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Transcript of Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: CarboQC Lab and at-line...
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC
Lab and at-line Beverage Carbonation Meter
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Contents of this presentation
Basics of CO2 analysis
Multiple Volume Expansion method
CarboQC Lab and at-line beverage carbonation meter
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Basics of CO2 analysis
What are the fundamental laws involved?
How can the fundamental laws be applied to solve practical problems?
How is the CO2 solubility influenced and what are the consequences?
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Fundamental gas lawsin beverage CO2 measurement
cco2 = ξco2 * pco2Henry’s law
ptot = pco2+ pAir + pH2O Dalton’s law
c … concentration ξ … absorption / solubility p … pressurem … mass M … molar mass V … volume R … gas constant Z … compression factor T … temp.
m = p*M*V/R*T*Z ‘Real’ gas law
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CO2 measurement units
[g/l]Grams of CO2 per liter of liquid
Volumes [Vol.]Volumes of CO2 at 0°C and 1 atm diss. per liquid volume
1 Vol. = 1.976 g/l Conversion
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Combining the fundamental laws: #1
What happens in a bottle/can/chamber?
p2*V2L* ξ 2 gas mass dissolved in liquid volume V2L
p2*V2G*M/(R*T2*Z2) gas mass in gas volume V2G
p1L*V1L* ξ 1 gas mass dissolved in liquid volume V1L
p1G*V1G*M/(R*T1G*Z1) gas mass in gas volume V1G
Initial state (1): before volume / temperature / solubility change no equilibrium or equilibrium between phases
Final state (2): after volume / temperature / solubility change equilibrium between phases
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Combining the fundamental laws: #2 What happens in a bottle/can/chamber?
22222
1111111
2 *)**/(*
**)**/(**
LG
LLGGG
VZTRMV
VpZTRMVpp
2222002
111110011
2 *)*/(**
**)*/(***
LVZTZTV
LVpZTZTVpp
LG
LLGGG
p2 = ?
Gas solubility (Volumes of dissolved gas per volume of liquid
at standard conditions)
L = ξ / (M/(R*T0*Z0))
Equilibrium pressure in final state (2)
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
From: Rammert / Pahl,Brauwelt Nr. 12Nürnberg 1991
CO2 absorptioncoefficient /solubility isinfluenced by- temperature- sugar- acids & flavors- CO2 pressure- dissolved air - etc.
CO2 absorption coefficient
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Non-equilibrium state at bottle/can filling
e.g. 10% headsp.
90%
liquid
volume
At filling: Most CO2
dissolved in beverage,little CO2 in headspaceif not actively enriched
Equilibrium: CO2
distributed approx.proportional to liquidto headspace ratio
Headspace:Cans: 3...5%Bottles: 5...12%
0.33 Vol.
3.32 Vol.
~100% CO2
e.g.
3.65 Vol.
~0% CO2
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Headspace related temperature effect
10% gasvolume
90%
liquid
volume
CO2 dissolvedin beverageat 40°F / 4°C inequilibrium state:
CO2 dissolvedin same beverageat 70°F/ 21°C inequilibrium state:
Beveragecontainer:e.g. 10%headspace
0.40 Vol.
3.25 Vol.3.40 Vol.
0.25 Vol.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Multiple Volume Expansion Method
What happens to the gas partial pressures when the volume of the measuring chamber is expanded?
How and why does the Multiple Volume Expansion Method work?
What are the results?
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CO2 and air equilibrium pressures as a function of volume expansion
0,0
0,2
0,4
0,6
0,8
1,0
1,2
0 10 20 30 40 50
% Volume expansion
arb
itra
ry p
ress
ure
un
its
CO2 pressure
Air pressure
The air pressure decreases excessively because the solubility of air is much lower than that of CO2 !
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CO2 measurement w/o air compensation
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
0 10 20 30 40 50
% Volume expansion
CO
2 V
olu
me
s
0% air sat.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CO2 measurement w/o air compensation
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
0 10 20 30 40 50
% Volume expansion
CO
2 V
olu
me
s
0% air sat.
10% air sat.
20% air sat.
30% air sat.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CO2 error due to dissolved air
CO2 error due to dissolved air
0,00
0,05
0,10
0,15
0,20
0,25
0,30
0 10 20 30 40 50
% Volume expansion
Vo
l. C
O2
err
or
10% Air sat.
20% Air sat.
30% Air sat.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
How does the Multiple Volume Expansion Method work?
A measuring chamber is completely filled with sample and sealed.
The volume of the measuring chamber is expanded.
Pressure and temperature equilibrium is generated.
Equilibrium pressure and temperature are measured.
The measuring chamber volume is further expanded, equilibrium is generated and pressure and temperature are again measured.
The two pressures/temperatures are used for CO2 determination and dissolved air compensation.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQCMultiple Volume Expansion Method
1,00
1,02
1,04
1,06
1,08
1,10
0 10 20 30 40 50
% Volume expansion
CO
2 V
olu
me
s
1. measurement
deviation ?
correction !
2. measurement
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Why does the Multiple Volume Expansion Method work?
The Multiple Volume Expansion method makes use of the fact that the solubility of CO2 is much higher than that of air.
By expanding the volume of the measuring chamber the partial pressures of CO2 and air change very differently.
Therefore CO2 and air partial pressures can be distinguished and the effect of dissolved air removed.
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQCMultiple Volume Expansion - Results
2,40
2,50
2,60
2,70
2,80
2,90
3,00
3,101 4 7
10
13
16
19
22
25
CO
2 [
v/v
]
0,00
0,50
1,00
1,50
2,00
2,50
3,00
3,50
4,00
DO
2 [
pp
m]
P/T (Calc.)
CO2 / CarboQC
DO2 [ppm]
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC Lab and at-line beverage carbonation meter
New patented MVE Multiple Volume Expansion method
No influence from dissolved air
For accurate and traceable CO2 measurements
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC
Measuring chamber
Display
Keypad
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC Rear view
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC
ON / OFF switch
Water-tight connection plug
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC withsemi-automaticfilling device
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Specifications of the CarboQC
Measuring range
0 to 12 g/l (0 to 6 Vol.) at 30°C (86°F)
0 to 20 g/l (0 to 10 Vol.) < 15°C (59°F)
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Specifications of the CarboQC
Repeatability 0.005 bar (0.07 psia)0.05°C (0.1°F)0.01 g/l (0.005 Vol.)
Reproducibility 0.015 bar (0.21 psia)0.1°C (0.2 °F)0.05 g/l (0.025 Vol.)
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Benefits of the CarboQC
No influence from dissolved air
Highly accurate absolute pressure sensor no weather and sea level influence
Very accurate temperature measurement due to impeller technique
No calibration/adjustment with reference methods or CO2 standards necessary
Zero point calibration simply with (tap) water
Small amounts of sample
Fast and accurate results in a wide temperature range
Versatile and easy to use with PFD filling device
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Comparison to Zahm & Nagel results
Zahm & Nagel requires snifting (venting) at bottles to decrease air influence leads to temperature & headspace volume dependent loss of CO2
Zahm & Nagel is subject to full influence of air at cans due to no snifting being possible
Zahm & Nagel pressure and temperature measurement provides only limited accuracy
Headspace related temperature effect causes deviations
The CarboQC provides more precise results than Zahm & Nagel
CarboQC results are lower due to lack of air influence
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
Comparison to membrane-type instruments
Drift due to change of membrane permeability
Frequent recalibration necessary
Influenced by sample pressure and flow rate
Limited temperature range of calibration
Large amount of sample required
Reliable measurement, no drift
Virtually no calibration necessary
No influence of sample pressure and flow rate
Accurate results on cold and warm samples
Small amount of sample
CarboQC Membrane-type
Anton Paar GmbH Anton-Paar-Str. 20, 8054 Graz, Austria-Europe Internet: http://www.anton-paar.com
CarboQC summary
Lab and at-line beverage carbonation meter
Patented Multiple Volume Expansion method No influence from dissolved air
Easy to use, fast and accurate
Wide measurement temperature range
Small amount of sample