A STUDY ON NITROGEN BASED COMPOUNDS AS AN ALTERNATIVE FUEL IN INTERNAL COMBUSTION ENGINES

1. A STUDY ON NITROGEN BASED
COMPOUNDS AS AN ALTERNATIVE FUEL
IN INTERNAL COMBUSTION ENGINES
Sameer Shah
Dept of Mechanical Engineering
Sir M. Visvesvaraya Institute of Technology
Bangalore

2. INTERNAL COMBUSTION ENGINE
An internal combustion engine is a
mechanical device in which the burning
of a fuel occurs in a confined space
called a combustion chamber. This
exothermic reaction of a fuel with an
oxidizer creates gases of high
temperature and pressure, which are
permitted to expand.
These high pressure gases push the
piston down creating a propelling force
for the vehicle.

3. Types of Engines
Spark Ignition Engines (SI
Engines)
Compression Ignition Engines
(CI Engines)
• The term spark-ignition
engine refers to internal combustion
engines, generally petrol engines,
where the combustion of the air-
fuel mixture takes place by a spark
ignition from a spark plug. This is
in contrast to compression-ignition
engines, typically diesel engines,
where the heat generated
from compression together with the
injection of fuel is enough to
initiate the combustion process,
without needing any external spark.
• The diesel engine (also known as
a compression-ignition or
CI engine) is an internal
combustion engine in
which ignition of the fuel that has
been injected into the combustion
chamber is initiated by the high
temperature which the fuel
achieves when it is
greatly compressed (adiabatic
compression).

4. Fuels used in IC Engines
• Petrol or Gasoline
• Diesel
• Petroleum Gas
• Biodiesel
• Hydrogen

5. Current problems associated with these
fuels
• Petrol –High scarcity and causes pollution.
• Diesel – Incomplete combustion due to heavier
hydrocarbon molecules.
• Petroleum gas – Engine starting problems and
reduces the life of engine.
• Biodiesel – Variation in quality, ineffective at low
temperatures.
• Hydrogen – Difficult to store, highly flammable.

6. Can Nitrogen based compounds be used as an
alternate fuel??
• Most of the current fuels had few disadvantages but
the major drawback observed in widely used fuels
like petrol and diesel was production of harmful
gases which pollutes the environment.
• Few fuels such as biodiesel and hydrogen are quite
expensive and requires high end production and
refining processes. Also hydrogen storage is a major
problem.

7. List of Highly specialized Nitrogen based
compounds and basic Research level fuels
Fuel Mixture Chemical Formula Application
Ammonium Perchlorate
+Trimethylammonium
perchlorate
NH4ClO4 + C17H26ClN3O6S Basic research level;
Combustion
Ammonium nitrate +
Ammonia
NH4NO3 + NH3 IC engines, research at
very
basic level
Hydrazine+ MMH/UDMH+
hydrazine hydrate +
urea/ammonia + metal
hydride
2N2H4+CH3(NH)NH2/C2H8N2
+ H6N2O CO(NH2)2 / NH3 +
metal hydride
Basic research level;
Engines (water-,land, air
based)
Hydrazine/UDMH/
MMH+NO2
N2H4/C2H8N2 / CH3(NH)NH2
+ NO
Missile Propellant

8. List of Reasonable Nitrogen based fuels from
literature survey.
Fuel Chemical Formula Application
Ammonia NH3 SI-engine
Ammonia in dual-fuel
applications
NH3+additional fuels SI & CI
Engine
Hydrazine(monopropella
nt)
N2H4 Fuel-cell, Rocket
propellant
Liquid Nitrogen N2 Expansion Engine

9. Ammonia and its properties
Ammonia is compound of nitrogen and hydrogen with the formula NH3. It is
a colourless gas with a characteristic pungent smell.
The combustion of ammonia to nitrogen and water is exothermic
4 NH3 + 3 O2 → 2 N2 + 6 H2O (g) (ΔHo
r= −1267.20 kJ/mol)
Internal combustion engines, both Spark Ignition and Compression Ignition,
have been tested with ammonia as fuel, but ammonia has few disadvantages:
• Low flame speed
• High auto-ignition temperature (1200 °C)
• High heat of vaporization

10. Overcoming the problems of Ammonia
during combustion
• High-pressure fuel injection
• Powerful Spark Ignitors
• Addition of additives to ammonia – hydrogen and
gasoline in case of SI engines and Dimethyl Ether
and biodiesel in case of CI engines.
• Changing the architecture of engine and engine block
material to increase the compression ratio
• Modification in mechanical parts to support
combustion of ammonia under high compression
conditions.

11. Ammonia as fuel in Spark Ignition Engines
• i) Ammonia without additives – it causes improper
combustion which can be overcome by using strong
ignitors and supercharging.
• ii) Ammonia with Hydrogen – H because of its high
flammability acts as combustion promoter along with
ammonia.
• iii) Ammonia with Gasoline – it requires high
compression ratio of 10:1, and ammonia has to be
directly injected in gaseous form.

12. Ammonia as fuel in Compression Ignition
Engines
• i) Ammonia without additives – Combustion does not
occur even at compression ratios of 30:1, hence only
ammonia cannot be used as a fuel in CI engines.
• ii) Ammonia with Dimethyl Ether – 80% ammonia
and 20% ether was required for optimal combustion.
• iii) Ammonia with biodiesel – additive fuel should
have higher cetane number for effective combustion

13. Methods to increase Compression ratio
• By reducing the cylinder diameter
• By reducing the cylinder length/stroke length
• Change to a dome shaped piston.
• By using fuels having higher cetane rating.

14. Direct Fuel Injection
As you can see in the figure, gasoline direct
fuel injection engine, apart from the
intake/exhaust valves and spark plug there
is a fuel injector inside the cylinder’s head.
This is the direct fuel injection technology
which currently is one of the most efficient
designs in both performance and fuel
consumption. The fuel is driven to the
injectors through electronically controlled
(by vehicle’s ECU) rail and each fuel
injector is electronically controlled to spray
fuel at a defined pressure for a specified
time. This way it can provide best results in
the whole RPM range and solve problems
such as cold start.

18. AmVeh – Fuel System

19. Pair claim they can make ammonia to fuel cars
for just 20 cents per litre (Roughly 9.4 rupees per
litre)
John Fleming of Silver Eagles Energy and Tim Maxwell from Texas Tech
University, say they have developed a way to make ammonia that is cheap enough
so that it could be used as fuel for cars. And if that’s not enough incentive, they
claim they can make the ammonia for just 20 cents a litre (approximately 75 cents
a gallon).
To make the ammonia, the hydrogen produced is pumped into a compression
chamber where a piston squeezes it, causing it to heat up; in this case to 400C°.
The result is then allowed to escape into another compartment where a reaction is
set off by an iron oxide catalyst. This makes the hydrogen grow even hotter to the
point where it begins creating ammonia. The ammonia and leftover hydrogen is
then allowed to cool down and decompress in yet a third compartment, and in so
doing causes another piston to move back and forth creating energy that is fed
back into the system to help lower electric consumption. Then, the ammonia is
chilled to -75C° and pumped into a tank for use.

20. Conclusions
• Ammonia can be used as an alternative fuel in
Internal Combustion engines with slight modification
in engine architecture.
• Certain additives can be added to enhance the
combustion process.
• It is a clean fuel and does not pollutes the
environment.

21. Thank You…