Tank to Grave Management of new Low-GWP Refrigerants (Hantering av nya låg-GWP köldmedier från installation till destruktion)

The project “Tank to Grave Management of new Low-GWP Refrigerants” is a project funded within the Termo program (heating and cooling for future energy systems), the 5th funding call (contributing to a Sustainable Energy System through Heating and Cooling) by the Swedish Energy Agency.

Project acronym:

TGM-LGWPRef

Funded by:

Swedish Energy Agency

Project Number:

P2022-00477

Time period:

2022-09-12 – 2024-12-31

Project partners:

KTH

EcoScandic Oy (Finland)

Linde Gas AB (Sweden and Greece)

Ahlsell AB (Sweden)

HUURRE AB (Sweden)

Thermia AB (Sweden)

Background

Refrigeration is one of the “twenty most significant engineering achievements of the 20^th Century” [1], [2], inevitable in today’s society. Refrigerants (the working fluid in heat pump and refrigeration systems) started their evolution with the 1^st generation, e.g., NH₃, propane and CO₂ [2]. In 1930-1995 chlorofluorocarbons (CFCs) (Freons), e.g. R-11, R-12 and R-22, became the 2^nd generation [2], [3], for being non-flammable, non-toxic and durable [4], [2]. For their impact on ozone depletion, Montreal protocol replaced these with the 3^rd generation in hydrofluorocarbons (HFCs), e.g. R134a and R32 [4]. HFCs have significant global warming potential (GWP) [4], [2], and thus with F-gas regulation and the Kigali Amendment to Montreal protocol, are being partly phased out within this decade. This led to less stable refrigerants as the 4^th generation, in hydrofluoroolefins (HFOs) [2], [4], e.g. R1234yf and R1234ze(E) [4], used by the industry in blends, e.g. R448A and R464A [4] [3]. Some of these blends are however non-azeotropic, risking compositional changes when recharged to or leaked from the systems [4]. Besides, the oils in these systems exhibit different affinity to the blend components, thus posing risk for composition glides and decomposition [4]. The knowledge of these phenomena is limited/unavailable today and thus their effects on the refrigeration/heat pump system’s function and efficiency.

In this context, within a recently completed project by KTH with RISE (Swedish Energy Agency, nr. 2019-003370), while contributing to the IEA HPT Annex 54 on Heat Pump Systems with Low GWP Refrigerants, a Gas Chromatograph (GC) (Trace 1310 from Thermo Fisher) was procured. This GC, as shown in Figure 1, is for analyzing the new low-GWP refrigerant blends to contribute to the state-of the art and to the relatively unknown knowledge on their composition glides and decomposition in use e.g., in real heat pump and refrigeration installations.

Figure 1. The State-of-the-art Gas Chromatograph (Trace 1310 from Thermo Fisher) that will be used for the analysis of low-GWP refrigerants at KTH, Energy Technology, Applied Thermodynamics and Refrigeration

Project summary

With this background, this new project TGM-LGWP Ref (P2022-00477) is set to investigate low-GWP refrigerants throughout their entire useful lifetime, from the source cylinder to the final destruction point. Here, department of Energy Technology at Royal Institute of Technology KTH partners with stakeholders from the entire value chain, i.e., EcoScandic Oy- Finland, Linde Gas AB- Sweden and Greece and Ahlsell AB, HUURRE AB and Thermia AB- Sweden. Complementarily, a reference group is being formed with e.g. Coop AB, EKA analysis AB, NIBE AB, Svensk Freonåtervinning AB and H. Jessen Jürgensen, etc. Thereby, the project plans and results will be discussed and disseminated along the entire value chain.

Aim and objectives

Within this background, this new project aims to investigate if low-GWP refrigerants used in real heat pump and refrigeration installations maintain their expected original compositions (or if not, their variations and decompositions) and to find more environmentally-friendly routes for their recovery, recycling and disposal at the end-of-life. Key experimental inputs will come from GC-based systematic investigations on these refrigerants during their service life, from tank (pristine conditions) to grave (at disposal). To achieve this, the project objectives are:

Map the state-of-the-art of tank-to-grave management of new low-GWP refrigerants, concerning the approaches today, to evaluate/explore:
- the compositions (and potential variations) of new low-GWP refrigerants during their use upon e.g. recharging, leakages, possible oil dissolution and decomposition, in real heat pump and refrigeration installations
- the recovery, recycle and their end of life management (disposal) of new low-GWP refrigerants
Develop/establish a suitable systematic methodology to specifically analyze these low-GWP refrigerant blends with Gas Chromatography
Identify and analyze the compositional variations (glides and/or decomposition) that could occur in these new low-GWP refrigerants at the various phase of their lifetime, and their potential impacts on the functionality and efficiency of these refrigeration and heat pump systems
Explore the potential for the recovery and recycle of these new low-GWP refrigerants, and the environmental impacts of their disposal, and therein possibly more environmentally routes for their end-of-life management.

Outcomes (Plan)

Progress and results discussions and project execution plan refinements at several project group meeting, reference group meetings
2-3 master’s thesis projects with final reports that will be published with open access in KTH DiVA
The completion of 01 master’s level student project and report (MJ 2409 Applied Energy Technology, Project Course, 9.0 credits in 2018)
Around 2 conference publications with oral presentation of the results and possible articles in proceedings
1-2 journal publications based on the key results
Several interim reports and a final report submission to the Swedish Energy Agency
Close collaboration with the stakeholders along the entire value chain, and continuous dissemination of the results coupled with a final dissemination workshop aimed at all interested stakeholders.

Publications

Upcoming…

References:

[1]	G. Constable och B. Somerville, A Century of Innovation: Twenty Engineering Achievements that Transformed our Lives, Washington, DC: John Henry Press: , 2003, 2003, p. 248.
[2]	M. O. McLinden och M. L. Huber, ”(R)Evolution of Refrigerants,” Journal of Chemical Engineering Data, vol. 65, p. 4176−4193, 2020.
[3]	ASHRAE, ”ASHRAE REFRIGERANT DESIGNATIONS,” ASHRAE, 80 Technology Parkway NW, Peachtree Corners, Georgia 30092 US, 25 May 2021. [Online]. Available: https://www.ashrae.org/technical-resources/standards-and-guidelines/ashrae-refrigerant-designations. [Använd 02 February 2022].
[4]	B. Palm, Personal Communication- The Evolution of Refrigerants, Stockholm: KTH Royal Institute of Technology, 2021.