Emission Profiles of Airborne Particulate Size-Segregated Carbonaceous Fractions of Stationary Diesel Engine and Impact Assessment of their Depositions in Human Lungs

Stationary diesel engines, especially diesel generators, are increasingly being used in both developing countries and developed countries because of increased power demand. Emissions from such engines can have adverse effects on the environment and public health. In this study, particulate emissions from a domestic stationary diesel generator running on ultra-low-sulfur diesel (ULSD) and biodiesel derived from waste cooking oil were characterized for different load conditions. Results indicated a reduction in particulate matter (PM) mass and number emissions while switching diesel to biodiesel. With increase in engine load, it was observed that particle mass increased, although total particle counts decreased for all the fuels. The reduction in total number concentration at higher loads was, however, dependent on percentage of biodiesel in the diesel-biodiesel blend. For pure biodiesel (B100), the reduction in PM emissions for full load compared to idle mode was around 9%, whereas for ULSD the reduction was 26%. A large fraction of ultrafine particles (UFPs) was found in the emissions from biodiesel compared to ULSD. Nearly 90% of total particle concentration in biodiesel emissions comprised ultrafine particles. Particle peak diameter shifted from a smaller to a lower diameter with increase in biodiesel percentage in the fuel mixture. IMPLICATIONS There has been an increased usage of stationary diesel engines, especially backup power generators to meet the growing energy demand. Biodiesel derived from waste cooking oil has received increasing attention as an alternative fuel. However, data are only sparsely available in the literature on particulate emissions from stationary engines, fueled with blends of diesel and biodiesel. This study provides insights into the influence of waste-cooking-oil-derived biodiesel on engine performance and the particulate emissions from a stationary engine. The results of the study form a scientific basis to evaluate the impact of biodiesel emissions on the environment and human health.

Characteristics of vegetable oils for use as fuel in stationary diesel engines—Towards specifications for a standard in West Africa

Problems are discussed associated with the burning of heavy fuels in medium-speed, two-cycle, trunk-piston types of engine. Tests with a stationary engine are described, and performances, rates of cylinder-bore wear, and degrees of fouling are compared, when five classes of fuel are burnt. Pre-treatment of fuels in the centrifuge is considered, and the results from practical experience show how certain fuels with high ash content, probably in an oil-soluble form, promote rapid cylinder-bore wear, even after being subjected to thorough treatment. Comparative rates of deterioration of the lubricating oil are recorded when different classes of fuel are burnt, and figures are given which show how fuels with a high sulphur content promote the formation of sulphuric acid in the crank chamber. Findings with the stationary engine are correlated to marine requirements, and the economy aspect is presented of bunkering a lower grade of fuel in a coastwise vessel of 2,500 tons dead weight. The conclusion is reached that a marine Diesel fuel, preferably a distillate, instead of gas oil could be bunkered with financial advantage, but that in the light of present knowledge the use of a boiler-grade fuel could not be recommended.

An experimental investigation of hydrogen-enriched air induction in a diesel engine system

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

Identification of the protein kinase C isoenzymes in human lung and airways smooth muscle at the protein and mRNA level

<div class="htmlview paragraph">The present paper is an effort to evaluate ethanol in diesel fuel and its main alternatives. The fuels used were an ultra low sulfur diesel fuel containing 15% by volume gas-to-liquid (GTL), JP-5 and JP-8 fuels produced in Greece and biodiesel produced from animal fats. The fuels were tested for compliance to the respective specifications at the Fuels Laboratory of the National Technical University of Athens (NTUA). The test fuel matrix consisted of blends of 5-15 % by volume ethanol with diesel, JP-5, JP-8 and with mixtures of the above with 5% by volume biodiesel. The test fuels were used in a stationary single-cylinder diesel engine with indirect injection, in order to evaluate their performance and emissions under various loads.</div>

In this research, the potential effects of titanium dioxide (TiO2) nanoparticles on improving a stationary diesel engine characteristic fuelled with a biofuel mixture-diesel blend (B25: 25% vol. biofuel mixture containing biodiesel, waste cooking oil and ethanol + 75% vol. diesel) are experimentally investigated. TiO2 nanoparticles are dispersed in B25 fuel at 50, 100, and 150 ppm concentrations. Subsequently, they are tested in a stationary research diesel engine at a rotational speed of 1500 rpm and specific loads. Nanoparticles enhance combustion, offering increased cylinder gas pressure, net heat release rate, and reduced ignition delay period and combustion duration. The engine performance is enhanced more with increasing nanoparticle concentration. TiO2 nanoparticles with a 150 ppm rate reduce brake-specific fuel consumption by 3.21% and increase the brake effective efficiency by 3.67%, on average, compared to B25 fuel without nanoparticles. CO emission and smoke opacity are reduced by up to 31.89% and 24.56% with TiO2 nanoparticles. However, under the same operating conditions, NO emission increases to 30.58% compared to sole B25. Nevertheless, the NO emission of nanofuels is still less than that of diesel fuel. This study's results indicate that using TiO2 nanoparticles as a nano fuel additive can enhance the stationary engine's operation fueled with the biofuel mixture-diesel blend. Keywords: Biofuel, Diesel engine, Fuel additive, Nanoparticles

In this study, combustion characteristics and nano-size soot particle emissions from a stationary conventional diesel engine have been experimentally investigated using butanol/diesel blends. Experiments were conducted on a single cylinder stationary diesel engine at a constant speed of 1500 rpm for neat diesel and butanol/diesel blends (i.e., 10%, 20% and 30% butanol on volume basis) at different engine loads. Piezoelectric pressure transducer installed in the engine combustion chamber was used for measuring cylinder pressure data. In-cylinder pressure data for 2000 consecutive engine cycles was recorded and averaged data was used for the analysis of combustion characteristics. Butanol/diesel blends show higher rate of heat release in comparison to neat diesel and heat release rate increases with butanol percentage in the blend. Opacity meter and exhaust particle sizer were used for analyzing smoke opacity, size and mass distributions of soot particles respectively at different engine operating conditions. Soot particle distribution from 5 nm to 1000 nm was recorded at each test condition. Results show that total particle concentration decreases with an increase in engine operating loads. It was found that butanol/diesel blends have lower total particulate concentration and the surface area.

This research has developed a methodology to estimate energy losses associated with auxiliary systems and mechanisms subject to friction in a stationary diesel engine. The study methodology is based on mathematical models used to calculate engine friction forces and power losses. The analysis involves the cooling, the lubrication, the fuel injection system, and the engine's valve train, bearings, and piston mechanism. A stationary diesel engine with four load conditions and three rotational speed conditions has been taken as a reference for the study. The analysis of the results has showed that fuel injection is the auxiliary system with the highest energy consumption. In general, the cooling system, the lubrication, and the injection represent loss energy equivalent to 0.3%, 0.5%, and 0.9% of the chemical energy of the fuel. The interaction between the cylinder liner and the piston skirt is the main source of energy loss associated with friction processes. For valve train mechanisms, bearings and pistons it has been evidenced that these represent 1.25%, 1.91%, and 5.26% of the chemical energy of the fuel. In general, the methodology proposed in this research is a tool that allows diagnosing energy losses in auxiliary systems and engine mechanisms, which is useful for evaluating future strategies focused on energy improvement.

<div class="section abstract"><div class="htmlview paragraph">Gas engines (fuelled with CNG, LNG or Biogas) for generation of power and heat are, to this date, taking up larger shares of the market with respect to diesel engines. In order to meet the limit imposed by the TA-Luft regulations on stationary engines, lean combustion represents a viable solution for achieving lower emissions as well as efficiency levels comparable with diesel engines. Leaner mixtures however affect the combustion stability as the flame propagation velocity and consequently heat release rate are slowed down. As a strategy to deliver higher ignition energy, an active pre-chamber may be used. This work focuses on assessing the performance of a pre-chamber combustion configuration in a stationary heavy-duty engine for power generation, operating at different loads, air-to-fuel ratios and spark timings. The engine was originally a 6-cylinder compression ignition engine which is here employed as a single cylinder engine and then suitably modified to host the pre-chamber (with its natural gas injection system and spark plug) with a new bowl piston to decrease compression ratio. A 0D model is built to make a thermodynamic analysis to characterize the local conditions in the pre-chamber before spark timing (temperature, pressure and composition), based on a compressible nozzle equation for the mass transfer between the chambers and a simplified Woschni model for the pre-chamber’s heat transfer. A mathematical expression was found to describe the relationship between the local conditions and the early stage of the combustion. Experimental results showed the beneficial effect of spark delay and mixture leaning for the reduction of NOx emissions, while CO, unburned hydrocarbons and engine performance see improvement with lower air-to-fuel ratios and spark advance.</div></div>

Compressed air energy storage is one of the green energy storage and conversion systems. In this work, the compressed air was directly supplied to a stationary diesel engine to investigate the effects of compressed air characteristics on the process of thermal-work conversation in diesel engines. Then, the thermal efficiency of supplying compressed air to a diesel engine is compared against a simple hybrid system that consists of a compressed air engine and a baseline diesel engine. The results indicate that the compressed air affects the thermal work conversion of diesel engine. The gross indicated mean effective pressure is being used to quantify the in-cylinder pressure work that transferred to the piston motion only for the combustion and expansion strokes, which increases as the pressure of compressed air increases and decreases as the temperature of the compressed air increases. The gross indicated thermal efficiency that represents the ability of thermal-work conversion is maximum at intake pressure of 300 kPa and intake temperature of 303 K with a value of 44.3%, which is 19.7% higher than that of the baseline diesel engine with 100 kPa intake pressure and 303 K intake temperature. The diesel engine using compressed air shows 6.64% higher overall efficiency than the simple hybrid system. The soot emissions increase with increasing intake pressure, and decrease with increasing intake temperature. As the intake temperature increases, NOx emissions increase. As the intake pressure increases, NOx emissions first decrease and then increase.

Stringent legislative emission norms demand to curb the stationary and automobile related engine pollution. Though several methods are available to control such harmful pollution, Exhaust Gas Recirculation, EGR is very popular in controlling pollution. EGR is one of the most effective means of reducing NOx emissions from diesel engines and is likely to be used in order to meet present and future strict emissions standards. The results of the experiments conducted on a single cylinder naturally aspirated stationary DI Diesel engine with two heat exchangers to vary the EGR temperatures are presented in this paper. Incorporation of two heat exchangers enabled to vary the temperature of the recirculated exhaust gas. Results are obtained for three different EGR cooling, first passing it through one heat exchanger then through two heat exchangers and finally recirculated without passing through any heat exchanger. As the test engine is meant for stationary application its speed is automatically governed. It was found that hot EGR renders significant reductions in NOx emission with minimum deterioration in UBHC, smoke and thermal efficiencies. The EGR percentage could not be extended beyond 50% as engine started running rough. A reduction in NOx up to 94% was recorded for hot EGR case. Without any remarkable drawbacks in fuel consumption, the NOx and HC emissions can be considerably reduced at low part load operation. The EGR has a beneficial effect especially at the low and medium part load range.

This study has evaluated the influence of hydrogen in a biodiesel fuel produced from palm oil residual material. For the development of the research, an analysis of the energy and exergy distribution, performance parameters, and emission characteristics has been carried out. The experimental tests have been carried out on a stationary diesel engine operated at three load conditions: 60%, 80%, and 100%. The engine has been fuelled with four types of fuel: D100%, POME5%, POME5% + 0.10 lpm and POME5% + 0.20 lpm, respectively. Overall, the POME5% fuel causes a 7.28% decrease in combustion chamber peak pressure and a 12.33% increase in engine BSEC. The results obtained show that the POME5% + 0.10 lpm and POME5% + 0.20 lpm fuel blends produce a 2.86% increase in peak pressure and a 3.86% decrease in engine BSEC compared to POME5% biodiesel. Additionally, a 4% and 3.72% increase in energy and exergy efficiency is obtained. The blends POME5% + 0.10 lpm and POME5% + 0.20 lpm allow a reduction of 11.72% and 12.73% in HC and CO emissions compared to pure diesel. The study shows that hydrogen can potentially encourage palm oil waste as a raw material in biodiesel production.

In the current investigation, an analysis of the performance parameters and emissions has been carried out in a stationary diesel engine fed with an alternative fuel blend from industrial palm oil waste (Palm Oil Mill Effluent, POME). Additionally, the influence of hydroxy gas injection in the combustion chamber has been evaluated. A test engine, which has operated at four torque levels and at a constant speed of 3600 rpm, has been used for the study. The fuel blend tested has been POME10%, and the volumetric flow of the hydroxy gas has been 0.075 and 1 LPM. From the results, it has been possible to demonstrate that POME10% biodiesel causes inefficiency in fuel use due to less homogeneity and greater fuel injection than standard diesel. In general, it has been evidenced that POME10% causes a decrease of 3.3% and 3.8% in fuel pressure and in maximum engine efficiency. However, the presence of hydroxy gas makes it possible to offset these negative effects. Additionally, the combined use of POME10% and hydroxy gas allows a decrease of 8.0%, 9.2%, and 10.1% in CO2, HC, and smoke opacity emissions compared to the engine running only with the engine POME10%. In general, hydroxy gas is a promising alternative to offset the negative effects caused by the use of biodiesel from waste materials such as palm oil mill effluent.