Technology innovation for reefer trucks and last mile distribution using Phase Change Materials(PCM)

A cold chain is a temperature-controlled supply chain mechanism. It is an unbroken chain, an uninterrupted series of storage and distribution activities which maintains a given temperature range. It is used to help extend and ensure the shelf life of products such as fresh agricultural produce, seafood, frozen food, photographic film, chemicals and pharmaceutical drugs ,or perishable goods in general.

The various important stages of cold chain is represented in the below image.


   è Temperature Controlled Warehousing- Cold Chain can never be complete without being able to warehouse the merchandise at a desired temperature .
     è Refrigerated Transport- This forms the backbone of any Cold Chain system and provides mobility to the commodities.
è Integrated last mile distribution- Cold Chain cannot succeed unless it is duly supported by an efficient temperature controlled last mile distribution network.
Major Challenges being faced by Cold Chain Industry
A successful Cold Chain can only be run by ensuring that the entire mechanism is leak proof, in doing so the entire chain proves to be a highly energy intensive sector gurgling up precious natural resources in storing as well as in moving the commodity.

A necessary evil of the Cold Chain is the fuel coupled cooling being used in reefer units to maintain the requisite temperature while on the go. This not only drains the natural fossil fuels which are any ways dwindling down but also releases a hug carbon footprint which could take decades for the earth to minus out. An average reefer truck could emit up to 72 gm of CO2 per Km (Wild, 2010). Another major strain is laid on the monetary resources of the units involved in trying to maintain the efficiency of the Cold Chain. Speaking in terms of the money, for every hour that a reefer truck runs it spends approximately- Rs. 200 (Pluss Polymers Pvt Ltd, 2014). This in itself causes a huge strain on the fund flow of the companies executing cold chain for its products and eventually loads the additional burden on the end user/consumer.
What are Phase Change Materials?
Phase Change Materials as the name suggest are materials that exhibit the ability to store high amount hot/cold energy during its phase transition from solid phase to liquid phase or vice versa at a designed temperature. In a way Phase Change Materials (PCMs) are like Thermal Batteries which provide precise temperature control over a certain period of time without the active engagement of a cooling mechanism.

Phase Change Materials can be incorporated in the cold chain to overcome losses at various stages in warehousing, transport and last mile distribution.

Application PCMs in Reefer vehicles
Reefer units are commonly of the following 2 types-
1)      Long Haul Units- Those that use Reefer Trucks in transportation for beyond 24 Hours. These units deliver the perishables for beyond a small geographical territory. These Reefer Units can make use of PCMs in the form of “Active Eutectic Plates”. Eutectic plates filled with PCMs can provide back up of 24hours and more. In this the Plates are mounted inside the container and provide active cooling during transit by partial application of the engine block of the truck. Thus significantly reducing fuel consumption.

2)      Short Haul Units- last mile distribution forms the last rung of any cold chain system. For an efficient cold chain the last mile distribution network should be highly efficient. PCMs can be integrated directly in the form of “Tabs” charged over night to passively maintain temperature control while last mile delivery. Another Plug’n’Chill technology developed by TESSOL systems using savE® PCMs is used for last mile delivery. In this system an nose mountain unit charges the PCMs overnight and the PCM panels maintain precise temperature control while the reefer is on the move. Temperature excursion can be checked for over 12 hours with this kind of technology.

The following table shows the cost benefit analysis between a PCM based reefer trucker and conventional truck.

Without PCM
With PCM
Cost of Truck and the insulated container
8.5 Lakhs
8.5 Lakhs
Cost of the refrigeration equipment including  Phase Change Materials & charging unit  for PCM based truck
3.75 Lakhs
Cost of Refrigeration unit for conventional Truck
2.5 Lakhs
Total Capital cost
11 Lakhs
12.25 Lakhs
Diesel Consumption for the vehicle  
4 Litres per hour
2.5 Litres Per Hour
Cost of Electricity
Rs.6 per unit(10 units per day)
Total Running Cost
10 Lakhs /annum
6.5 Lakhs /annum
Investment in Capital cost of PCM based reefer truck over conventional truck
1.25 Lakhs (One Time cost)
Savings per annum using PCM system
3.5 Lakhs (per annum)
The above table makes it amply clear that usage of PCMs can help tackle all three issues plaguing the Cold Chain sector- Fuel consumption, Carbon Emission and Financial Strain. Incorporation of PCMs is also simple, requiring minimal engineering and retrofitting.
Unlike in India, the west has been fast in picking up this innovative energy channelizing material which can prove to be helpful in saving millions of gallons of fuel per year. This situation proves to be a win-win proposition for both the producers of the goods and the units providing cold chain movement of the goods.  
The way ahead…..

Phase Change Materials are the answer to many issues being tackled by the Cold Chain Transport industry on a regular basis. The Cold Chain sector is a growing sector and with its growth alternative technologies such as PCMs have to be introduced for the development new methods for eliminating temperature excursion. 

Author- Vishnu Sasidharan

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