The New Future of Coolants

Generally the engine coolant in the market place are glycol based. Both ethylene glycol and propylene glycol contain toxic that may give adverse implications for the environment. The engine coolant material based on propylene glycol is essentially little friendlier for the environment but the material comes from non-renewable sources.

Several studies have tried to provide an alternative solution with the aim of making the engine cooling so that the product has a low cost and environmentally friendly. Here are some alternative materials to make the engine coolant in the future are:


1. Glycerin

Glycerin is mostly known for its use in the food industry as well as in personal care products. It is also used as antifreeze and even as one of the ingredients to manufacture explosives. Glycerol, also referred to as glycerin or glycerine is a chemical compound that a generally nontoxic, sweet-tasting viscous liquid. The formula for glycerin is . It has 3 carbon (C) atoms, 8 hydrogen (H) atoms, and 3 oxygen (O) atoms.

Chemical Formula:

Chemical Structure:    


The chemical structure of glycerin  shows that each carbon atom is bonded to an OH group. These OH groups are what we call hydroxyl groups. Because of this, glycerine is classified as a polyol, which is an alcohol containing more than one hydroxyl group. Glycerin is soluble in water because of the hydroxyl (OH) groups attached to the carbon atoms. These hydroxyl groups are also responsible for the hygroscopic nature of glycerin, which means that it readily retains or taken up water.


The density of glycerol is 1.261 g/ml. Its boiling point is 290 ℃ and its melting point is 17.8 ℃.  These values show that glycerine is denser than water, its boiling point is higher than water and its melting point is higher than water.


Today glycerin is considerably cheaper than both ethylene and propylene glycol currently used in engine coolants. For this reason and lower toxicity comparable to that propylene glycol, glycerin was rapidly reconsidered as base for a number of commercial antifreeze and coolant products. The freezing point and boiling point of 50% glycerin and 50% water as describe below:

source: iarjset

It was noted that the optimum coolant temperature at outlet was almost 38 ℃.


2. Ammonia

Ammonia (), colourless, pungent gas composed of nitrogen and hydrogen. It is the simplest stable compound of these elements and serves as a starting material for the production of many commercial important nitrogen compounds. The ammonia structure:

The ammonia can be applied directly or in the form of ammonium salts such as ammonium nitrate (), ammonium sulphate , and various ammonium phosphates. In the textile industry, ammonia is used in the manufacture of synthetics fibres, such as nylon and rayon. In addition, it is employed in dyeing and scouring of cotton wool and silk. Ammonia server as a catalyst in the production of some synthetic resins.


Ammonia is used in various metallurgical processes, including the nitrating of alloy sheets to harden their surfaces. Because ammonia can be decomposed easily to yield hydrogen, it is a convenient portable source of atomic hydrogen for welding. In addition, ammonia can absorb substantial amount of heat from its surroundings (i.e., one gram of ammonia absorbs 327 calories of heat), which makes it useful as a coolant in refrigeration and air-conditioning equipment.


The ammonia characteristic

  • a colourless non-flammable liquefied gas
  • vapour is lighter than air – 0.6 compared to air 1.0
  • Ignition temperature 651 ℃ (vapour concentration between 15% and 28%)
  • corrodes galvanized metals, cast iron, copper, brass or copper alloys
  • weight of liquid ammonia 5.15 pounds per gallon (water weight 8.33 pounds per gallon)
  • boiling point liquid ammonia at atmospheric pressure -2.2 ℃
  • liquid ammonia expands to 850 times its liquid volume at atmospheric pressure


Ammonia Temperature Pressure Diagram


Using ammonia as a coolant in refrigeration has many advantages: lower operating costs and improve safety, naturally supplying environmental gains and infusing a new level of efficiency into the operations of refrigerated warehouses and processes. These days, the potential for ammonia-based systems – to deliver measurable financial and environmental gains – is getting the attention of the industry. Ammonia refrigeration continues to expand with new partnerships between industry leaders, end users and government agencies, answering the demands of global supply chain with a highly effective and efficient technology.


3. CryoSolplus

The cryosolplus is a dispersion that mixes water and paraffin along with stabilizing tensides and a dash of the anti-freeze agent glycol. CryoSolplus advantages are it can absorb three times as much heat as water, and functions better as buffer in extreme situations. Water has about 4 timers the heat capacity of air, on the basis of mass or weight and 3000 times more on basis of volume, a more relevant relationship when the weight is consideration.


The amazing ability of CryoSolplus is due to the solid paraffin droplets suspended in the dispersion. These droplets melt when the coolant absorbs heat, effectively storing the heat inside. When the coolant cools, the paraffin droplets solidify again. These droplets are called phase change materials.


According to Fraunhofer Institute for Environmental  research the characteristic of CryoSolplus as describes below:


Freezing and Melting Curves of CryoSolplus

source: Fraunhofer Institute


Melting peak point [°C]
Freezing peak point [°C]
Heat of fusion [kJ/kg
Density liquid [kg/l]
Volume expansion
0.77 (15 °C)
10 %
0.78 (20 °C)
10 %
0.75 (70°C)
10 %

CryoSolplus is good at conducting away heat, moving it very quickly from the battery cells into the coolant.



The new breakthrough and research is needed in manufacturing the coolant. The aims of this research are to meet several criteria: environmentally friendly, a renewable material and available, cheap and with the lowest possible production costs.


Related Post: The Importance of Engine Coolant. What it is and why it matters?

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