning

Group

M. Giang, M. Grannas,D. Gruszczynski, J. Hunt,

D. Irwin, Y. Lerat, C. Puccini,R. Schmanke, J. Steegstra, M. Wallace,

M. Wilcox, G. Wilson,K. Brockler, J. Fornalik