A comprehensive analysis of hydrogen fuel cell integration in fishing vessels

HHO gas is a fuel supplement produced through the electrolysis process of water in an HHO generator, where HHO gas falls under the category of alternative energy and is classified as a new energy source. The fundamental principle of internal combustion engines is generally to convert the chemical energy of liquid fuel into mechanical energy. The production of hydrogen through the electrolysis process is continuously evolving to facilitate the use of environmentally friendly fuels, with potential impacts on engine performance and exhaust gas emissions. This study examines the effect of adding HHO gas to electronic fuel injection (EFI) type-L gasoline engines on exhaust gas emissions and fuel consumption. It has been proven that the addition of HHO gas to the combustion process of gasoline engines, particularly EFI type-D, results in reduced emission levels (CO by 15.31% and HC by 16.27%). Moreover, the introduction of 0.1 Mol of HHO gas into EFI type-L engines through the air filter leads to a significant impact on exhaust gas emissions and a 2.8% increase in fuel consumption compared to not using HHO gas. This could be attributed to the distinct characteristics of EFI systems compared to conventional engines, as they are not accustomed to fuel supplements being injected into the engine.


Introduction
HHO stands for Hydrogen-Hydrogen-Oxygen, also known as Brown's Gas.HHO is a mixture of hydrogen and oxygen gases generated through the electrolysis of water using electric current3.It is believed that HHO can assist in reducing fuel consumption in fishing vessels by enriching the air-fuel mixture entering the engine [1].HHO is injected into the engine's fuel system, resulting in an air-fuel mixture that is richer in hydrogen and oxygen [2].This is claimed to enhance fuel combustion efficiency, thereby reducing fuel consumption and leading to cleaner exhaust emissions [3].However, it should be noted that several studies and field tests have not provided sufficient evidence to conclusively demonstrate that HHO usage significantly reduces fuel consumption in fishing vessels.Moreover, the use of HHO also entails risks, such as the potential for explosions if the produced HHO gas is not stored or utilized properly [4].Therefore, prior to implementing HHO for fuel consumption reduction in fishing vessels, thorough evaluation and testing are necessary to ensure its safety and effectiveness [5].
The utilization of HHO for fishing vessels can have varying economic impacts contingent upon numerous factors, including the cost and effectiveness of HHO usage, as well as fluctuating fuel prices [6].On one hand, employing HHO in fishing vessels can contribute to operational cost reduction by lowering fuel consumption [7].This can aid fishermen in augmenting their income by diminishing operational expenses.Furthermore, HHO usage can assist in mitigating the environmental impact of fossil fuel consumption, thereby enhancing the image and reputation of fishermen in the eyes of the public and consumers.Conversely, the acquisition and installation costs of HHO devices on fishing vessels can be quite high and require significant investment4.Additionally, the efficacy of HHO usage has not been fully proven and remains a subject of debate among experts [8].If HHO usage proves ineffective, it can lead to losses for fishermen and diminish their income [9].Moreover, fluctuating fuel prices can also influence the economic implications of HHO usage in fishing vessels5.If fuel prices drop 1298 (2024) 012023 IOP Publishing doi:10.1088/1755-1315/1298/1/012023 2 significantly, the benefits of HHO usage may become insignificant and not justify the investment costs [10].

HHO Gas
Hydrogen is one of the most abundant elements, forming the basis of all matter in the universe.Its atoms consist of a single electron orbiting around its nucleus.Hydrogen transitions into a liquid state at a temperature of 20 K (-423 º F; -253 º C) [11].When reacted fully with oxygen, fuel generates a considerable amount of energy.The energy content of various fuels is presented in Table 1.HHO gas or Brown's gas is a gas produced by the electrolysis of water, which is a combination of two gases, hydrogen (H2) and oxygen (O2).The simple equation for converting water into HHO can be expressed as follows: Electrolysis cells connected to an electric current will separate water into hydrogen and oxygen: The electrolysis process can be accelerated with the aid of a catalyst, and during the process, the catalyst does not affect the form of the electrolytic outcome.The catalyst aims to expedite electrolysis reaction and reduce the amount of activation energy required in a process: Thus, the chemical reaction occurring in electrolysis is [13]: Electrolysis is a chemical process that converts electrical energy (electric current) into chemical energy (redox reactions) [11].It involves the decomposition of the constituent elements of water.By applying an electric current, two water molecules react by capturing two electrons at the cathode, reducing into H2 gas and hydroxide ions (OH-) are formed [12].At the anode pole, two other water molecules will be broken down into oxygen gas (O2), releasing 4 H+ ions and flowing electrons to the cathode.As a result of these reactions, H+ ions and OH-ions neutralize each other and form water molecules again.The hydrogen and oxygen gases produced by this reaction form bubbles and accumulate around the electrode.This principle is then utilized to produce hydrogen and hydrogen peroxide (H2O2) [13].
The key components of this electrolysis process are the electrodes and the electrolyte solution.In the electrolysis process, two electrodes are required: the cathode as the negative pole and the anode as the positive pole [14].The electrolysis process occurs in a specially designed chamber, called an HHO generator, which is a gas-producing unit.HHO generators are classified into 2 types: dry cell HHO generators and wet cell HHO generators.In the dry cell type, the electrodes are not immersed in the electrolyte, and the electrolyte only fills the gaps between the electrodes themselves.The area of the electrode plates submerged in water is where electrolysis occurs to generate HHO gas, while the remaining area is not submerged in water and the plates are in a dry state.In the wet cell type, all electrodes are immersed in an electrolyte solution inside a water container [15].

Catalyst
A catalyst is defined as a substance that accelerates the rate of a reaction, yet the catalyst itself undergoes no chemical change.The catalyst is not included in the stoichiometric reaction equation, and its concentration in the reaction mixture remains unchanged [14], [16].This is only possible if, in one stage of the reaction, the catalyst participates and is regenerated in subsequent stages [17].Hence, a catalyst is absent from the reaction equation, and its concentration does not appear in the equilibrium expression.Thus, a catalyst doesn't affect the position of the reaction equilibrium.Generally, a catalyst will lower the activation energy [18].
In the process of electrolysis, the catalyst is a dissolved substance in water (H2O) and forms a solution as an electrolyte.Commonly used catalysts in electrolysis include vinegar (H3C-COOH), baking soda (NaHCO3), and potassium hydroxide (KOH).Using a smaller amount of catalyst reduces the rate of HHO gas production.Conversely, excessive use of catalyst raises the process temperature [19].Typically, the electrolysis process to generate HHO gas employs KOH and NaHCO3 catalysts.The use of KOH catalyst in electrolysis is preferable to NaHCO3 catalyst because it produces more significant amounts of HHO gas and consumes less electrical power.Calculating catalyst concentration with a solvent is done using the molarity formula as follows [20]: Where: Jk = Catalyst amount (grams) M = Molarity Mr = Relative atomic mass

Design and Fabrication of an HHO Generator
An electrolysis cell with a generator casing measuring 25 cm × 30 cm is employed.The plates used are made of stainless steel 316L.The plate configuration involves 2 anode and cathode plates measuring 9 cm × 14.5 cm, along with a cover and neutral plates measuring 3 cm × 14.5 cm.This design is tailored to meet the current requirements of a four-wheeled vehicle's automotive battery, ensuring that the current does not exceed the total capacity of 15 Amps.Within the reactor cell, the neutral plates are arranged vertically, consisting of a total of 3 plates.These plates are separated by dividers, each spaced 1 mm apart for every cell.This arrangement facilitates a separation space during the electrolysis process, as depicted in Figure 2.

Methode 2.1. Fungtion Test
Functional testing of the HHO generator is conducted to determine whether the constructed generator operates as expected and to ensure that there are no gas leaks.The functional test involves passing an electric current through the HHO gas generator using an automotive battery (accu) and utilizing KOH catalyst with a solution concentration of 0.1 mol.The generator is installed using the installation scheme illustrated in Figure 3.The output hose for HHO gas and the positive cable connected to the relay and automotive battery are covered with cable protectors to shield them from engine heat.

Exhaust Gas Emission and Fuel Consumption Testing
The testing process involves two stages: one without the addition of HHO gas and the other with the addition of HHO gas.The testing is carried out at idle RPM, 1500 RPM, and 2500 RPM.Fuel consumption testing consists of two phases: the first phase involves testing with gasoline fuel alone, and the second phase involves testing with the addition of HHO gas.The tests are conducted with a full tank of gasoline, and the vehicle covers a specific distance while collecting data three times.

Results and Discusion
This section presents the research findings and discussions, which include carbon monoxide, hydrocarbons, carbon dioxide, oxygen, and air-fuel ratio from the combustion process in internal combustion engines (IC engines).

Emision
Carbon monoxide is a colorless, odorless, and tasteless gas that is produced from incomplete combustion of carbon compounds, a common occurrence in internal combustion engines.Carbon monoxide forms when there is insufficient oxygen during the combustion process.It is highly flammable and produces a blue flame, resulting in the formation of carbon dioxide.

Figure 4. Graph Carbon Monoxide Consentration
The graph illustrates the emission levels of CO without using gasoline fuel at idle engine speed, which is 0.00%, 1500 RPM engine speed, which is 0.00%, and 2500 RPM engine speed, which is 0.00%.With the addition of 0.1 Mol of HHO gas, the data obtained at idle engine speed is 0.01%, 1500 RPM engine speed is 0.01%, and 2500 RPM engine speed is 0.01%.Elevated CO levels are generally caused by an imbalanced mixture of gasoline fuel and air, where the gasoline fuel content is excessively high.In injection engines, especially Type L, gasoline fuel is injected into the combustion chamber based on the airflow sensor that detects the amount of air in the air filter.The addition of HHO gas results in more fuel being injected, leading to incomplete combustion in the combustion chamber.
Hydrocarbons are compounds consisting of carbon (C) and hydrogen (H) elements.All hydrocarbons have carbon chains and hydrogen atoms bonded to those chains.The term is also used to define aliphatic hydrocarbons.Methane gas (swamp gas) is a hydrocarbon with one carbon atom and four hydrogen atoms (CH4).Ethane is a hydrocarbon composed of two carbon atoms joined by a single

Figure 5. Hydrocarbon Concentration
The results show hydrocarbon gas emissions with gasoline fuel at idle engine speed, which is 2.7 ppm, 1500 RPM engine speed, which is 5.67 ppm, and 2500 RPM engine speed, which is 12.33 ppm.With the addition of 0.1 Mol of HHO gas, the data obtained at idle engine speed is 111 ppm, 1500 RPM engine speed is 68.3 ppm, and 2500 RPM engine speed is 62 ppm.The elevated HC emissions after adding 0.1 Mol of HHO gas indicate three possible causes: a malfunctioning catalytic converter (CC), incorrect air-fuel ratio (AFR), or incomplete combustion of gasoline in the combustion chamber.If the catalytic converter is functioning normally but HC remains high, it suggests symptoms of an incorrect AFR or misfire.For vehicles equipped without a catalytic converter (CC), the tolerable HC emission level is 500 ppm, and for those equipped with a CC, the tolerable HC emission level is 50 ppm.The test engine with code 1 NZ-FE has been equipped with a catalytic converter (CC).Before adding 0.1 Mol of HHO gas, the average HC results were low and below the tolerance limit.However, after adding 0.1 Mol of HHO gas through the air filter, the average HC emissions exceeded the tolerance limit.According to the Ministry of Environment regulations, these emission levels are still considered acceptable because the CO level is below 1.5% and HC is below 200 ppm for vehicles manufactured after 2007 [14].
Carbon dioxide, also known as carbonic acid, is a chemical compound consisting of two oxygen atoms and one carbon atom.It exists as a gas at standard temperature and pressure and is an important greenhouse gas due to its strong infrared absorption.Carbon dioxide plays a crucial role in the carbon cycle and is produced as a byproduct of fossil fuel combustion.In Figure 6, the emission results for carbon dioxide (CO2) with gasoline fuel show that at idle engine speed, it is 16.17%, at 1500 RPM engine speed, it is 16.03%, and at 2500 RPM engine speed, it is 15.93%.With the addition of 0.1 Mol of HHO gas, the data obtained at idle engine speed is 16.33%, at 1500 RPM engine speed, it is 16.03%, and at 2500 RPM engine speed, it is 15.87%.
CO2 concentration directly indicates the combustion process status in the combustion chamber.Higher levels are generally better.When the air-fuel ratio (AFR) is ideal, CO2 emissions typically range between 12% and 15%.CO2 emissions at idle engine speed without HHO gas and with the addition of HHO gas at idle and 1500 RPM engine speeds show non-ideal concentrations.The ideal CO2 emission concentrations occur without HHO gas at 1500 and 2500 RPM engine speeds and with the addition of HHO gas at 2500 RPM engine speed.If the AFR provides too little or too much fuel, CO2 emissions will drop dramatically.If CO2 is below 12%, other emissions should be considered to determine whether the AFR is fuel-rich or fuel-lean.It's important to note that the source of CO2 is solely within the combustion chamber.If CO2 is too low but CO and HC are normal, it indicates exhaust pipe leaks [7].
Oxygen, represented by the symbol O and atomic number 8, is a chemical element.In the periodic table, oxygen is a non-metal in Group VIA (chalcogen) and can readily react with almost all other elements (typically forming oxides).At standard temperature and pressure, two oxygen atoms bond to form O2, a colorless, tasteless, and odorless gas.Oxygen is the third most abundant element in the universe by mass, following hydrogen and helium.The emission results for oxygen (O2) with gasoline fuel show that at idle engine speed, it is 0.16%, at 1500 RPM engine speed, it is 0.07%, and at 2500 RPM engine speed, it is 0.06%.With the addition of 0.1 Mol of HHO gas, the data obtained at idle engine speed is 0.08%, at 1500 RPM engine speed, it is 0.07%, and at 2500 RPM engine speed, it is 0.06%.The oxygen concentration in the exhaust gas emissions before and after adding 0.1 Mol of HHO gas indicates low values.Low oxygen concentration suggests that all oxygen is utilized in the combustion process, which can indicate a tendency towards a fuel-rich mixture.In such conditions, low oxygen concentration would be accompanied by high CO emissions.In the case of CO emissions from an EFI Type L gasoline engine without HHO gas, the values are low, indicating complete combustion.After adding HHO gas, CO concentration rises, indicating an excessive fuel mixture in the combustion process.High oxygen concentration can suggest a lean fuel mixture condition, but it can also indicate other factors and high CO and HC emissions when oxygen is excessively high [2].

Air-Fuel Ratio Relative (λ)
To achieve optimal power generation through the combustion process in an engine, three main conditions must be met: high compression pressure, accurate ignition timing, and strong spark plug ignition with the proper air-fuel mixture.The results of the air fuel ratio relative (λ) for gasoline fuel are shown.At engine idle speed, the ratio is 1.006, at 1500 rpm it is 1.002, and at 2500 rpm it is 1.002.Upon adding 0.1 M of HHO gas, the data obtained at engine idle speed is 0.998, at 1500 rpm it is 1.000, and at 2500 rpm it is 0.999.The air fuel ratio relative (λ) values without using HHO gas, at idle speed, 1500 rpm, and 2500 rpm, indicate stoichiometric mixtures.Adding 0.1 Mol of HHO gas demonstrates a stoichiometric mixture at 1500 rpm and a fuel-rich mixture at idle and 2500 rpm.
Combustion conditions can also exist in fuel-lean mixtures, stoichiometric mixtures, and fuelrich mixtures.Fuel-lean mixtures occur when the ratio of air to fuel is imbalanced due to a small amount of fuel, fuel-rich mixtures arise from an imbalanced air-fuel mixture with an excess of fuel, and stoichiometric mixtures occur when the air-fuel ratio is in perfect or precise condition [10].

Fuel Consumption
Internal combustion engines used in motor vehicles have varying cylinder volumes and cylinder counts according to the purpose of the vehicle.The cylinder volume determines the amount of fuel consumed for the engine to operate effectively.
In this study, an analysis was conducted on fuel consumption when the engine is operated with gasoline fuel both without and with the addition of HHO gas.The data obtained is presented in the form of data tables and graphs, as shown in Figure 9.The average fuel consumption with gasoline fuel alone can cover a distance of 9.823 km/l.With the addition of 0.1 Mol of HHO gas, the mileage is reduced to 9.556 km/l, which is lower than the engine without HHO gas.This is related to the air-fuel ratio system, which might not be compatible with the fuel-air mixture controlled by the injector system in the engine.As a result, the process of achieving a complete fuel-air mixture is not attained.In this research, using an L-type injection engine, it's evident that fuel consumption becomes 2.8% less efficient after adding 0.1 Mol of HHO gas compared to not using HHO gas.This is because the airflow sensor detects an increase in the amount of air due to the addition of HHO gas to the air filter, causing the air-fuel ratio (AFR) to read too much air sucked in, resulting in a fuel-rich mixture.Gasoline fuel is injected into the combustion chamber based on the airflow sensor detecting the amount of air in the air filter.

Comparative Exhaust Gas Emission Analysis
This research was conducted with the addition of 0.1 Mol of HHO gas using an L-type EFI engine.As there is no direct comparison available, a comparative analysis is performed by referring to a study conducted with a D-type EFI engine.the addition of HHO gas to a 1200 cc cylinder capacity EFI engine of the D type showed a reduction in HC emissions by 5.5% and CO emissions by 3.57%, as indicated in Table 4.The decrease in exhaust gas emissions from the gasoline EFI engine of the D type is due to the engine's operational principle, which measures the vacuum pressure in the intake manifold rather than the amount of air.This causes the injection of gasoline fuel to remain unaffected by the addition of HHO gas, and the HHO gas contributes to more complete combustion in the combustion chamber.
In contrast, the gasoline EFI engine of the L type experiences an increase in exhaust gas emissions.This is because the engine operates based on a sensor that measures the amount of air entering the combustion chamber through the air filter, determining the quantity of fuel to be injected.After adding HHO gas to the gasoline engine of the L type, the sensor detects an increase in both air and fuel injected into the combustion chamber.This results in the HHO gas not leading to complete combustion in the combustion chamber.By comparing the measurement results with the standards for a gasoline engine with a 1300 cc cylinder capacity (Table 3) and a gasoline engine with a 1200 cc cylinder capacity (Table 4), the exhaust gas emissions are evident.

Conclusion
The addition of 0.1 Mol of HHO gas to the gasoline EFI engine of the L type through the air filter during the combustion process leads to an increase in the emissions of carbon dioxide, hydrocarbons, carbon monoxide, oxygen, and the air-fuel ratio number, indicating an excessive fuel mixture.The increased exhaust gas emissions occur due to the operational principle of the EFI engine of the L type.After adding 0.1 Mol of HHO gas, the EFI system of the L type experiences a malfunction, resulting in an excessive amount of fuel in the combustion chamber and causing the mixture of HHO gas and gasoline fuel to not burn completely during the combustion process of the internal combustion engine.
The average fuel consumption is more wasteful by 2.8% due to the addition of HHO gas, as the air-fuel ratio (AFR) is in a fuel-rich mixture state.This condition arises because the EFI engine of the L type experiences a malfunction after adding 0.1 Mol of HHO gas through the air filter.This malfunction results in excessive fuel being injected into the combustion chamber, leading to a fuel-rich mixture state.

Table 1 .
Fuel Oil Calories