Kieselguhr vs. Cross-Flow Filtration; Economical & Ecological Aspects

Kieselguhr vs. Cross-Flow Filtration; Economical & Ecological Aspects



2011 International Brewing Conference Bangkok

Thursday 16th June, 2011

Geoff Leeder, Thomas Weigand, Juerg Zuber

FILTROX Engineering AG, St. Gallen, Switzerland


FILTROX AG, St. GallenA family-owned Swiss company,established in 1938 The world s leading supplierof equipment & systems for beer & beverage filtration

SwissQuality&Reliability


1. Interest of breweries in cross-flow filtration

2. Market situation current & future

3. Advantages & disadvantages of kieselguhr filtration

4. Advantages & disadvantages of cross-flow filtration

5. Technical & economical comparison

6. Conclusions

Contents of presentation


It was easy to see when he was not telling the truth!

Do you know this guy?

We ll come back

to this later


Cross-flow filtration of mainstream beer

30th EBC Congress, Prague (2005): ProgrammeDE recycling in industrial operation results from 6 months operation (Pall)Cross-flow filtration of beer a true alternative to DE filtration (Sartorius)Conception & field report about a novel filter system for KG-free beer filtration (KHS)Full-scale results of KG-free beer membrane filtration & in-line stabilisation in one process step (Norit)High throughput micro filtration of beer (Bavaria)

will kieselguhr be relegated to the past?


others100+

beer-recovery plants60+

winerest beerlemon juice & vinegardextrose syrupcider (mainstream) & cider leesbrewery yeast & tank bottomsberry juicesmicro filtrationapple juiceultra filtration

FILTROX s industrial experience with cross-flow


MF cider191Aston Cider, U.K.2004

ceramic membranes

polymeric membranes

MF brewery yeast239Boituva, Brazilworld s biggest!

2008

MF cider300H.P. Bulmer, U.K.1997

MF brewery yeast26Fürstenberg, Germanyworld s first!retrofitted with ceramic

1988

1993

UF apple juice181Rauch, Austria1986

applicationsize (m²)customeryear

Examples of cross-flow installations


Cross-flow filter to recover beer from yeast


What is the situation on the market?

Cross-flow filtration

Under investigation for brewing applications for 25 yearsAggressively marketed for more than 10 yearsToday, typically 1~3 installations sold yearly worldwide

Kieselguhr filtration

The dominant means to clarify beer for more than 50 yearsFILTROX still sells more than 20 installations in a bad year(please don t forget our competitors; even if I would like to!)

So why the excessive interest in cross-flow?


It is a fact that, today, kieselguhr is usually selectedto filter beer. This is due to its:

Low priceReady availability (multiple sources)Excellent filtration resultsHigh throughput per square metre filter areaGood adjustability / flexibility

What is the situation on the market?


Cross-flow filtration

Polymer membranes (known)Ceramic membranes (relatively-new)Still-to-be-discovered membranes

Pre-coat filtration

Kieselguhr and/or perliteRegenerable filter aids (happening!)Still-to-be-discovered filter aids

maybe Granny knows best

What could be the future?


Beer, a natural product, will always exhibit varying filterability

Adjustability to varying filtration properties is mandatory

Wide choice of filter aids is available from multiple suppliers

High throughputs (up to 1,200 hl/hr) with low floor space arepossible

Lower water- & energy-consumption compared to cross-flow

Why kieselguhr (pre-coat) filtration?


Candle filter


No moving parts

High reliability for kieselguhr filtration(& PVPP stabilisation)

Negligible spare parts (a few O-rings)

Minimal, unskilled maintenance

High throughputs (up to 1,200 hl/hr)

Low losses (for regenerable filter aid)

Candle filter


Interchangeable spare parts


Industrial experience since 1986(juice, wine, cider, vinegar, beer-recovery, etc)

Approaching 200 plants installed

Tested beer filtration using polyethersulphone (PES) membranesin 5 European breweries (1995~1999)

Installed more than 100 hollow-fibre PES plants for wine

Tested rotating-disk metal membranes

Tested back-pulsing, back-flushing, inter-CiP, uniform TMP

What does FILTROX know about cross-flow?


Unpredictable & inconstant fluxesFrequent (sometimes weekly!) failure of capillariesRelatively-short service life; 1~2 years

Expensive replacement (single source!)Expensive formulated cleaning agents requiredA lot of non bio-degradable solid waste (plastic)

Lion-Nathan, BrisbaneIBD convention 2010

Why did FILTROX abandon PES membranes?


Yeast sampled in BBT:0~1 cell per 2,000 ml

perfect!

Can kieselguhr do better re. microbiology?


It can contain cristobalite; suspected (but unproven) carcinogen

(if inhaled as a fine dust)

There can be disposal issues

(in some countries)

What are the drawbacks of kieselguhr?


Safe & dust-free handling of kieselguhr powder using:

Bag-slitting machines

Big-bag systems

Powder silos(combined with big-bag or standard sacks)

Convenient handling of discharged sludge using:

Sedimentation/decant tank

Reduces waste volume by concentrating from 10% to 30% solids

Handling kieselguhr powder & waste kieselguhr


Big-bag station & sludge tank


But not always as easy as it looks


Is it a health hazard?

The danger for the consumer never existed;beer is for drinking not for inhaling! (even if aroma-hopped)

Operators can be protected by a simple face-mask!

Fully-automatic systems are available for handling kieselguhr

Bag-slitting machines, big-bag, silo plants avoid exposure to kieselguhr powder

What is wrong with kieselguhr?


Are resources limited?

Totally wrong!

Known deposits of KG are about 900 million tonnesthe last time I drove on the Lompoc Road, there were somepretty impressive mountainsides that comprise kieselguhrProf. Charlie Bamforth, U.C. Davis, California

Global annual consumption is currently 1.8 million tonnes

More than 400 years are left!When will we run out of oil? (the raw material for PES)



Is kieselguhr detrimental to the environment?

Waste kieselguhr (organic part) can be processed to biogas; inorganic residues are used as soil improvers

Waste kieselguhr can be used as a component of building bricks

Waste kieselguhr can be mixed with spent grain used as cattle feed (it polishes the cows teeth & gives them a beautiful smile), or burned in a fluidised bed

Disposal cost can be reduced by concentrating using:sludge tanksbelt filter presses



Is cross-flow more sustainable?

Cross-flow requires more electrical power(burning fossil fuels creates CO2; contributes to global warming)

Cross-flow requires more water for cleaning

Cleaning membranes can require enzymes & oxidizing agents(disposal of effluents!)

Do not forget the production & disposal of oil-based plastics!

Cross-flow has no true ecological advantage



Failure of individual capillaries can be as frequent as weekly

Each module contains 2,150 capillaries

Each filter skid contains 20 modules

One 600 hl/hr filter has 5 skids; or 215,000 capillaries

Good luck finding the broken one!

Cross-flow PES membranes are prone to failure


Actually, it is not such a problem just plug and play


plastic plug


Accommodating & repairing failures:

Install turbidity metres on the outlet of each skid(costs money but at least you speed up locating the problem)Install surplus area to accommodate the lost capacity(costs money but at least your 600 hl/hr plant is not 500 hl/hr)Remove & test each module one-by-one(immersed in a water bath under air pressure like an inner tube)Block the bubbling capillary with an epoxy-coated plug(creating a stagnant capillary for growing micro-organisms)

All you need is a maintenance team sitting on standby!



Supplier A

500 cleaning cyclesEquals around 1~1½ years

Supplier B

4,000 hoursConsidering 24/7 operation means only 6 months!

Both neglect nominal individual failures

Typical guarantees for membrane life


Filter of 600 hl/hr

per 12 m2 module (Supplier B) US$ 2,500.00large plant (100 modules) US$ 250,000.00 /year

Examples

Heineken Warka (Supplier A) US$ 0.08 /hlKoeln (Supplier A) US$ 0.18 /hlSupplier B (G. Walker) US$ 0.20 /hl

Membrane replacement costs


Examples

Heineken Warka (Supplier A) 0.35 kWhr/hlKoeln (Supplier A) 1.22 kWhr/hlCarlsberg Frederica (Supplier B) 0.40 kWhr/hlSupplier C 0.41 kWhr/hl

Conventional (kieselguhr + PVPP) 0.13 kWhr/hl

Cross-flow power consumption


Power consumption comparison (BASF)


Examples

Heineken Warka (Supplier A) 0.31 hl/hlCarlsberg Frederica (Supplier B) 0.07 hl/hl ?Supplier C 0.20 hl/hl

Conventional (kieselguhr + PVPP) 0.16 hl/hl

Cross-flow water consumption


Water consumption comparison (BASF)


Greenhouse gas emission comparison (BASF)


Environmental fingerprint comparison (BASF)


Examples

Heineken Warka (Supplier A) 0.7 %Carlsberg Frederica (Supplier B) 0.02 % ?Supplier B (G. Walker) 0.4 %Supplier C 0.1 %

Conventional (kieselguhr + PVPP) 0.05 %

Cross-flow beer losses


For 2 mio hectolitres, TCO (5 years), cross-flow costs 30% more

Total cost of ownership comparison

consumption per Filtration per year per hl consumption per Filtration per year per hlKieselguhr kg/hl 0.11

385.00

154,000.00

0.08

0.00

0.00

0.00Kieselguhr disposal kg/hl 0.55

192.50

77,000.00

0.04

0.00

0.00

0.00Water m³/F 72

25.92

10,368.00

0.01 91

32.00

43,020.00

0.02Waste water m³/F 60

11.40

4,560.00

0.00 91

17.00

22,705.00

0.01Air Nm³/F 60

2.40

960.00

0.00 23

1.00

1,243.00

0.00Carbon dioxide Nm³/F 120

12.00

4,800.00

0.00 174

7.00

9,401.00

0.00Cooling kWhr/F 967

14.51

5,802.00

0.00 431

4.00

5,179.00

0.00Steam kg/F 840

12.60

5,040.00

0.00 1102

9.00

11,984.00

0.01Electrical power kWhr/F 500

20.00

8,000.00

0.00 810

20.00

26,761.00

0.01Oxidising agent ltr/F N/A

0.00

0.00

0.00 3

1.00

1,067.00

0.00Special cleaner ltr/F N/A

0.00

0.00

0.00 8

45.00

59,608.00

0.03Caustic concentrate ltr/F 90

9.00

3,600.00

0.00 266

13.00

17,721.00

0.01Acid concentrate ltr/F 8

5.60

2,240.00

0.00 51

26.00

34,541.00

0.02Beer loss % 0.4

160.00

64,000.00

0.03 0.2

28.00

37,867.00

0.02Spare parts

10,000.00

0.01

20,167.00

0.01Membranes/modules

276,296.00

0.14Manpower

30,000.00

0.02

30,000.00

0.02Amortisation (5 years)

474,684.00

0.24

608,199.00

0.30

Run length hl/F 5,000 1,500No. cycles F/year 400 1,334Output hl/year 2,000,000 2,000,000

Investment

2,373,420.00

3,040,990.00

Totals

850.93

855,054.00

0.43

203.00

1,205,759.00

0.60

TCO (5 years)

4,275,270.00

6,028,795.00

Parameters FILTROX KG-F Cross-flow (average)


Kieselguhr-free does not automatically mean cross-flowCross-flow is technically possible for mainstream beer filtration but operational issues, especially frequent membrane failure, will not be welcomedBig international groups are returning to conventional filtration after first experience with cross-flow for mainstreamWith candle filters, there are no surprises in OpEx, as no membrane replacement (from single source) is necessaryReliability of the candle filter is well known

Conclusions


Did his nose grow longer during the presentation?

What about this guy?

No, so do not discount

kieselguhr filtration!


Documents

Kieselguhr vs. Cross-Flow Filtration; Economical & Ecological Aspects