Performance of a diesel engine fueled by waste cooking oil biodiesel

A direct injection diesel engine fueled by a diesel/biodiesel blend from waste cooking oil up to B100 (a blend of 100% biodiesel content) indicated a combustion efficiency rise by 1.8% at full load. The soot peak volume fraction was reduced by 15.2%, while CO and HC concentrations respectively decreased by 20 and 28.5%. The physical and chemical delay periods respectively diminished by 1.2 and 15.8% for engine noise to pronounce 6.5% reduction. Injection retarding by 5° reduced NO_x to those original levels of B0 (a blend of zero biodiesel content) and combined respective reduction magnitudes of 10 and 7% in CO and HC at 75% load. Increasing the speed reduced CO and HC respectively by 26 and 42% at 2.36 times the droplet average strain rate. By coupling the turbulence model to the spray break-up and chemical kinetics models, increasing the injection pressure simultaneously reduced CO, HC and NO_x at 17% exhaust gas recirculation ratio.     

Effect of injection parameters on the combustion and emission characteristics in a common-rail direct injection diesel engine fueled with waste cooking oil biodiesel

The objective of this paper was to study the effects of the injection pressure and injection timing on the combustion and emission characteristics in a single-cylinder common-rail direct injection (CRDI) diesel engine fueled with waste cooking oil (WCO) biodiesel and commercial diesel fuel. The fuel property including fatty acid composition for the biodiesel were measured and compared with those of the conventional diesel fuel. The engine tests were conducted at two injection pressures (80 and 160 MPa) and different injection timings from −25 to 0 crank angle degree (CAD) after top dead center (aTDC) under two different engine loads. The results showed that the indicated specific fuel consumption (ISFC) with respect to the injection timings of the biodiesel was higher than that of the diesel fuel under all experimental conditions. The peak cylinder pressure and the peak heat release rate of the biodiesel were slightly lower, while the ignition delay was slightly longer under all operating conditions. In terms of emissions, the biodiesel had benefits in reduction of smoke, carbon monoxide (CO), hydrocarbon (HC) emissions especially with high fuel injection pressure. The nitrogen oxide (NO_x) emissions of the biodiesel were relatively higher than those of the diesel under all experimental conditions.     

The effect of biodiesel fuel obtained from waste frying oil on direct injection diesel engine performance and exhaust emissions

In this study, usage of methyl ester obtained from waste frying oil (WFO) is examined as an experimental material. A reactor was designed and installed for production of methyl ester from this kind of oil. Physical and chemical properties of methyl ester were determined in the laboratory. The methyl ester was tested in a diesel engine with turbocharged, four cylinders and direct injection. Gathered results were compared with No. 2 diesel fuel. Engine tests results obtained with the aim of comparison from the measures of torque, power; specific fuel consumptions are nearly the same. In addition, amount of emission such as CO, CO₂, NO_x, and smoke darkness of waste frying oils are less than No. 2 diesel fuel.     

Performance of a common rail diesel engine using biodiesel of waste cooking oil and gasoline blend

High viscosity, high pour point and low volatility are the major application blocks for biodiesel. In this study gasoline is mixed with biodiesel and they can be soluble with each other at any proportion. Combustion and emission characteristics are investigated on a turbocharged, in-line 6-cylinder, common rail diesel engine. Results showed that pour points, viscosities and distillation temperatures obviously decrease with gasoline ratio. Peak combustion pressures of biodiesel/gasoline blend fuels increase slightly. Ignition delays, peak heat release rates and combustion temperatures increase at partial and medium loads. HC and CO emissions increase at partial and medium loads and drop at high loads. NO_X emissions of blend fuels grow by 4.2% and 6.7% compared with biodiesel averagely at 1400r/min, while soot emissions decline by 31.6% and 38.6%. For ultrafine particles (<220 nm), diameters to peak number concentration of blend fuels are smaller than that of biodiesel. Number concentrations decrease by 30% and 49% averagely compared to biodiesel. Especially, gasoline plays a significant reduction role on ultrafine particles at low and medium loads and soot emissions at high loads.     

Experimental investigation of the influence of blending on engine emissions of the diesel engine fueled by mahua biodiesel oil

The present article elaborates on the various emission characteristics of mahua oil with diesel fuel in a diesel engine at various blending conditions. Experimental investigation results are studied for various parameters such as exhaust emission of carbon monoxide (CO), hydrocarbon (HC), and oxides of nitrogen (NO) gases and exhaust gas temperature. Results show that residual oxygen, CO, HC, and NO emission were the lowest for mahua biodiesel compared with diesel. The experimental results proved that the use of mahua oil biodiesel as fuel in the diesel engine is a viable alternative to diesel fuel. Mahua biodiesel oil may be beneficial in decreasing greenhouse gas emissions without any engine modification. Mahua oil has the possibility of becoming a sustainable fuel source as biodiesel.     

Exergy analysis of small DI diesel engine fueled with waste cooking oil biodiesel

ABSTRACT

This study investigates the merits of exergy analysis over energy analysis for small direct injection (DI) diesel engine using the blend of waste cooking oil biodiesel and petroleum diesel. Taguchi’s “L’ 16” orthogonal array has been used for the design of experiment. The engine tested at different engine speeds, load percentages, and blend ratios, using the waste cooking oil biodiesel. Basic performance parameters and fuel input exergy, exergetic efficiency (second law efficiency), exergy associated with heat transfer, exergy associated with the exhaust gas and destruction of exergy are calculated for each blend of waste cooking oil biodiesel and diesel. Results show that the optimum operating conditions for minimum brake-specific fuel consumption (BSFC) and exergy destruction are achieved when engine speed at 1900 rev/min, load percentage is 75%, and the engine is fueled with B40.     

Performance characteristics of a low heat rejection diesel engine operating with biodiesel

Vegetable oils are a promising alternative among the different diesel fuel alternatives. However, the high viscosity, poor volatility and cold flow characteristics of vegetable oils can cause some problems such as injector coking, severe engine deposits, filter gumming, piston ring sticking and thickening of lubrication oil from long-term use in diesel engines. These problems can be eliminated or minimized by transesterification of the vegetable oils to form monoesters. These monoesters are known as biodiesel. The important advantages of biodiesel are lower exhaust gas emissions and its biodegradability and renewability compared with petroleum-based diesel fuel. Although the transesterification improves the fuel properties of vegetable oil, the viscosity and volatility of biodiesel are still worse than that of petroleum diesel fuel. The energy of the biodiesel can be released more efficiently with the concept of low heat rejection (LHR) engine. The aim of this study is to apply LHR engine for improving engine performance when biodiesel is used as an alternative fuel. For this purpose, a turbocharged direct injection (DI) diesel engine was converted to a LHR engine and the effects of biodiesel (produced from sunflower oil) usage in the LHR engine on its performance characteristics have been investigated experimentally. The results showed that specific fuel consumption and the brake thermal efficiency were improved and exhaust gas temperature before the turbine inlet was increased for both fuels in the LHR engine.     

Experimental investigation of the performance and emissions of a heavy-duty diesel engine fueled with waste cooking oil biodiesel/ultra-low sulfur diesel blends

The major obstacle to biodiesel commercialization is the high cost of raw materials. Biodiesel from waste cooking oil is an economical source and thus an effective strategy for reducing the raw material cost. Using waste cooking oil also solves the problem of waste oil disposal. This study investigated the emissions of polycyclic aromatic hydrocarbons (PAHs), carcinogenic potencies and regulated matters, and brake specific fuel consumption from a heavy-duty diesel engine under the US-HDD transient cycle for five test fuels: ultra-low sulfur diesel (ULSD), WCOB5 (5 vol% biodiesel made from waste cooking oil + 95 vol% ULSD), WCOB10, WCOB20, and WCOB30. Experimental results indicate using ULSD/WCOB blends decreased PAHs by 7.53%-37.5%, particulate matter by 5.29%-8.32%, total hydrocarbons by 10.5%-36.0%, and carbon monoxide by 3.33%-13.1% as compared to using ULSD. The wide usage of WCOB blends as alternative fuels could protect the environment.     

Study on combustion characteristics and particulate emissions of a common-rail diesel engine fueled with n-butanol and waste cooking oil blends

Biodiesel is a promising alternative fuel because of its renewability and extensive source of raw materials. Butanol can be blended in biodiesel to reduce the kinematic viscosity and promote the fuel atomization. In this respect, biodiesel was blended with 10% and 20% n-butanol, and the combustion characteristics and particulate emissions of the fuel blends were tested in a turbocharged, 6-cylinder, common rail diesel engine at a constant speed of 1400 rpm under seven engine loads. The experimental results show that under various engine loads, all of the butanol and biodiesel fuel blends provide faster combustion than diesel due to the higher oxygen content of n-butanol and the lower cetane number of butanol which results in stronger premixed combustion. The addition of butanol is beneficial to concentrating the heat release and thus shorten the combustion duration. With an increased proportion of butanol, soot emissions of butanol and biodiesel fuel blends decrease, the number concentration and volume concentration of ultrafine particles (UFPs) reduce noticeably. Meanwhile, the geometric mean diameters of UFPs decrease with an increase in butanol. With an increase of the engine loads, the number concentration peaks of UFPs gradually transfer from the size range of nucleation mode particles (NMPs) to the size range of accumulation mode particles (AMPs) due to the elevated combustion temperatures and high equivalence ratios. Moreover, biodiesel and fuel blends exhibit a higher percentage of NMPs as compared to diesel because of the fuel-bound oxygen, zero aromatics, and low sulfides.     

Effects of Fischer-Tropsch diesel fuel on combustion and emissions of direct injection diesel engine

Effects of Fischer-Tropsch (F-T) diesel fuel on the combustion and emission characteristics of a single-cylinder direct injection diesel engine under different fuel delivery advance angles were investigated. The experimental results show that F-T diesel fuel exhibits shorter ignition delay, lower peak values of premixed burning rate, lower combustion pressure and pressure rise rate, and higher peak value of diffusion burning rate than conventional diesel fuel when the engine remains unmodified. In addition, the unmodified engine with F-T diesel fuel has lower brake specific fuel consumption and higher effective thermal efficiency, and presents lower HC, CO, NO _x and smoke emissions than conventional diesel fuel. When fuel delivery advance angle is retarded by 3 crank angle degrees, the combustion duration is obviously shortened; the peak values of premixed burning rate, the combustion pressure and pressure rise rate are further reduced; and the peak value of diffusion burning rate is further increased for F-T diesel fuel operation. Moreover, the retardation of fuel delivery advance angle results in a further significant reduction in NO _x emissions with no penalty on specific fuel consumption and with much less penalty on HC, CO and smoke emissions. __________ Translated from Chinese Internal Combustion Engine Engineering, 2007, 28(2): 19–23 [译自: 内燃机工程]     

Optimization of heterogeneous biodiesel production from waste cooking palm oil via response surface methodology

Heterogeneous transesterification of waste cooking palm oil (WCPO) to biodiesel over Sr/ZrO₂ catalyst and the optimization of the process have been investigated. Response surface methodology (RSM) was employed to study the relationships of methanol to oil molar ratio, catalyst loading, reaction time, and reaction temperature on methyl ester yield and free fatty acid conversion. The experiments were designed using central composite by applying 2⁴ full factorial designs with two centre points. Transesterification of WCPO produced 79.7% maximum methyl ester yield at the optimum methanol to oil molar ratio = 29:1, catalyst loading = 2.7 wt%, reaction time = 87 min and reaction temperature = 115.5 °C.     

Tribological behavior of diesel/biodiesel blend from waste cooking oil and ethanol

One kind of novel biodiesel waste cooking oil ethyl ester (WCOEE) was prepared via transesterfication reaction between waste cooking oil and ethanol. The tribological behavior of diesel/WCOEE blend was evaluated with a four-ball tribometer. The wear resistance, extreme pressure, and friction reduction of the blend were improved with increasing WCOEE. The optimal content of WCOEE in the blend was 20 vol%. It was also found that free fatty acids (FFAs) had a positive effect on the wear resistance of blend. The lubrication improvement of the blend was ascribed to the formation of polyester film and high polarity of fatty acid ethyl ester.     

Impact of waste cooking oil in biodiesel blends on particle size distributions from a city-car engine

Using biodiesel as a blending component in diesel engine has demonstrated to reduce hydrocarbon and particulate matter emissions. Literature showed that biodiesel type, engine architecture and test conditions deeply affect performance and emission characteristics. Among suitable biodiesel fuels, waste cooking oil (WCO) is considered very attractive due to the reduced environmental impact without sacrificing engine performance.This paper aims at investigating how mixing ratio of biodiesel from WCO and mineral diesel affects the particle size distributions of a current state of art small displacement diesel engine.Experimental tests have been performed on an up-to date light common rail diesel engine. Its complete operative field has been investigated. The results obtained show that the use of biodiesel blends from WCO reduces the total number of particles emitted from the engine with respect to the diesel fuel; the reduction is more evident as the percentage of biodiesel in the blend increases. The number of particles in WCO biodiesel soot with diameter smaller than 10 nm is reduced as compared to diesel fuel; the same trend is observed for diameters larger than 200 nm; comparable particle numbers were obtained in the ultrafine range (Dp < 100 nm).     

Combustion and performance evaluation of a diesel engine fueled with biodiesel produced from soybean crude oil

In this study, the biodiesel produced from soybean crude oil was prepared by a method of alkaline-catalyzed transesterification. The important properties of biodiesel were compared with those of diesel. Diesel and biodiesel were used as fuels in the compression ignition engine, and its performance, emissions and combustion characteristics of the engine were analyzed. The results showed that biodiesel exhibited the similar combustion stages to that of diesel, however, biodiesel showed an earlier start of combustion. At lower engine loads, the peak cylinder pressure, the peak rate of pressure rise and the peak of heat release rate during premixed combustion phase were higher for biodiesel than for diesel. At higher engine loads, the peak cylinder pressure of biodiesel was almost similar to that of diesel, but the peak rate of pressure rise and the peak of heat release rate were lower for biodiesel. The power output of biodiesel was almost identical with that of diesel. The brake specific fuel consumption was higher for biodiesel due to its lower heating value. Biodiesel provided significant reduction in CO, HC, NO_x and smoke under speed characteristic at full engine load. Based on this study, biodiesel can be used as a substitute for diesel in diesel engine.     

Competitiveness,role, and impact of microalgal biodiesel in the global energy future

This paper examines the competitiveness, role, and impact of microalgal biodiesel in the 21st century using a global energy system model with a detailed technological representation. The major conclusions are the following. First, the competitiveness of microalgal biodiesel decreases as CO₂ stabilization constraints become more stringent. The share of microalgal biodiesel and renewable jet fuel produced from it in total global final energy consumption over the time horizon 2010–2100 is 5.1% in the case without CO₂ constraints compared with 3.9% and 0.7% in the case of CO₂ stabilization at 550 ppmv and 400 ppmv, respectively. This is because production and combustion of microalgal biodiesel release as much CO₂ as is captured from anthropogenic sources and assimilated by microalgae and because CO₂ prices raised by stringent CO₂ stabilization constraints make the economics of microalgal biodiesel unattractive. Second, the competitiveness of microalgal biodiesel is also greatly affected by microalgal production cost and microalgal lipid yield. Under a 400 ppmv CO₂ stabilization constraint, a 50% microalgal production cost decrease leads to increase in total global microalgal biodiesel production over the time horizon by a factor of 6.5, while a 50% microalgal lipid yield increase leads to increase in it by a factor of 4.5. Third, microalgal biodiesel plays an important role in satisfying the energy demand in the transport sector, thereby replacing petroleum products and Fischer–Tropsch synfuels. An increasing proportion of microalgal biodiesel is converted into renewable jet fuel over time to be used as a fuel for aircraft. Fourth, either without CO₂ constraints or under the 550 ppmv CO₂ stabilization constraint, the participation of microalgal biodiesel in the global energy market would have a large impact on the global energy supply and consumption structure. This is not only because of its substitution for other forms of final energy, but also because of the need to satisfy the demand for CO₂ for microalgal production.     

Emission analysis of different blends of karanja biodiesel with producer gas in a twin cylinder diesel engine in dual fuel mode

The present study demonstrates the emission analysis of different blends of Karanja biodiesel and diesel with producer gas in dual fuel mode using a twin cylinder diesel engine for two cases of operations. In case 1, a test is carried out using the above test fuels both in single mode and dual fuel mode operation with a constant gas flow rate of 21.49 Kg/h under different load conditions. Similarly, in case 2, a test is performed at a constant load of 10 kW under different gas flow rates using the same test fuels in the dual fuel mode only. The study reveals that all blended fuels show better emissions compared to diesel in both cases of operations. Dual fuel mode operation of all tested fuels shows lower smoke and oxide of nitrogen emissions compared to their single mode operation under all load conditions, whereas other emission parameters are found to be on the higher side.     

Experimental investigations on the effect of fuel injection parameters on diesel engine fuelled with biodiesel blend in diesel with hydrogen enrichment

Fuel injection pressure and injection timing are two extensive injection parameters that affect engine performance, combustion, and emissions. This study aims to improve the performance, combustion, and emissions characteristics of a diesel engine by using karanja biodiesel with a flow rate of 10 L per minute (lpm) of enriched hydrogen. In addition, the research mainly focused on the use of biodiesel with hydrogen as an alternative to diesel fuel, which is in rapidly declining demand. The experiments were carried out at a constant speed of 1500 rpm on a single-cylinder, four-stroke, direct injection diesel engine. The experiments are carried out with variable fuel injection pressure of 220, 240, and 260 bar, and injection timings of 21, 23, and 25 °CA before top dead center (bTDC). Results show that karanja biodiesel with enriched hydrogen (KB20H10) increases BTE by 4% than diesel fuel at 240 bar injection pressure and 23° CA bTDC injection timing. For blend KB20H10, the emissions of UHC, CO, and smoke opacity are 33%, 16%, and 28.7% lower than for diesel. On the other hand NOx emissions, rises by 10.3%. The optimal injection parameters for blend KB20H10 were found to be 240 bar injection pressure and 23 °CA bTDC injection timing based on the significant improvement in performance, combustion, and reduction in exhaust emissions.     

Performance, emissions and heat release characteristics of direct injection diesel engine operating on diesel oil emulsion

Emulsions of diesel and water are often promoted as being able to overcome the difficulty of simultaneously reducing emissions of both oxidises of nitrogen (NO_x) and particulate matter from diesel engines. In this paper we present measurements of the performance and NO_x and hydrocarbon emissions of a diesel engine operating on a typical diesel oil emulsion and examine through the use of heat release analysis differences found during its combustion relative to standard diesel in the same engine. While producing similar or greater thermal efficiency and improved NO_x and hydrocarbon emission outcomes, use of the emulsion also results in an increase in brake specific fuel consumption. Use of the emulsion is also shown to result in a retarded fuel injection, but smaller ignition delay for the same engine timing. As a result of these changes, cylinder pressures and temperatures are lower.     

Effect of straight vegetable oil blends and biodiesel blends on wear of mechanical fuel injection equipment of a constant speed diesel engine

Vegetable oils and biodiesel have emerged as strong alternative fuels worldwide. However use of new fuels in existing engines leads to issues such as wear of vital moving components, and fuel injection equipment (FIE). It is important to ensure that new alternative fuel does not affect the FIE adversely. In this experimental study, a non-firing engine FIE simulator test rig prototype was developed and 250 h endurance test of FIE was performed with an objective to ensure the long-term compatibility and durability of biofuel blends. The components of FIE such as plunger, nozzle needle, valve, and valve holder were investigated for wear. Test fuels used in this study were Karanja blends (K20, K5), Jatropha blends (J20, J5), Biodiesel blends (B20, B5) and baseline mineral diesel in a non-firing engine FIE simulator. The compatibility of FIE with test fuels in terms of dimensional loss, weight loss and surface texture variations using optical microscopy before and after the endurance test was compared. Biodiesel blends showed relatively lower wear compared to mineral diesel however SVO blends showed no definite trend of the wear results compared to baseline mineral diesel.     

Influence of biodiesel on engine combustion and emission characteristics

This paper discusses the influence of biodiesel on the engine combustion characteristics. The considered fuel is neat biodiesel from rapeseed oil. The considered engine is a bus diesel engine with injection M system. The engine characteristics are obtained by experiments and numerical simulation. The results obtained with biodiesel are compared to those obtained with mineral diesel under various operating regimes. In this way, the influences of biodiesel usage on the injection pressure, injection timing, ignition delay, in-cylinder gas pressure and temperature, heat release rate, exhaust gas temperatures, harmful emissions, specific fuel consumption, and on engine power are analyzed. Furthermore, the relationships among fuel properties, injection and combustion characteristics, harmful emissions, and other engine performance are determined. Special attention is given to possible explanations of higher NO_x emission in spite of lower in-cylinder gas temperature.