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