SINERGI Vol. 29, No. 3, October 2025: 625-632
http://publikasi.mercubuana.ac.id/index.php/sinergi
http://doi.org/10.22441/sinergi.2025.3.006

Experimental investigation of HHO blending in combustion
engine performance
Awaludin Martin, Abda Hidayatullah, Yogie Rinaldy Ginting, Annisa Wulan Sari*
Department of Mechanical Engineering, University of Riau, Indonesia

Abstract
The transition to renewable energy sources has become increasingly
critical due to the adverse effects of greenhouse gas emissions. One
alternative to reducing fossil fuel dependence is hydrogen. Hydrogen
technology can be integrated into internal combustion engines
without major design modifications. This study investigates the
effects of HHO gas blending on engine performance under varying
brake load conditions. The carburetor was modified to allow HHO gas
from electrolysis to enter the combustion chamber. The results
indicate that HHO blending led to a 4.9% increase in brake power, a
1.66% improvement in thermal efficiency, and a 3% reduction in
brake-specific energy consumption (BSEC). Additionally, among
different potassium hydroxide (KOH) concentrations, the 30% wt
solution exhibited the lowest power consumption for electrolysis.
This is an open-access article under the CC BY-SA license.

INTRODUCTION
The
increasing
concentration
of
greenhouse gases has contributed to rising global
temperatures [1, 2, 3]. In response, various
nations have committed to limiting temperature
increases to below 1.5°C and achieving net-zero
emissions by 2050, as outlined in the COP26
agreement. Reducing fossil fuel usage is
imperative to achieving these targets, and
hydrogen is a promising alternative due to its high
energy density and clean combustion properties
[4, 5, 6].
In order to achieve these targets, fossil
energy reduction must be implemented globally by
all stakeholders. An alternative renewable energy
in reducing the use of fossil fuels is hydrogen
[5][6]. Hydrogen as a fuel produces heat and water
as emissions. The heating value of hydrogen gas
is about 142.18 MJ/Kg (HHV) and 120 MJ/Kg
(LHV) at 25˚C [7]. The value of hydrogen is much
higher than other fuels. Table 1 provides the
significant differences characteristics between
hydrogen and other fuels, highlighting the
advantages of hydrogen gas.

Keywords:
Electrolysis;
Hydrogen;
Internal Combustion;
Performance;
Article History:
Received: September 24, 2024
Revised: January 23, 2025
Accepted: February 17, 2025
Published: September 2, 2025
Corresponding Author:
Annisa Wulan Sari
Mechanical Engineering
Department, Universitas Riau,
Indonesia
Email:
annisasw@lecturer.unri.ac.id

Table 1. Comparison of Hydrogen, Gasoline,
and Diesel Properties [8]
Properties
Auto-ignition
temperature (K)
Laminar lame
speed (m/s)
AFR (kg/kg)
Lower Heating
value (mJ/kg)

H2

Gasoline

Diesel

853

623

523

4-76

0,3-0,4

0,3-0,4

34,4

14,7

14,5

119,9

43,9

42,5

Hydrogen can be produced through several
methods, including hydrocarbon reforming (grey
hydrogen), carbon capture-enhanced reforming
(blue hydrogen), biomass processing, and
electrolysis powered by renewable energy (green
hydrogen) [9][10].
Electrochemical water electrolysis is a
commonly
used
method
for
producing
environmentally friendly hydrogen gas. This
process involves applying direct current (DC)
electricity to break the bond energy of water
molecules, separating them into hydrogen and
oxygen elements with a purity of up to 99.99% [7].

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

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SINERGI Vol. 29, No. 3, October 2025: 625-632

The chemical reactions involved in the electrolysis
process are as follows [12]:
(1)
Reaction = 2H2O(l) → 2H2 (g) + O2(g)
Anode
Katode

= 2H2O(l) → O2(g) + H+(aq) + 4e+

-

= 4H (aq) + 4e → 2H2(g)

(2)
(3)

Under standard conditions, the enthalpy
(ΔH) of water is 285.85 kJ/mol, as calculated using
the following equation:
2H2O(l) → 2H2 (g) + O2(g) ΔH = 285,85 kJ/mol

(4)

ΔH is the sum of:
ΔH

= ΔG + TΔS

(5)

Where
ΔG = 237,13 kJ/mol
(6)
TΔS = 48,72 kJ/mol
(7)
Gibs free energy (ΔG) in electrolysis is the
minimum energy required for the electrolysis
reaction. The minimum voltage (Erev) can be
calculated through the following equation:
ERev = ΔG = 1,23 V
𝑧.𝐹

(8)

At the same time, energy input during the
electrolysis process influences temperature (T)
and entropy (ΔS). Consequently, the minimum
voltage (VTN) required for the electrolysis process
under standard conditions is determined by the
following equation:
VTN = ΔH = 1,48 V
𝑧 .𝐹

(9)

F is Faraday's constant (F=96485 C/mol), and z is
the number of electrons (2 for hydrogen and 4 for
oxygen). In practice, the voltage required for
electrolysis exceeds the theoretical minimum
because of overpotential caused by resistive
losses, reaction kinetics, gas pressure, electrode
conductivity, electrolyte conductivity, distance
between electrodes, and gas bubbles on the
electrode surface [13].
The theoretical volume of hydrogen
production is determined using the following
equation [14]:
𝑖 . 𝑉𝑚 . 𝑡
𝑉𝐻2𝑖𝑑𝑒𝑎𝑙 =
(10)
2.𝐹
Where 𝑉𝐻 𝑖𝑑𝑒𝑎𝑙 is the theoretical volume of
2

hydrogen, i is the current strength (A), t is the time
(s), and F is Faraday's constant (96.485 C/mol).
Vm is the molar volume.
An internal combustion engine can blend
hydrogen
without
requiring
significant
modifications to its design. Blending hydrogen gas
with fossil fuels improves combustion efficiency by
reducing energy losses [15]. It also enhances

626

flame ignition properties and improves the
combustion characteristics of hydrocarbon fuels
[16]. Hydrogen plays a key role in reducing
exhaust emissions from the transportation sector.
The global vehicle count is projected to reach 1.6
billion by 2035, continuing to consume fossil fuels
and emit pollutants that contribute to greenhouse
gas emissions [17]. Therefore, hydrogen offers a
practical approach to accelerating the energy
transition while maintaining economic activity [18].
Gad et al. [19] utilized electrolyzed gas at
0.5 LPM, mixed with gasoline engine combustion
at 3000 rpm. This study showed an increase in
volumetric efficiency, thermal efficiency, and airfuel ratio by 7.5%, 8%, and 11%, respectively,
reduced SFC by 9%, and reduced CO, HC, NOx,
and CO2 production by 18%, 9%, 15%, and 11%,
respectively. Purayil et al. [20] tested a singleslider spark ignition engine with variations of 5 mg
to 6 mg of gasoline and variations of hydrogen
between 2, 5, 8, 11, and 14 LPM. This study
showed that hydrogen gas at a flow rate of up to
11 LPM significantly reduces brake-specific
energy consumption (BSEC) by 92.27% and
increases BTE by 25%.
Hassan et al. [21] used a spark ignition
engine with a capacity of 183 cc to mix hydrogen
gas at 1500 rpm engine speed. The results
showed an increase in engine efficiency by up to
47.24%, reduced BSEC by up to 32.1%, reduced
CO production by up to 91.7%, and reduced HC
by up to 34.84%. Adaileh and al Qdah [22]
investigated the effects of using 3 LPM HydrogenHydrogen oxygen (HHO) gas. The results showed
an increase in adequate shaft power from 1198.2
watts to 1413 watts. Specific Fuel Consumption
(SFC) decreased from 968 g/kW to 792 g/kW, and
BTE improved from 16.93% to 23.48%.
Furthermore, The HC emissions decreased from
240 ppm to 215 ppm.
Assad and Penazkov [23] showed that the
concentration of hydrogen in mixing fuel and air
could reach 20% of the total air entering the
cylinder. This study also showed that using up to
20% of hydrogen increased the pressure in the
combustion chamber by 19% to reach 5.8 Mpa,
and the temperature in the combustion chamber
increased by 140 K.
Based on the literature, HHO gas has
proven to be a promising fuel for internal
combustion engines. Previous studies have
focused on understanding the effects of blending
HHO in combustion engines, examining various
parameters such as HHO flow rates, engine
speed, and cylinder capacity [19, 20, 21, 22].
However, further analysis is still needed to
evaluate the impact of HHO addition on engine
performance under varying load conditions.

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

p-ISSN: 1410-2331 e-ISSN: 2460-1217

This study aims to investigate the effects of
HHO blending on engine performance under
varying brake loads, focusing on parameters such
as brake power (BP), brake-specific energy
consumption (BSEC), and brake thermal
efficiency (BTE).
METHOD
Hydrogen Electrolyzer Setup
The electrolyzer design in this study,
which was developed and finalized prior to the
commencement of the experiments, is detailed in
Table 2, highlighting the pre-determined
arrangement of components such as the
electrodes, neutral plates, and electrolyte flow
system to ensure compatibility with the research
objectives and operational conditions.
The illustration of the electrolyzer are
provided in Figure 1. The stack consists of 2 cells,
each containing one anode plate (positive) and
one cathode plate (negative), one neutral plate
(not electrified) between the anode and cathode
with a distance of 3 mm from each plate. Each
plate is made of stainless steel 316 due to its high
corrosion resistance and durability in alkaline
solutions, while the neutral plate serves to
minimize electrical interference between the
anode and cathode.
The power source was a 12V 60Ah
battery. A 12V 60Ah battery supplied power, with
current variations of 30A, 40A, and 50A applied for
each KOH concentration (20% wt, 25% wt, and
30% wt). The gas production rate and power
consumption were measured using a flow meter
and a wattmeter.
Based on these evaluations, the
electrolysis tests revealed that the average gas
production rates at current strengths of 30A, 40A,
and 50A were 0.25 L/min, 0.3 L/min, and 0.4
L/min, respectively. Therefore, the electric power
consumption for all currents at each molarity
variation was recorded using a wattmeter.
Table 2. Specification of Electrolyzer
Parameters
Type of Electrolyzer
Type of Electrode
Dimension of Elektroda
Number of cells
Number of stacks
Number of neutral plates
Capacity of electrolyzer

Description
Wett Cell
Stainless Steel 316
1 mm X (10 X 10) cm
14
7
7
1 Liter

(a)

(b)

Figure 1. Electrolyzer Circuit: Anode, Cathode,
and Neutral Plate (a), Electrolyzer Parts (b)
Experimental Procedure
The experiments were conducted in the
Energy Conversion Laboratory at the University of
Riau. Figure 2 illustrates the schematic of the
experimental setup used in this study. The flow
rate of the gas was measured using a flow meter.
The gas was then transported through a pipe,
blended with air, and directed into the intake
manifold via the carburetor.
The engine used in this experiment was a
three-cylinder, four-stroke gasoline engine, as
detailed in Table 3. The fuel used was gasoline
with an octane rating of 90, commonly known as
Pertalite. The experiment began when the engine
speed reached 2200 rpm, at which point the
generated HHO gas was directed into the
carburetor through a pipeline. A flashback arrestor
was installed for safety. Brake loading was varied
at 0.25 kg/cm², 0.5 kg/cm², and 0.75 kg/cm². The
engine speed and fuel consumption time were
recorded using a tachometer and a stopwatch
while consuming 5 ml of fuel.
The first experiment began with gas
generated from a 30A current at 20%wt KOH,
which produced 0.25 LPM HHO gas, and the
brake load was set at 0.25 kg/cm2. Since the
engine was operated under variations in the brake
loading and KOH molarity, the effects of gas
addition on engine performance were analyzed
using the following parameters
Table 3. Specification of Gasoline Engine
Parameters
Type of machine
Number of cylinders
Capacity of the cylinder
Ratio compression
Bore x stroke
Maximum Power
Maximum Torque

Description
3-cylinder, four-stroke
3
993 cc
9.5:1
76 mm x 73 mm
34.59 kW/ 5600 RPM
75.5 Nm/3200

.

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

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SINERGI Vol. 29, No. 3, October 2025: 625-632

Figure 2. Schematic Experimental Setup
The effects of HHO blending were analyzed by
evaluating BP, BSEC, and BTE, calculated using
the following equations:
(10)
𝑇.2.𝜋.𝑛 (w)
𝐵𝑃 =
60

BSEC =
𝐵𝑇𝐸 =

(ṁ𝑔 . 𝐿𝐻𝑉𝑔 + ṁ𝐻2 . 𝐿𝐻𝑉

𝐻2 )

(J/w)

(11)

𝑁𝑒

x 100 (%)

𝑁𝑒

(12)

(ṁ𝑔 . 𝐿𝐻𝑉𝑔 + ṁ𝑔 . 𝐿𝐻𝑉

𝐻2 )

RESULTS AND DISCUSSION
This experiment consists of two stages. In
the first stage, the electrolyzer generates HHO
gas by varying the current and molarity of
potassium hydroxide (KOH). During this stage, the
average HHO production and electricity
consumption were measured by a flowmeter and
a wattmeter. In the second stage, the HHO gas
and air mix in the combustion engine. The HHO
flow rate used was the average data obtained from
the first stage. Then, the engine performance was
analyzed by comparing the performance before
and after blending HHO gas.
Energy Consumption for HHO
According to Ohm's law, a higher potential
difference (voltage) results in a greater flow of
current, facilitating the conduction of free ions.
However, resistance within the system—such as
that in the electrodes, electrolytes, and reaction
container—causes a decrease in the input electric

628

current after passing through the electrolysis
circuit. The voltage and current flowing through
the system directly impact power consumption.
Therefore, if power consumption is not
proportional to hydrogen production, the process
will not be economically efficient [24].
Variations in current strength of 30A, 40A,
and 50A were tested for each molarity of KOH
(20%wt, 25%wt, and 30%wt). Based on
electrolysis tests in each variation in KOH
molarity, the average gas production rate at
current strengths of 30A, 40A, and 50A was 0.25
LPM, 0.3 LPM, and 0.4 LPM, respectively. The
test also showed that to achieve these gas flow
rates, the electric power consumption decreased
by 30%wt KOH electrolyte compared to 25%wt
and 20%wt KOH.
Figure 3 indicates that the electrical power
consumption decreases as the molarity of KOH
increases. The phenomenon is explained by the
catalytic properties of KOH, which accelerate
reaction kinetics and reduce water resistance.
Lower resistance allows more ions per unit of time
to separate H2O into its elements [25][26]. At a
KOH concentration of up to 30%wt, the specific
electrolyte conductivity is significantly higher
compared to lower concentrations. Higher
conductivity reduces the voltage required for the
electrolysis process. As a result, power
consumption
decreases,
improving
the
electrolyzer's efficiency in producing the same
amount of gas [27].

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

75

69

100

75

3,73
3,82
3,87
3,91
2,52
2,58
2,61
2,63

3
2
1
0

50
0,25

4

1,28
1,31
1,31
1,32

125

118

150

122

131

175

5

Brake Power (kW)

184

200

186

196

225

78

Energy Consumption (W)

p-ISSN: 1410-2331 e-ISSN: 2460-1217

0,3

0,4

Flow Rate Gas HHO (L/Min)
20wt% 25wt% 30%wt
Figure 3. Energy Consumption vs Flowrate Gas
HHO
The Effects of HHO Gas on the Internal
Combustion Engine
As brake loading increases, the engine
generates higher torque to maintain stable
operation. The demand for higher torque leads to
increased fuel consumption, which subsequently
raises brake power output. The trend observed in
Figure 4 illustrates the relationship between brake
power and brake loading. At lower brake loading
levels, the increase in brake power is relatively
modest due to the lower torque demand.
However, at higher loading levels, the increase
becomes more significant.
Figure 4 shows the addition of varying HHO
flow rate, blended in the combustion chamber,
under different brake loading conditions. The
addition of HHO enhances the brake power output
at the same brake loading levels. The
improvement occurs because the HHO gas acts
as an auxiliary fuel, improving the engine
performance by enhancing the flame speed and
helping the fuel burn more completely. This leads
to a more efficient energy conversion, which
directly contributes to the observed increase in
brake power.
In this experiment, the most significant
increase in brake power, up to 4.9%, occurs when
the brake load is 0.75 kg/cm2, increasing from 3.73
kW to 3.91 kW with the addition of 0.4 LPM HHO.
Nabil et al. [28], also observed an increase in
brake power using HHO flow rates of 0.47 LPM to
0.51 LPM. Their results showed a brake power
increase of up to 17.9% in a 150 CC engine and
22.4% in a 1300 CC engine. The difference in
brake power gain was influenced by variations in
engine capacity and rotation speed, which
determine the amount of HHO burned during each
combustion cycle. An increase in brake power
indicates improved engine performance.

0,25
0,5
0,75
Brake Loading (kg/cm2)
0 L/m
0,25 L/m
0,3 L/min
0,4 L/m
Figure 4. Brake Loading vs Brake Power
Brake-specific energy consumption (BSEC)
was analyzed by observing the fuel consumption
required to generate brake power. Higher brake
loading results in reduced fuel consumption
because the engine speed decreases, which in
turn reduces the amount of fuel injected into the
combustion chamber. A decrease in fuel
consumption to generate a brake power at the
same brake loading indicates improved efficiency.
Figure 5 shows the effect of all variations of
HHO blending under varying brake loading
conditions on the BSEC. The experiment shows
that HHO blending reduces fuel consumption
under all brake load conditions, with the most
significant reduction observed in BSEC, up to 3%,
occurring at a brake load of 0.25 kg/cm2 with an
HHO flow rate of 0.4 LPM; the decrease is from
5.75 MJ/kWh to 5.57 kWh.
A similar trend in BSEC reduction was also
reported by Purayil et al. [20], who used hydrogen
flow rate variations of 2, 5, 8, 11, and 14 LPM. The
most significant BSEC reduction was obtained
from 47.5 Mj/kWh to 3.7 MJ/kWh, representing a
92% decrease at a hydrogen flow rate of 11 LPM.
The same result was also obtained by Gad et al.
[19]. This study used 0.5 LPM HHO, with A
decrease in specific fuel consumption (SFC) by up
to 9%.
The reduction in BSEC observed in the
experiment can be attributed to the unique
combustion characteristics of HHO gas. Its high
diffusivity enables homogeneous mixing with air in
the combustion chamber [29], while its high
flammability and heating value accelerate the
combustion process, enhancing energy release
[6][30]. Additionally, its high burning speed
shortens the combustion duration, optimizing the
conversion of thermal energy into mechanical
work. These properties collectively improve the
combustion efficiency of the air-fuel mixture, as
evidenced by the reduction in fuel consumption
observed in this study [31].

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

629

0,25
0,5
0,75
Brake Loading (kg/cm2)
0 L/m 0,25 L/m 0,3 L/m 0,4 L/m
Figure 5. Brake Loading vs BSEC
Thermal efficiency was also evaluated in
this study, with the results presented in Figure 6.
The findings indicate that thermal efficiency
improves with increasing brake loading. As brake
load increases, the engine operates closer to its
optimal efficiency range, where a larger proportion
of combustion energy is converted into useful
work. This reduces the relative impact of frictional
and thermal losses on total energy output.
The results also show that thermal
efficiency increases with higher HHO gas flow
rates. This improvement can be attributed to the
combustion characteristics of HHO gas. The
hydrogen content in HHO has a high burning
speed, enabling faster and more complete
combustion of the primary fuel. Additionally, the
homogeneous mixing of HHO with air ensures an
optimal air-fuel mixture, minimizing unburned
hydrocarbons and reducing energy losses.
Consequently, the conversion of chemical energy
into mechanical work is enhanced, leading to
increased thermal efficiency.
The experiment demonstrates the potential
of HHO gas to improve thermal efficiency without
requiring significant modifications to engine
design under varying brake load conditions. It
provides a more straightforward approach to
emission reduction compared to other green
energy solutions, such as electric vehicles. The
use of hydrogen presents a practical pathway for
accelerating the energy transition while
maintaining economic activity. Therefore, it offers
an immediate solution to reducing fuel
consumption and lowering emissions at an early
stage.
The highest improvement in thermal
efficiency, up to 1,66%, was achieved at an HHO
flow rate of 0.4 LPM and a brake load of 0.75
kg/cm2. The result showed that efficiency
increased from 63.37% to 65%.

630

63,37
64,41
64,84
65,03
41,77
42,71
42,84
42,91

85
75
65
55
45
35
25
15

20,79
21,23
21,38
21,31

Thermal Efficiency (%)

5,75
5,59
5,59
5,57

8,66
8,49
8,48
8,45

21
19
17
15
13
11
9
7
5

17,25
16,97
16,96
16,89

BSEC (MJ/kWh)

SINERGI Vol. 29, No. 3, October 2025: 625-632

0,25
0,5
0,75
Brake Loading (kg/cm2)
0 L/m 0,25 L/m 0,3 L/m 0,4 L/m
Figure 6. Brake Loading vs Thermal Efficiency
Although the improvements observed in this
study are less significant than those reported by
Gad et al. [19] (an 8% increase in thermal
efficiency with 0.5 LPM HHO in a single-cylinder
engine) and Adaileh & Al Qdah [22] (an increase
in BTE from 16.93% to 23.48% with 3 LPM HHO
in a four-cylinder engine). They provide valuable
insights into the effects of HHO blending in multicylinder engines using a relatively lower HHO flow
rate. This relatively modest improvement suggests
that the effectiveness of HHO is influenced not
only by its flow rate but also by engine
configuration and combustion characteristics.
The data in Table 4 shows that the
improvement of engine performance does not
necessarily scale linearly with HHO flow rate. For
example, while Hassan et al. [21] achieved a
47.24% increase in efficiency with only 0.2 LPM
HHO in a single-cylinder engine. The present
study of 0.4 LPM HHO in a three-cylinder engine
resulted in only a 1.6% increase.
One possible reason for the smaller
improvement observed in this study is the use of a
multi-cylinder engine, which distributes the HHO
mixture differently compared to the single-cylinder
setups used in previous research.
Table 4. Comparison between the Present Study
and Some of the Previous Studies
Author

Flowrate
HHO (LPM)

Cylinder

Thermal
Efficiency

[19]

0.5

1

Increase 8%

[20]

11

1

[21]

0.2

1

[22]

3

4

Present
work

0.4

3

Increase
25%
Increase
47.24%
Increase
6.55%
Increase
1.6%

SFC/
BSEC
Decrease
9%
Decrease
92.27%
Decrease
32.1%
Decrease
7.85%
Decrease
3%

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

p-ISSN: 1410-2331 e-ISSN: 2460-1217

Additionally, the lower HHO flow rate (0.4 LPM)
may have contributed to the more moderate
enhancement in engine performance.
Despite the modest improvements, this
study demonstrates that even at lower HHO flow
rates, positive effects on engine performance can
still be achieved. This is particularly significant for
practical applications, where using less HHO
offers a more sustainable and cost-effective
approach to improving fuel efficiency and reducing
emissions.
CONCLUSION
This experiment demonstrates that HHO
blending enhances brake power, improves
thermal efficiency, and reduces fossil fuel
consumption under controlled load conditions.
The findings highlight its potential as a practical
and viable solution for reducing fossil fuel
consumption in daily applications. The key results
obtained are as follows:
1. Effect of KOH Molarity on Electrical Power
Consumption
The results show a decreasing trend in
electrical power consumption as KOH molarity
increases. The lowest power consumption across
all variations of current strength and KOH molarity
was observed at a KOH concentration of 30% wt.
2. Effect of HHO Blending on Engine
Performance
HHO blending in the combustion chamber
led to improved engine performance. The optimal
performance was achieved at an HHO flow rate of
0.4 L/min, resulting in a 4.9% increase in brake
power, a 1.6% improvement in thermal efficiency,
and a 3% reduction in brake-specific energy
consumption.
ACKNOWLEDGMENT
The authors gratefully acknowledge the
generous financial support given by the DIPA
LPPM through the RIPEKDOM Scheme - in
accordance with the Fiscal Year 2024 Research
Contract University of Riau of Contract Number:
942/UN19.5.1.3/AL.04/2024.
REFERENCE
[1] Md. M. Islam et al., “Response of Indonesian
mineral supply to global renewable energy
generation: Analysis based on gravity
modelapproach,” Geoscience Frontiers, p.
101658,
Jun.
2023,
doi:
10.1016/j.gsf.2023.10 1658.
[2] A. Martin, Y. R. Ginting, I. Kurniawan, D. R.
Agusta, and N. Khotimah, “Production of biocoal based on empty fruit bunches by
torrefaction method with fixed bed and

tubular continuous reactors,” SINERGI, vol.
28, no. 2, p. 259, Apr. 2024, doi:
10.22441/sinergi.2024.2.006.
[3] A. Martin, R. Hartono, and R. Asrian,
“Utilizing waste heat gasoline engine in the
design and fabrication of a fin and tube
evaporator for the Organic Rankine Cycle
(ORC),” SINERGI, vol. 27, no. 2, p. 171, Apr.
2023, doi:10.22441/sinergi. 2023. 2.004.
[4] K. Ali, D. Jianguo, D. Kirikkaleli, G. Mentel,
and M. Altuntaş, “Testing the role of digital
financial inclusion in energy transition and
diversification towards COP26 targets and
sustainable development goals,” Gondwana
Research, vol. 121, pp. 293–306, Sep. 2023,
doi: 10.1016/j.gr.2023. 05.006.
[5] Z. Zikri et al., “Study on the production of
hydrogen gas from water electrolysis on
motorcycle engine,” J Mech. Elec. Pow.,
Vehi. Tech., vol. 13, no. 1, pp. 88–94, Jul.
2022, doi: 10.14203/j.mev.2022.v13.88-94.
[6] Nasruddin, A. Martin, M. I. Alhamid, and D.
Tampubolon, “Adsorption Isotherms of
Hydrogen on Granular Activated Carbon
Derived from Coal and Derived from Coconut
Shell,” Heat Tran. Eng., vol. 38, no.4,
pp.403–408,
Mar.
2017,
doi:
10.1080/01457632.2016.1194703.
[7] A. A. Ingle, “Oxy Hydrogen Gas Generator
Design and Development for SI Engine,”
vol.08, no. 10, pp.1691–1701, Oct. 2021.
[8] F. Musy et al., “Hydrogen-fuelled internal
combustion engines: Direct Injection versus
Port-Fuel Injection,” Int J Hydrogen Energy,
Jul. 2024, doi: 10.1016/j.ijhydene.2024.
07.136.
[9] M. Noussan et al., “The Role of Green and
Blue Hydrogen in the Energy Transition-A
Technological and Geopolitical Perspective,”
Sustainability, vol. 13, no. 1, p. 298, Dec.
2020, doi:10.3390/su 13010298.
[10] M.
Newborough
and
G.
Cooley,
“Developments in the global hydrogen
market: The spectrum of hydrogen colours,”
Fuel Cells Bulletin, vol. 2020, no. 11, pp. 16–
22, Nov. 2020, doi: 10.1016/ S14642859(20)30546-0.
[11] S. Shiva Kumar and V. Himabindu,
“Hydrogen production by PEM water
electrolysis – A review,” Mater Sci Energy
Technol, vol. 2, no. 3, pp. 442–454, Dec.
2019, doi:10.1016/j.mset. 2019.03.002.
[12] Anton Ottosson, “Integration of Hydrogen
Production via Water Electrolysis at a CHP
Plant,” Luleå University of Technology,
Norrbotten County, 2021.

A. Martin et al., Experimental investigation of HHO blending in combustion engine …

631

SINERGI Vol. 29, No. 3, October 2025: 625-632

[13] F. Gambou et al., “A Comprehensive Survey
of Alkaline Electrolyzer Modeling: Electrical
Domain
and
Specific
Electrolyte
Conductivity,” Energies (Basel), vol. 15, no.
9,
p.
3452,
May
2022,
doi:
10.3390/en15093452.
[14] D. Choi and K.-Y. Lee, “Experimental Study
on Water Electrolysis Using Cellulose
Nanofluid,” Fluids, vol. 5, no. 4, p. 166, Sep.
2020, doi: 10.3390/fluids 5040166.
[15] F. Salek, M. Zamen, and S. V. Hosseini,
“Experimental study, energy assessment and
improvement of hydroxy generator coupled
with a gasoline engine,” Energy Reports, vol.
6, pp. 146–156, Nov. 2020, doi:
10.1016/j.egyr.2019.12.009.
[16] L. Wang et al., “Review on blended
hydrogen-fuel internal combustion engines: A
case study for China,” Energy Reports, vol. 8,
pp. 6480–6498, Nov. 2022, doi: 10.1016/
j.egyr.2022.04.079.
[17] L. V. Amaral et al., “Combustion and specific
fuel consumption evaluation of a singlecylinder engine fueled with ethanol, gasoline,
and a hydrogen-rich mixture,” Case Studies
Therm Engi vol. 57, p. 104316, May 2024,
doi: 10.1016/j. csite.2024.104316.
[18] M. Arana et al., “Acoustic and psychoacoustic
levels from an internal combustion engine
fueled by hydrogen vs. gasoline,” Fuel, vol.
317, p. 123505, Jun. 2022, doi:
10.1016/j.fuel.2022.123505.
[19] M. S. Gad et al., “Impact of produced
oxyhydrogen gas (HHO) from dry cell
electrolyzer on spark ignition engine
characteristics,” Int. J .Hydrogen Energy, vol.
49, pp. 553–563, Jan. 2024, doi:
10.1016/j.ijhydene.2023.08.210.
[20] S. T. P. Purayil, S. Al-Omari, and E. Elnajjar,
“Effect of hydrogen blending on the
combustion performance, emission, and
cycle-to-cycle variation characteristics of a
single-cylinder GDI spark ignition dual-fuel
engine,” Int. J. Thermo., vol. 20, p. 100403,
Nov. 2023, doi: 10.1016/j.ijft.2023.100403.
[21] H. Hassan et al., “Enhancement of the
performance and emissions reduction of a
hydroxygen-blended gasoline engine using
different catalysts,” Appl Energy, vol. 326, p.
119979,
2022,
doi:
doi.org/10.1016/
j.apenergy.2022.119979.
[22] W. M. Adaileh and K. S. AlQdah,
“Performance improvement and emission
reduction of gasoline engine by adding
hydrogen gas into the intake manifold,” Mater
Today Proc, vol. 60, pp. 1769–1778, 2022,
doi:10.1016/j. matpr.2021.12.314.

632

[23] M. Assad and Penazkov,“Comprehensive
analysis of the operation of an internal
combustion engine fueled by hydrogencontaining mixtures,” Energy Reports, vol.9,
pp.
4478–4492,
Dec.
2023,
doi:
10.1016/j.egyr. 2023.03.101.
[24] C. E. Rustana et al., “The Effect of Voltage
and Electrode Types on Hydrogen
Production from The Seawater Electrolysis
Process,” J Phys Conf Ser, vol. 2019, no. 1,
p. 012096, Oct. 2021, doi: 10.1088/17426596/2019/1/012096.
[25] S. Wang, A. Lu, and C.-J. Zhong, “Hydrogen
production from water electrolysis: role of
catalysts,” Nano Conver., vol. 8, no. 1, p. 4,
Dec. 2021, doi: 10.1186/s40580-021-00254x.
[26] A. W. Sari, A. Martin, and M. Habibillah,
“Design of Wet Cell Type Hydrogen
Electrolyzer Using Distilled Water as Raw
Material,” in 2024 4th International
Conference on Electrical Engineering and
Informatics (ICon EEI), Oct. 2024, pp. 17–21.
doi:10.1109/IConEEI64414. 2024.10748096.
[27] F. Gambou et al., “A Comprehensive Survey
of Alkaline Electrolyzer Modeling: Electrical
Domain
and
Specific
Electrolyte
Conductivity,” Energies (Basel), vol. 15, no.
9, p. 3452, May 2022, doi: 10.3390
/en15093452.
[28] T. Nabil and M. M. Khairat Dawood,
“Enabling efficient use of oxy-hydrogen gas
(HHO) in selected engineering applications;
transportation and sustainable power
generation,” J. Clean. Prod., vol. 237, p.
117798,
Nov.
2019,
doi:
10.1016/j.jclepro.2019.117798.
[29] Injection
Technologies
and
Mixture
Formation Strategies for Spark-Ignition and
Dual-Fuel Engines. SAE International, 2022.
doi: 10.4271/9781468603125.
[30] M. R. Lad et al., “Development of Medium
Duty H2 ICE for ON & OFF Highway
Application,” SAE Technical Paper, Jan.
2024. doi: 10.4271/2024-26-0170.
[31] M. Mohamed et al.,
“Experimental
investigation for enhancing the performance
of hydrogen direct injection compared to
gasoline in spark ignition engine through
valve timings and overlap optimization,” Fuel,
vol.
372,
p.
132257,
2024,
doi:
10.1016/j.fuel.2024.132257

A. Martin et al., Experimental investigation of HHO blending in combustion engine …