1. GASS™-2040
Gas
Analysis
Sampling
Systems

2. GASS-2040 New product introduction at AWMA
Combines capabilities of Probe / Mini-GASS™ and GASS™-II systems
Can be mounted anywhere, including directly on stack flange with optional integral sample probe
Most complete sample conditioning system on the market
GASS-II discontinued, all other GASS systems still available

3. The General Problem Sample conditioning receives little attention,
Gas analysis for Emissions or Process Monitoring involves three steps:
1. Sampling Conditioning Analysis
Samples are typically: Hot Wet Dirty
Analyzers require samples to be: Cool Dry Clean
Sample conditioning receives little attention,
but is often the most difficult step of the three.

4. Sampling Methods In-situ analysis 2. Extraction 
a. Wet (filtered only)
b. Dilution
c. Drying
1) Absorption
2) Condensation
3) Selective permeation 

5. Typical Problems in Gas Samples
Gases
Rarely a problem
Liquids
Water
Acid mists (sulfuric acid)
Solids
Ammonia salts
Excessive particulates

6. Water Problems Clogging or damage to analyzers or components
Requirement for heated lines or analyzers
Long calibration times due to adsorption/desorption
Interference in infrared (or other) measurements
Loss of water-soluble analytes
Participation in unwanted chemical reactions

7. Sulfur Dioxide Solubility in Water
100 90 80 70 60
SO2 Solubility (ml SO2/100 ml H2O) 50 40 30 20 10 10 20 30 40 50 60 70 80 90
100
Temperature (Deg. C)

8. Sulfur Dioxide Solubility in Water
Temperature
Degree C
SO2 Solubility in H2O
ml SO2 / 100 ml H2O
Temperature
Degree C
SO2 Solubility in H2O
ml SO2 / 100 ml H2O 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17
79.8
77.2
74.7
72.2
69.8
67.5
65.2
63.0
60.8
58.7
56.6
54.7
52.7
50.8
49.0
47.3
45.6
43.9 18 19 20 21 22 23 24 25 26 27 28 29 30 35 40 90
100
42.4
40.8
39.4
38.0
36.8
35.3
34.0
32.8
31.6
30.4
29.3
28.2
27.2
22.5
18.8
2.1 .0

9. Unwanted Reactions 1. Formation of Sulfuric Acid
a. 2SO2 + O2  2SO3
SO3 + H2O H2SO4
b. NO2 + SO2 + H2O H2SO4 + NO
2. Formation of Ammonia Salts
a. NH3 + SO2 + H2O NH4HSO3
b. NH3 + SO3 + H2O NH4HSO4



 
 

10. Acid Mist Problems Mists are very corrosive, viscous, clogging
Difficult to remove; slow to coalesce
into sizeable droplets when cooled
Special coalescing filters helpful

11. Ammonia Salts Problems
Present special problems
Ammonia is gas, passes through probe filter
Forms clogs if allowed to cool, react with
SO2 or SO3 and H2O to form ammonium salts
Requires special absorbents to remove
ammonia before cooling to prevent clogs

12. Excessive Particulates
Easiest to solve
Probe filter with heated blowback
Secondary filter with finer porosity
Inertial bypass filters if necessary

13. The Solution GASS™-2040 Gas Analysis Sampling Systems
Retain water-soluble analytes (HCl, SO2, NOX)
Achieve low final sample dew points (down to -25oC)
Accept high sample flow rates (up to 25 L/minute)
Accommodate nearly any sample (customized)
Eliminate heated sample lines (stack mounting)

14. GASS™-2040 Gas Analysis Sampling System

15. GASS™-2040 Overview Stainless steel NEMA-4X enclosure
Integral probe with heated filter and blowback
Hastelloy heat exchanger
Coalescing/particulate filter with automatic drain
Ammonia scrubber(s)
Wide range of dryers, double dryers
PLC with Ethernet for remote control
Safety interlocks and alarms
Sample pump, other options to customize system

16. Integral Probe, Filter and Blowback

17. Integral Probe, Filter and Blowback
Range of probe lengths and materials
Directly connected, no heated line
Probe filter stainless steel or glass-coated
Temperature controlled by PLC
Avoids losses of analytes in filter
Blowback heated, closely coupled
Blowback timing controlled by PLC
Avoids condensation during blowback

18. Coalescing / Particulate Filter and Drain

19. Coalescing / Particulate Filter

20. Coalescing / Particulate Filter

21. Coalescing / Particulate Filter
Two-layer, coalescing and particle element
Temperature controlled by PLC
Removes particles >0.1 micron and mists
Hastelloy heat exchanger
Improves acid mist removal
Available in stainless steel or PVDF Kynar®
Corrosion resistant

22. Automatic Drain

23. Automatic Drain Coalesced liquid removed by eductor
Drain timing controlled by PLC
Reliable, no peristaltic pump
Eductor entirely PTFE Teflon®
Full corrosion resistance
Teflon check valve
Positive seal when not operating

24. Ammonia Scrubber 

25. Ammonia Scrubber

26. Ammonia Scrubber

27. Ammonia Scrubber Proprietary scrubbing media
Long-lasting, selective for ammonia
No tools needed for media replacement
Easy maintenance
Stainless steel with stainless steel shell
or polysulfone shell for visibility
Corrosion resistant

28. Nafion® Gas Dryer 

29. NAFION® Chemical Structure
[ (CF2 CF2 )m CF CF2 ] n O
CF2
CF CF3 Z O
WHEN:
m = 5 to 13.5
n = ca 1,000
z = 1,2,3...
x = 1 to 13
CF2
CF2
SO3 H ● [H2O]X

30. NAFION Gas Dryer Principle

31. NAFION Dryer Schematic

32. PD-Series Polytube Dryers

33. NAFION Selectivity Nafion permeation selectivity is based on
chemical reactivity, not size
Only compounds that chemically associate with
sulfonic acid permeate through Nafion
Bases associate with sulfonic acid and permeate
through Nafion
Very few bases are gases at typical operating
temperatures, so very few compounds permeate

34. Effect on Analytes Removes water directly as water vapor.
No condensate forms to dissolve analytes.
Removes compounds with hydroxyl groups (-OH)
H2O, some organics
Retains important compounds
O2, O3, CO, CO2, NOX, SO2, SO3, H2S, Hg, HCl

35. PD-Series Performance Chart
DEWPOINT (oC)
-40
-50
-30
FLOW (liters/min.)
PD-50T 1 2 3 4 5 6 7 8 9 10
-45
-35
12”
24”
48”
72”
-25
-20
-15
-10 -5 15 20
PD-100T 12 14 16 18
PD-200T 24 28 32 36 40
MODEL

36. Low Final Dew Points Dew point as low as -45oC can be achieved.
Dew point of -10oC to -25oC is typical.
Performance is a function of dryer size and sample flow rate.
Analytical results and reliability improved by reducing water interferences.
Acid mist problems overcome.

37. PLC 

38. PLC Digital selection of operating conditions
Precise control of operating parameters
Standard unit, easy programming
Easy maintenance and updating
Optional Ethernet connection
Remote control and data display

39. Optional Heatless Dryer

40. Optional Heatless Dryer

41. Optional Heatless Dryer

42. Optional Heatless Dryer
Steady supply of dry air for system use
Continuous 60 L/min. to -45ºC dewpoint
No line pressure surges
Inactive canister repressurized before reuse
Very reliable with no maintenance
Electronic switching, permanent spring-
loaded molecular sieve

43. Optional Sample Pump 

44. Optional Sample Pump Pump head mounted in heated zone
Prevents sample condensation
Pump motor mounted in unheated zone
Improves pump reliability
Pump head stainless steel or Teflon
Corrosion-resistant, long life
Sample transported under pressure
Avoids contamination from minor leaks

45. GASS-2040 Options Integral Probe Probe Filter Blowback Bypass Filter
Coalescing Filter
Automatic Drain
Ammonia Scrubbers
Dryer Sizes
Purge Heatless Dryer
Ethernet Connection
X- or Z-Purge
Kynar® Fittings
Sample Pump
Purge Eductor

46. Summation Proven technology, years of experience
GASS™-2040 combines all necessary sampling and conditioning in one package
Proven technology, years of experience
Opportunity to eliminate heated lines
Many options; buy only what is needed
Smaller systems available for less demanding applications