GREEN MATTERS
Isn’t it time to check all the boxes? This report from Climalife looks at the humble heat transfer fl uid.
D
As professionals, and as part of our daily lives, we are all constantly looking to reduce emissions either directly, by using
products with the lowest climate change potential or indirectly by reducing energy usage and using products with a low manufacturing carbon footprint. In the refrigeration, air-conditioning and heat pump industry there are many great examples of low carbon footprint projects using energy effi cient systems and very low GWP refrigerants, only to then use a non-renewable heat transfer fl uid (HTF) such as monopropylene glycol (MPG) or monoethylene glycol (MEG). Both MEG and MPG are derived from fossil fuels, however there is an alternative which is plant based, manufactured from a renewable feedstock source, and does not require compromise.
Renewable low carbon source The main purpose of any carbon mitigating technology should be to reduce the impact on the environment largely by off setting non- renewable carbon with renewable carbon. With this in mind, the considerations of environmental
impact begin way before the product is actually used and include the manufacturing process. In recent years the concept of embodied carbon has been introduced, which not only considers the environmental footprint of the fi nal product in use, but also takes into account the carbon emissions involved with bringing the product to market.
Bio-sourced HTFs such as Greenway Neo
N from Climalife have been shown to have a signifi cantly lower embodied carbon, with >41% lower energy usage resulting in up to 42% lower emissions from raw material extraction to post- production delivery compared to the production of traditional MPG. The base material for this bio- sourced HTF is manufactured via a fermentation and purifi cation process from renewable dent corn, which is already grown on an industrial scale. The fi nal product is 1,3-propanediol, an isomer of the non-renewable 1,2-propanediol (MPG) traditionally used.
Long lasting eff ective corrosion inhibitors As corrosion is likely occur without a suitable corrosion inhibitor package present, using pure
Figure 1: Comparison of manufacturing GHG emissions using non-renewable energy.
glycol is not recommended. Many manufacturers of HTFs use traditional mineral-based inhibitor packages, but these can degrade over time and they also form a protective fi lm on all metal surfaces, including heat exchangers, which can result in a reduction of the heat transfer rates lowering the system performance. An alternative to these mineral-based options, and the option used in HTFs produced by Climalife, are long life hybrid corrosion inhibitors also known as H-OAT (Hybrid Organic Acid Technology) which not only provide excellent long-lasting corrosion protection (ASTM D1384) but are also only deposited on the areas subject to corrosion avoiding the heat transfer blocking eff ect of the mineral-based inhibitors.
Being plant based, HTFs based on
1,3-propanediol are biodegradable (90-100% in 28 days by the Zahn-Wellens/EMPA Test, OECD 302 B) leading to a reduced risk of soil pollution in the event of a leak and making them ideal for use in ground source heat pump systems. Development of bacteria, mould, fungi, and
algae are all possible and detrimental in secondary cooling circuits, but use of a product such as Greenway® Neo N which is bacteriostatic (ISO 11930) can prevent it from becoming an issue.
Figure 2: Viscosity profi les for Greenway NEO N, MPG and MEG 24 June 2024 •
www.acr-news.com
Energy and system cost savings As might be expected the properties of 1,3-propanediol are similar to the traditional 1,2-propanediol but there are some diff erences which lead to potentially signifi cant additional operational benefi ts.
Download the ACR News app today
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60
