Stationary Engine Research Articles

An integrated approach to explore UASB reactors for energy recycling in pulp and paper industry: a case study in Brazil

Brazil is currently focused on its energy matrix transition in favor of increasing of the share of renewable energy carriers for both enhanced energy security and mitigation of greenhouse gas emissions. In this context, the country`s pulp and paper industry whose different wastes teams are not generally exploited, could play a critical role. Accordingly, the main objective of this work is to develop a conceptual ‘systemic’ biorefinery framework integrating the treatment of pulp and paper mill wastewater using upflow anaerobic sludge blanket (UASB) reactor with energy recovery through biogas production and its conversion into heat and power in stationary engines and boilers, respectively. Based on the results obtained through the present case study, it was revealed that the adoption of UASB reactors by the paper mill industry could properly addresses the environmental concerns faced while could contribute to the national agenda favoring an increasing share of renewable energies in the country`s energy matrix. The financial analysis showed that the investment required for the implementation of UASB reactors within a biorefinery platform would be minor vs. the investment in the whole mill and would be returned in 6.4 yr with a high return on investment even when operated at half of operational capacity. Moreover, through the developed UASB reactor-based biorefinery, the Brazilian pulp and paper industry as a whole could avoid 1.06 ×105 CO2eq tons, effectively contributing to the decarbonization of the country`s economy.

Aftertreatment of Carbon Particles Emitted by Diesel Engine Using a Combination of Corona and Dielectric Barrier Discharge

The collection and incineration mechanisms in the particulate matter (PM) aftertreatment technique proposed by the author were investigated. An experiment for actual exhaust gas was performed by sampling 10 NL/min of exhaust gas from the flue gas from a stationary diesel engine generator. The reactor for PM aftertreatment comprised a glass tube with surrounding corona needles that projected negative charges. Various combinations of voltages applied to each of the corona needles and the surface electrodes were compared. The results enhanced the hypothesis that negatively charged PM is attracted by the dielectric surface that is positively charged by positive ions supplied by the electrode on the glass surface. Subsequently, conditions for carbon incineration by nonthermal plasma were investigated using a simulated dielectric barrier discharge electrode and carbon black particles applied to the surface. It was found that the gap length over which the carbon-adhered area and the surface electrode face each other is the key factor for the rate of incineration.

Application of different numerical models capable to simulate combustion of alternative fuels in internal combustion engine

PurposeThe internal combustion engine operated on gaseous fuels shows great potential in terms of integration of the renewable and traditional sources for an effective solution for clean energy production challenge. Different fuel mixtures that can be used to power the engine are characterized by various combustion properties, which can affect its overall efficiency. The purpose of this paper is to provide reasonable answer, how the operation condition can change due to different fuel, without enormous cost of prototyping processes using physical models a digital model can be seen as promising technique.Design/methodology/approachPresented work discusses the application, and extensive description of two commercial codes Ansys Fluent and Forte for modeling stationary engine fueled by compressed natural gas (CNG) and biogas. To check the model accuracy, all carried out numerical results were compared against experimental data collected at in-house test rig of single cylinder four stroke engine. The impacts of tested gaseous fuel on the engine working conditions and emission levels were investigated.FindingsCarried out simulations showed good agreement with experimental data for investigated cases. Application on numerical models give possibility to visualize flame front propagation and pollutant formation for tested fuels. The biogas fuel has shown the impaired early flame phase, which led to longer combustion, lower efficiency, power output, repeatability and in some cases higher HC and carbon monoxide (CO) emissions as a result of combustion during the exhaust stroke. Looking at the CO formation it was observed that it instantly accrue with flame front propagation as a result of methane oxidation, while for NOx formation revers effect was seen.Originality/valueThe application of new approach for modeling combustion process in stationary engines fueled by CNG and alternative biogas fuel has been discussed. The cons and pros of the Forte code in terms of its application for engine prototaping process has been discussed.

Off-design optimisation of organic Rankine cycle (ORC) engines with different heat exchangers and volumetric expanders in waste heat recovery applications

Organic Rankine cycle (ORC) engines in real applications experience variable heat-source conditions. In this paper, the off-design performance of small- to medium-scale ORC engines recovering heat from stationary internal combustion engines (ICEs) is investigated. Of particular interest are the employment of screw vs. piston expanders, and two heat exchanger (HEX) architectures. Unlike previous studies where the performance of the expander and HEX are assumed fixed during off-design operation, here we consider explicitly their varying and interacting characteristics within the overall system. Nominal sizing results reveal indicated isentropic efficiencies > 80% for twin-screw and > 85% for piston expanders. Following nominal design, the ORC engine operation is optimised for ICE part-load (PL) operation. Although the heat transfer coefficients in the evaporator decrease by up to 30% at PL, the effectiveness in this HEX increases by 20% due to the larger temperature differences across the component. The screw expander efficiency reduces by up to 3% at off-design operation, whilst that of the piston expander increases by up to 16%. Optimised off-design maps indicate that the ORC engine power output reduces to 77% (piston) or 68% (screw) of its full-load value when the ICE operates at 60% PL, and that ORC engines with plate HEXs generate 5–11% more power than those with double-pipe HEX designs. Under variable ICE operation, smaller ORC engines with piston expanders generate more power than larger engines with screw expanders, highlighting the resilient off-design operation of piston machines. The modelling tool developed here can predict ORC performance over a wide operating envelope and provides performance maps that can be used by operators to optimise ORC engine operation in variable conditions and by ORC vendors to inform component design decisions.

The effects of the air-fuel ratio on a stationary diesel engine under dual-fuel conditions and multi-objective optimization

The fundamental combustion characteristics and engine performance of a dual-fuel engine, fueled with diesel and natural gas, were investigated using a commercial 1D simulation program (GT-Power). Furthermore, the effects of air-fuel ratio under dual-fuel combustion conditions were studied, and optimized design points that minimize brake-specific fuel consumption (BSFC) and nitrogen oxides (NOX) emissions simultaneously were determined using a multi-objective Pareto optimization method. The engine model was validated based on experimental results and previous work under various engine loads. The thermal efficiency of the engine, which was modified from a diesel to a dual-fuel engine, showed a decreasing tendency as the natural gas substitution ratio (NSR) increased due to changes in the combustion characteristics. The decline in thermal efficiency in dual-fuel combustion could be improved somewhat by optimizing the injection strategy. Under dual-fuel combustion conditions, an optimum air-fuel ratio value for BSFC could be determined, especially for higher NSR conditions. However, NOX emissions showed a tendency to increase with increasing air-fuel ratio. The relationship between the trends was more than a simple tradeoff, so multi-objective Pareto optimization was conducted to minimize both BSFC and NOX emissions, with start of injection timing and air-fuel ratio as variables. Ultimately, optimal design points were determined.

Enhancement in combustion, performance, and emission characteristics of a biodiesel-fueled diesel engine by using water emulsion and nanoadditive

The present study details the enhancement in combustion, performance, and emission characteristics of SB fueled diesel engine by using water emulsion (10% and 20%) and CNT nanoparticle (100 ppm). The biodiesel was prepared from soybean crude oil by trans-esterification process, and the fuel properties were measured. Experiments were performed in a single cylinder, four-stroke, and natural aspirated stationary diesel engine under varying BMEP conditions. The measured fuel properties of SB, 10WSB, and 100CNT10WSB are at par with standard limits, whereas 20WSB and 100CNT20WSB viscosity values are not par with standard limits. Studies in the engine revealed that the combustion starts later for water/biodiesel blends, and ICP, NHR, and RPR are higher compared to pure SB. The nanoparticle inclusion with emulsion fuels reduces the peak ICP and NHR values. Emulsion fuels show a good improvement in BSFC, BSEC, and EGT when compared to pure SB, and the nanoparticle inclusion further improves the performance parameters. The emission characteristics of test fuels show that the water/biodiesel blends have a lower magnitude of NOx and smoke emissions, and 10WSB shows better HC and CO emissions when compared to SB and 20WSB. An inclusion of CNT nanoparticle further reduces the emissions level.

Acetylene an Potential Alternative Fuel for Stationary Diesel Engine

The present study focuses on incorporation of alternative fuels along with existing internal combustion engines (ICE) without making major modifications. Acetylene has good combustion qualities with auto ignition temperature of 3050C. To increase the use of acetylene as non-petroleum gas in ICE, we carried experimentation on a single cylinder constant speed diesel engine. In this study, direct injection (DI) and constant speed compression ignition (CI) engine tested with pure diesel and diesel-acetylene dual fuel mode. We conducted experiments to study the performance characteristics of DI diesel engine in dual fuel mode by aspirating acetylene gas in the inlet manifold with a flow rate of 2 liters/minute (lpm) of acetylene. Observation recorded that, during idling condition to get the same power output when aspirated with the 2 lpm acetylene, 3.5% less amount of diesel required. For maximum load 9% less amount of diesel required. And 12% less amount of diesel required during partial loading condition. Also, the performance shows increased trend in indicated power and brake power by 1-2%. It was also observed that use of acetylene gas has more influence on emission of CO2. Emission results showed that without a catalytic convertor, 8% decreased amount of CO2 released during idling condition. Similar emission results of engine found during full load condition when acetylene used along with diesel, supporting the health of environment for reduction of global warming.

Development of a Novel High Efficiency, Low Cost Hybrid SOFC/Internal Combustion Engine Power Generator

The unique and beneficial characteristics of solid oxide fuel cell (SOFC) technology hold much promise for their eventual widespread adoption in numerous residential and commercial building applications. Nevertheless, cost and durability challenges remain that currently limit SOFC technology penetration in stationary energy applications. Under the U.S. DOE ARPA-E INTEGRATE program, the Colorado School of Mines and it partners are developing a novel hybrid stationary power system comprised of an intermediate temperature (600°C), solid oxide fuel cell stack integrated with a high efficiency stationary engine and novel balance-of-plant (BOP) equipment. In collaboration with Colorado State University, Kohler Power Systems, and Air-Squared, Inc., the project aims to demonstrate a system that can generate power (125 kW) from natural gas at high electric efficiency (>70%-LHV), and low cost (<900 $/kW). Project activities on the hybrid SOFC/IC engine system development and system requirements are discussed.

Individual effects of antioxidant additive and SCR system on the NOx reduction of a CI engine powered by cottonseed oil blend

The rapid utilization of fossil fuel has paved the way for the large amount of pollutants such as NOx and other harmful components. Pre-treatment of fuel and after-treatment of exhaust process becomes vital due to India’s commitment towards BS VI emission norms by 2020. This paper is aimed to reduce the NOx emission in a stationary engine powered by cottonseed oil blend with antioxidant additive. The vanadium-based SCR (Selective Catalytic Reduction) system is used in the exhaust system for the after-treatment of oxides of nitrogen. The load varied from 0% to full load for performance and emission analysis. The results show that the NOx emissions of the CI engine running on cotton seed oil blend with the catalytic convertor under urea injection is reduced by 88% at full load. Furthermore HC emission reduction is also noticed significantly with the after-treatment strategy being applied.

Production, combustion and emission impact of bio-mix methyl ester fuel on a stationary light duty diesel engine

NOx emissions are the major threat in biodiesel fuelled engines due to fuel bound oxygen and presence of double bonds in their molecular structure. An attempt has been made to reduce the biodiesel NOx emission by varying the saturation level with the help of an approach called “bio-mix”. In this study, bio-mix fuel has been prepared from the waste resources of raw mixture of pig fat and waste cooking oil. Five samples of raw bio-mix oil have been prepared from the different blend ratio of pig fat and waste cooking oil and converted into biomix methyl ester (BMME) samples through transesterification process such as BMME-1, BMME-2, BMME-3, BMME-4 and BMME-5 respectively. All the bio-mix samples have been tested on a single cylinder, light duty stationary diesel engine. Results show that the percentage of saturated fatty acids, cetane number, and calorific values have increased whereas viscosity and iodine values have decreased with an increase in blend ratio. Bio-mix methyl ester fuel shows better combustion, performance compared with waste cooking oil biodiesel (WCOB). Bio-mix methyl esters shows higher in-cylinder pressure and heat release rate which is lower than WCOB at all engine load condition. All the emissions such as NOx, Smoke, CO, and HC have been found lower for BMME compared to WCOB. The non-road diesel engines are also consuming the fossil diesel fuel and hence, this study suggest that bio-mix fuel can be a viable alternative fuel for stationary diesel engines widely used in utility power generation, agriculture and construction equipments.

Performance, regulated and unregulated exhaust emission of a stationary compression ignition engine fueled by water-ULSD emulsion

The interest in water-diesel emulsion fuel (EM) is increased recently because of the significant reduction in emissions from diesel exhaust, especially NOx and PM. In this study, a diesel engine configured for experimental investigations was fueled by ultra-low sulfur diesel (ULSD) and a diesel-water emulsion (EM). Both fuels’ combustion characteristics were studied at a speed of 1500 rpm and using a load of 2.5 and 5 bars and variable injection timings. Regular and irregular pollutants were studied at the same conditions as well as at variable engine loads and speeds to better understanding for their formation conditions. As for the first time (in the case of an engine running with a water-diesel emulsion) irregular pollutants for EM emulsion were measured.The measured results indicated that the use of water-diesel emulsion reduced the heat released in the combustion chamber, which causes an increase in the brake specific fuel consumption and ignition delay. For the tested loads, the diffusion combustion duration for EM was decreased when the injection timing was retarded while the opposite was occurred for premixed combustion duration. The regulated NOx and Smoke Number were reduced when EM was used compared to ULSD while CO and HC levels were increased at low engine’s speed and loads. Besides, these concentrations are depending on injection timing (they were higher at restarted timing). The unregulated emissions measured (Formaldehyde, Acetaldehyde, Methane, Acetylene, Ethylene, and propylene, Ammonia, and Acetone) were increased with using EM, especially at no and low loads, indicating the high impact of the combustion chamber temperature on these pollutants formation.

Modelling and experimental study on performance and emission characteristics of citrullus colocynthis (thumba oil) diesel fuelled operated variable compression ratio diesel engine

This experimental investigation aimed to depict the effects of varying loads at various compression ratios with thumba methyl esters in different proportions as fuel on a variable compression ratio diesel engine. Series of tests were conducted on a single cylinder, 3.6 kW, water cooled, variable compression ratio, stationary diesel engine, as per the full factorial design to measure the performance and emission characteristics. The engine load, compression ratio and blending ratio for citrullus colocynthis (thumba oil) based diesel were taken as input parameters and their effects on engine performance and emissions characteristics such as BTE, BSFC, HC, NOx & CO were investigated experimentally and analytically. Experimental data was analysed and modelled using the full factorial design in three different stages to achieve the optimum results for performance and emission characteristics. For each stage, second order and third order estimate models were developed and were checked for assumptions of Analysis of Variance i.e. normality & homogeneity of data. The optimum performance & emission characteristics were observed with 20% thumba-diesel blend, at a compression ratio of 18 at maximum load. It was found that the optimum values of BSFC, BTE, HC, CO & NOx was 0.456 kg/kWh, 19.725%, 38.432 ppm, 0.026% and 348.744 ppm respectively at load of 10 kg, CR of 18, and blend percentage of 20. A good agreement between experimental results and predication results depicts that the developed models can be used with competence to optimize similar type diesel engine parameters using citrullus colocynthis (thumba oil) blend without engine modification.

Continuous slow dynamic slope approach for stationary base internal combustion engine mapping

Engine control optimization, with its always growing complexity, is in permanent focus of engine researchers and developers all over the world. Automotive engines are dominantly used in dynamic conditions, but generally, steadystate operating points are used for building up mathematical models which are later subject to the numerical optimization. For this purpose, a large amount of steadystate regimes needs to be evaluated through experimental work at the engine test stand, which is an extremely time and funds consuming process. Consequently, the methodology for data gathering during engine dynamic excitation could lead to significant savings at the expense of acceptable data accuracy loss. The slow dynamic slope method starting from a stationary operating point was evaluated by several authors in the past. In this paper, slow dynamic slope method with exclusively transient excitation will be presented drawing attention to some of its advantages and drawbacks. The rate of change of engine load as a main control parameter during dynamic test is of great importance for the quality of the final data and for total test duration. In this regard, several tests of different duration were applied for fixed engine speed values to cover engine speed-load usage domain. An approximation of stationary testing results obtained in this way could be used for evaluation of the map gradients and thus as a guide-line for additional stationary tests based on design of experiment method.

Reducing Exhaust Gas Emissions of Stationary Diesel Engines Using Water Bath

This work was conducted with the aim of reducing exhaust gas emissions of stationary diesel engines, particularly those used locally by the private sector for electric power generation. A specially designed water bath equipped with perforated tubes submerged in water and supplied with water circulation to maintain the cleanness of water was used for this purpose. The diesel engine exhaust gas was admitted to the water bath through the perforated tubes such that the exhaust gas is “cleaned up” thoroughly before being released to the atmosphere. An experimental work was conducted on a four-stroke, air-cooled, one-cylinder diesel engine to verify the feasibility of using this technique in reducing exhaust gas emissions before applying it to large size diesel engines. The experimental results indicated that the use of the proposed water bath led to enormous reductions in oxides of Nitrogen (NOx), unburnt Hydrocarbons (HC), Carbon Monoxide (CO), and exhaust gas temperatures. In addition to a relatively small reduction in exhaust noise. For the engine power range considered in this work (0.4-2 kW), NOx was reduced by 62-73%, unburned HC was reduced by 72-85%, CO was reduced by 41-68%, exhaust gas temperature was reduced by 89-91% and exhaust noise was reduced by 1-7%.

Effect of Fuel and Air Dilution on Syngas Combustion in an Optical SI Engine

To mitigate the increasing concentration of carbon dioxide in the atmosphere, energy production processes must change from fossil to renewable resources. Bioenergy utilization from agricultural residues can be a step towards achieving this goal. Syngas (fuel obtained from biomass gasification) has been proved to have the potential of replacing fossil fuels in stationary internal combustion engines (ICEs). The processes associated with switching from traditional fuels to alternatives have always led to intense research efforts in order to have a broad understanding of the behavior of the engine in all operating conditions. In particular, attention needs to be focused on fuels containing relatively high concentrations of hydrogen, due to its faster propagation speed with respect to traditional fossil energy sources. Therefore, a combustion study was performed in a research optical SI engine, for a comparison between a well-established fuel such as methane (the main component of natural gas) and syngas. The main goal of this work is to study the effect of inert gases in the fuel mixture and that of air dilution during lean fuelling. Thus, two pure syngas blends (mixtures of CO and H2) and their respective diluted mixtures (CO and H2 with 50vol% of inert gases, CO2 and N2) were tested in several air-fuel ratios (stoichiometric to lean burn conditions). Initially, the combustion process was studied in detail by traditional thermodynamic analysis and then optical diagnostics were applied thanks to the optical access through the piston crown. Specifically, images were taken in the UV-visible spectrum of the entire cycle to follow the propagation of the flame front. The results show that hydrogen promotes flame propagation and reduces its distortion, as well as resulting in flames evolving closer to the spark plug. All syngas blends show a stable combustion process, even in conditions of high air and fuel dilution. In the leanest case, real syngas mixtures present a decrease in terms of performance due to significant reduction in volumetric efficiency. However, this condition strongly decreases pollutant emissions, with nitrogen oxide (NOx) concentrations almost negligible.

Evaluation of Using Biogas to Supply the Dual Fuel Diesel Engine of an Agricultural Tractor

It is known that biogas without prior purification to biomethane is a commonly used fuel only for the stationary internal combustion engines but not for vehicle engines. The current study evaluates the use of biogas without its prior upgrading to biomethane as fuel for tractor engines. The following tests were carried out: biochemical methane potential tests, dynamometer engine tests, and field tests with the use of a tractor. The average methane content in biogas obtained from vegetable wastes exceeded 60%. The tests performed on the engine dynamometer showed that the engine powered by dual fuel worked stably when diesel was replaced by 40% biogas (containing 50% of CO2) or 30% methane. Dual fuel supplying of the engine caused an increase in the concentration of hydrocarbons and carbon monoxide in the exhaust gases and a decrease or no effect in the concentration of particulate matter and nitrogen oxides. It did not significantly affect the dynamics of the vehicle and its useful properties. Biogas that contains a maximum of 50% CO2 and from which H2S, moisture, and siloxanes have been largely removed, is suitable as a fuel for tractors. Such biogas can be obtained in biogas plants from different substrates, e.g., vegetable or agriculture wastes as well as biodegradable municipal wastes.

Potentials of OME/diesel blends for stationary power production – Improving emission characteristics of a diesel CHP unit

Polyoxymethylene dimethyl ethers (OME) with the chemical structure H3CO[-CH2-O-]nCH3 are a promising alternative fuel for improving emissions characteristics of internal combustion engines and can be produced from renewable sources. Especially the PM-NOx trade-off of diesel engines is known to be effectively mitigated by blending OME with diesel. Recent investigations concentrate on the utilization OME fuels in mobile applications. However, these fuels could also be of interest for stationary engines used in gensets and combined heat and power units (CHP). In the present paper we examine the use of OME2-6/diesel blends up to 50% in a CHP unit in practical operation equipped with a heavy-duty six-cylinder engine, applying different load conditions and engine settings, including Exhaust Gas Recirculation (EGR) and the adjustment of injection timings. No negative effects on the performance and efficiency of the engine were observed with the OME blends. Particulate Matter (PM) and Particle Number (PN) decreased significantly with increasing content of OME in the blend, especially when EGR was applied. The Particle Number Size Distribution (PNSD) showed a trend towards smaller particle sizes. NOx rose slightly in direct comparison, but this was by far overcompensated by the reduction achieved through EGR. The results indicate that OME fuels in combination with EGR could become a feasible option for emission reduction in diesel gensets and CHP units due to the very low particle emissions, which mitigate the risk of EGR cooler fouling.

Exergo-economic analysis of different power-cycle configurations driven by heat recovery of a gas engine

In the present work a 34.3 kW stationary gas engine considered as prime-mover of bottoming thermodynamic cycles. The waste heat recovery cycles of engine exhaust gas consist of several configurations of organic Rankine cycle and combination of Rankine/Kalina cycles, also the engine jacket water heat is recovered by trilateral flash cycle. The performance of bottoming cycles was investigated from thermodynamic and thermo-economic points of view. For the organic Rankine cycle, three fluids including Benzene, Toluene and Cyclohexane have been compared. Also, considering that the trilateral flash cycle is a suitable cycle for heat recovery from a low temperature heat source due to its better matching between the temperature profiles of cycle working fluid and heat source fluid, this cycle is considered as bottoming waste heat recovery cycle for engine jacket water. In order to compare different working fluids and cycle configurations, three objective functions including energy efficiency, exergy efficiency and specific investment cost for the 18 studied cases are compared. The results reveal that, energy, exergy efficiency and specific investment cost of all configurations with toluene as working fluid of organic Rankine cycle is the highest and least compared to the other working fluids, respectively. But for configuration Rankine with Open Feed Heater-Kalina-Trilateral Flash Cycle, benzene fluid is better in terms of specific investment cost, however the energy and exergy efficiency of this cycle is also maximal with toluene fluid. Also, the results depict that configurations Rankine with Internal Heat exchanger – Trilateral Flash Cycle and Rankine with Open Feed Heater_Kalina_Trilateral Flash Cycle thermodynamically, and configurations Rankine with Internal Heat exchanger – Trilateral Flash Cycle and Rankine with Open Feed Heater – Trilateral Flash Cycle exergo-economically show the better performance. In this regard, employing configurations Rankine with Internal Heat exchanger – Trilateral Flash Cycle, Rankine with Open Feed Heater-Kalina – Trilateral Flash Cycle and Rankine with Open Feed Heater – Trilateral Flash Cycle in base mode leads to 6.85 kW, 6.48 kW and 6.54 kW increment in net power produced imposing 3318 $/kW, 4090 $/kW and 3377 $/kW specific investment cost, respectively.

Erosion processes of electrodes – Experiments and modeling

The scope of this work was to identify and examine lifetime limiting processes of spark plugs as used in stationary gas engine applications. Experimental investigations and analytic methods were applied in order to analyze and understand the wear process, especially in terms of electrode material. Physical parameters to describe rate of oxidation and diffusion processes were obtained and employed to set up a simulation model capable of lifetime prediction. Parameters not directly measurable, such as temperature load where the arc strikes the electrode, are extracted from a separate local, in-depth thermal analysis. Furthermore, ignition parameters such as level of ignition current and spark duration were systematically varied to determine their impact on the ignition system and to refine the wear model. Field tests on a Jenbacher Type 6 Gas engine have been conducted to observe the erosion of electrodes in gas engines due to the main contributing factors: combustion, spark energy input and oxidation. Using a specific spark plug test rig where combustion does not take place, the processes can be reduced to either spark energy impact or oxidation. Long-term testing as well as single spark experiments provide greater insight into the wear rate. Following this test rig step, the erosion of the electrode material caused by oxidation alone was investigated in a furnace using thermogravimetry. Before and after the tests, optical inspections (DOF), computer tomography (CT), energy dispersive x-ray spectroscopy (EDX), x-ray diffraction (XRD) and differential thermal analysis (DTA) were applied to analyze the electrode material. The understanding of wear phenomena obtained from these experiments in combination with the new simulation model developed provide the opportunity to predict lifetime and to evolve more durable spark plug designs.

Investigation of exhaust emissions from a stationary diesel engine fuelled with biodiesel

This paper studied the production of waste cooking biodiesel as an alternative fuel for diesel engine. The biodiesel was produced through conventional transesterification process using the base catalyst (KOH). A multi-cylinder diesel engine was used to evaluate the emission of 20% (B20) waste cooking biodiesel fuel at different engine speeds and full load condition. It was found that the characteristics of biodiesel are within the limit of specified standards (American Society for Testing and Materials, ASTM D6751) and comparable to diesel fuel. Engine emission results indicated that waste cooking biodiesel fuel sample reduces the average carbon monoxide (CO) and particulate matter (PM) emissions except nitrogen oxides (NOx) than diesel fuel. Finally, it can be concluded that 20% of waste cooking biodiesel can significantly contribute to lower the harmful emission of an unmodified stationary diesel engine to the environment.