by Karim Tarzi, marketing manager Foams, Honeywell
Honeywell is launching the latest addition to its fourth-generation platform of blowing agents for the polyurethanes industry at the UTECH Europe 2102 trade show being held 17-19 April in Maastricht, Netherlands. Solstice Liquid Blowing Agent (LBA) is a highly energy-efficient, low-global-warming blowing agent. The first in the series, Solstice Gas Blowing Agent, was commercialised in Europe in the second quarter of 2008.
Solstice LBA brings significant benefits for different applications. It can be used in the appliance sector; in spray foam applied under a range of demanding environmental conditions ; or in structural insulated panel applications.
On a global basis, the industry, individual government regulators, and non-governmental groups (NGOs) continue to seek solutions with low global warming and energy efficiency across all energy-consuming applications, including household refrigerators and construction materials. This new addition to Honeywell’s line of blowing agents demonstrates the company’s intention to achieve these goals.
Responding to environmental concerns
The use of fluorocarbon blowing agents started in the mid-1950s with the chlorofluorocarbon trichlorofluoromethane (CFC-11). Concerns over ozone depletion during the 1970s led to the development of a second generation of high performance blowing agents, the hydrochlorofluorocarbons (HCFCs), such as HCFC-141b.
Although conversion to HCFC-141b reduced the ozone depletion potential (ODP) of the blowing agent by 90 percent, subsequent regulation required the phase out of these blowing agents.
A third generation of blowing agents was developed — the hydrofluorocarbons (HFCs) — including HFC-245fa. These HFC materials satisfied the requirements of ozone-depletion regulations while retaining the high performance and non-flammability required of many uses of insulating foam.
Honeywell has been the leader in the development of fluorocarbon blowing agents and now leads the development of fourth generation blowing agent technology, which is driven by the continued need for energy efficient and low-global-warming solutions.
In its quest to develop these fourth generation materials, Honeywell’s goal was to retain all the positive attributes of the HFCs: high energy efficiency performance, nonflammability, low volatile organic compound (VOC) content, and ease of conversion. These properties continue to differentiate fluorocarbon blowing agents as the best choice for high performance rigid foam insulation and for those applications where a flammable blowing agent is either unsafe, too costly to use, or fails to provide the desired foam performance.
The fourth-generation materials were formulated to have a significantly lower global warming potential, reducing the climate change impact of the materials. This can be a key criteria point for product selection.
“We have succeeded in creating a highly energy-efficient blowing agent that also has a very low GWP of below 5,” said Paul Sanders, managing director for Honeywell Fluorine Products in Europe, Middle East, Africa and India. “By keeping the good attributes of HFCs, improving energy efficiency, and dramatically reducing the global warming potential, we are making it even easier for our customers to adopt the new products in both developed and developing countries.”
Solstice LBA: green performer
This new high performance material, while containing fluorine, also contains an olefin structure. The presence of a double bond in the molecule backbone makes the halo-alkenes a separate and distinct class from their predecessors. The chemical structure of these new agents results in a drastically shorter atmospheric lifetime than that of HFC materials, thereby resulting in a much lower global warming potential (GWP).
“Solstice LBA is a great molecule that offers improved performance and superior environmental performance compared to today’s blowing agents,” said Dave Williams senior technical manager, Honeywell.
“Results obtained so far have far exceeded expectations. The molecule yields higher energy efficiency than HFC-245fa in all applications we have evaluated, including appliances, spray foam, and insulated panels, while also offering the possibility of lower cost solutions and optimisation of performance through its inclusion in blends.” Superior appliance performance Energy -efficiency standards for refrigerators and freezers continue to increase in most countries. Meeting these energy standards determines whether a refrigerator can be sold in that country.
In a recent trial of 0.623 m³refrigerators and freezers manufactured using Solstice LBA, the refrigerators exceeded the US Energy Star label requirements by an average of 9.5 percent.
According to Jim Bowman, senior engineer at Honeywell, “This highly energy efficient household refrigerator/freezer was demonstrated to meet the requirements of ‘proposed’ US Department of Energy 2014 energy standard without employment of further energy solutions to this refrigerator/freezer platform, such as vacuum insulation panels or compressor modification.
Spray foam applications
Regulation and the growing number of ‘green’ builders are the two main issues within the construction industry driving demand for the next generation blowing agents” said Mary Bogdan, Honeywell’s’ senior principal scientist.
“We are aware of a growing number of architects and specifiers interested in using high-performance materials within the Passive House concept. Rigid foams using Solstice LBA help to meet these requirements.” Blending is a new technology that is developing quickly as end users consider optimisation of cost and performance through the use of various blowing agents.
Commercial options for fourth-generation blowing agents include a combination of the Solstice LBA and the Solstice Gas Blowing Agent. “This combination has proven very successful for spray foam applied in cold regions, where the properties imparted by the two molecules help to improve the reactivity of the formulation,” explained Bogdan.
Blends with other blowing agents, such as water, are under development by Honeywell, and are expected to broaden the choices in blowing agents for customers. For example, in countries where energy standards are high, OEMs can use pure Solstice LBA as a blowing agent.
For countries where energy standards are not as high, however, OEMs can dilute it with water to meet the energy performance and also lower costs.
Further, as energy standards increase (which they will eventually), they can decrease the amount of the diluent.
Insulated (sandwich) panel and pour-in-place applications
Solstice LBA has also proven highly effective in insulated panel applications. “Blends of hydrocarbon with Solstice LBA could provide a viable option to balance cost with physical properties and thermal insulation requirements for insulated panel applications”, said Jim Y. K. Ling, global technology sector leader.
“For panel applications that require superior thermal insulation at low temperatures, pure Solstice LBA or blends of hydrocarbons and Solstice LBA may provide a better solution than just hydrocarbons.” Initial laboratory results with pure Solstice LBA shows up to 10 percent initial lambda improvement compared to hydrocarbons, which could offer clear advantages like R-value improvement or panel thickness reduction.
Both of these are critical for new building construction as well as renovation.
At high temperatures, polyol premixes made with use of Solstice LBA have a 14 percent lower vapour pressure than polyol premixes using currently available blowing agents like HFC- 245fa. This makes spray foam formulations easier to handle and to store.
“We fully anticipate that, due to the superior properties of Solstice LBA, many end users will start using it ahead of regulatory requirements,” suggests Williams.
Benefits of 4th gen molecule
Solstice LBA is a non-flammable liquid by ASTM E-681 test methods, and exhibits no flashpoint or vapour-flame limits.
In transport, storage, and in factory use as a blowing agent, Solstice LBA has no limitations on hazards classification.
Solstice LBA is a near drop-in replacement for liquid HFC blowing agents and does not require costly hydrocarbon storage and handling or risk-mitigation equipment.
Solstice LBA is liquid at room temperature and can be used in most existing foam equipment with little or no modification, minimising or eliminating the need for large capital-conversion costs.
Solstice LBA is an extremely promising replacement for foam insulation blowing agents currently in use that can make significant contributions to reducing global warming.
The energy efficiency benefits of Solstice LBA, combined with its low global warming potential and safety in use, make it the right choice as a replacement for Enovate 245fa, HCFC-141b and 365mfc and hydrocarbons for use in foam insulation blowing agents.
Provides low GWP / VOC
Low GWP materials, because of their very short atmospheric lifetime, often prove to have photochemical ozone creation potential. This measure shows the propensity for ground level ozone formation — photochemical ozone creation potential (POCP) — which is reported, and compared to that of ethane, which has a POCP of 12.3 (Nielsen, University of Copenhagen). Solstice Gas Blowing Agent has a measured POCP of 6.4, well below that of ethane. The POCP of Solstice LBA is also estimated to be in this range and well below that of ethane.
Global legislative and commercial status
Honeywell’s Solstice Gas Blowing Agent has recently been listed as an acceptable substitute for HCFC foams under the US EPA’s Significant New Alternatives Policy (SNAP) programme. In addition, the US EPA Toxic Substances Control Act (TSCA) office has issued a Pre-Manufacturing Notice (PMN) for Solstice Gas Blowing Agent, allowing for commercial sale of this product in the US SNAP listing and TSCA approval for Solstice LBA has been applied for and is pending.
In Europe, Solstice Gas Blowing Agent has been registered under REACH and registration of Solstice LBA is in progress. In addition, both Solstice Gas Blowing Agent and Solstice LBA provide a substantial reduction in greenhouse gas emissions when used in place of high GWP F-gases regulated under the EU F-gas Regulation.
In Japan, both Solstice Gas Blowing Agent and Solstice LBA have been approved for commercial sale. Product registrations for both products are ongoing in the rest of the world.
Solstice Gas Blowing Agent has been available commercially since 2008, and Honeywell recently announced that it will build a commercial scale plant in Baton Rouge, expected to start up in 2013. Solstice LBA is expected to be commercial in late 2012/2013.
