Heating Value Of Fuel Research Articles

Effects of hydrogen addition on ignition characteristics and engine performance of ammonia-hydrogen blended fuel: A kinetic analysis

To investigate the effects of hydrogen addition on the ignition characteristics and engine performance of ammonia-hydrogen fuel, a reaction kinetics mechanism suitable for high-pressure engine conditions was proposed. The study explores the influence of hydrogen blending ratios on the ignition delay time (IDT) of ammonia-hydrogen fuel, revealing the sensitive reactions and evolution characteristics of reaction pathways during the ignition process of ammonia-hydrogen fuel promoted by hydrogen. The study also investigates the impact of hydrogen blending ratios on the engine performance of ammonia-hydrogen fuel. The results show that the IDT of ammonia significantly decreases with increasing hydrogen blending ratios and temperature. The addition of hydrogen to ammonia significantly lowers the autoignition temperature boundary of the mixture. Under low-temperature and low-pressure conditions, ammonia, which would not ignite originally, ignites due to the addition of hydrogen. The addition of hydrogen shifts the sensitive reactions of the mixture from NH3 and NH2-related reactions to H2/O2-related reactions, without altering the reaction pathway of ammonia, only changing the pathway flux of components such as NH2, H2NN, H2NO, and HONO. In a spark-ignition (SI) engine, maintaining the total fuel heat value and ignition timing constant, an increase in hydrogen blending ratio significantly raises the peak cylinder pressure. However, due to the forward movement of the heat release process, the power performance of engine experiences varying degrees of reduction. Therefore, it is necessary to delay the ignition timing of engine with the increase in hydrogen blending ratio, moving the combustion center beyond the top dead center (TDC). Furthermore, increasing the hydrogen concentration in the blend significantly raises the temperature and pressure during the engine combustion process, leading to an increase in the concentration of thermal NOX in the emissions.

Clove oil additives in vegetable oil: an assessment of fuel properties

Vegetable oil, obtained from plants such as coconut or Jatropha curcas, serves as a valuable renewable energy source. Nonetheless, it presents certain limitations in comparison to diesel fuels, namely, low volatility and high viscosity. One straightforward approach to overcome these limitations is the addition of high-volatility oil and low-viscosity oil. In this study, we incorporated 10% clove oil into coconut oil and Jatropha curcas oil. Fuel properties, including density, viscosity, flash point, and heating value, were measured in accordance with international standards. Additionally, Thermogravimetric Analysis (TGA) testing was performed to detect decomposition during the heating process. The findings indicated that the addition of clove oil increases density (from 0.922 g/ml to 0.934 g/ml), while other properties decrease, such as viscosity (from 30.12 cst to 27.7 cst), flash point (from 286°C to 182°C), and heating value (from 37.1 MJ/kg to 35.8 MJ/kg). TGA demonstrated that the inclusion of clove oil resulted in increased decomposition within the temperature range of 200°C–400°C, suggesting that clove oil falls into the category of medium-volatile oils. Although the addition of clove oil were able to modify the fuel properties of vegetable oil, it did not align with the characteristics of conventional diesel fuel and necessitates further modification for practical implementation

Combustion and emission characteristics for various swirler geometries and fuel heating values in a premixed low swirl combustor system

This study investigated combustion and emission characteristics with various swirler parameters (i.e., swirl angle and perforated screen blockage) and fuel heating values (4,000 kcal/Nm3∼9,560 kcal/Nm3, 16.3 MJ/kg∼55.5 MJ/kg in SI unit) using the premixed low swirl combustor system. Flashback limits were evaluated as a flame stability and flame structures were analyzed by acquiring chemiluminescence (OH* and CH*) and OH-Planar Laser Induced Fluorescence (PLIF) signals. NOx and CO emissions were evaluated by calculating emission indices (EINOx and EICO). As a result, the swirl angle did not affect flame stability, whereas screen blockage increased flashback limits. The highest screen blockage (β = 0.8) showed the flashback limit of 5.6 kW, around 1.5 times higher than the lowest screen blockage (β = 0.6). Also, the blockage affected the radical distributed position due to the ratio between swirling and non-swirling flow. The lower heating value fuel showed reduced flashback limits, decreased radical intensities, and lower emissions (EINOx and EICO). The lowest heating value gas (HV 4000) had an EINOx of less than 0.5 g/kg and an EICO of less than 5 g/kg, respectively. In conclusion, these findings would be helpful databases for optimizing heating values to solve environmental pollution issues.

Estimating the higher heating value and chemical exergy of solid, liquid, and natural gas fossil fuels

The escalating global population has spurred a significant surge in energy demand. While developed nations pivot towards renewable energy sources, many developing countries rely heavily on fossil fuels. Understanding these fuels' higher heating value and chemical exergy is crucial for energy analysis, second law analysis, optimal energy generation, and resource conservation.This study introduces an adaptable analytical method for calculating the higher heating value and chemical exergy of fossil fuels (coal, oil, natural gas). It demonstrates minimal error, with approximately a 3.5 % deviation for higher heating value and 8 % for chemical exergy compared to empirical relations.Novel relationships, developed through linear regression and computer programming, address research gaps and exhibit a maximum 2.6 % difference for higher heating value and 5.4 % for chemical exergy compared to existing empirical references. These contributions will greatly benefit energy professionals and engineers.This research addresses critical gaps in current methodologies for estimating higher heating value and exergy by offering a compact form for calculating various fossil fuels within a wide range of Carbon-to-Hydrogen ratios (3–105). Additionally, it provides specific equations applicable to both mole and mass fractions for natural gases, primarily composed of methane, with mole fractions ranging from 55 % to 99 %.

Large-eddy simulation investigation on the effects of inlet swirl/Reynolds number and fuel heating value on a turbulent kerosene spray flame

To progress toward the high efficiency and low emission aviation engine technology, it is mandatory to understand the complex phenomena including kerosene spray atomization, evaporation, turbulent mixing and combustion in the engine combustor. Nowadays with the rapid growth of computational capacity over the world, large-eddy simulation (LES) performs a more and more important role in understanding the complex multi-phase combustion process of kerosene fuels in aviation engine configuration. In the present work, LES is employed to investigate a swirling kerosene spray jet flame in a model combustor, which has been studied experimentally. The turbulent combustion is modeled by the flamelet generated manifold (FGM) approach with a 3-component surrogate kerosene skeletal mechanism. The averaged gas velocity and temperature predicted by LES generally agrees well with the experimental measurements. Local extinction is observed at the inner shear layer of the swirling spray flame, due to droplet-turbulence-flame interactions. A parametric study with 11 cases is then performed to investigate the effects of inlet swirl/Reynolds number and fuel heating value on the kerosene flame. As the swirl number increases, the enhanced turbulent mixing between kerosene fuel and air facilitates the combustion process, but combustion instabilities may occur if the swirl number is too high. A higher Reynolds number can promote the turbulent combustion via a stronger recirculation zone, but it also has strong dilution effects on the combustion field. Variations in the fuel heating value directly impact the temperature field, but the flow field, major species concentrations and droplet phase statistics are only slightly affected. These LES results give clues to achieve optimal combustion performance in realistic aviation engine configurations via better arrangements of fuel and air injections.

Exploring differences in FFCO2 emissions in the United States: comparison of the Vulcan data product and the EPA national GHG inventory

Quantitative assessment of greenhouse gas emissions is an essential step to plan, track, and verify emission reductions. Multiple approaches have been taken to quantify U.S. CO2 emissions from fossil fuel combustion (FFCO2), the primary driver of global climate change. A 2020 study analyzing atmospheric 14CO2 observations (a key check on bottom-up estimates) and multiple inventories found significant differences in the U.S. total FFCO2 emissions. The specific reasons for the differences were left for future work. Here, we take up this task and explore the differences between two widely used U.S. FFCO2 inventories, the Vulcan FFCO2 emissions data product and the Environmental Protection Agency (EPA) GHG inventory, developed using mostly independent data sources. Where possible, we isolate definitions and data sources to quantify/understand discrepancies. We find that the initial 2011 emissions difference (104 MtC yr−1; RD = 10.7%) can be reduced by aligning the two estimates to account for differing definitions of emission categories or system boundaries. Out of the remaining 90.6 MtC yr−1 gap (RD = 6.2%), we find that differences can be largely explained by data completeness, emission factors, and fuel heating values. The remaining difference, 45.4 MtC yr−1 (3.2%), is difficult to isolate due to limited EPA documentation and disaggregation of emissions by sector/fuel categories. Furthermore, the final net difference obscures countervailing gross differences (∼40 MtC yr−1) within individual sectors. Nevertheless, this comparison suggests the potential for a national estimation approach that can simultaneously satisfy reporting at the national/global scale and the local scale, maintaining internal consistency throughout and offering detailed decision support to a much wider array of stakeholders.

A review of gas turbine inlet cooling technologies

Gas turbine (GT) performance is primarily dependent on the inlet air temperature. The power output of gas turbine is dependent on the flow of mass through the gas turbine. This is why at hot weathers with less dense air, the power output drops, but at cold weather with high dense air, the power output rises. The inlet air cooling (IAC) technology is one of the major drivers that enhance the gas turbine performance, especially during the hot weathers. The performance of gas turbine is affected by various factors such as inlet air cooling, fuel type, fuel heating value, air temperature, turbine inlet temperature, humidity, site elevation, inlet and exhaust losses, air extraction, diluent injection, performance degradation, etc. The aim of this technical review is based on the comparative analysis of different gas turbine inlet air cooling (GTIAC) technologies and its applications based on the climate conditions. The power consumption due to inlet air cooling calls for major concern since it reduces the GT net power output. Different GTIAC has its unique benefits and challenges. The biggest gains from evaporative cooling are achieved during hot, low-humidity climates. Furthermore, the review paper showed that the efficiency of the evaporative cooler is majorly dependent on the moisture present in the air. The work also reveals that the feasibility of each GTIAC application is basically dependent on the location.

Execution and emission characteristics of automotive compression ignition engine powered by cerium oxide nanoparticles doped water diesel emulsion fuel

The rising consumption of oil and air pollution in developing countries compelled us to seek suitable alternative fuels for the existing compression ignition engines used in power generation, transportation, and industrial sectors, all of which play a strong role in the development of the nation's economy. Moreover, rising demand and consumption also causes a huge impact on our economy as we are dependent on other nations to cater to our needs as domestic production fails to fulfill the present requirement and leads to huge import bills that affect the ordinary man. A water/diesel (W/D) emulsified formulation helps to diminish the engine exhaust discharge without compromising the engine’s performance. The current task experimentally evaluates the execution and discharge characteristics of cerium oxide nano-particles doped water diesel emulsion fuel viz E15, E15CeO2(40), E15CeO2(60), and E15CeO2(80) on multi-cylinder automotive compression ignition engine at steady 1650 rpm, under variable test load situation. Mechanical stirring was used to make E15 water diesel emulsion fuel, whereas ultrasonicator and mechanical stirrer were used to make E15CeO2(40), E15CeO2(60), and E15CeO2(80) blends. Surfactants span 80 and tween 80 were used. The concentrations of cerium oxide nanoparticles in emulsion fuel samples were 40, 60, and 80 ppm, respectively. The characteristics like thickness, flash point, and heating value of test fuels were evaluated and reported within the range as specified by governing standards. The execution and discharge characteristics of various emulsion fuel samples were compared to standard diesel. At maximum load, cerium oxide doped fuels greatly improve engine performance while lowering environmentally harmful engine pollutants such smoke opacity, NOx, carbon monoxide, and hydrocarbon emissions by 40.27%, 33.60%, 30%, and 18.75%, respectively.

Design and testing of a Multi-Fuel industrial burner suitable for syn-gases, flare gas and pure hydrogen

The complete design and validation procedure of a novel Multi-Fuel heavy-duty burner is illustrated, starting from the conception and CFD analysis, up to an extensive experimental campaign assessing the actual performance of an industrial scale prototype.The need for an innovative burner to be employed in utility boilers comes from the context of energy transition with still increasing steam demand for process/industrial applications. The capability to burn a wide range of fuels, going from natural gas to flare-gases, syn-gases and fuels with even lower heating values, up to pure hydrogen, with high efficiency and low emissions is mandatory: it is shown and explained how all the above tasks are pursued starting from the early stage of conceptual design, leading to the development of a 2.5 MW prototype; then the burner operation is studied more in depth by CFD analysis, with particular attention to the implementation of MILD combustion regime: internal recirculation along with mixing, namely fuel dilution in flue gases leads to distributed volumetric reaction with oxygen, involving low peak temperatures with high conversion efficiency. Furthermore, numerical analysis helps to investigate the effectiveness of a central stabilizing flame, the coupling between furnace and burner in view of the tests, and also helps to evaluate different injection patterns for the fuel jets.As a final step, a 1.5 MW prototype is tested in a refractory lined furnace: the performance is assessed with natural gas, either pure or diluted with nitrogen to mimic a low heating value syn-gas, and with increasing percentage of hydrogen up to 95% as thermal input. Different levels of input to the central stabilizing flame are tested, and excellent flame stability of burner operation is proven. NOx emissions decrease for lower heating value fuels, increase for hydrogen/natural gas mixtures up to 35% H2, and remain almost constant above this threshold. Though, keeping a very low excess of air and almost no carbon monoxide in the exit flue gases, the absolute NOx levels compare very well with state of the art Ultra-Low-NOx industrial burners developed for standard fossil fuels. The presented data set can be relevant both for industrial designers, as a reference for heavy-duty burners operating with a wide range of fuels, up to pure hydrogen, and for academic researchers investigating on combustion, even in MILD regime.

Influence of H2 blending on NOx production in natural gas combustion: Mechanism comparison and reaction routes

Hydrogen blending in natural gas is an effective way of carbon reduction. The effect of hydrogen blending on the reaction pathway of NOx emission from natural gas combustion in industrial furnaces is studied by chemical kinetic calculations. To ensure the reliability of kinetic calculation, the NOx prediction accuracy of the mechanisms GRI and PG2018 were compared by validation with corresponding experiments. It is found that the PG2018 mechanism is more accurate for NOx prediction than GRI 2.11 and GRI 3.0, especially for N2O-intermediate and NNH pathways. The effect of hydrogen blending on the chemical pathways of NOx production was obtained based on PSR reactor and burner stabilized laminar flame with a well-controlled temperature profile. The results show that in the PSR reactor, N2O-intermediate and thermal NOx are predominating pathways for NOx formation. NOx emissions of unit fuel heating value first rise with the increase of blending ratio and then reduces rapidly while the blending ratio is greater than 50%, which is mainly due to the suppression of thermal NOx and the increase of N2O-intermediate NOx. It can be found from calculation results of burner stabilized flame that the prompt NOx decreases dramatically in the laminar flame and the NOx production via NNH increases slightly as hydrogen blending ratio increases. With increasing hydrogen blending ratio, thermal NOx is suppressed, and the N2O-intermediate pathway is suppressed also at the flame sheet but enhanced in the flue gas due to the increment of the H2O content. NOx emission decreases with increasing hydrogen blending ratio in laminar flame at a given combustion temperature.

The use of steam dryer with heat recovery to decrease the minimum exhaust flue gas temperature and increase the net efficiency of thermal power plant

Net power plant efficiency is the ratio of exportable electrical power output to the product of fuel consumption rate and fuel heating value. Conventionally, power plants are designed to attain the maximum net power plant efficiency by using regenerative feed water heating, in which extracted steam from steam turbine is used to increase feed water temperature. An important factor that determines the net power plant efficiency is the temperature of flue gas exhausted from the power plant. Decreasing this temperature increases the net power plant efficiency. However, exhaust flue gas temperature should not be lower than the lower limit in order to avoid the corrosion resulting from condensation of sulfuric acid vapor in flue gas on heat exchanger tubes. The lower limit can be raised by reducing fuel moisture content and raising air temperature at boiler inlet. In this paper, it is proposed that low-pressure extracted steam should be used for fuel drying in steam dryer, and vapor released from steam dryer should be used for air heating in heat recovery air preheater. By doing so, the lower limit of exhaust flue gas temperature is decreased, and the net efficiency of the power plant is increased. A case study of a 600-MW lignite-fired power plant is used to demonstrate that the integration of steam dryer and heat recovery air preheater is economically justified.

Influences of Biopetrol-Ethanol Fuel on Performance and Emission in Internal Combustion Engine

The purpose of this study is to experimentally investigate the engine performance and pollutant emission of a commercial SI engine using ethanol–gasoline blended fuels with various blended rates (0%, 5%, 10%, 20%, and 30%). Fuel properties of ethanol–gasoline blended fuels were first examined by the standard ASTM methods. Results showed that by increasing the ethanol content, the heating value of the blended fuels is decreased, while the octane number of the blended fuels increases. It was also found that with the increment of ethanol content, the Reid vapor pressure of the blended fuels initially increases to a maximum at 10% ethanol addition, and then decreases. Results of the engine test indicated that using ethanol–gasoline blended fuels, torque output and fuel consumption of the engine slightly increase; CO and HC emissions decrease dramatically as a result of the leaning effect caused by the ethanol addition; and CO2 emission increases because of the improved combustion. Finally, it was noted that NOx emission depends on the engine operating condition rather than the ethanol content.

Depolymerization of Kraft lignin to liquid fuels with MoS2 derived oxygen-vacancy-enriched MoO3 in a hydrogen-donor solvent system

Depolymerization of Kraft lignin represents an attractive strategy to obtain alternatives to fossil fuels. In this work, via the controlled oxidation of MoS2 precursor, an oxygen-vacancy-enriched MoO3 was synthesized and employed to catalyze the depolymerization of Kraft lignin in a new solvent system without external H2 gas. Systematic characterizations exemplified that the calcination temperature significantly affected the morphology and concentration of oxygen vacancy of prepared MoO3, and the appropriate temperature in this work was proved to be 350 °C. In the optimized hydrogen-donor solvent system that contained 20 mL 1, 4-dioxane, 20 mL isopropanol and 5 mL methanol, MoO3-350 catalyst gave a 87 wt% yield of petroleum ether soluble products, and the higher heating value (HHV) of liquid fuels (33.4 MJ/kg) was dramatically increased compared with the original Kraft lignin (25.23 MJ/kg). Methanol and isopropanol were analyzed to be capable of promoting the solubility of Kraft lignin and supplying hydrogen in the reaction system, respectively. Underpinned by characterizations and products analysis, the schematic representation of possible reaction pathway was given.

A comparison of machine learning algorithms for estimation of higher heating values of biomass and fossil fuels from ultimate analysis

Higher heating value (HHV) is one of the most important parameters to consider while obtaining energy efficiently from fuels. It provides means to estimate the quality of the fuel. However, measuring the HHV of fuels requires advanced devices, is expensive and time consuming. Thus, sufficient estimation of the HHV is crucial for development of fuel technologies and numerous studies have been performed about this subject. In this study, several machine learning algorithms (DTR, SVR, GPR, RFR, Multi-Linear Regressions, and Polynomial Regression) were utilized to construct models for estimation of the HHV from the largest open dataset of ultimate analysis of fuels on a dry, ash-free basis. The mathematical analysis is conducted for numerous different solid, liquid, and gaseous fuels such as biomass, biochar, municipal solid waste, kerosene, gasoline, fuel oil, algae, natural gas etc. 10-fold cross validation method was used to assess the validity of the constructed models in an unbiased manner. The R2, adjusted R2, RMSE, N-RMSE, and AAE values of each model were computed for performance evaluations. Finally, the results were compared with the literature, and advantages and disadvantages of each method were discussed in terms of both computational complexity and prediction accuracy. The RFR and DTR models performed exceptionally well in estimation of HHV of all classes of fuels with R2 values of 0.9814 and 0.9664, respectively. In addition, the statistical values of the ultimate analysis for each constructed class of fuel are investigated for each class of fuel and an extensive Krevelen diagram was produced from the largest dataset to date, which illustrated the relationships between the atomic O/C ratio and the atomic H/C ratio of the fuels.

Techno-Economic Analysis of Scenarios on Energy and Phosphorus Recovery from Mono- and Co-Combustion of Municipal Sewage Sludge

This study evaluates the techno-economic feasibility of energy and phosphorus (P) fertilizer (PF) recovery from municipal sewage sludge (MSS) through incineration in new combustion plants. We evaluated the economic impact of five critical process design choices: (1) boiler type, (2) fuel (MSS mono-combustion/co-combustion with wheat straw), (3) production scale (10/100 MW), (4) products (heat, electricity, PF), and (5) ash destination. Aspen Plus modeling provided mass and energy balances of each technology scenario. The economic feasibility was evaluated by calculating the minimum selling price of the products, as well as the MSS gate fees required to reach profitability. The dependency on key boundary conditions (operating time, market prices, policy support) was also evaluated. The results showed a significant dependency on both energy and fertilizer market prices and on financial support in the form of an MSS gate fee. Heat was preferred over combined heat and power (CHP), which was feasible only on the largest scale (100 MW) at maximum annual operating time (8000 h/y). Co-combustion showed lower heat recovery cost (19–30 €/MWh) than mono-combustion (29–66 €/MWh) due to 25–35% lower energy demand and 17–25% higher fuel heating value. Co-combustion also showed promising performance for P recovery, as PF could be recovered without ash post-treatment and sold at a competitive price, and co-combustion could be applicable also in smaller cities. When implementing ash post-treatment, the final cost of ash-based PF was more than four times the price of commercial PF. In conclusion, investment in a new combustion plant for MSS treatment appears conditional to gate fees unless the boundary conditions would change significantly.

Теплотехнические и экологические характеристики сжигания отработанных нефтепродуктов в промышленных установках

Spent petroleum products can be efficiently used as an energy source in industrial thermal power engineering. Matters concerned with the energy efficiency and environmental safety of using this type of fuel and development of burners for spent petroleum products are extremely relevant. To analyze the energy efficiency of industrial plants that use spent petroleum products as fuel, the heating value of these products has to be known. The data on the lower heating value and viscosity of various petroleum fuels published in the literature are systematized. The results obtained make it possible to estimate the heating value of spent petroleum products by using their viscosity as a parameter. A set of works aimed at developing an evaporative burner for high-quality combustion of various spent petroleum products has been accomplished. Based on experimental studies of the combustion of various spent petroleum products in the evaporative burner, relationships between the viscosity, lower heating value, and flame length and temperature are revealed. By using the obtained relationships between the thermal parameters characterizing the combustion of spent petroleum products, it becomes possible to assess the possibility of effectively neutralizing such pollutants as halogens and polychlorinated biphenyls. The boundary of the domain in which spent petroleum products can be combusted in an environmentally efficient manner with neutralizing such pollutants as halogens and polychlorinated biphenyls has been determined and described analytically. Dependences of the maximum allowable concentrations of pollutants in spent petroleum products on their viscosity, lower heating value, and flame temperature are presented. The obtained results can be used to develop domestic regulatory documents on energy efficient and environmentally friendly combustion of spent petroleum products in thermal engineering plants.

Gravimetric and instrumental methods comparison for experimental determination of carbonate carbon content in solid mineral fuels

The content of combustible elements in solid mineral fuels (carbon, hydrogen, etc.) are very important, since they most directly affect the heat value. It should be noted that the fuel heat value depends on many other constituents, such as ash and moisture. In this paper, special attention has been paid to carbon content. In solid mineral fuels, carbon is found alone or bound in the form of various compounds. One of them is mineral carbonate compounds bound as carbonate carbon, which originates from absorbed CO2 from atmosphere. Determination of carbonate carbon content of solid mineral fuels was performed by standard gravimetric method (according to ISO 925: 2019), and newly developed instrumental method, using thermogravimetric analyzer LECO TGA 701. Comparison of obtained experimental results was done. Four types of coal, Kolubara lignite, Kostolac lignite, brown coal, and control coal sample were included in experimental analysis. In addition, moisture in the samples was also determined using analytical method and inspected using LECO TGA 701 thermogravimetric analyzer, as well as total carbon content using the LECO CHN 628 elemental analyzer. An analysis and comparison of the obtained results was performed, and comments and conclusions are presented. The experiments were done in the department for fuel characterization, Laboratory for Thermal Engineering and Energy, Institute of Nuclear Sciences Vinca.

Numerical simulation of the effect of LPG blending on the characteristics of a diesel engine

AbstractThe present work aims to investigate numerically the effect of LPG blending on the characteristics of diesel engines subjected to variable compression ratio, injection timing, and engine speed. Three blends of LPG are used, which are 10% LPG + 90% diesel, 20% LPG + 80% diesel, and 30% LPG + 70% diesel. The numerical investigation is carried out using the simulation software Diesel‐RK. Increasing the percentage of LPG in diesel starts combustion early where the lowest delay period is recorded for a blend of 30% LPG + 70% diesel 6.36 deg. The combustion pressure and heat release are decreased due to the difference in the heating values of blended fuels. Although the peak energy release for diesel is 0.05458 (1/deg.) at 375 deg. BTDC, it was 0.0542, 0.05424, and 0.0537 (1/deg.) at 375 deg. BTDC for 10%, 20%, 30% LPG, respectively. Diesel with 30% LPG has a higher spray penetration followed by 20% LPG then 10% LPG and diesel come last. The diesel with 10% LPG gives a 5.35% reduction in NOx, while diesel with 20% and 30% LPG emit less NOx emission by 9.05% and 16.5%, respectively. Increasing the percentage of LPG in diesel yields to reduce soot concentration because LPG has lower carbon to hydrogen ratio. The lowest ability to emit smoke is detected for fuel with 30% LPG where a 7.4% reduction is obtained. It is worth noting that blending LPG with diesel can fight the trade‐off relation between Soot‐NOx as a reduction in both of them is obtained. Based on the results obtained, the blending ratio is 30% LPG. The obtained results are validated with the results of other researchers.

Understanding the role of nanoparticle size on energy, exergy, thermoeconomic, exergoeconomic, and sustainability analyses of an IC engine: A thermodynamic approach

This paper aims to thermodynamically and economically discuss the role of nanoparticle size on a CI engine performance. Accordingly, three different sizes (28, 45, and 200 nm) of titanium oxide nanoparticles are added into the canola oil methyl ester-diesel blends (C10) at the same mass fractions of 100 ppm. The experiments were conducted on a single-cylinder, air-cooled diesel engine. During the experiments, the engine speed was constant at 1800 rpm, and the engine was loaded from 2.5 and 10 Nm with gaps of 2.5 Nm. It is seen that the viscosity, heating value, and cetane number of the resultant test fuels dropped as the particle size gets smaller. In the results, brake-specific fuel consumption (BSFC) initially increased by 5.5% with the biodiesel added into diesel fuel. However, the addition of nanoparticles noteworthy dropped the BSFC value by roundly 16.91% for C10 + 28 nm TiO2, 12.97% for C10 + 45 nm TiO2, and 10.24% for C10 + 200 nm TiO2. As the engine load increases, BSFC dropped and energy as well as exergy efficiencies for each test fuel improved. The efficiency of the first and second laws at 12 Nm is found to be 25.97% and 24.37% for DF, 25.36% and 23.77% for C10, 27.60% and 25.88% for C10 + 28 nm TiO2, 27.03% and 25.34% for C10 + 45 nm TiO2, 26.65% and 24.99% for C10 + 200 nm TiO2, respectively. Collectively, average energy efficiencies of test fuels are 6.65% bigger than exergy efficiencies. On the other hand, it is noticed that the energy loss rate, energy rate, exergy rate, exergy loss rate, exergy destruction rate, and thermoeconomic metrics are increasing with any increment in engine load for each test fuel. The lowest values of energy and exergy efficiency benchmarks are found for C10 test fuel, while the highest ones are detected for C10 + 28 nm TiO2 test fuel. The addition of nanoparticles considerably increases the unit cost and specific exergy cost of test fuels. Despite their high unit costs, the most suitable fuels in terms of both exergoeconomic, and sustainability aspects are, nevertheless, the nanoparticles-added fuels due to their high exergy efficiencies. In the conclusion, this paper declares that the particle size of nanomaterials is a very effective physical property on the IC engine performance, and the small particle sizes of the same type nanoparticles should be preferred in terms of better energy, exergy, thermoeconomic, exergoeconomic, and sustainability results.

Determination of Optimum Point of Composition of Fuel Calories in Producing electrical Energy in Coal Fired Power Plant

Coal-fired power plant (CFPP) is a type of power plant that is widely used for 35,000 MW electricity projects in Indonesia. CFPP must adjust to its operating strategies with the availability of abundant low-rank coal, and it will affect CFPP performance. This study aims to determine the optimum heating value of fuels, the trend of net plant heat rate (NPHR), the cost of electricity production (component C), and the optimum point of the CFPP operation. The data used is from CFPP operations. First, data is analyzed by descriptive statistics and formed into a regression model. The next step is to estimate the parameters of the population data. The regression model obtained was then carried out the goodness of fit test and residual analysis. Then, the variable’s values are changed to the Z-score and plotted in the regression model. The model interpretation is carried out and conclusions can be obtained to find out the optimum point. The conclusion of this study is the optimum point of generating electricity in CFPP can be achieved by using coal calorific values of 4,450 kCal/kg, NPHR of 2,683.6 kCal/kWh, and COE (component C) of Rp 436.5/kWh when using coal at a price of 732.2/kg and Net Power of 279 MW.