Alternative Technologies for the
Rigid Foam Sector
Miguel W. Quintero
UNDP Consultant
November, 2012
UNDP, Sao Paulo, November, 2012
OVERVIEW
•
•
•
•
Polyurethane Rigid Foam
Role of the Blowing Agent
Desired characteristics of blowing agents
Available options to replace HCFCs
 Mature technologies
 Emerging technologies
• Conclusions
UNDP, Sao Paulo, November, 2012
THERMAL INSULATING FOAM
Appliances
– Refrigerators, freezers
– Commercial refrigeration (Bottle containers, displays)
– Water heaters, etc.
Construction/ Transportation/ Piping
– Panels (continuous, discontinuous)
– Blocks
– In situ applications (spray)
– Pipe insulation & PIP
UNDP, Sao Paulo, November, 2012
POLYURETHANE (PU) RIGID FOAM
Closed cells are the key !
Blowing agents are
enclosed
UNDP, Sao Paulo, November, 2012
PU Formulation
Network Formation
Kinetics Control
Polyether Polyols
Polyester Polyols
Catalysts
Surfactants
Water
Blowing Agents
+
Stabilizers
PMDI/MDI/TDI
CH
OCN
NCO
2
+
4,4'-MD I
NCO
NCO
CH2
NCO
CH2
n
CO2
UNDP, Sao Paulo, November, 2012
polymeric MDI
f=2.7
FULLY FORMULATED POLYOL
INGREDIENT
PARTS BY WEIGHT
Polyether Polyol
Polyester Polyol
80
20
Amine catalyst - gelling
Amine catalyst - blowing
Silicone surfactant
Flame Retardant
Water
External blowing agent (HCFC-141b)
1.0
0.5
1.0
10
2.0
22
Blowing agent content around 18 % ! In total foam 9 %
UNDP, Sao Paulo, November, 2012
ROLE OF THE BLOWING AGENT
Physical Expansion of the Foam
– Generation of CO2 by iso-water reaction
– Evaporation of the external blowing agent
Contribution of thermal performance
– Remains in the closed cells
– Low gas thermal conductivity
UNDP, Sao Paulo, November, 2012
REQUIRED FOAM PROPERTIES
•
Easy of Processing
 Ability to fill all the cabinets
• De-mould Time
 Productivity
•
Insulation Capability
•
Mechanical Strength
…at the lowest foam density!
UNDP, Sao Paulo, November, 2012
BLOWING AGENT CHARACTERISTICS
Foam requirement
Relevant Blowing Agent Characteristic
Ease of Processing
Flammability
Boiling Point
Solubility in the polyols
De-mould time
Insulating Performance
Mechanical Strength
UNDP, Sao Paulo, November, 2012
Broadly independent
Gas thermal conductivity
Permeability through cell wall
Boiling Point
Solubility in the PU matrix
STATUS IN DEVELOPED COUNTRIES
Blowing Agent Consumption – Developed Countries – 2010
(tonnes)
140.000
120.000
100.000
80.000
60.000
40.000
20.000
CFCs
HCFCs
HFCs
UNDP, Sao Paulo, November, 2012
HCs
HCOs
CO2
HFOs
Blowing Agents in PU Rigid Foams
CFC 11
CFC 11
50% reduced
c-pentane
HCFC 141b
HFC 134a
HFC 245fa
HFC 365mfc/
HFC 227ea
UNDP, Sao Paulo, November, 2012
Iso-/n-Pentane
c-pentane/LBHC
HYDROCARBONS
HCFC-141b Cyclo-Pentane
n-Pentane
Iso-Pentane
Iso-Butane
Chemical Formula
CCl2FCH3
(CH2)5
CH3(CH2)3CH3
CH3CH(CH3)CHCH3
CH3CH(CH3)CH3
Molecular Weight
117.0
70.1
72.1
72.1
58.1
Boiling Point ( 0C )
31.9
49.3
36
28
-11.7
8.8
11.0
14.0
13.0
15.9
5.6 – 17.7
1.4 - 8.0
1.4 - 8.0
1.4 - 7.6
1.8 - 8.4
725
<25*
<25*
<25*
<25*
2.0 – 4.0
2.0 – 4.0
2.0 – 4.0
2.0 – 4.0
2.0 – 4.0
Gas Conductivity
(mW/m.K @ 100C)
Flammable Limits in
Air (vol.%)
GWP (100 yr time
horizon)
Price (USD/kg)
^ Measured at 0º C * Precise figure varies according to local atmospheric conditions
UNDP, Sao Paulo, November, 2012
HYDROCARBONS
Most popular blowing technology/ improved with experience
Not suitable for spray
K values slightly higher than HFCs: gap is closing
Blends (c/ iso) to improve density
Low operating costs (Low BA cost)
Max. cost effectiveness factor: US $ 9.79/ Kg of substance
Flammable/ High capital investing cost
What about small/ medium enterprises?
UNDP, Sao Paulo, November, 2012
SATURATED HFCs
HCFC-141b
HFC-134a
Chemical Formula
CCl2FCH3
CH2FCF3
Molecular Weight
117.0
102
134
148
170
Boiling Point ( 0C )
31.9
-26.2
15.3
40.2
-16.5
Gas Conductivity
(mW/m.K @ 100C)
8.8
12.4
12.5 (20 ºC)
10.6 (25 ºC)
11.6
5.6 – 17.7
None
None
3.8-13.3
None
GWP (100 yr time
horizon)
725
1430
1030
794
3220
Price (USD/kg)
2–4
6 – 13
9 - 13
8 - 12
8 - 12
Flammable Limits in
Air (vol.%)
UNDP, Sao Paulo, November, 2012
HFC-245fa
HFC-365mfc
HFC-227ea
CF3CH2 CHF2 CF3CH2 CF2 CH3 CF3CHF CF3
CO2 FROM WATER
CONVENTIONAL FORMULATIONS
• Adhesion issues due to foam friability
• Reduced energy efficiency/ High K value
• High CO2 permeability/ High molded density
NEW GENERATION
Improved Adhesion & Foam Structure
Formic Acid for flow-ability (corrosiveness)
Note: Used in all formulations for co-blowing
Used for Spray Foam in U.S. & Europe & Japan (Supercritical CO2)
UNDP, Sao Paulo, November, 2012
BLOWING AGENTS IN DEVELOPED COUNTRIES
• Hydrocarbons – Dominant Technology
 Not used in spray
 Blended with saturated HFCs (HFC-245fa) to improve thermal performance
• Saturated HFCs
 Used in North America for appliances (HFC-245fa)
 Preferred option for spray
 Panels manufacture (fire properties)
 Small and medium enterprises (SMEs)
• Water blown foams (CO2)
 Small and medium enterprises (SMEs)
 Spray (Supercritical CO2 in Japan)
• Limited use of oxygenated hydrocarbons (Methyl Formate, Methylal)
UNDP, Sao Paulo, November, 2012
EVALUATION PROGRAMME FOR A NEW BLOWING AGENT FOR RIGID INSULATING FOAM
Toxicology and ecotoxicology testing (ODP, GWP, toxicology)
Processing characteristics:







Solubility in polyols
Stability in polyol blends
Flash point/flammability of polyol blend
Flow properties
Reaction times including jig dwell times (“De-mould time”)
Atmospheric concentrations during processing and comparison with flammable limits in air
Effects on equipment – seals and metal parts
Physical & Fire properties






Closed cell content
Density/strength relationships
Dimensional stability & Thermal conductivity versus temperature and ageing using accelerated methods
Foam friability
Adhesion to different substrates & Compatibility with contact materials
Fire code testing for construction industry foam-based components
Trials under commercial production conditions and long term testing of articles
UNDP, Sao Paulo, November, 2012
HCFC-141b
Methylal
Methyl Formate
Chemical Formula
CCl2FCH3
CH3 OCH2OCH3
CH3(HCOO)
Molecular Weight
117.0
76.1
60
Boiling Point ( 0C )
31.9
42
31.5
Thermal Conductivity
(gaseous)
(mW/m*K @ 150C)
8.8
N. A.
10.7 (@ 250C)
5.6 – 17.7
2.2 – 19,9
5,0 – 2.0
GWP (100 years horizon)
725
”Negligible”
"Negligible”
Price (USD/kg)
2–4
1.4 -1.7
2–4
Substance
Flammability limits (% vol.)
UNDP, Sao Paulo, November, 2012
Substance
Cyclo-pentane
Cyclo-pentane
Cyclo-pentane
Cyclo-pentane
Methylal
Methylal
Methylal
Methylal
Methyl Formate
Methyl Formate
Methyl Formate
Parts in polyol
Pure
4
6
8
Pure
4
6
8
4
6
8
Source: Intertox, 2010
UNDP, Sao Paulo, November, 2012
Flash Point (º C)
- 42.0
18.5
13.0
7.0
-18.0
26.5
13.0
6.0
53.5 - 59.0
53.0
39.0
Methyl Formate (Ecomate)
• Patented technology by Foam Supplies
 Applied in 18.12.2001
• 1.000 tonnes in 2010
 Total blowing agent market: 360.000 ton
 Australia, Brazil and South Africa
 Integral Skin and Flex-moulded
• Completed pilot project by UNDP
 Higher foam thermal conductivity versus HCFC-141b
 Higher densities versus HCFC-141b
UNDP, Sao Paulo, November, 2012
Methyl Formate (MF) (Ecomate)…
CONCERNS ON RIGID FOAM
•Flammability of polyol blends
•MF…a good solvent for the PU matrix
 Foam density increase
 Reduced MF content in cell gas…decreased thermal insulation
•Lack of information on long term foam performance (dimensional stability,
thermal conductivity)
•Lack of information on MF atmospheric concentrations during processing
 Limited experience in spray
•Decomposition of MF and Formic Acid formation
 Corrosiveness. Machine suppliers have developed protection kits
 Deterioration of thermal insulation by decomposition in the gas cell
Source: 2010 FTOC assessment report
UNDP, Sao Paulo, November, 2012
EMERGING OPTIONS – UNSATURATED HFCs/HCFCs (HFOs)
SolsticeTM Gas BA
Formacel® 1100
SolsticeTM Liquid BA
AFA-L1
1234ze(E)
1336mzzm(Z)
1233zd(E)
Undisclosed
Chemical Formula
Trans-CF3CH=CHF
Cis-CF3-CH=CH-CF3
Trans-ClCH=CH-CF3
Undisclosed
Molecular weight
114
164
130.5
<134
Boiling Point (0C )
-19
33
19
10.0<T<30.0
13
10.7
10.6 (25 ºC)*
9
Not up to 28ºC^
No
No
No
<6
8.9
<7***
<15
11.0 – 17.0
11.0 – 17.0
11.0 – 17.0
11.0 – 17.0
Name
Common name
Gas
conductivity(mW/
mK @ 10ºC)
Flammable Limits
in Air (vol.%)
GWP (100 years
Price (US$/kg)
UNDP, Sao Paulo, November, 2012
Commercial refrigerators/freezers plus vending equipment
Technology
Pros
Cons
Cyclopentane &
cyclo/iso blends
HFC-245fa, HFC365mfc/227ea
Low GWP
Low operating costs
Good foam properties
Non-flammable
Good foam properties
High GWP
High operating costs
High thermal conductivity
& high foam density
Low incremental capital cost
Improved insulation (cf. HC)
Non-flammable
High operating costs
Low GWP
High thermal conductivity
& high foam density-
Improved formulations (second
generation)
Moderate incremental capital cost
(corrosiveness protection)
Flammable although blends with
polyols may not be flammable
High operating costs
Low GWP
CO2 (water)
Methyl Formate
Highly flammable
Comments
High incremental capital cost,
uneconomic for SMEs
Well proven technology
Liquid Unsaturated
HFC/HCFCs (HFOs) Low GWP
Non-flammable
UNDP, Sao Paulo, November, 2012
High operating costs
Low incremental capital cost
First expected commercialization
in 2014
Promising thermal performance
Low incremental capital cost
NOT A SINGLE TECHNOLOGY
• Hydrocarbons
 Pre-blended Hydrocarbons
 Third stream to mixhead
• New generation of water blown systems
• Unsaturated HFC & HCFCs (HFOs)
 Reduced formulations ?
http://ozone.unep.org/new_site/en/assessment_panels
UNDP, Sao Paulo, November, 2012