1. No category

International Conference on Chemical, Metallurgical and Civil Engineering (ICCMCE'2015) March 16-17, 2015 Abu Dhabi (UAE)
Design of Self-Heating Containers Using
Sodium Acetate Trihydrate for Chemical Energy
– Food Products
Rameshaiah GowdaraNarayanappa, Prithvi Chandh Manikonda, Manoj Kumar,
Suraj Bhavan, and Vikram Singh

Crystallisation is an exothermic process that evolves heat when
a nucleation site is activated inside a supersaturated solution.
When we boil the solid, we melt it back to liquid state. We can
repeat this cycle forever, theoretically, just as we can freeze
and melt water as many times as we like. For design and
Fabrication purpose different conducting and insulating
materials need to be tested.
Abstract— Long ago heating of food was only related to fire or
electricity. Heating and storage of consumer foods were satisfied by
the use of vacuum thermo flaks, electric heating cans and DC
powered heating cans. But many of which did not sustain the heat for
a long period of time and were impractical for remote areas. The use
of chemical energy for heating foods directed us to think about the
applications of exothermic reactions as a source of heat. Initial
studies of calcium oxide showed desirability but not feasible because
the reaction was uncontrollable and irreversible. In this research work
we viewed at crystallization of super saturated sodium acetate
trihydrate solution. Supersaturated sodium acetate trihydrate has a
freezing point of 540C (1300F), but it observed to be stable as a liquid
at much lower temperatures. Mechanical work is performed to create
an active chemical energy zone within the working fluid, when
crystallization process is initiated. Due to this, the temperature rises
to its freezing point which in turn heats the contents in the storage
container. Present work- endeavor to design a self-heating storage
container that is suitable for consumer dedications.
II. PROCEDURE
This experiment deals with the use of Supersaturated
Sodium acetate trihydrate for heating purpose. Supersaturated
sodium acetate trihydrate has a freezing point of 58 degree
Celsius (130 degree F), but it is observed to be stable as a
liquid at much lower temperatures. When a mechanical work is
performed to create an active zone within the working fluid,
crystallisation process is initiated. Due to this the temperature
rises to its freezing point (58 degree C) which in turn heats the
contents in the storage cell. Sodium acetate trihydrate crystals
melt at
58 °C, dissolving in their water of crystallization.
When they are heated to around 100 °C, and subsequently
allowed to cool, the aqueous solution becomes supersaturated.
This solution is capable of cooling to room temperature
without forming crystals. By providing a suitable mechanical
work, a nucleation centre is formed which causes the solution
to crystallize into solid sodium acetate trihydrate again. The
bond-forming process of crystallization is exothermic, hence
heat is emitted. The latent heat of fusion is about 264–289
kJ/kg. The sodium acetate crystal can be recycled to liquid
form by boiling. When you boil the solid, you melt it back to
the liquid state. We can repeat this cycle forever, theoretically,
just as you can freeze and melt water as many times as you like
(since sodium acetate is a food additive and it is non-toxic).
Table I
Keywords—Super saturation, crystallization, vacuum thermo
flask, self-heating container, exothermic reactions.
I. INTRODUCTION
N recent year’s food heating before consumption has
become a major criteria especially in remote areas, cold
climatic regions, high altitude regions, military encampments,
etc. Many people may have the concept that whenever keeping
food warm, it should be related to fire or electricity. But in our
investigation, we will try to reach the same purpose with
chemical approach i.e. the use of portable heating storage units
that can provide an instant plan of action to troubleshoot
consumption issues. So to achieve above we are using
crystallisation property of supersaturated solutions.
I
Rameshaiah GowdaraNarayanappa is Associate professor, Department of
Chemical Engineering, B M S College of Engineering , P.B. No. 1908, Bull
Temple Road, Basavangudi, Bangalore- 560019, Karnataka,
INDIA,
([email protected] , [email protected] , Mobile No.
+91 82771 26901)
Prithvi Chandh Manikonda, Manoj Kumar, Suraj Bhavani, Vikram Singh,
are Research Scholars, Department of Chemical Engineering, B M S College
of Engineering, P.B. No. 1908, Bull Temple Road, Basavangudi, Bangalore560019, Karnataka, INDIA (email: [email protected],
[email protected], [email protected], vikram1singh90@
gmail.com)
http://dx.doi.org/10.15242/IIE.E0315529
CONDUCTING MATERIALS FOR DESIGN
Conducting materials
Alluminum
Brass
Copper
Silver
“W= Watt, m= meter, K=kelvin”
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Conductivity
204 W·m−1·K−1
124 W·m−1·K−1
385 W·m−1·K−1
420 W·m−1·K−1
International Conference on Chemical, Metallurgical and Civil Engineering (ICCMCE'2015) March 16-17, 2015 Abu Dhabi (UAE)
TABLE II
INSULATING MATERIALS FOR DESIGN
Insulating materials
Conductivity
0.026 W·m−1·K−1
0.42 W·m−1·K−1
0.15 W·m−1·K−1
0.12 W·m−1·K−1
Air
Polystyrene
Plastic
Wood
“W= Watt, m= meter, K=kelvin”
III. PROCESS
Fig. 1 Details of the process flow
IV. CONCLUSION
The thermodynamic and heat transfer properties of sodium
acetate trihydrate was studied and is implemented in an
effectively designed storage vessel for ready heating of the
stored food for consumer satisfaction.
ACKNOWLEDGMENT
We wish to express our sincere gratitude to Dr.
Mallikarjuna Babu, Principal and BMS COLLEGE OF
ENGINEERING for providing the academic ambience for
our project. We would also like to take this opportunity to
thank Dr. Samita Maitra, Head of the department, Chemical
Engineering, BMSCE for her continuous support.
REFERENCES
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[2] Lacy, H. E. Electrically heated cup. U.S. Patent 2046125 A, June 30,
1936.
[3] Fisher, B.; Spector, G. Rechargeable battery heating unit U.S. Patent
3931494 A, January 6, 1976
[4] U.S.
Food
and
Drug
Administration
http://web.archive.org/web/20070812132324/www.fda.gov/ora/inspect_
ref/itg/itg17.html
[5] Chem fax, Supersaturated Sodium Acetate Solution. flinn sci. 2009, 1-2,
91215.
[6] Hollingsw, C. A.; Dietz, P. L.; Jr. Brukner, J. S. Linear Crystallization
velocities of sodium acetate in supersaturated solutions. J. Phys. Chem.,
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[7] Taylor, P.G.; Beevers, C.A. The crystal structure of sodium thiosulphate
pentahydrate Acta Cryst. (1952). 5, 341-344
http://dx.doi.org/10.1107/S0365110X52001027
http://dx.doi.org/10.15242/IIE.E0315529
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