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Study of Heavy Duty Vehicle Exhaust Emissions and Fuel
Consumption with the use of a JetStar Hydrogen Gas Generator
Prepared by: Peter Barton P.Eng
Head, Engineering and Vehicle Testing
Emissions Research and Measurement Division
Environmental Technology Centre
Environment Canada
24 February 2005
ERMD Report # 2004-032
Jetstar Hydrogen Gas Generator #2004-032 1
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Table of Contents
1. Abstract
..............................................................................................................3
2. Project
Title........................................................................................................4
2.1 Objective
.........................................................................................................................
4
2.2 Project Participants
.........................................................................................................
4
3.
Background........................................................................................................4
4. Test Description
.................................................................................................5
4.1 Test Vehicle
....................................................................................................................
6
4.2 Test Fuels
........................................................................................................................
6
4.3 Fuel Temperature and Fuel Cooling
...............................................................................
7
4.3.1 Flash Point
..............................................................................................................
7
4.3.2 Fuel Density
............................................................................................................
7
4.4 Fuel Heat
Exchanger.......................................................................................................
7
5. Test Program Methodology
..............................................................................8
5.1 Service
Accumulation.....................................................................................................
8
5.2 Chassis Dynamometer Testing
.......................................................................................
8
5.3 Facility and Equipment Description
...............................................................................
9
5.4 Chassis Dynamometer
....................................................................................................
9
6. Testing
Procedure............................................................................................10
6.1 JetStar
Installation.....................................................................................................
12
7. Results and
Discussion....................................................................................15
7.1 Fuel fraction hydrogen of
water....................................................................................
15
7.2 JetStar Advertised Water
Consumption....................................................................
16
7.3 Empirical Measurements and System Efficiency
......................................................... 17
7.4 Overall System Efficiency
............................................................................................
19
8. Exhaust Emissions and Fuel Consumption
Results.....................................20 8.1 Combustion
Efficiency
.................................................................................................
20
9. Conclusions
......................................................................................................23
10. Appendix
..........................................................................................................25
Jetstar Hydrogen Gas Generator #2004-032 2
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Study of Heavy Duty Vehicle Exhaust Emissions and Fuel
Consumption with the use of a JetStarTM Hydrogen Gas Generator
1. Abstract
At the request of Synergic Distribution Inc., the fuel
consumption and exhaust emissions were evaluated for a 2004
International class 8 Diesel Truck, equipped with a Cummins ISX400
engine while operating with and without the JetStar hydrogen gas
generator.
The JetStar is an aftermarket retrofit hydrogen powered
generator that uses electrolysis to produce hydrogen and oxygen on
demand, from water, and injects it into the intake manifold after
the turbocharger. JetStar literature states that the product, when
used as a retrofit for diesel engines, results in increased power,
cleaner emissions and a significant savings in fuel and maintenance
costs.
Chassis dynamometer exhaust emission tests were conducted in
order to evaluate the effectiveness of the JetStar product to
reduce fuel consumption and exhaust emissions. Modified Arterial
and Commuter heavy duty vehicle chassis dynamometer exhaust
emission test cycles were used during this program.
The evaluation regime indicated that the use of the JetStar
hydrogen generator product did not affect combustion efficiency of
the test vehicle engine nor did it improve exhaust emission rates
or fuel consumption. The combustion efficiency of the engine
remained above 99.59% through out the program, regardless of the
test cycle or whether the JetStar was operational or not.
Exhaust emission rates of carbon monoxide, oxides of nitrogen,
total hydrocarbons, and total particulate mass (soot) did not show
any statistically significant change with use of the JetStar
generator. Similarly, fuel consumption did not indicate any
statistically significant change from the vehicle baseline
configuration with the use of the JetStar system.
The second question is whether the on-board generation of a
hydrogen/oxygen gas mixture through electrolysis is efficient from
an energy balance standpoint.
The calculations based on the advertised water consumption and
empirical measurements made during the program indicate that the
JetStar electrolysis system is, in the best case, 60.3% efficient
at converting electrical energy from the alternator to a process
gas mixture of hydrogen and oxygen. In other words, it requires
approximately 1.65 times the electrical energy from the alternator
compared to the chemical energy in the form of hydrogen.
Similarly, the efficiency of using the electrical system of a
vehicle to generate hydrogen through electrolysis was calculated to
be approximately 11.4%. To generate one unit(MJ) of hydrogen energy
with the JetStar system requires 8.77 units (MJ) of energy from
diesel fuel.
Based on the JetStar advertised water consumption of 1.8 litres
per 5000 miles (8047 km), the energy from hydrogen injected into
the intake manifold of the diesel engine is equivalent to 0.00829
litres of diesel fuel per 100 kilometres.
Jetstar Hydrogen Gas Generator #2004-032 3
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2. Project Title
The study of a heavy-duty diesel fuelled vehicle exhaust
emissions and fuel consumption with the use of a JetStar hydrogen
gas generator.
2.1 Objective
To characterize and compare the exhaust emissions and fuel
consumption from a diesel fuelled heavy duty vehicle operating with
and without the hydrogen generator.
2.2 Project Participants Synergic Distribution Inc. Emissions
Research and Measurement Division, Environment Canada
3. Background
With increasing pressure on governments and vehicle
manufacturers to improve fuel consumption and exhaust emissions
from all forms of vehicle and internal combustion engines, a myriad
of concepts have been brought forward in an effort to improve
overall vehicle efficiency.
The typical internal combustion engine used in the modern
vehicle is fuelled with gasoline, propane or natural gas for spark
ignition (SI) engines or diesel fuel for diesel engines.
For spark-ignition engines, running at stoichiometric air/fuel
ratio, the combustion efficiency is usually in the range 95 to 98
percent.1 For diesel engines, which always operate lean, the
combustion efficiency is normally higher above 98 percent.2
With the advent of stricter exhaust emission standards for
passenger cars and light trucks, vehicle and engine designers have
incorporated electronic engine management systems in order to
ensure that the air/fuel mixture is always at the chemically
correct or stoichiometric proportion for complete combustion. These
electronic engine systems continuously monitor the exhaust gas
composition, throttle position, and mass of engine intake air,
among other parameters, and adjust the amount of fuel delivered to
the engine.
Current electronically fuel injected spark ignited engines have
done away with the traditional tune-up that was conducted to
recalibrate the carburettor in an attempt to maintain the
stoichiometric air/fuel ratio and allow close to complete
combustion. A present day tune-up consists of evaluating the
various sensors, like the very important oxygen sensor, to ensure
proper operation and changing oil, fuel, and air filters, and spark
plugs.
In comparison to an uncontrolled gasoline vehicle built in the
late 1960s, three-way catalytic converters and electronic engine
management have reduced exhaust emissions by well over 95%.
Fuel consumption of a vehicle is a function of more than simply
the combustion efficiency of the engine. Driving style, traffic
patterns, ambient temperature and wind conditions, the overall
condition of the vehicle and the vehicle load, all play a role in
vehicle fuel consumption.
1 Internal Combustion Engine Fundamentals, John B. Heywood,
McGraw-Hill 1988, P.82 2 Internal Combustion Engine Fundamentals,
P.83
Jetstar Hydrogen Gas Generator #2004-032 4
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In a SI engine, only 25% to 28% of the heat energy from the
combustion of the fuel is used to produce usable power to drive the
wheels. The rate is 34% to 38% for a diesel engine.3 As a result,
an improvement in the combustion efficiency for a SI engine of 5%
could only produce a maximum theoretical reduction in fuel
consumption of the engine of 1.25%.
4. Test Description
In this study a heavy-duty vehicle was subjected to an exhaust
emission test schedule, which simulates typical operating cycles of
a heavy-duty duty truck. The following is a general outline of the
exhaust emissions evaluation portion of the development
project.
3 Internal Combustion Engine Fundamentals, table 12.1, P.
674
Jetstar Hydrogen Gas Generator #2004-032 5
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4.1 Test Vehicle
Table 1. Vehicle Description
Test Vehicle International Tractor Model 9200i6X4
Chassis Manufacturer International Truck Model Year 2004 Chassis
Serial # 2HSCEAPRS5C051252 Engine Manufacturer Cummins Engines
Engine Model ISX400400ST Engine Model # 79047047 Engine Family
4CEXH0912XAJ
P/N 3683289 S/N 23027738 D/C 05082004 ESN 79047047
Engine #s
ECM CODE : AB10417.04-80 000SC
Engine Displacement 15 litres Advertised Engine Power 400 bhp @
2000 rpm
Eaton Fuller Transmission Manual 10 speed
Air Intake Turbo Charged Alternator Leece-Neville BLP2309
12V, 160 Amps
Certified Emission Rate (engine dynamometer) EPA/CARB NOx+NMHC
2.5 grams/bhp-hr Particulate Mass 0.10 grams/bhp-hr
Table 2. Chassis Dynamometer Testing Conditions
Chassis Dynamometer Testing ConditionsInertia Weight kgs
23551
lbs 52000Absorbed Power @ 50 miles/hr hp 43.7
@ 80.45 km/hr kW 32.6 4.2 Test Fuels
Commercially available seasonal diesel fuel was used. The
specifications of the test fuel can be found in the appendix.
Jetstar Hydrogen Gas Generator #2004-032 6
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The ERMD purchases test fuel in bulk in order to ensure that the
fuel supply remains constant within each test program. Test fuel is
supplied to the vehicle directly from fuel barrels in order not to
have to drain and refill the vehicle fuel tanks. This set-up also
facilitates the use of a fuel cooler to ensure that the fuel does
not overheat during testing.
4.3 Fuel Temperature and Fuel Cooling
Very high fuel temperatures affect fuel density and present a
potential safety hazard.
Fuel density changes with temperature, and therefore the mass of
fuel that can be injected into the cylinder. There is growing
anecdotal evidence to suggest that heavy duty vehicles with low air
flow around the fuel tanks are experiencing engine de-rating due to
high fuel temperature. The fuel temperature presents a very real
variable that needs to be taken into account in a comprehensive
chassis dynamometer testing program.
4.3.1 Flash Point
The Flash Point4 of a fuel is the temperature at which the
quantities of vapour, which a combustible fluid emits into the
atmosphere, are sufficient to allow a spark to ignite the
vapour-air mixture above the fluid. Safety considerations
(transport, storage) indicate that diesel fuels must meet the
requirements for Class A III (flash point >55C).
4.3.2 Fuel Density
There is a reasonably constant correspondence between a diesel
fuels calorific value and its density; higher densities have a
higher calorific value. Assuming constant injectionpump settings
(and thus constant injection volume), the use of fuels with widely
differing densities in a given system will be accompanied by
variations in mixture ratios stemming from fluctuations in
calorific value. Higher densities provoke increased particulate
emissions, while lower densities lead to reductions in engine
output5.
4.4 Fuel Heat Exchanger
The heat exchanger used by the ERMD to cool the fuel is a tube
and shell design using the domestic water supply as the cooling
medium. The heat exchanger is connected into the fuel return line
between the engine and the fuel barrel. The heat exchanger is used
to maintain the fuel temperature in a stable fashion and with-in
the operating parameters of both the engine and the fuel. Figure 1
illustrates the heat exchanger set-up.
4 Bosch Automotive Handbook 5th Edition, Society of Automotive
Engineers. P. 242 5 Bosch Automotive Handbook 5th Edition, Society
of Automotive Engineers. P. 242
Jetstar Hydrogen Gas Generator #2004-032 7
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Figure 1 Fuel Barrel and Fuel Heat Exchanger Set-up
The heat exchanger was used to maintain the fuel temperature in
a stable fashion and with-in the operating parameters of both the
engine and the fuel.
5. Test Program Methodology
5.1 Service Accumulation
Service accumulation was conducted to allow for activation of
the product as per instructions in the product literature or
product spokesperson. Three hundred kilometres of accumulation was
performed with the JetStar installed to allow for any electronic
learn functions in the vehicle electronic management system to
stabilize. The accumulation was performed on the chassis
dynamometer simulating both city and highway driving.
When delivered to the ERMD, the initial odometer reading was
4830 km. Service accumulation began at 4912 km and was completed at
5218 km.
5.2 Chassis Dynamometer Testing
The driving cycles used were a modified Arterial and the
Commuter heavy-duty chassis dynamometer exhaust emission driving
cycles. Three repeats of these cycles were performed
Jetstar Hydrogen Gas Generator #2004-032 8
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with and without the JetStar installed in order to provide a
measure of the repeatability of the tests.
5.3 Facility and Equipment Description
The test equipment for this program consists of an
environmentally controlled vehicle test cell containing a heavy
duty vehicle chassis dynamometer and a corresponding exhaust
emissions sampling system and analyzer bench. This test
instrumentation complies with the set-up requirements for light
duty vehicle exhaust emission compliance testing as designated in
the Canadian Environmental Protection Act (CEPA) Division 5. The
testing procedures and requirements are identical to those found in
the USEPA Code of Federal Regulations (CFR), volume 40, part
86.
The emission rates of THC, CO, CO2, and NOx were determined by
collecting a proportional sample of the dilute exhaust in Tedlar
"bags" and analysing the contents of the bag using a Heated Flame
Ionization Detector (for THC), Non-Dispersive Infrared instruments
(for CO and CO2) and a Heated Chemiluminescence instrument (for
NOx). Continuous analysis of these exhaust components was also
performed. Particulate Mass (PM) rates were determined using the
gravimetric method. Fuel consumption was determined by the carbon
balance method used throughout the industry. The fuel consumption
calculation is located in the Appendix.
5.4 Chassis Dynamometer
The exhaust emission chassis dynamometer has the capability of
simulating both road load power (RLP) or absorbed power and the
inertia weight of the vehicle. Control of the vehicle load is
controlled by an electronic dynamometer controller that
continuously adjusts the forces exerted on the vehicle based on the
initial input parameters and the indicated vehicle speed. Figure 2
illustrates the truck set-up on the chassis dynamometer.
Jetstar Hydrogen Gas Generator #2004-032 9
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Figure 2 2004 International Truck Set-up in Chassis Dynamometer
Test Laboratory
6. Testing Procedure
All of the laboratory test procedures comply with the protocols
detailed in the CEPA 99 Division 5 document, and the USEPA CFR
Volume 40, Part 86 and Part 600 for heavy-duty vehicle exhaust
emissions testing and calculation of fuel consumption.
With all of the baseline tests complete, an ERMD technician
installed the JetStar in accordance with instructions in the
Installation Manual and per discussions with Synergic
representatives.
Chassis dynamometer service accumulation of 300 kilometres was
conducted before the product tests were conducted.
A series of three Arterial and Commuter heavy-duty chassis
dynamometer exhaust emission driving cycles were conducted with the
product in operation on the vehicle.
Table 3 provides details of the test cycles and both cycles are
illustrated graphically in Figures 3 and 4.
Table 3. Exhaust Emission Test Cycles
Test Cycle
Cycle Duration (seconds
)
Average
Speed (kph)
Maximum Speed (kph)
Distance (kilometers)
Distance (miles)
Modified Arterial 450 21.91 49.68 2.74 1.70
Modified Commuter 450 42.13 68.30 5.27 3.28
Jetstar Hydrogen Gas Generator #2004-032 10
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50 100 150 200 250 300 350 4000
5
10
15
20
25
30
35
0 450
Time (sec)
Spe
ed (m
ph)
Figure 3. Modified Arterial Test Cycle
0
5
10
15
20
25
30
35
40
45
0 50 100 150 200 250 300 350 400 450
Time (sec)
Spe
ed (m
ph)
Figure 4. Modified Commuter Test Cycle
Jetstar Hydrogen Gas Generator #2004-032 11
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6.1 JetStar Installation
The JetStar system was installed as per the Dynamic Installation
Manual provided. The main unit was installed on the back of the
tractor as illustrated in Figure 5. Two issues dealing with wiring
and safety arose during the installation and required
clarifications from Synergic technicians. The JetStar system comes
with a heavy duty six conductor wiring harness, however, only four
of those wires are used, the other two wires being redundant. No
mention of this could be found in the installation manual and
advice from the Synergic technicians was required. Additionally,
the system is designed to be active when the ignition switch is
turned on. This could be a safety issue as there could be
hydrogen/oxygen gas produced with out the engine running, the
result being a build-up of an explosive gas mixture in the engine
intake manifold. As a safety precaution, and under the advice of
the Synergic technicians, the JetStar electrical power was routed
through the switch for the vehicle driving lights. This strategy
prevented any electrolysis from taking place unless the driving
light switch was turned on.
Figure 5 Installation of JetStar
Jetstar Hydrogen Gas Generator #2004-032 12
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Figure 6 JetStar Water bottle installation.
The injector was installed in the intake manifold after the
turbocharger. The turbocharger raises the air pressure in the
intake manifold, significantly above atmospheric. In order to flow
the hydrogen-oxygen gas mixture from the electrolysis process, the
JetStar system must build up enough pressure to overcome the high
pressure in the engine intake manifold. The system comes with a
Swagelock pressure relief valve rated at 50 to 150 psi. It was
assumed the valve was preset to open at 50 psi. To verify this, an
oil filled Winters pressure gauge was installed ahead of the valve.
A picture of the set-up can be found in Figures 7 and 8.
Jetstar Hydrogen Gas Generator #2004-032 13
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Figure 7 JetStar installed and operating in intake manifold.
Figure 8 Pressure gauge reading >50psi.
Jetstar Hydrogen Gas Generator #2004-032 14
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7. Results and Discussion
The purpose of this study was to determine the effect of using
an on-board electrolysis system to produce a hydrogen/oxygen
gaseous mixture and inject it into the intake manifold of an
internal combustion engine. There are two issues in this study.
Firstly, is there any benefit in injecting minute quantities of
hydrogen/oxygen mix into an internal combustion engine with respect
to exhaust emissions or fuel consumption? Secondly, is the
production of the hydrogen/oxygen gas mixture from an on-board
electrolysis system efficient from an energy balance
standpoint?
The original premise of an on demand hydrogen generator is that
by adding hydrogen to the intake manifold of an internal combustion
engine, the hydrogen will either add energy to the air/fuel mixture
thus displacing some of the carbon based fuel (diesel, gasoline),
or the hydrogen will improve the combustion efficiency of the
engine thereby improving exhaust emissions and reducing fuel
consumption.
The following tables are the results of calculations to
determine system efficiency of the JetStar electrolysis hydrogen
production and the possible diesel fuel displaced by the injection
of hydrogen into the combustion chamber.
Inputs to the tables were derived from the advertised water
consumption of the JetStar system and empirical data taken during
the course of the study.
The final table, Table 11, illustrates the efficacy of on-board
hydrogen production for vehicles.
7.1 Fuel Fraction Hydrogen of Water
The fuel fraction hydrogen of water (FFH2) is the portion of
water that is hydrogen, based on the molecular weight of each
constituent. The FFH2 is used in the calculation of energy in the
form of hydrogen that the JetStar electrolysis system produces from
a given quantity of water.
The formula for determining the FFH2 is :
H20 + Energy H2 + O2 FFH2 = MWH2/MWH2O MWH2O : Molecular Weight
of Water (H2O)
MWH2 : Molecular Weight of Hydrogen (H2)
Jetstar Hydrogen Gas Generator #2004-032 15
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Table 4 Determination of Fuel Fraction Hydrogen of Water
C
@ 0C @ 20C of Hydrogen 0.09 0.08 kg/m3 of Oxygen 1.43 1.33 kg/m3
of Diesel 0.8522 kg/l of Wate
alorific Value (MJ/kg)
Properties 120Properties 0Properties 42.5Properties r 1.00
kg/l
raction Hydrogen of Water(H2O)0
Fuel F
Carbon Monoxide
(CO)Carbon
Dioxide (CO2) Water (H2O) Hydrogen (H2) O
12.011 28.011 44.01015.9991.008 18.015 2.016
Density
Molecular Weights (MW)
xygen (O2)
CarbonOxygen 31.999Hydrogen
Fuel Fraction of H2 = MWH2/MWH2O = 0.1119 Mass of H2O
7.2 JetStar Advertised Water Consumption
The Dynamic Fuel Systems Inc. JetStar brochure indicates that
the water consumption of the system is 1.8 litres per 5000 miles or
90 hours. Table 5 calculates the volume of water used per kilometre
and minute.
Table 5 Calculated Water Consumption
Water consumptionadvertised water consumptionone 1.8 litre
bottle per 5000 miles or 90 hours.
Volume (litres)distance
(kilometres) litres/kmml/km (g/km)
Volume (litres) time (minutes) litres/minute
millilitres/minute of Water (ml/min,
grams/minute)
1.8 8047 0.000224 0.2237 1.8 5400 0.000333 0.3333
5000 miles 90 hours
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Table 6 illustrates the quantity of energy in the form of
hydrogen that is produced when the electrolysis is conducted at the
rate calculated in Table 5. For simplicity, the electrolysis is
considered to be 100% efficient at converting water to hydrogen and
oxygen.
In order to better illustrate the amount of energy released by
the electrolysis process, a conversion is made to the equivalent
energy from diesel fuel. If the hydrogen was free, not produced on
board, then the hydrogen energy would have the possibility of
displacing 0.00829 litres/100km of diesel fuel.
Table 6. Hydrogen Energy Calculations based on Water
Consumption
Water Consumption of Jetstar 1.8 litres Water/5000 miles
grams H2O/km FFH2
grams H2/km
Calorific Value
(MJ/kg)
Energy contribution of H2/kilometer
0.2237 0.1119 0.0250 120 0.0030 MJ/km
Diesel Fuel 42.5 MJ/kg
0.00007 kg/km of diesel fuel 0.00008 litres/km of diesel fuel
0.00829 litres/100km of diesel fuel
Water Consumption of Jetstar 1.8 litres Water/90 hours
grams H2O /minute FFH2
grams H2/minute
Calorific Value
(MJ/kg)
Energy contribution of
H2/minute0.3333 0.1119 0.0373 120 0.0045 MJ/minute
Diesel Fuel 42.5 MJ/kg
0.00011 kg/minute of dies0.00012 litres/minute of dies0.00742
litres/hour of dies
Energy from Hydrogen is equivalent to el fuel el fuel el
fuel
Energy from Hydrogen is equivalent to
7.3 Empirical Measurements and System Efficiency
The JetStar requires electrical power from the vehicle
alternator to operate. The current was measured over several
driving cycles and the average was found to be 15.1 amps at a
nominal 12 volts. When the system was running there was little
variation in current draw, regardless of the vehicle speed and
load.
The electrical power to the JetStar system is calculated at
0.651 MJ/hr. The calculation of the diesel fuel needed to generate
that quantity of electrical power is based on the conversion
efficiency of using the internal combustion engine to burn diesel,
convert that heat to rotating motion, and turn the alternator. The
partial calculation table is illustrated below in Table 7. The
complete table can be found as Table 11.
Jetstar Hydrogen Gas Generator #2004-032 17
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Table 7 Conversion Efficiency
Chemical uel (Diesel)
Combustion Efficiency
Mechanical Efficiency
Alternator Efficiency
100% 99.5% 38.0% 50.0%Cumulative
fficiency 99.5% 37.8% 18.9%
F
E
Averge Electrical Current Draw Electrical Power IN
Current (A)Voltage (V) (nominal) Power (W)
15.1 12 180.7 0.651 MJ/hr
Conversion Efficiency Diesel to Electrical 18.9%
Power (J/hr)650546
Diesel Fuel required to continuously generate 0.081 kg/hr180.7
Watts 0.095 litres/hr
Where:
Combustion efficiency: >99.5% (tables 11 and 12)
Mechanical Efficiency: typical is 34 38% 6
Alternator Efficiency: typical is 50%7
Table 8 Electrical Power IN
To measure the gaseous flow rate from the JetStar system a Bios
International DryCal DC-Lite Primary Flow Meter was used. The flow
rate was measured to be 0.65 litres/minute. The documentation from
Dynamic Fuel Systems Inc. indicates that there is no separation of
the hydrogen and oxygen gases as would be typical in a commercial
electrolysis unit. That being said the assumption is that there is
no separation and the following calculations are based on a gaseous
mixture of hydrogen and oxygen. Therefore, since one mole of water
disassociates into one mole hydrogen and half mole of oxygen, the
mass flow rate of hydrogen can be calculated and thus based on the
density and calorific value (heating value), the energy is
calculated on a per minute basis. Since power is energy/time, the
power OUT due to hydrogen in the gas is written in MJ/hour.
6 Internal Combustion Engine Fundamentals, John B. Heywood,
McGraw-Hill 1988, P.674 7 Bosch Automotive Handbook 5th ed Pg.
881
Jetstar Hydrogen Gas Generator #2004-032 18
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Table 9 Gaseous Flow Rate from JetStarTM
Gasous Flow Rate from Jetstar
H2 H2
Energy contribution of H2/minute
Energy contribution of H2/hour
Displacement of Diesel Fuel by H2
Measured Gaseous Flowrate kg/minute MJ/kg MJ/minute MJ/hr
litres(diesel)/minutelitres/min m3/min
0.65 0.00065 0.00005 120 0.00654 0.392 0.00018
H2O + E ---> H2 + O2 H2 2.01594 g/moldensity 0.0839 kg/m3
MJ/hr litres(diesel)/minute
0.392 0.00018Bios International DryCal DC-Lite Primary Flow
MeterModel No. DCL-H Rev. 1.08.Serial No. 1851
Chemical Power OUT
Jetstar EfficiencyChemical Power OUT 0.392 MJ/hr 60.3%Electrical
Power IN 0.651 MJ/hr
Example of Large Commercial Electrolysis Hydrogen Generator
Hydrogen Generator Efficiency
Electricity consumption
per MJ of Hydrogen
The JetStar system efficiency is now simply the power OUT
divided by the power IN. In other words the system requires
approximately 1.65 times more electrical power from the alternator
than is available in the process gas injected into the intake
manifold of the engine.
Table 10 JetStar Efficiency
This compares reasonably well with the example below of a
commercial electrolysis hydrogen generator.
4.2 kWh/m3 46.67 kWh/kg 0.389 kWh/MJ 1.4
MJ(elec)/MJ(chemical)71.4% Efficiency
http://www.stuartenergy.com/our_products/hydrogen_generation.html
Ratio of Electrical energy IN to Chemical energy OUT
Electricity consumption per volume of Hydrogen
Electricity consumption per mass of Hydrogen
7.4 Overall System Efficiency
Table 11 describes the overall efficiency of converting diesel
fuel to hydrogen using a vehicle on-board electrolysis hydrogen
generator.
Jetstar Hydrogen Gas Generator #2004-032 19
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Table 11
Calculated System EfficiencyChemical Fuel (Diesel)
Combustion Efficiency
Mechanical Efficiency
Alternator Efficiency
100% 99.5% 38.0% 50.0%Cumulative Efficiency 99.5% 37.8%
18.9%
H2 Gen Efficiency
Overall System Efficiency
60.3% 11.4%
11.4%
Combustion Efficiency Measured
Mechanical Efficiency
Internal Combustion Engine Fundementals, Pg. 674
Chemical Energy to Heat Energy (diesel fuel to heat)
Heat Energy to Mechanical Energy
Alternator Efficiency
Bosch Automotive Handbook 5th ed, Pg. 881
Hydrogen Generator Efficiency Calculated above.Overall System
Efficiency
Efficiency of converting Chemical energy (diesel) to Chemical
energy (Hydrogen, Oxygen)
Electrical Energy to Chemical Energy
Mechanical Energy to Electrical Energy
8. Combustion Efficiency, Exhaust Emissions and Fuel
Consumption
The purpose of this test program was to evaluate the product for
its effect on vehicle exhaust emissions and fuel consumption. The
test vehicle had a series of chassis dynamometer exhaust emission
and fuel consumption tests conducted in the baseline or original
equipment manufacturers (OEM) configuration, and an identical
series while using JetStar fuel conditioning product.
8.1 Combustion Efficiency
The combustion efficiency calculation is based on the carbon
balance calculation.
Combustion efficiency = (CO2*MWC/MWCO2)
(CO2*MWC/MWCO2+ CO*MWC/MWCO+ HC*FFC+TPM* MWC/MWTPM)
Where:
CO2, CO, HC are mass based exhaust emissions rates (grams/mile,
grams/kilometre, grams, grams/kW-hr)
MWC is the molecular weight of elemental carbon, (12.0112)
MWCO2 is the molecular weight of CO2 (44.0100)
MWCO is the molecular weight of CO (28.0106)
FFC is the fuel fraction carbon for the fuel or HC
Jetstar Hydrogen Gas Generator #2004-032 20
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Test fuel FFC = 0.8656 from fuel analysis
MWTPM is the molecular weight of the Total Particulate Mass,
(12.0112)
For the purposes of this study TPM is assumed to be 100%
elemental carbon
The combustion efficiency of the Cummins engine remained very
steady throughout the test program. Over the course of 6 Arterial
cycles and 6 Commuter test cycles the combustion efficiency of the
engine only varied between 99.59% and 99.71%, irrespective of the
of the test cycle or whether the JetStar product was installed or
not.
The following tables describe the emission rates of the
regulated emissions of Total Hydrocarbons (THC), Carbon Monoxide
(CO), Oxides of Nitrogen (NOX ) , Total Particulate Mass (TPM,
soot) and the unregulated emissions of carbon dioxide (CO2) over
the Arterial and the Commuter Heavy Duty Truck test cycles
conducted in this study. All of the emission rates are reported in
grams/mile (g/mi). The fuel consumption was calculated from the
exhaust emission rates using the carbon balance method and is
reported in litres/ 100 kilometres.
The arithmetic mean and standard deviation of the exhaust
emission and fuel consumption test results are presented in the
results to provide an indication of the test repeatability and
statistical significance of the results.
The coefficient of variation (COV) is a measure of the relative
dispersion of the data and is calculated by dividing the standard
deviation by the mean of the data. The COV is generally expressed
as a percentage.
The small standard deviation shown in Tables 12 and 13 indicates
good repeatability of the vehicle during the test program
Table 12 and 13 illustrate the comparison of the Commuter and
Arterial cycle results and indicates that the JetStar product does
not have a statistically significant effect on exhaust emissions or
fuel consumption.
Jetstar Hydrogen Gas Generator #2004-032 21
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Table 12 Commuter Cycle Chassis Dynamometer Exhaust Emission
Test Results and Fuel Consumption
ENVIRONMENT CANADAEmissions Research and Measurement
Division
International Model 9200i6X4
Fuel: Commercially available low sulphur dieselDriver: Mike
WhiteLab # 1
Configuration Test Date
Carbon Monoide
(CO)
Carbon Dioxide (CO2)
Oxides of Nitrogen
(NOx)
Total Hydrocarbon
(THC)Total Particulate
Mass (TPM)Combustion Efficiency
g/mi g/mi g/mi g/mi g/mi %
Baseline 22-Dec-04 1 1.04 807 8.48 0.26 0.102 99.65%22-Dec-04 2
1.12 819 7.70 0.26 0.113 99.64%22-Dec-04 3 1.01 821 7.94 0.32 0.088
99.65%
Number of Sample 3Average 1.05 815 8.04 0.28 0.101 99.64%
stdev 0.06 7.70 0.40 0.03 0.01 0.00Coefficient of Variance 5.32
0.94 4.95 12.37 12.02 0.01
Configuration Test Date CO CO2 NOx THC TPM
Fuel Consumption
L/100km
18.7018.9919.03
18.910.180.95
Combustion Efficiency
g/mi g/mi g/mi g/mi g/mi %
with JetStar 23-Dec-04 1 1.00 808 9.28 0.24 0.1052
99.66%23-Dec-04 2 0.99 811 9.04 0.26 0.0940 99.67%23-Dec-04 3 1.08
805 8.41 0.27 0.1054 99.64%
Commuter Test Cycle
Commuter Test Cycle
FuelL/100km
18.7318.8018.66
Number of Sample 3Average 1.02 808 8.91 0.26 0.102 99.66%
18.73
stdev 0.05 3.00 0.45 0.02 0.01 0.00 0.07Coefficient of Variance
5.10 0.37 5.06 5.95 6.44 0.02 0.36
Baseline vs. JetStarsigma 0.05 5.84 0.43 0.03 0.01 0.00 0.14
t distribution 0.66 1.58 -2.51 1.07 -0.05 -1.04 1.60 95%
confidence level 2.78 2.78 2.78 2.78 2.78 2.78 2.78
n =N1+N2-2 4 4 4 4 4 4 4% difference(
(final-initial)/initial)*100
Significant ? NO NO NO NO NO NO NO
Jetstar Hydrogen Gas Generator #2004-032 22
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Table 13 Arterial Chassis Dynamometer Exhaust Emissions and Fuel
Consumption
ENVIRONMENT CANADAEmissions Research and Measurement
Division
International Model 9200i6X4
Fuel: Commercially available low sulphur dieselDriver: Mike
WhiteLab # 1
Configuration Test Date
Carbon Monoide
(CO)
Carbon Dioxide (CO2)
Oxides of Nitrogen
(NOx)
Total Hydrocarbon
(THC)Total Particulate
Mass (TPM)Combustion Efficiency
Fuel Consumption
g/mi g/mi g/mi g/mi g/mi % L/100km
Baseline 21-Dec-04 1 3.15 1685 7.87 0.67 0.3883 99.50%
39.1121-Dec-04 2 2.94 1666 8.48 0.64 0.3426 99.53% 38.6621-Dec-04 3
3.00 1637 7.56 0.64 0.3339 99.52% 37.99
Number of Sample 3Average 3.03 1663 7.97 0.65 0.355 99.51%
38.59
stdev 0.11 24.27 0.47 0.02 0.03 0.00 0.56Coefficient of Variance
3.57 1.46 5.89 2.67 8.23 0.01 1.46
Configuration Test Date CO CO2 NOx THC TPMCombustion Efficiency
Fuel
g/mi g/mi g/mi g/mi g/mi % L/100km
with JetStar 23-Dec-04 1 3.13 1698 9.68 0.58 0.3172 99.53%
39.4123-Dec-04 2 3.22 1742 8.91 0.61 0.3388 99.53% 40.4323-Dec-04 3
2.94 1697 8.29 0.65 0.3484 99.53% 39.38
Number of Sample 3Average 3.10 1712 8.96 0.61 0.335 99.5%
39.74
stdev 0.14 25.79 0.70 0.03 0.02 0.00 0.60Coefficient of Variance
4.58 1.51 7.81 4.99 4.76 0.00 1.51
Baseline vs. with JetStarsigma 0.13 25.04 0.60 0.02 0.02 0.00
0.58
t distribution -0.64 -2.43 -2.03 1.93 1.05 -2.25 -2.42 95%
confidence level 2.78 2.78 2.78 2.78 2.78 2.78 2.78
n =N1+N2-2 4 4 4 4 4 4 4% difference(
(final-initial)/initial)*100
Significant ? NO NO NO NO NO NO NO
Arterial Test Cycle
Arterial Test Cycle
9. Conclusions
The purpose of this study was to determine the effect of using a
JetStar on-board electrolysis system to produce a hydrogen/oxygen
gaseous mixture and inject it into the intake manifold of an
internal combustion engine. There are two issues addressed in this
study. Firstly, is there any benefit in injecting minute quantities
of a hydrogen/oxygen mix into an internal combustion engine with
respect to exhaust emissions or fuel consumption? Secondly, is the
production of the hydrogen/oxygen gas mixture from an on-board
electrolysis system efficient from an energy balance
standpoint?
A total of 12 valid chassis dynamometer exhaust emission and
fuel consumption tests were conducted in order to evaluate the
effectiveness of the JetStar product to reduce fuel consumption and
exhaust emissions. The Arterial and the Commuter Heavy Duty Vehicle
chassis dynamometer exhaust emission test cycles were used during
this program.
Jetstar Hydrogen Gas Generator #2004-032 23
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The evaluation regime indicated that the use of the JetStar
hydrogen generator product did not affect combustion efficiency of
the test vehicle engine nor did it improve exhaust emission rates
or fuel consumption of the vehicle. The combustion efficiency of
the engine remained between 99.5% and 99.8% through out the program
regardless of the test cycle or whether the JetStar product was
installed or not.
Exhaust emissions rates of carbon monoxide, oxides of nitrogen,
total hydrocarbons, and total particulate mass (soot) and
calculated fuel consumption did not show any statistically
significant change with use of the JetStar product.
The second question was whether the on-board generation of a
hydrogen/oxygen gas mixture through electrolysis is efficient from
an energy balance standpoint.
Based on the JetStar, advertised water consumption of 1.8 litres
per 5000 miles (8047 km), the energy from hydrogen injected into
the intake manifold of the diesel engine is equivalent to 0.00829
litres of diesel fuel per 100 kilometres.
The calculations based on the advertised water consumption and
empirical measurements made during the program indicate that the
JetStar electrolysis system is, in the best case, 60.3% efficient
at converting electrical energy from the alternator to a process
gas mixture of hydrogen and oxygen. In other words, it requires
approximately 1.65 times the electrical energy from the alternator
compared to the chemical energy in the form of hydrogen.
Similarly, the efficiency of using the electrical system of a
vehicle to generate hydrogen through electrolysis was calculated to
be approximately 11.4%. To generate one unit(MJ) of hydrogen energy
with the JetStar system requires 8.77 units (MJ) of energy from
diesel fuel.
Jetstar Hydrogen Gas Generator #2004-032 24
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10. Appendix
A -1. Diesel Fuel Specifications
CommercialSpecification Low Sulphur
Currentrep 28/10/04rcvd 22/9/04
Density(Kg/m3) 852.2Specific Gravity 0.8526
Gravity deg API=141.5/SG-131.5 34
Cetane Number (ASTM D613) 44.4Cetane Index
Carbon (wt%) 86.31Hydrogen (wt%) 13.22Nitrogen (mg/L)
Total Sulfur % (max) 0.039Total Sulfur (ppm,ug/L) 392
Volume % Aromatics (minimum) 16.6Volume % Saturates 82.2
Flashpoint, min C 77Flashpoint, minFCloud Point, C -18.7
Viscosity, Centistokes 2.84
Distillation Range, % Evap(corrected)(deg. C)
IBP (initial boiling point) 139.210% 19750% 27190% 337
End Point 378
Jetstar Hydrogen Gas Generator #2004-032 25
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A-2. JetStar Electrical Current Draw
Jetstar Current Draw measurements
Meter Reading Current (amps) Voltage Power (Watts)Average
0.01471 14.71 12.00 176.52high 0.0152 15.2 12 182.4low 0.0138 13.8
12 165.6
Meter Reading Current (amps) Voltage Power (Watts)Average
0.01511 15.11 12.00 181.33high 0.016 16 12 192low 0.0148 14.8 12
177.6
Meter Reading Current (amps) Voltage Power (Watts)Average
0.01471 14.71 12.00 176.52high 0.0152 15.2 12 182.4low 0.0138 13.8
12 165.6
Meter Reading Current (amps) Voltage Power (Watts)Average
0.01571 15.71 12.00 188.47high 0.0166 16.6 12 199.2low 0.013 13 12
156
Current (amps) Power (Watts)Overall Average 15.1 180.7
Jetstar Hydrogen Gas Generator #2004-032 26
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A-3. Fuel Consumption Calculation
The calculated fuel economy was based on the following carbon
balance equation:
GCPG = grams of carbon per US gallon of fuel
GCPG = 3785.4 * fuel fraction carbon *fuel density
(for diesel assume GCPG=2778)
Hydrocarbons (HC), Carbon Monoxide (CO), Carbon Dioxide (CO2 )
reported in grams per mile
MPGC = miles per US gallon Carbon
MPGC = GCPG/ ((0.866*HC ) + (0.429*CO) + (0.273 * CO2))
To convert to fuel consumption in litres/100 kilometres:
Litres/100km = 235.22/MPGC
Jetstar Hydrogen Gas Generator #2004-032 27
AbstractProject TitleObjectiveProject Participants
BackgroundTest DescriptionTest VehicleTable 1. Vehicle
DescriptionTest FuelsFuel Temperature and Fuel CoolingFlash
PointFuel Density
Fuel Heat Exchanger
Test Program MethodologyService AccumulationChassis Dynamometer
TestingFacility and Equipment DescriptionChassis Dynamometer
Testing ProcedureJetStar Installation
Results and DiscussionFuel Fraction Hydrogen of WaterJetStar
Advertised Water ConsumptionEmpirical Measurements and System
EfficiencyOverall System Efficiency
Combustion Efficiency, Exhaust Emissions and Fuel
ConsumptionCombustion Efficiency
ConclusionsAppendixMPGC = miles per US gallon Carbon