- The University of North Texas and University of Washington independently developed liquid nitrogen powered vehicles in 1997. - The vehicle was named LN2000 and was a converted 1984 Grumman-Olson Kubvan mail delivery van. - Liquid nitrogen is used as the fuel in a cryogenic heat engine. It is non-polluting and nitrogen is abundantly available in air. - However, liquid nitrogen vehicles have not been commercialized due to safety issues and lack of funds for further research.

1. Presentation
On
Liquid Nitrogen
as a Non-Polluting
Fuel
Shubham
Raghuvanshi
10ME001118

2. • In 1997, the liquid nitrogen powered vehicles was independently
developed by University of North Texas (UNT) and University of
Washington (UW).
• The propulsion systems in these vehicles were cryogenic heat
engines in which a cryogenic substance is used as a heat sink for
heat engine.
• The vehicle (car) was named as LN2000.
• It was a converted 1984 Grumman-Olson Kubvan mail delivery
van.
Introduction

3. What is Liquid Nitrogen Vehicle?
 It is a vehicle which uses Cryogenic fluid(liquid
nitrogen) as a working fluid.
 Propulsion system is a cryogenic heat engine in
which a cryogenic substance is used as a heat sink.
CRYOGENICS
Cryogenic can be defined as the branch of the physics that deals with the
study of the production of very low temperature (below −150 °C, −238
°F or 123 K) and the behavior of materials at those temperatures.

4. A liquid nitrogen propelled car(LN2000)

5. Why Nitrogen as a Vehicle Fuel?
 High cost and limited availability of fossil fuels like petrol and
diesel.
 Due to high level of pollution associated with the combustion
of fossil fuels.
 And the most important is the huge availability of Nitrogen
gas(78% of air is nitrogen).

6. Cryogenic Heat Engine
 It is a engine which uses very cold substances to produce
useful energy.
 There is always some heat input to the working fluid during
the expansion process.

7. Liquid Nitrogen(LN2)
 Liquid Nitrogen is the cheapest, widely produced and most
common cryogen.
 It is mass produced in air liquefaction plants
 The liquefaction process is very simple.
 Normal, atmospheric air is passed through dust precipitator
and pre-cooled.

8. Atmospheric
Air passes
Fractional
Distillation
Dust
Precipitator
Inter cooler
Nozzle
LN
2
Insulated
chamber
Expansion
Turbo
pumps
Dewar Flask
Nitrogen cycle showing the production of liquid nitrogen

9.  It is then compressed inside large turbo pumps to about 100
atmospheres(10.13 MPa).
 Once the air has been cooled to room temperature it is
allowed to expand rapidly through a nozzle into an insulated
chamber.
 By running several cycles the temperature of the chamber
becomes low enough. The air entering it starts to liquefy.
 Liquid nitrogen is removed from the chamber by fractional
distillation and is stored inside well-insulated Dewar flasks .

10. Major components of the Nitrogen powered car

11. Main Components of the
Engine:
 A pressurized tank(24 gallon) to store liquid nitrogen.
 Pressurant bottles of N2 gas substitute for a pump. The gas
pushes the liquid nitrogen out of the Dewar that serves as a fuel
tank.
 A primary heat exchanger that heats (using atmospheric heat)
LN2 to form N2 gas, then heats gas under pressure to near
atmospheric temperature.
 An Expander to provide work to the drive shaft of the vehicle.
 An economizer or a secondary heat exchanger, which preheats
the liquid N2 coming out from the pressurized tank taking heat
from the exhaust.

12. Setup position of various components
of nitrogen powered car

13. Advantages over electric cars:
 A liquid nitrogen car is much lighter and refilling its tank takes
only about 10-15 minutes.
 The exhaust produced by the car is environmental friendly.
 A cryogenic car could have three times the range of an electric
car of the same weight and no battery disposal concerns .

14. Drawbacks:
 The N2 passing through the tubes of the heat exchanger
is so cold that the moisture in the surrounding air would
condense on the outside of the tubes, obstructing the air
flow.
 Then there's the safety issue. Should a nitrogen car be
kept in a poorly ventilated space and, if the Nitrogen
leaks off, it could prove fatal.
 Turning N2 gas into a liquid requires a lot of energy. So
while cryogenic cars have zero emissions, they rely on
energy produced at emission generating power plants.

15. Probable Solutions:
 A tube within a tube design.
 N2 passes back and forth inside a set of three nested tubes.
 By the time it reaches the outermost tubes, the N2 is warm
enough that the exterior wall of the tube remains above the
freezing point of water.
 Route the exhaust from the fossil fuel power plants through
cryogenic plants, so that the pollutants and the greenhouse
gases could be condensed for later disposal

16. Efficiency:
 The LN2 car can travel 79 miles(127.58 km) on a full 24
gallon(90 liter) tank of liquid nitrogen going 20 MPH.
 Its maximum speed is over 35 MPH.

17. Why not commercialized?
Even though the technology is 10 to 12 years old, still it has not
come to the market for two reasons.
 Safety issues have not been sorted out as yet.
 Lack of funds for research.

18. Conclusion:
 In a real sense, the more such vehicles are used, the
cleaner the air will become.
 In addition to the environmental impact of these vehicles,
refueling using current technology can take only a few
minutes, which is very similar to current gas refueling
times.
 Extra research work is needed to utilize the most of the
available energy

19. THANK YOU