Fuel Gas Research Articles

Self-consistent charge transport model with ionization for the alphie plasma thruster

The Alternative Low-Power Hybrid Ion Engine (alphie) is a new technology for space propulsion based on plasma. Its distinct characteristic is the counterflow of charges (ions and electrons) passing through its two-grid system. This means that electrons coming from an external cathode are accelerated toward the ionization chamber, in which a neutral gas (typically Ar) is injected. The strong magnetic field therein confines these electrons, which ionize and exchange energy with the propellant gas. Thus, the operation of alphie is strongly affected by the electrons coming from the external cathode and their collisions with the neutral atoms. This work studies the counterflow employing a particle-in-cell simulation of ions and electrons passing through a single hole as a function of the electron cathode currents (Ice) and potential drops between grids (VAC). Transparency of the grid system to ions and electrons and the ion current extracted by the grid system are studied under sweeps of these two parameters. The number of ionization events by each high-energy electron entering the ionization chamber is evaluated using a physical model based on the gas density and the cross section for ionization. These new ions are then extracted by the same electric field that accelerates the electrons inward. Thus, simulations are self-consistent, since the ionizing electron flow from the external cathode drives the ion outflow at the exit section of the two-grid system. The electrical transparency of the two-grid system to ions and electrons, related to the axial charge currents, is also studied under sweeps of aforementioned operation parameters. This new way to deal with ionizations can be useful to study other plasma thrusters in which electrons for ionization come from an external cathode without modeling the complex structure of the ionization chamber.

Study on Exhaust Gas Characteristics of SI Engine Using Fuel (Gasoline) & HHO Gas

Experiments have been carried out to investigate the effect of HHO gas on the emission and performance of SI engines. Water was converted into hydrogen and oxygen consisting of a 2:1 volume ratio by electrolysis process, which is called HHO (oxyhydrogen gas). An HHO fuel cell had been fabricated to generate the HHO gas required to feed the engine. This HHO is then mixed with filtered air, which is after the air filter system and before the inlet manifold system of the vehicle. In this investigation, a 125-cc single-cylinder 4-stroke air-cooled engine was used. The exhaust gas characteristics were sampled and measured using a gas analyzer. It was observed that when HHO gas had been introduced into the air/fuel mixture, it consequently reduced the concentration of NO, NOx, CO, engine temperature, and HC by about 50%, 50%, 38%, 5% & and 45% respectively. Also, a reduction in fuel consumption is noticed for the same engine RPM and load conditions when HHO gas was imported into the A/F mixture. Also, when HHO is introduced into the system, the concentration of O2 CO2 increases by about 50% and 23% respectively.

Comparative Analysis of Exhaust Emission of Retrofitted SI Engine Runs by Different Fuels

The purpose of this study was to experimentally inspect the pollutant emission of a retrofitted SI engine using octane, compressed natural gas, and liquefied petroleum gas fuels operated at different speeds. The study was conducted using a retrofitted SI engine. The engine was coupled with an exhaust gas analyzer to measure the composition of the exhaust emission gas. The results showed that the carbon dioxide (CO2) and carbon monoxide (CO) content is lower when CNG is used compared to octane. The CO2 emission was even lower for LPG than CNG, as LPG has a lower carbon-energy ratio and higher octane quality than LPG and burns faster as a lean mixture. The O2 emission supports that octane and CNG burn as a lean mixture whereas LPG burns as rich. Again, the HC emissions are more prominent and CO emissions are higher for LPG than CNG. Because, it showed incomplete combustion with LPG as fuel due to inappropriate air-fuel mixture in the gas-air mixing chamber, which was specifically designed for CNG. Nitrogen oxide (NOx) emission was minimal when the engine was operated with LPG due to incomplete combustion, and it was found maximum for octane, where medium NOx content was found in the case of CNG. Moreover, the relative air fuel ratio or excess air factor, λ increased as the engine operating speed was raised. Because at high speed, there is some turbulence effect and increased combustion duration.

Investigating the Effects of Environmentally Friendly Additives on the Exhaust Gas Composition and Fuel Consumption of an Internal Combustion Engine

This article shows the effect of the addition of effective microorganisms and silver on the exhaust gas composition and fuel consumption. Exhaust emission standards are becoming increasingly stringent, which makes it difficult for engine manufacturers to meet them. For this reason, intensive work is underway to use alternative propulsion systems on ships, and for diesel engines, alternative fuels. Among other things, this applies to mixtures of petroleum-based fuels with vegetable oils and their esters. Unfortunately, their use, due to their physicochemical properties, can negatively affect the performance of the engine and the wear of its components. Therefore, the aim of this study was to see how additives of effective microorganisms in the form of ceramic liquid and tubes, and a silver solution and colloidal silver would affect some engine parameters, including the exhaust gas composition and fuel consumption. The authors are not aware of the results of previous research on this issue. The tests were carried out on a diesel engine for four types of green additives at concentrations of 2% and 5%, at different ranges of its load. The additives added to the diesel fuel were characterised, and the test stand was presented, along with the parameters of the tested fuel. The effect of additives on selected engine parameters, including fuel consumption, was presented. The characteristics of hourly fuel consumption and selected components of the exhaust gas, including nitrogen oxides, carbon monoxide and carbon dioxide as a function of the concentration of ecological additives are shown and analysed. It was found that the most beneficial additive that had a positive effect on the exhaust gas composition and fuel consumption was a silver solution in a 2% concentration. There was a decrease of up to 4% in the NOx content of the exhaust gas, a decrease in carbon monoxide of more than 28%, a decrease in carbon dioxide of 4.6% and a decrease in fuel consumption of around 3% was achieved under the tested conditions. The use of these additives is an innovative solution that has a positive impact on reducing the emissions of harmful compounds into the atmosphere. In further research, it will be necessary to study the effect of this additive on the combustion process in the engine and the wear of its components, as well as to confirm the results obtained in real operating conditions.

Bacteriological Analysis and Plasmid Profiles of Surfaces of Some Hospital Kitchen Equipment in Benin City, Nigeria

The surfaces of hospital kitchen equipment could be a major source of transmission of resistant pathogens to patients. Hence, the objective of this paper was to assess the bacteriological and plasmid profiles of surfaces of tables, sinks, chopping-boards, gas cookers and freezer handles hospital kitchen equipment in Benin City, Nigeria using appropriate standard microbiological techniques. Bacterial plasmids were isolated and separated using the agarose gel electrophoresis. Plasmid curing was performed using acridine orange. The antimicrobial sensitivity pattern showed that the bacterial isolates exhibited varying degree of resistance to the antibiotics. Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were highly resistant to the antibiotics, having multiple antibiotic resistances (MAR) index of 0.6. Micrococcus spp. and Klebsiella pneumoniae were the least resistant to the antibiotics. Plasmid analysis revealed the presence of single and multiple-banded plasmids with sizes ranging from 100-1000bp. After curing, all the isolates (except S. aureus, E. coli and P. aeruginosa) were sensitive to all the antibiotics, indicating a significant reduction in antibiotic resistance after curing. The results revealed that plasmids played a significant role in conferring resistance on the isolates. Regular cleaning and disinfection should be strictly observed in hospital kitchens to prevent outbreaks and spread of resistant pathogens in hospitals.

Hydrocarbon fuels, combustion characteristics & insulating refractories in industrial furnace

Liquid fuels like Furnace Oil, Light distillate oil, Diesel & gaseous fuels like PNG (Piped Natural Gas), LPG (Liquefied Petroleum Gas) are predominantly used at present in industrial applications. Single fuel, Dual fuel & Multi-fuel options are available in the market. All these fuels are called hydrocarbon fuel. A loss of drop of oil in every second can waste about 4000 liters in a year. Selection of right type of fuel depends on various factors like availability, storage, handling, Pollution & landed cost of the fuel. These different fuels used for combustion in industrial furnace are discussed herewith. Complete combustion in industrial furnace enhances efficiency, control pollution as well as global warming. Efficient use of fuel leads to complete combustion. This paper deliberates about combustion of fuel and how complete combustion is to be achieved in industrial furnace. Stoichiometric ratio ensures complete combustion. Industrial furnace uses refractories to form a combustion chamber with proper insulation to ensure temperature within the combustion chamber is as per requirement of the job. The outside skin temperature of industrial furnace is about 35ºC to 45ºC from safety point of view. To maintain this temperature difference with minimum wall thickness needs proper refractory selection which must withstand high temperature. The main objective of this research paper is to propose strategies to select the right fuel, proper insulating material to achieve complete combustion & minimum heat losses through the walls of combustion chamber. This will help in making an efficient design and optimize combustion controls to keep heat losses at minimum level.

Acceleration of cryogenic pellets for Shattered Pellet Injection

Shattered Pellet Injection (SPI) is considered as a method to effectively mitigate the effect of severe disruptions in tokamaks. For the development of SPI technology in ITER, the Centre for Energy Research, in collaboration with H-ion Kft and VTMT Kft, designed, constructed and operates a Disruption Mitigation System (DMS) Support Laboratory. To simulate pellet acceleration, we developed a zero-dimensional model. The model uses the parameters of pellet material, propellant gas characteristics, dimension of the barrel and fast valve (FV), opening characteristics, temperature, and filling pressure of the FV in order to calculate the time dependent pellet position, pellet velocity, FV pressure and barrel pressure during the acceleration process. The goal of the acceleration model is to forecast velocities for parameters where no data is available as of yet. This paper describes the model and compares its results to two significantly different setups: the SPI measurements at the ASDEX Upgrade test laboratory and the ITER DMS Support Laboratory. We show that our model is capable of predicting tendencies and revealing the sticking stress of pellets to the barrel.

Converting Iraqi Hazardous Crude Oily Sludge into Value-Added Activated Carbon using KOH Activation Technique

Annually, a high amount of hazardous oily sludge (OS) is produced by North Refineries Company (NRC) Baiji. This work aims to study the specifications of oily sludge in crude oil storage tanks and to convert it into activated carbon (AC) by pyrolysis using KOH activated agent. The physical properties of OS have been measured and analyzed. The AC is produced by carbonizing oily sludge to char under N2 flow using KOH at an impregnation ratio of 2:1 KOH/char. The pore structure, morphology of the surface, and surface chemistry of the AC produced were characterized using Brunauer-Emmet-Teller (BET), Fourier Electron Scanning Electron Microscopy (FESEM), and Fourier-Transform Infrared Spectroscopy (FTIR). The result shows the surface area of the produced AC was 350 m2/g with a mesoporous structure. Based on the findings, the obtained surface area of the AC indicates the oily sludge was a light precursor, which is helpful in producing gas and liquid fuels rather than solid fuel.

The Effect of Film Development on Primary Breakup in a Prefilming Airblast Atomizer

Abstract Liquid fueled gas turbines are likely to remain a dominant force in aviation propulsion for the foreseeable future, and therefore understanding the atomization process is key to meeting future emissions and performance legislation. To make experiments and simulations possible, simplified geometry and boundary conditions are often used, for example, simulations of primary atomization often use a fixed film height and velocity. This paper aims to quantify the effect of a fully developed unsteady film on the atomization process. A custom Coupled Level Set & Volume of Fluid (CLSVOF) solver with adaptive meshing built in OpenFOAM v9 is used. A simulation of the atomization process in the Karlsruhe Institute of Technology atomization experiment (Warncke et al., 2017, “Experimental and Numerical Investigation of the Primary Breakup of an Airblasted Liquid Sheet,” Int. J. Multiphase Flow, 91, pp. 208–224) is presented. A precursor simulation of the film development is used to provide accurate, temporally and spatially resolved inlet boundary conditions. These results are compared to previous CLSVOF simulations from Wetherell et al. (2020, “Coupled Level Set Volume of Fluid Simulations of Prefilming Airblast Atomization With Adaptive Meshing,” ASME Paper No. GT2020-14213)” using traditional boundary conditions. The unsteady film has doubled the modal ligament length and widened the distribution, and is now in better agreement with experimental measurements. A clear correlation in both time and space is observed between the film, atomization process, and spray. The sauter mean diameter (SMD) is significantly increased, again giving better agreement with the experiment. A discussion of extracting statistical descriptions of the spray is given, outlining the unfeasible computational cost required to converge droplet diameter distributions and other high order statistics for a case such as this.

A Methodology for the Preliminary Design of a High-Efficiency Multistage Plasma Thruster

AbstractSpace electric propulsion represents a class of power-limited systems that utilize the interaction of electromagnetic fields with ionized inert gas propellants to generate thrust. This technology has emerged as a highly fuel-efficient and sustainable alternative to chemical propulsion systems, particularly for satellite constellations. However, the miniaturization potential of EP systems is impeded by certain limitations, necessitating the exploration of novel architectures. The high-efficiency multistage plasma thruster (HEMP-T) stands as a promising contender for stand-alone missions due to its employment of a cusped magnetic-field topology, which effectively mitigates plasma-wall interactions and enhances overall efficiency even at low thrust levels. Despite the growing interest in HEMP-Ts, there is a dearth of comprehensive and streamlined preliminary design procedures for these systems. Prior research has predominantly focused on extensive numerical analyses, neglecting the development of efficient and accessible design tools. To bridge this gap, this paper presents a novel preliminary design tool derived from integrating established analytical models available in the literature. The proposed design tool also incorporates an iterative procedure that refines geometric properties using a 2D magnetostatic solver. Through the application of this tool, a 4 mN HEMP thruster was analyzed. This finally exhibited a specific impulse of approximately 2000s and a good efficiency level of 23%. Also, the results obtained for a 10 mN application align closely with those achieved by other types of EP thrusters.

Automated Gas Line Shut Off Mechanism Using Solenoid Operated Valve and Gas Leak Detector (At the Event of Gas Leakage in PNG Line)

Gas leaks that cause deadly flames have become a major issue in homes and other places where domestic gas is handled and utilized. Gas leaks cause a variety of mishaps that result in financial damage as well as personal injuries and/or loss. The project’s goal is to create a system that detects gas leaks and notifies the subscriber through alarm and status display, as well as shutting off the gas supply valve as the main safety precaution. The turning off of the supply valve prevents further gas flow to the cooker, preventing a fire breakout caused by an attempt to ignite the cooker. The device, which functions more like a first- aid kit, utilizes a usually closed solenoid valve to shut off the gas valve before asking for assistance via visual display and loud alert to anyone in the vicinity. The system is clever in that it does not cause a loud nuisance by constantly sounding the alarm, but rather the siren stops beeping once the concentration of the gas in the atmosphere after leaking falls below the predetermined value and the valve is opened again for regular operations. This effort will reduce injuries and losses caused by explosions caused by gas leaks, as well as enhance the safety of people and property while utilizing home cooking gas.

Environmental friendly energy resources improving air quality in urban area

The article concerns a very important issue related to the air quality in Kraków, a historic city with a rich history and cultural tradition. Kraków is the capital of the Małopolska Voivodeship, located in southern Poland. Due to the common phenomenon of smog in winter and the related problem of significant exceedances of permissible air pollutants, Kraków was the first city in Poland which implemented a complete ban on the combustion of solid fuels (coal, wood and also all types of biomass). It is allowed to use only district heat, gaseous fuels, light fuel oil, electricity and renewable energy sources as heat pumps, solar collectors and photovoltaics. The article attempts to analyze the results of air quality tests in the period after the implementation of restrictions on the type of energy sources used in relation to the previous years. The starting point for this analysis is the presentation of emissions of combustion products of energy carriers with various calorific values in heating devices with various energy efficiency. Environmental aspects are also analyzed, such as average annual temperatures, wind speeds and directions, precipitation, and the number of days with fog. Thanks to this, the picture of the changes introduced in Kraków becomes complete and allows you to understand the environmental effects that have occurred. The analysis of air quality was carried out with regard to six pollutants: TSP (total suspended particulate), PM10 and PM2.5 particulate matter, benzo(a)pyrene, sulfur dioxide (SOx), and nitrogen oxides (NOx). Additionally equivalent emission has been calculated. The obtained results indicate an improvement in air quality in relation to the previous heating periods, which allows to draw a conclusion that regulatory actions such as a ban on the burning of solid fuels was justified and that this sector (individual heat generation) has a significant impact on the state of the environment. A significant reduction in all analyzed pollutants – TSP, PM10 and PM2.5, B(a)P and SOx is evident, and the only the exception is NOx.

A phenomenological design method of the parallel packed bed reactors for chemical looping combustion of gas fuels

The parallel packed bed reactor (PPBR) is a promising route for industrial application of chemical looping combustion. This paper introduces a phenomenological approach for the rational design of PPBR, serving as a manner to efficiently obtain comprehensive design results. Based on the macroscopic propagation of heat and reaction fronts, it elucidates the dynamic heat/mass transfer within the bed. Subsequently, it is applied to design a 1.5 MWth reactor. The risk of carbon deposition in the bed is firstly investigated from a thermodynamic perspective. Then, the study reveals that the height-to-diameter ratio of the reactor must meet certain constraints to ensure stable and cost-effective operation, and these constraints are extended to the scale-up process. Sensitivity analysis is utilized to investigate the effect of key parameters on the design schemes and performance. Effects of particle size on intra-particle gas diffusion is analyzed. Finally, detailed design schemes and performance of the reactor are determined.

Fast Shutter optioneering study for the ITER Disruption Mitigation System

ITER needs a Disruption Mitigation System (DMS) for protection from the consequences of plasma disruptions during high-power operation. The current DMS for ITER is based on the Shattered Pellet Injection (SPI) technology. This works on the basic principle of a cryogenic pipe gun with around a half-meter-long acceleration barrel. It is important to avoid any contact between the pellet and the internal surfaces of the flight line to minimize the risk of premature pellet breakage. Therefore, the internal dimensions of the flight tube of the SPI are relatively large compared to the pellet hence providing a bypass for propellant gas resulting in a significant quantity arriving in the plasma ahead of the pellet. This will cause an undesirable instability in the plasma and compromise the effectiveness of disruption mitigation. The described events appear on a scale of a few milliseconds. One possible solution for this issue could be using a fast-acting shutter in the flight line, which will close after the pellet has passed through to hold back the propellant gas. Due to the environmental requirements, the shutter needs to close an approximately 40 mm aperture within a few ms, the shutter has limited space and limited access and acts under a magnetic field, therefore it should endure a high number of cycles and should perform well in a very demanding situation. This paper describes the optioneering study of the shutter and possible solutions for the demanding criteria. The laboratory testing of the Electromechanical Test Bench and the Prototype design are also detailed in separate papers.

Evaluation of dust and gas explosion potential in chemical looping processes

The explosibility of metals typically used as oxygen carriers in chemical looping processes are reviewed. Chemical looping processes use intensified process conditions such as elevated temperatures and pressures to accelerate reduction and oxidation reactions of metals. A review of literature on metals indicates they are generally non-explosible under standard test conditions, however, at conditions used in chemical looping processes the opportunity to remove kinetic limitations exists resulting in reclassification of these dusts as marginally explosible under these circumstances. Potential locations and scenarios for explosions involving oxygen carriers in chemical looping processes are described. Operating conditions (temperature, pressure) and oxygen carrier qualities (base metal, support/loading) are reviewed for their effect on explosion severity parameters. These studies show explosions are unlikely to be severe in chemical looping reactors, but severity can increase while likelihood decreases in windboxes and in downstream process units following cooling. The potential for explosions where a metal oxide dust acts as the oxidizing agent for gaseous fuels through heterogeneous (chemical looping combustion – CLC) and homogenous (chemical looping oxygen uncoupling – CLOU) pathways as may be found in chemical looping processes is introduced, which we term a metal oxide reducing environment (MORE) explosion. Methane was shown to have the potential for the most serious consequences when reacting with copper- and manganese-oxides due to their reduction both being exothermic and increasing the quantity of gas present. Hematite and nickel oxide do not demonstrate this behaviour with common gaseous fuels. Potential prevention and mitigation strategies for explosions in chemical looping processes are briefly introduced. Particulate management strategies, venting, and downstream concerns are discussed.

Review of Developed Methods for Measuring Gas Uptake and Diffusivity in Polymers Enriched by Pure Gas under High Pressure.

Gas emission and diffusion through polymeric materials play crucial roles in ensuring safety and monitoring gas concentrations in technology and industry. Especially, the gas permeation characteristics for O-ring material should be investigated for sealing application in a hydrogen infrastructure. To accommodate the requirements of different environments, we first developed four complementary effective methods for measuring the gas absorption uptake from polymers enriched by pure gas under high pressure and determining the gas diffusivity. The methods included the gravimetric method, the volumetric method, the manometric method, and gas chromatography, which are based on mass, volume, pressure, and volume measurements, respectively. The representative investigated results of the developed methods, such as gas uptake, solubility, and diffusivity are demonstrated. The measuring principles, measuring procedures, measured results, and the characteristics of the methods are compared. Finally, the developed methods can be utilized for testing transport properties, such as the leakage and sealing ability, of rubber and O-ring material under high pressure for hydrogen fueling stations and gas industry.

Processes in an Oxygen–Methane Combustion Chamber with Gaseous Fuel

Processes in an Oxygen–Methane Combustion Chamber with Gaseous Fuel

Study of Corrosion, Wear, and Thermal Analysis of Materials for Internal Combustion Engines and their Compatibility: A Review

Several types of research have been carried out on using alternative biofuel in internal combustion engines to salvage the depletion of fossil fuels. While most of these studies focused on the emission characteristics and control of global warming, little attention has been given to the corrosion, wear, thermal behaviour, and compatibility of the internal combustion engine materials to biodiesel. Thus, this study focused on the various corrosion and wear mechanisms associated with the internal combustion engine components like piston and cylinder heads, as well as the thermal behaviour efficiencies of the engine after interaction with the biodiesel fuels. The review cut across the wear study of internal combustion engine materials in varying fuel environments. Thermal analysis of different materials applied for internal combustion engines for sustainable fuel media. Corrosion study of various materials employed in the application of ICE engines. Also, the study discusses some significant challenges related to the compatibility of ICE with biodiesel and gaseous fuels. The study’s outcome indicates that an adequate fuel blend with nano additives can help improve the combustion process, emission reduction, and thermal efficiency of the internal combustion engine components. Furthermore, practical design in the internal combustion engine components like pistons will help compatibility with the material in the biodiesel blends, thus reducing wear, corrosion, and other failures associated with the internal combustion engine.

Impact of Fuel Quality on Gas Turbine Components

Most industrial gas turbines operate with various gaseous and liquid fuels. For effective and sustainable performance, it is essential to determine the best fuel suitable for the operation of the gas power system. The heating value, Joule Thompson coefficient, dew point, Wobbe index, and other physical characteristics of the suggested fuel must be ascertained. This research explains a means of providing consistent treatment to determine the listed physical properties. It also reviews the impact that specific fuel characteristics have on the combustion process, as well as the overall operation of a gas turbine and its components.

Reducing Environmental Impact of Jet Engines by Hydrogen Co-combustion

Due to the need to mitigate global warming, there is a growing interest in alternative fuels for various means of transport, including aviation gas-turbine engines. The work aimed to check the impact of hydrogen co-combustion on the performance and emissions of aircraft engines. Zero-dimensional models of JetCat P140 RXI and DGEN 380 engines developed in the GSP (Gas Turbine Simulation Program) program were used in the research. Combustion calculations in GSP are based on the real gas model and NASA Chemical Equilibrium Applications (CEA) equations. The performance of the engines fueled by Jet A-1 and blends containing hydrogen or methane were calculated. The simulations were performed at the design point on the ground, and then in flight for selected altitudes and flight speeds. With an increase in the gas content in the blend, the thrust and temperature behind the turbine slightly increase, and the specific fuel consumption decreases, because hydrogen and methane have a higher calorific value. The performance of JetCat and DGEN 380 engines was calculated for blends of kerosene with methane or hydrogen. This knowledge will be used to convert these engines to gaseous fuels. In terms of fuels and emissions, GSP has limitations related to the set of available chemicals and the zero-dimensional model of the combustor.