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.     

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.     

Effect of metal based additive on performance emission and combustion characteristics of diesel engine fuelled with biodiesel

This study investigates the use of ferric chloride (FeCl₃) as a fuel borne catalyst (FBC) for waste cooking palm oil based biodiesel. The metal based additive was added to biodiesel at a dosage of 20 μmol/L. Experiments were conducted to study the effect of ferric chloride added to biodiesel on performance, emission and combustion characteristics of a direct injection diesel engine operated at a constant speed of 1500 rpm at different operating conditions. The results revealed that the FBC added biodiesel resulted in a decreased brake specific fuel consumption (BSFC) of 8.6% while the brake thermal efficiency increased by 6.3%. FBC added biodiesel showed lower nitric oxide (NO) emission and slightly higher carbon dioxide (CO₂) emission as compared to diesel. Carbon monoxide (CO), total hydrocarbon (THC) and smoke emission of FBC added biodiesel decreased by 52.6%, 26.6% and 6.9% respectively compared to biodiesel without FBC at an optimum operating condition of 280 bar injection pressure and 25.5^o bTDC injection timing. Higher cylinder gas pressure, heat release rate and shorter ignition delay period were observed with FBC added biodiesel at these conditions.     

Performance, emission and combustion characteristics of biodiesel fuelled variable compression ratio engine

Experiments has been carried out to estimate the performance, emission and combustion characteristics of a single cylinder; four stroke variable compression ratio multi fuel engine fuelled with waste cooking oil methyl ester and its blends with standard diesel. Tests has been conducted using the fuel blends of 20%, 40%, 60% and 80% biodiesel with standard diesel, with an engine speed of 1500 rpm, fixed compression ratio 21 and at different loading conditions. The performance parameters elucidated includes brake thermal efficiency, specific fuel consumption, brake power, indicated mean effective pressure, mechanical efficiency and exhaust gas temperature. The exhaust gas emission is found to contain carbon monoxide, hydrocarbon, nitrogen oxides and carbon dioxide. The results of the experiment has been compared and analyzed with standard diesel and it confirms considerable improvement in the performance parameters as well as exhaust emissions. The blends when used as fuel results in the reduction of carbon monoxide, hydrocarbon, carbon dioxide at the expense of nitrogen oxides emissions. It has found that the combustion characteristics of waste cooking oil methyl ester and its diesel blends closely followed those of standard diesel.     

Potential of biodiesel from waste cooking oil in Mexico

The aim of this study is to evaluate the potential use of biodiesel produced from waste cooking oil (WCO) in Mexico and its CO₂ emission reduction potential for the Mexican transport sector and associated costs. The results show, based on 2010 data, that the potential of biodiesel from WCO is between 7.8 PJ and 17.7 PJ that represent between 1.5% and 3.3% of petro-diesel consumption for the road transport sector and can reduce between 0.51 and 1.02 Mt of CO₂, (1.0%–2.7% of CO₂-associated emissions), depending on the recovery ratio of WCO from vegetable oil consumption for cooking and considering CO₂ emissions for biodiesel production and methanol emissions during production and combustion in the blend. Primary energy used to produce 1 MJ of WCO-biodiesel is 0.8727 MJ, while literature reports 1.2007 MJ to produce 1 MJ of petro-diesel. Biodiesel costs are similar to petro-diesel costs if WCO is free. The paper offers suggestions for policies that promote increased recollection of WCO for biodiesel production and reduced illegal marketing of WCO, which is the main barrier to increase biodiesel production from WCO. The data used for the analysis is based on a case study of a WCO biodiesel plant that operates in Mexico City.     

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.     

Potential of waste palm cooking oil for catalyst-free biodiesel production

Disposal of waste palm cooking oil (WPCO) via an environmental-friendly route is of major importance in the quest for sustainable development. In this study, WPCO was utilized instead of refined vegetable oils as the source of triglycerides for biodiesel production. WPCO contains several impurities, such as water and free fatty acids, which limit its application in catalytic transesterification processes. Consequently, a catalyst-free process using supercritical methanol was employed to investigate the potential of WPCO as an economical feedstock for biodiesel production. The parameters that influence the reaction, including reaction time, temperature and the molar ratio of alcohol to oil, were investigated. For comparison purposes, refined palm oil (RPO) was also subjected to supercritical methanol reaction and it was found that both processes produced comparable optimum yields of 80% at their respective optimum conditions. Hence, it can be concluded that WPCO has high potential as an economical and practical future source of biodiesel.     

Influence of injection timing on performance, emission and combustion characteristics of a DI diesel engine running on waste plastic oil

Environmental concern and availability of petroleum fuels have caused interests in the search for alternate fuels for internal combustion engines. Waste plastics are indispensable materials in the modern world and application in the industrial field is continually increasing. In this context, waste plastics are currently receiving renewed interest. As an alternative, non-biodegradable, and renewable fuel, waste plastic oil is receiving increasing attention. The waste plastic oil was compared with the petroleum products and found that it can also be used as fuel in compression ignition engines. In the present work, the influence of injection timing on the performance, emission and combustion characteristics of a single cylinder, four stroke, direct injection diesel engine has been experimentally investigated using waste plastic oil as a fuel. Tests were performed at four injection timings (23°,20°,17° and 14° bTDC). When compared to the standard injection timing of 23° BTDC the retarded injection timing of 14° bTDC resulted in decreased oxides of nitrogen, carbon monoxide and unburned hydrocarbon while the brake thermal efficiency, carbon dioxide and smoke increased under all the test conditions.     

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.     

Effects of oxyhydrogen on the CI engine fueled with the biodiesel blends: A performance,combustion and emission characteristics study

The main purpose of this study is to analyse the effects of oxy hydrogen (HHO) along with the Moringa oleifera biodiesel blend on engine performance, combustion and emission characteristics. HHO gases were generated using the typical electrolysis process using the potassium hydroxide solution. The experiments were performed under various engine loads of 25%, 50%, 75%, and 100% in a constant speed engine. Biodiesel from the M. oleifera was prepared by the transesterification process. Further, the procured biodiesel blends mixed with neat diesel at the concentration of 20% (B20) and 40% (B40). In addition to above, the HHO gas flow rate to the engine chamber maintained at the flow rate of 0.5 L^-1. The use of the 20% and 40% blends with HHO reported less BTE compared to the neat diesel. However, B20 reported marginal rise in the BTE due to the addition of the HHO gas. On the other hand, addition of HHO gas to the blends significantly dropped the brake specific fuel consumption. With regard to the emissions, addition of the biodiesel blends reduced the concentration of the CO, HC, and CO₂. Nevertheless, no reduction reported in the formation of the NO. However, adding the HHO to the biodiesel reduced the average NOx by 6%, which is a substantial effect. Overall, HHO enriching biodiesel blends are the potential replacement for the existing fossil fuels for its superior fuel properties compared to the conventional diesel.     

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.     

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.     

Hydrogen enriched waste oil biodiesel usage in compression ignition engine

In the present study, hydrogen enrichment for biodiesel-diesel blends was evaluated to investigate the performance and emission characteristics of a compression ignition engine. Biodiesel was obtained from waste oil and blended to pure diesel fuel by volume fraction of 0%, 10% and 20%. After that, pure hydrogen was introduced through the intake air at different flow rates. Effects of pure hydrogen on performance and emission characteristics were investigated by evaluating power, torque, specific fuel consumption, CO, CO₂ and NO_x emissions. Experimental study revealed that waste oil biodiesel usage deteriorated performance and emission parameters except CO emissions. However, the enrichment test fuels with hydrogen fuel can improve performance characteristics and emission parameters, whereas it increased NO_x emissions. Brake thermal efficiency and specific fuel consumption were improved when the test fuels enriched with hydrogen gas. Because of absence of carbon atoms in the chemical structure of the hydrogen fuel, hydrogen addition dropped CO and CO₂ emissions but increment in cylinder temperature caused rising in NO_x emissions.     

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.     

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.     

Emission and performance characteristics of an indirect ignition diesel engine fuelled with waste cooking oil

Biofuel has so far been backed by government policies in the quest for low carbon fuel in the near future and promises to ensure energy security through partially replacing fossil fuels. At present biodiesel is mostly produced by transesterification reaction from oil-seed feedstock and has to conform to ASTM D6751 specifications. Biodiesel sustainability has sparked debate on the pros and cons of biodiesel and the question of food security. The use of waste cooking oil such as palm and coconut oil in diesel engines is more sustainable if they can perform similarly to ordinary diesel fuel (B0). This paper presents the experimental study carried out to evaluate emission and performance characteristics of a multi-cylinder diesel engine operating on waste cooking oil such as 5% palm oil with 95% ordinary diesel fuel (P5) and 5% coconut oil with 95% ordinary diesel fuel (C5). B0 was used for comparison purposes. The results show that there are reductions in brake power of 1.2% and 0.7% for P5 and C5 respectively compared with B0. In addition, reduction of exhaust emissions such as unburned hydrocarbon (HC), smoke, carbon mono-oxide (CO), and nitrogen oxides (NO_x) is offered by the blended fuels.     

Analysis of combustion characteristics,engine performance and exhaust emissions of diesel engine fueled with upgraded waste source fuel

Utilization of the waste products as an alternative fuel could reduce the dependence on fossil fuel. The three types of upgraded waste source fuels discussed in this paper were tire derived fuel (TDF), waste plastic disposal fuel (WPD) and upgraded waste cooking oil (UWCO). The detailed combustion pressure showed that kinematic viscosity and cetane number played an important role in determining the combustion quality. TDF's high kinematic viscosity and low cetane number affected its fuel vaporization process; thus, lengthening its ignition delay. UWCO showed the 14% higher power and 13.8% higher torque compared to diesel fuel (DF). WPD produced the lowest NOx due to its low pressure curve during combustion. TDF had produced the highest exhaust emissions (CO, CO₂, NO and NOx). Particulate matter (PM) emissions by UWCO blends were lower than DF. UWCO's soot concentration was 40% lower than DF and increased to 62.5% from low to high engine speed operation.     

Experimental investigation on diesel engine with diestrol-water micro emulsions

Experiments were conducted on a single cylinder direct injection diesel engine using diesel, biodiesel and biodiesel-diesel-ethanol (diestrol) water micro emulsion fuels to investigate the performance, emission and combustion characteristics of the engine under different load conditions at a constant speed of 1500 rpm. The results indicated that biodiesel and micro emulsion fuels had a higher brake specific fuel consumption (BSFC) than that of diesel. A slight improvement in the brake specific energy consumption (BSEC) was observed for micro emulsion fuels. The brake thermal efficiency of biodiesel and micro emulsion fuels were comparable to that of diesel. The emission characteristics like carbon monoxide (CO), carbon dioxide (CO₂), unburnt hydrocarbon (UHC), nitric oxide (NO) and smoke emissions for biodiesel and micro emulsion fuels were lower than diesel fuel at all load conditions. The cylinder gas pressure of micro emulsion fuels was lower than diesel at low loads but it became almost identical to diesel at medium and full load conditions. The heat release rate for micro emulsion fuels was higher than biodiesel and diesel fuels for all loads. Biodiesel showed shorter ignition delay for the entire load range and the longer ignition delay observed for micro emulsion fuels.     

A perspective on incorporation of glycerin purification process in biodiesel plants using waste cooking oil as feedstock

In biodiesel production through transesterification, glycerin is produced as a valuable co-product. Some biodiesel plants have incorporated a glycerin purification process since the beginning of operations. The objective of this study is to evaluate the benefits of the incorporation of a glycerin purification process to a biodiesel plant where has already been constructed without the initial consideration of including an extra process for glycerin. A cost–benefit analysis is applied to evaluate the potential benefit from the incorporation of this process, in cases of a high plant cost and a low plant cost, with and without a glycerin facility installation. Our results show that the installation of a glycerin purification process could benefit a biodiesel plant through glycerin recovery and a decrease in wastewater treatment cost. The current downward trend in the market price of glycerin could be offset by encouraging the development of new applications for glycerin in order to expand the existing market and to stabilize the market price. However, biodiesel plants using waste cooking oil in Japan still need government subsidy to sustain their business activity.     

The evaluation of a direct injection diesel engine operating with waste cooking oil biodiesel in point of the environmental and enviroeconomic aspects

In this study, the environmental and enviroeconomic analyzes were implemented to the single-cylinder, four-stroke, direct-injection diesel engine operating with diesel fuel, waste cooking oil biodiesel and their blends (B5, B10, B20, and B30) under different fuel injection pressures (170–220 bars) and engine speeds (1000–3200 rpm) and at full load conditions. The environmental and enviroeconomic analyzes results showed that B20 was the worst fuel at the other fuel injection pressures, while diesel fuel was the worst fuel at the original fuel injection pressure. It was determined that B100 gave the best results among the other fuels the entire engine operating conditions.