Phase Change Matters

• Innovate UK’s Knowledge Transfer Partnership has awarded funding to a joint effort by AMP Clean Energy and the University of Birmingham to develop a thermal energy storage system. The system will incorporate phase change material developed by the university for use in AMP’s Urban Reserve flexible electricity generation plants, which will turn waste heat into electricity. The amount of funding was not disclosed.

• Geocryologist Christopher Stevens of SRK North America will give a PCM-related presentation at this week's International  Conference on Cold Regions Engineering in Quebec City: "Phase Change Materials – Innovation in Adaptation Technology to Address Permafrost Thaw" (Aug. 21).

• Australian start-up 1414 Degrees has announced a joint project with Nectar Farms to test “SmartFarm” applications of 1414's technology, which stores electricity as thermal energy by heating and melting containers full of silicon. 

U.S. patent application 20190249058 (applicant Technogel Italia S.r.L., Pozzoleone, Italy):

"A method for the production of a temperature regulating polyurethane gel composition and corresponding articles includes fatty acid esters as a phase change material (PCM) directly incorporated in the fluid phase of a polyurethane gel without encapsulation. The liquid or melted PCM is solved in the polyol component of the gel and is able to crystallize and melt within the gel structure reversibly. The polyurethane gels are under-crosslinked and include an at least nominal three functional ethylene oxide-comprising alkylene oxide polyether polyol with 0 to 40% EO and an isocyanate with an effective functionality of from 1.5 to 3.5. The gels are useful in articles where the gel can be positioned close to the human body for temperature regulating purposes, and especially to improve the sleeping comfort of a resting person."

http://www.freepatentsonline.com/20190249058.pdf

U.S. patent application 20190249904 (applicant SIDCO Homes Inc., San Jose, Calif.):

"An eco-smart panel is described comprising a a solar thermal panel, a phase change material, a metal foil layer, and a structural frame constructed of materials including wood studs, gypsum, or fiberglass-reinforced concrete. The materials may be variously configured to create modular systems for fabricating buildings or structures. Eco-smart panels may be utilized to create buildings or structure with enhanced energy efficiency, increased fire resistance, increased flood resistance, and decreased construction cost and time."

http://www.freepatentsonline.com/20190249904.pdf

From Applied Thermal Engineering:

• Application and sensitivity analysis of the phase change material hysteresis method in EnergyPlus: A case study

From Scientific Reports:

• A promising form-stable phase change material prepared using cost effective pinecone biochar as the matrix of palmitic acid for thermal energy storage

From Applied Energy:

• Geometry-induced thermal storage enhancement of shape-stabilized phase change materials based on oriented carbon nanotubes
• Passive cooling through phase change materials in buildings. A critical study of implementation alternatives

From Cement and Concrete Composites:

• Thermal responses of concrete slabs containing microencapsulated low-transition temperature phase change materials exposed to realistic climate conditions

From Solar Energy Materials and Solar Cells:

• Preparation and thermal properties of low melting point alloy/expanded graphite composite phase change materials used in solar water storage system
• Frost and high-temperature resistance performance of a novel dual-phase change material flat plate solar collector

From Energy:

• Novel micro-encapsulated phase change materials with low melting point slurry: Characterization and cementing application

From IOP Conference Series: Materials Science and Engineering:

• Thermal performances and characterization of microencapsulated phase change materials for thermal energy storage

From Journal of Physics: Conference Series:

• Effect of thermal performance on melting and solidification of lauric acid PCM in cylindrical thermal energy storage

From Construction and Building Materials: • A sodium acetate trihydrate-formamide/expanded perlite composite with high latent heat and suitable phase change temperatures for use in building roof

From Materials Research Express:

• Investigation of magnesium nitrate hexahydrate based phase change materials containing nanoparticles for thermal energy storage

From Journal of the Brazilian Society of Mechanical Sciences and Engineering:

• Selection of phase change material for solar thermal storage application: a comparative study

From Renewable Energy:

• Experimental study on the thermal performance of a grey water heat harnessing exchanger using phase change materials

From International Journal of Energy Research:

• Climate applicability study of building envelopes containing phase change materials

A new dormitory at Williams College in Massachusetts is equipped with 18,200 square feet of mats filled with phase change material.

Garfield House, completed in time for the first students to move in this month, is designed to achieve Passive House PHIUS+ certification and LEED Gold certification. It features R-38 walls, R-60 roofs, triple-pane windows, high-efficiency energy recovery ventilation units, drainwater heat recovery and a 50 kw photovoltaic array.

The Infinite R PCM mats, made by Insolcorp LLC of New London, N.C., will help keep the passively cooled building comfortable when the weather is warm. The PCM is a salt hydrate with a peak melting point of 73 degrees F and a thermal storage capacity of about 170 joules per gram. The mats are deployed within Garfield's interior walls and above ceilings.

Jacob Higginbottom, director of higher education design at SGA in Boston, was project manager. He first learned about the potential use of phase change material in building envelopes and interiors in March 2018.

"A member of our team had run across the Infinite R product at a trade show and our client was looking for ways to introduce passive cooling techniques since it’s their campus standard to build residence halls without active cooling," said Higginbottom, right. "Upon research we convinced the client that this could help and they decided to give it a try."

Garfield House has no active cooling system. Did that present any special challenges?

"The fact that Garfield did not have cooling wasn’t necessarily a challenge for the PCM, but perhaps was more of an opportunity for the project itself," said Mick Dunn, Insolcorp president. "The project wasn’t without a cooling source altogether. The design team implemented well-designed ERV/ventilation to leverage cool overnight temperatures. As part of the Passive House design process, some issues were identified with cooling and being able to maintain comfort without the introduction of A/C. So we worked with them to analyze a suitable amount of PCM to help address that cooling issue and help negate the need for investment in mechanical cooling other than ventilation.

"We’ve had numerous applications where the PCM has been used with no active cooling. Most of these have been very large industrial applications where the PCM has been used to control peak plant temperatures in buildings with very high internal heat loads. The results have been very good, and we’ve seen reductions as much as 10 to 15F compared with baseline temps. Sometimes we’ll be using a higher temp PCM to promote natural re-freezing. In more conventional occupied office/housing applications we’d typically still be looking for some kind of mechanical cooling mechanism such as ventilation if air conditioning is not present. And we’d probably be more likely to consider this as a viable strategy in climates such as California or New England than say Florida where humidity and overnight temperatures are very high."

The engineering firm Thornton Tomasetti of New York conducted whole building energy modeling in WUFI Passive, the program required by the Passive House Institute US (PHIUS). The models project cooling demand of 0.74 kBtu per square foot per year and a cooling load of 1.64 Btu per hour per square foot. A PCM thermal simulation model projects a peak cooling reduction of 10 degrees F.

Will the building's actual performance be measured against these metrics in the first year of occupancy?

Elsa Mullin, senior sustainability consultant at Thornton Tomasetti, says PHIUS "does not require post-occupancy measurement and verification after initial occupancy."

Higginbottom said LEED certification for the design portion is completed. All construction requirements have been submitted and he expects a LEED Gold certificate from the U.S. Green Building Council by the end of the month.

He said the use of PCM won't be a factor in the certification process.

"A building like this can easily achieve LEED Gold without the use of this material," he said. "PCM was introduced to address thermal comfort. Active cooling does not dramatically affect the building energy consumption in a use type like this (most loads come from domestic HW and plug loads and ventilation fans which are still required irrespective of cooling design)."

It's the first time Higginbottom has used PCM in a project. He hopes to use it in future projects.

"The interesting part about this product is the ability to fine-tune a building towards net zero or net positive and also to flatten out the demand for cooling and possibly downsize equipment in the future and save money on operating and up front costs," he said. "We would like to have more research to back that up, but it’s a speculation on our part that this would be a benefit to building owners’ first costs and life-cycle costs."

U.S. patent application 20190231121 (applicant Ember Technologies Inc., Westlake Village, Calif.):

"An infant bottle feeding system includes an infant bottle with a chamber that receives a liquid, heating or cooling elements operable to heat or cool liquid in the chamber and sensors operable to sense parameters of the liquid in the chamber. The system optionally includes an electronic base removably attached to a bottom surface of the infant bottle and operable to deliver power to electronics in the infant bottle. The system optionally includes a thermal cover that fits over the infant bottle and releasably couples to the electronic base to enclose the infant bottle, the thermal cover insulating the infant bottle and inhibiting heat loss of the liquid in the chamber. The electronic base delivers power to the heating elements and sensors in the infant bottle only when the infant bottle is on the electronic base. The infant bottle, thermal cover and electronic base define a single travel pack unit when coupled together."

http://www.freepatentsonline.com/20190231121.pdf

U.S. patent application 20190231598 (applicant Alps South LLC, St. Petersburg, Fla.):

"A garment using a phase change material that change phase from solid to liquid at a low or high temperatures situated within a gel matrix. The phase change material may be used after surgical procedures to reduce swelling, edema and bruising. The gel matrix allows the material of the present invention to maintain a conformable and elastic form at room temperature. This invention provides the novelty of a low or high temperature phase change material that is conformable to surfaces or volumes of varying geometry."

http://www.freepatentsonline.com/20190231598.pdf

UK-based Croda International recently announced the launch of a microencapsulated form of biobased phase change material developed at the company's PCM technical center in Netherlands. The new material is designed to be used to control temperatures in bedding, mattresses, automotive interiors, clothing and other applications.

The development was led by Marco Auerbach and Jerome Gonthier, working with colleagues who have expertise in microencapsulation and acrylic polymer. Martin Butters, a specialist in PCM applications and business development, also supported the project.

Gonthier and Butters provided details on the new material in an email interview.

Q: What prompted the decision to develop this technology?

A: "Having established a range of high-quality bio-based PCMs, market demand led us to explore the microencapsulation of these PCMs. Microencapsulation converts the PCM into particles that are offered to the market in two forms, powder and water-based dispersion. Microencapsulated PCMs are often advantageous for use in composite materials such as coatings, fibers and other matrices where PCM leakage needs to be avoided."

Q: How long did it take to complete the project?

A: "Overall the project ran for about four years leading to the launch of the first products in 2018."

Q: Did the team surmount any unexpected challenges, technical or otherwise?

A: "The challenges were mainly those we expected – achieving microcapsules with good durability, very low levels of free wax and overcoming sub-cooling (reduction in crystallisation temperature due to microencapsulation)."

Q: When did Croda officially launch the technology commercially?

A: "The first products, CrodaTherm ME 29D (50% dispersion) and CrodaTherm ME 29P (powder), which are 29º C melting point products, were launched in Q4 2018. 32º C versions will be added to the range shortly and we expect the range to be further extended with other operating temperatures in due course."

Q: Does Croda manufacture fibers and textiles with the microencapsulated PCM? Or does it manufacture the MPCM and sell it to fiber and textile manufacturers?

A: "Croda does not produce fibers or textiles, instead we specialize in offering PCMs that are developed and manufactured in-house, for use in such applications (and many more)."

Q: What specs can you share on the MPCM, such as composition, peak melt point and latent heat storage capacity?

A: "We microencapsulate CrodaTherm bio-based PCMs with an acrylic-type shell. For CrodaTherm ME 29D and ME 29P, peak melting temperature is 29ºC and latent heat is typically about 180 J/g."

Q: Does the MPCM have any properties, such as latent heat storage capacity or ease of manufacture, that sets it apart from competing products?

A: "We use internally produced bio-based PCM, rather than paraffin waxes sourced externally from the market, meaning we have full control over quality and the products have high bio-based content and excellent thermal properties."

Q: Have textiles embedded with this MPCM undergone thermal effusivity testing or other tests that would confirm their effectiveness in managing temperatures in consumer products?

A: "Several tests have been carried out to confirm the performance of materials embedded with mPCM and further work will be carried out, including thermal effusivity."

Q: Will the technology be used in any products scheduled for release this year or next?

A: "A number of projects are underway for different applications, so we’ll have to wait and see!"

• PureTemp-enhanced fabrics were among the new materials presented at a gathering of architects, designers and journalists at the MatériO library in Paris this week. The materials library, which also has showrooms in Brussels, Seoul and Shanghai, lists thousands of "cutting edge" materials and technologies in its online database, including PureTemp's biobased PCM.

• Southern Research opened the new Energy Storage Research Center on its engineering campus in Birmingham, Ala., this month. The center will work to speed the development of clean and sustainable energy storage technology, including thermal energy storage systems. 

• Ecozen Solutions of India, which makes portable solar cold rooms for use on small farms, recently closed a Series A round of funding from investors including impact investment fund manager Caspian and Hivos-Triodos Fund, which is affiliated with Netherlands-based Triodos Bank. Omnivore Capital Management Advisors, which originally invested in Ecozen in 2015, also participated in the round, AgFunder News reports. The solar cold room's thermal storage unit can store power for more than 36 hours in case of cloudy or rainy weather. 

U.S. patent application 20190223636 (applicant Probalco BVBA, Kortrijk, Belgium):

"A pouch [510] filled with phase-change material [530], wherein the pouch comprises a preformed first wall [521] and a second wall, wherein the first wall comprises a bowl-shaped part, in which the phase-change material is accommodated, and a peripheral part, wherein the second wall is attached to the peripheral part of the first wall, wherein a high vacuum prevails in the pouch, and wherein the pouch is intended for placing against a wall to be heated or cooled. ... The present invention further relates to crockery provided with a pouch filled with phase-change material."

http://www.freepatentsonline.com/20190223636.pdf