Emission reduction potential of using gas-to-liquid and dimethyl ether fuels on a turbocharged diesel engine

A study of engine performance characteristics and both of regulated (CO, HC, NO_x, and smoke) and unregulated (ultrafine particle number, mass concentrations and size distribution) emissions for a turbocharged diesel engine fueled with conventional diesel, gas-to-liquid (GTL) and dimethyl ether (DME) fuels respectively at different engine loads and speeds have been carried out. The results indicated that fuel components significantly affected the engine performance and regulated/unregulated emissions. GTL exhibited almost the same power and torque output as diesel, while improved fuel economy. GTL significantly reduced regulated emissions with average reductions of 21.2% in CO, 15.7% in HC, 15.6% in NO_x and 22.1% in smoke in comparison to diesel, as well as average reductions in unregulated emissions of total ultrafine particle number (N_tot) and mass (M_tot) emissions by 85.3% and 43.9%. DME can significantly increase torque and power, compared with the original diesel engine, as well as significantly reduced regulated emissions of 40.1% in HC, 48.2% in NO_x and smoke free throughout all the engine conditions. However, N_tot for DME is close to that for diesel. The reason is that the accumulation mode particle number emissions for DME are very low due to the characteristics of oxygen content and no C-C bond, which promotes the processes of nucleation and condensation of the semi-volatile compounds in the exhaust gas, as a result, a lot of nucleation mode particles produce.     

Emission reduction from diesel engine using fumigation methanol and diesel oxidation catalyst

This study is aimed to investigate the combined application of fumigation methanol and a diesel oxidation catalyst for reducing emissions of an in-use diesel engine. Experiments were performed on a 4-cylinder naturally-aspirated direct-injection diesel engine operating at a constant speed of 1800 rev/min for five engine loads.The experimental results show that at low engine loads, the brake thermal efficiency decreases with increase in fumigation methanol; but at high loads, it slightly increases with increase in fumigation methanol. The fumigation method results in a significant increase in hydrocarbon (HC), carbon monoxide (CO), and nitrogen dioxide (NO₂) emissions, but decrease in nitrogen oxides (NO_x), smoke opacity and the particulate mass concentration. For the submicron particles, the total number of particles decreases. In all cases, there is little change in geometrical mean diameter of the particles. After catalytic conversion, the HC, CO, NO₂, particulate mass and particulate number concentrations were significantly reduced at medium to high engine loads; while the geometrical mean diameter of the particles becomes larger. Thus, the combined use of fumigation methanol and diesel oxidation catalyst leads to a reduction of HC, CO, NO_x, particulate mass and particulate number concentrations at medium to high engine loads.     

Experimental study on particulate and NOx emissions of a diesel engine fueled with ultra low sulfur diesel, RME-diesel blends and PME-diesel blends

Ultra low sulfur diesel and two different kinds of biodiesel fuels blended with baseline diesel fuel in 5% and 20% v/v were tested in a Cummins 4BTA direct injection diesel engine, with a turbocharger and an intercooler. Experiments were conducted under five engine loads at two steady speeds (1500 rpm and 2500 rpm). The study aims at investigating the engine performance, NO_x emission, smoke opacity, PM composition, PM size distribution and comparing the impacts of low sulfur content of biodiesel with ULSD on the particulate emission. The results indicate that, compared to base diesel fuel, the increase of biodiesel in blends could cause certain increase in both brake specific fuel consumption and brake thermal efficiency. Compared with baseline diesel fuel, the biodiesel blends bring about more NO_x emissions. With the proportion of biodiesel increase in blends, the smoke opacity decreases, while total particle number concentration increases. Meanwhile the ULSD gives lower NO_x emissions, smoke opacity and total number concentration than those of baseline diesel fuel. In addition, the percentages of SOF and sulfate in particulates increase with biodiesel in blends, while the dry soot friction decreases obviously. Compared with baseline diesel fuel, the biodiesel blends increase the total nucleation number concentration, while ULSD reduces the total nucleation number concentration effectively, although they all have lower sulfur content. It means that, for ULSD, the lower sulfur content is the dominant factor for suppressing nucleation particles formation, while for biodiesel blends, lower volatile, lower aromatic content and higher oxygen content of biodiesel are key factors for improving the nucleation particles formation. The results demonstrate that the higher NO_x emission and total nucleation number concentration are considered as the big obstacles of the application of biodiesel in diesel engine.     

Experimental investigation on regulated and unregulated emissions of a diesel engine fueled with ultra-low sulfur diesel fuel blended with biodiesel from waste cooking oil

Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultra-low sulfur diesel, bi oesel and their blends, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev/min. Blended fuels containing 19.6%, 39.4%, 59.4% and 79.6% by volume of biodiesel, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. Biodiesel used in this study was converted from waste cooking oil.The following results are obtained with an increase of biodiesel in the fuel. The brake specific fuel consumption and the brake thermal efficiency increase. The HC and CO emissions decrease while NO_x and NO₂ emissions increase. The smoke opacity and particulate mass concentrations reduce significantly at high engine load. In addition, for submicron particles, the geometry mean diameter of the particles becomes smaller while the total number concentration increases. For the unregulated gaseous emissions, generally, the emissions of formaldehyde, 1,3-butadiene, toluene, xylene decrease, however, acetaldehyde and benzene emissions increase.The results indicate that the combination of ultra-low sulfur diesel and biodiesel from waste cooking oil gives similar results to those in the literature using higher sulfur diesel fuels and biodiesel from other sources.     

Emissions characteristics of a diesel engine operating on biodiesel and biodiesel blended with ethanol and methanol

Euro V diesel fuel, pure biodiesel and biodiesel blended with 5%, 10% and 15% of ethanol or methanol were tested on a 4-cylinder naturally-aspirated direct-injection diesel engine. Experiments were conducted under five engine loads at a steady speed of 1800 r/min. The study aims to investigate the effects of the blended fuels on reducing NO_x and particulate. On the whole, compared with Euro V diesel fuel, the blended fuels could lead to reduction of both NO_x and PM of a diesel engine, with the biodiesel-methanol blends being more effective than the biodiesel-ethanol blends. The effectiveness of NO_x and particulate reductions is more effective with increase of alcohol in the blends. With high percentage of alcohol in the blends, the HC, CO emissions could increase and the brake thermal efficiency might be slightly reduced but the use of 5% blends could reduce the HC and CO emissions as well. With the diesel oxidation catalyst (DOC), the HC, CO and particulate emissions can be further reduced.     

Effect of intake air oxygen enrichment for improving engine performance and emissions control in diesel engine

Stringent emission regulations and health awareness about air pollution have led researchers to find alternative means of minimising emissions in diesel engines. In this article, the influence of oxygen enrichment is discussed to determine the effect on diesel engine performance, emission characteristics and combustion characteristics. Normal diesel and oxygen-enriched diesel are used in this experiment. The increase in oxygen concentration led to complete combustion, producing higher thermal efficiency and low harmful emissions. From the results, it is noted that oxygen-enriched diesel fuel showed reduction of CO, HC and smoke emissions, while NOx emission increased.

Abbreviations/Nomenclature DI: direct injection; NOx: oxides of nitrogen; O₂: oxygen; HC: hydrocarbon; PM: particulate matters; CO: carbon monoxide; CO₂: carbon dioxide     

Experimental investigation on the performance, gaseous and particulate emissions of a methanol fumigated diesel engine

Experiments were conducted on a 4-cylinder direct-injection diesel engine with fumigation methanol injected into the air intake of each cylinder. The fumigation methanol was injected to top up 10%, 20% and 30% of the power output under different engine operating conditions. The effects of fumigation methanol on engine performance, gaseous emissions and particulate emission were investigated. The experimental results show that there is a decrease in the brake thermal efficiency when fumigation methanol is applied, except at the highest load of 0.67 MPa. At low loads, the brake thermal efficiency decreases with increase in fumigation methanol; but at high loads, it increases with increase in fumigation methanol. The fumigation method results in a significant increase in hydrocarbon (HC), carbon monoxide (CO), and nitrogen dioxide (NO(2)) emissions. The concentration of nitrogen oxides (NOx) is significantly reduced except at close to full load condition. There is also a reduction in the smoke opacity and the particulate matter (PM) mass concentration. For the submicron particles, the total number of particles decreases at low and medium loads but increases at high loads. In all cases, there is a shift of the particles towards smaller geometrical mean diameter, especially at high loads. The increase in nano-sized particles and the increase in NO(2) emission could have serious impact on human health.     

Effects of methanol-containing additive on emission characteristics from a heavy-duty diesel engine.

This study was aimed to investigate the effect of methanol-containing additive (MCA) on the regulated emissions of hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), as well as the unregulated carbon dioxide (CO2) and polycyclic aromatic hydrocarbons (PAHs) from a diesel engine. The engine was tested on a series of diesel fuels blended with five additive levels (0, 5, 8, 10 and 15% of MCA by volume). Emissions tests were performed under both cold- and hot-start transient heavy-duty federal test procedure (HD-FTP) cycles and two selected steady-state modes. Results show that MCA addition slightly decreases PM emissions but generally increases both THC and CO emissions. Decrease in NOx emissions was found common in all MCA blends. As for unregulated emissions, CO2 emissions did not change significantly for all MCA blends, while vapor-phase and particle-associated PAHs emissions in high load and transient cycle tests were relatively low compared to the base diesel when either 5 or 8% MCA was used. This may be attributed to the lower PAHs levels in MCA blends. Finally, the particle-associated PAHs emissions also showed trends quite similar to that of the PM emissions in this study.     

Particle and gaseous emissions from compressed natural gas and ultralow sulphur diesel-fuelled buses at four steady engine loads

Exhaust emissions from thirteen compressed natural gas (CNG) and nine ultralow sulphur diesel in-service transport buses were monitored on a chassis dynamometer. Measurements were carried out at idle and at three steady engine loads of 25%, 50% and 100% of maximum power at a fixed speed of 60 km h^− 1. Emission factors were estimated for particle mass and number, carbon dioxide and oxides of nitrogen for two types of CNG buses (Scania and MAN, compatible with Euro 2 and 3 emission standards, respectively) and two types of diesel buses (Volvo Pre-Euro/Euro1 and Mercedez OC500 Euro3). All emission factors increased with load. The median particle mass emission factor for the CNG buses was less than 1% of that from the diesel buses at all loads. However, the particle number emission factors did not show a statistically significant difference between buses operating on the two types of fuel. In this paper, for the very first time, particle number emission factors are presented at four steady state engine loads for CNG buses. Median values ranged from the order of 10¹² particles min^− 1 at idle to 10¹⁵ particles km^− 1 at full power. Most of the particles observed in the CNG emissions were in the nanoparticle size range and likely to be composed of volatile organic compounds The CO₂ emission factors were about 20% to 30% greater for the diesel buses over the CNG buses, while the oxides of nitrogen emission factors did not show any difference due to the large variation between buses.     

Effects of ethanol-blended gasoline on air pollutant emissions from motorcycle

The effect of ethanol-gasoline blends on criteria air pollutant emissions was investigated in a four-stroke motorcycle. The ethanol was blended with unleaded gasoline in four percentages (3, 10, 15, and 20% v/v) and controlled at a constant research octane number, RON (95), to accurately represent commercial gasoline. CO, THC, and NOx emissions were evaluated using the Economic Commission for Europe cycle on the chassis dynamometers. The results of the ethanol-gasoline blends were compared to those of commercial unleaded gasoline with methyl tert-butyl ether as the oxygenated additive. In general, the exhaust CO and NOx emissions decreased with increasing oxygen content in fuels. In contrast, ethanol added in the gasoline did not reduce the THC emissions for a constant RON gasoline. The 15% ethanol blend had the highest emission reductions relative to the reference fuel. The high ethanol-gasoline blend ratio (20%) resulted in a less emission reduction than those of low ratio blends (< 15%). This may be attributed to the changes in the combustion conditions in the carburetor engine with 20% ethanol addition. Furthermore, the influence of ethanol-gasoline blends on the reduction of exhaust emissions was observed at different driving modes, especially at 15 km/h cruising speed for CO and THC and acceleration stages for NOx.     

Investigation on the gaseous and particulate emissions of a compression ignition engine fueled with diesel-dimethyl carbonate blends

The effect of dimethyl carbonate (DMC) on the gaseous and particulate emissions of a diesel engine was investigated using Euro V diesel fuel blended with different proportions of DMC. Combustion analysis shows that, with the blended fuel, the ignition delay and the heat release rate in the premixed combustion phase increase, while the total combustion duration and the fuel consumed in the diffusion combustion phase decrease. Compared with diesel fuel, with an increase of DMC in the blended fuel, the brake thermal efficiency is slightly improved but the brake specific fuel consumption increases. On the emission side, CO increases significantly at low engine load but decreases at high engine load while HC decreases slightly. NO_x reduces slightly but the reduction is not statistically significant, while NO₂ increases slightly. Particulate mass and number concentrations decrease upon using the blended fuel while the geometric mean diameter of the particles shifts towards smaller size. Overall speaking, diesel-DMC blends lead to significant improvement in particulate emissions while the impact on CO, HC and NO_x emissions is small.     

The effect of exhaust gas recirculation on performance and emission characteristics of HCCI engine

In this work, performance and emission characteristics tests are conducted on homogeneous charge compression ignition (HCCI)-mode engine using mango seed methyl ester. And also the effect of exhaust gas recirculation (EGR) on performance and emission of HCCI engine is analysed. The three different percentages of EGR were added with intake fresh air at 15%, 30% and 45%. The objective of this work is to obtain the optimum EGR percentage based on engine performance and emissions. The brake thermal efficiency (BTE) slightly increased than conventional unmodified direct injection (DI) diesel engine. 15% of EGR shows higher BTE than other percentages of EGR added with HCCI engine. Specific fuel consumption of HCCI-mode engine is lower than the normal diesel engine. The exhaustion of harmful emission of oxides of nitrogen has been reduced when biodiesel is used in HCCI-mode engine. However, smoke and CO emissions were reduced in HCCI-mode engine compared with DI diesel engine and further decreased by using EGR in HCCI-mode engine. HC emissions are slightly increased for HCCI-mode engine.     

Experimental investigation of engine emissions with marine gas oil-oxygenate blends

This paper investigates the diesel engine performance and exhaust emissions with marine gas oil-alternative fuel additive. Marine gas oil (MGO) was selected as base fuel for the engine experiments. An oxygenate, diethylene glycol dimethyl ether (DGM), and a biodiesel (BD) jatropha oil methyl ester (JOME) with a volume of 10% were blended with the MGO fuel. JOME was derived from inedible jatropha oil. Lower emissions with diesel-BD blends (soybean methyl ester, rapeseed methyl ester etc.) have been established so far, but the effect of MGO-BD (JOME) blends on engine performance and emissions has been a growing interest as JOME (BD) is derived from inedible oil and MGO is frequently used in maritime transports. No phase separation between MGO-DGM and MGO-JOME blends was found. The neat MGO, MGO-DGM and MGO-JOME blends are termed as MGO, Ox10 and B10 respectively. The experiments were conducted with a six-cylinder, four-stroke, turbocharged, direct-injection Scania DC 1102 (DI) diesel engine. The experimental results showed significant reductions in fine particle number and mass emissions, PM and smoke emissions with Ox10 and B10 fuels compared to the MGO fuel. Other emissions including total unburned hydrocarbon (THC), carbon monoxide (CO) and engine noise were also reduced with the Ox10 and B10 fuels, while maintaining similar brake specific fuel consumption (BSFC) and thermal efficiency with MGO fuel. Oxides of nitrogen (NOx) emissions, on the other hand, were slightly higher with the Ox10 and B10 fuels at high engine load conditions.     

Experimental investigation on regulated and unregulated emissions of a diesel/methanol compound combustion engine with and without diesel oxidation catalyst

The use of methanol in combination with diesel fuel is an effective measure to reduce particulate matter (PM) and nitrogen oxides (NOx) emissions from in-use diesel vehicles. In this study, a diesel/methanol compound combustion (DMCC) scheme was proposed and a 4-cylinder naturally-aspirated direct-injection diesel engine modified to operate on the proposed combustion scheme. The effect of DMCC and diesel oxidation catalyst (DOC) on the regulated emissions of total hydrocarbons (THC), carbon monoxide (CO), NOx and PM was investigated based on the Japanese 13 Mode test cycle. Certain unregulated emissions, including methane, ethyne, ethene, 1,3-butadiene, BTX (benzene, toluene, xylene), unburned methanol and formaldehyde were also evaluated based on the same test cycle. In addition, the soluble organic fraction (SOF) in the particulate and the particulate number concentration and size distribution were investigated at certain selected modes of operation. The results show that the DMCC scheme can effectively reduce NOx, particulate mass and number concentrations, ethyne, ethene and 1,3-butadiene emissions but significantly increase the emissions of THC, CO, NO₂, BTX, unburned methanol, formaldehyde, and the proportion of SOF in the particles. After the DOC, the emission of THC, CO, NO₂, as well as the unregulated gaseous emissions, can be significantly reduced when the exhaust gas temperature is sufficiently high while the particulate mass concentration is further reduced due to oxidation of the SOF.     

Influence of injection timing on engine performance,emission characteristics of Mimusops Elangi methyl ester

ABSTRACT

The improvement in engine performance and exhaust emissions reduction are the major important issues in developing a more efficient engine. The injection timing is one the major parameters that affect the engine performance and emissions for a diesel engine. The present work focused on characterising the in?uence of injection timing on engine performance and exhaust emissions. This has been critically investigated for B20?+?25?ppm (20% Mimusops Elangi methyl ester-80% diesel fuel?+?25?ppm of TiO₂ nanoparticle) additive as alternative fuel. The B20?+25 ppm TiO₂ nanoparticle additive produces more HC and CO emission, but reduce NO_X emission when injection timing is retarded. Advancement in injection timing for B20?+25?ppm TiO₂ nanoparticle additive results in an increase of brake thermal efficiency, decreases brake specific fuel consumption and giving out less HC, CO, smoke emissions but the marginal increase in the NO_X emission.     

Performance and emission characteristics of cashew nut shell oil on the CI engine

This article is an effort to address the need for a non-cooking oil-based biodiesel. Here, the experimental work is done on a single cylinder, direct injection CI engine using cashew nut shell oil biodiesel blends under constant speed. The cashew nut shell liquid (CNSL) biodiesel is blended with the diesel fuel and used as biodiesel blend. Blends used for testing are B20, B40 and B60. The effect of the fuels on engine power, brake thermal efficiency (BTE) and exhaust gas temperature was determined by performance tests. The influences of blends on CO, CO₂, HC and NO_x emissions were investigated by emission tests. The BTE values of biodiesel are closer to diesel. Compared to diesel, all the biodiesel blends gave lesser unburnt hydrocarbon (HC), carbon monoxide (CO) and smoke emissions. Slightly higher NO_x emissions were found in CNSL biodiesel blends, which is typical of the other biodiesels.     

柴油叉车排气污染分析与控制

柴油叉车使用过程中会产生NOx、CO、HC等有害气体及各种颗粒物（如碳烟、油雾、润滑油和油料添加剂粒子）和少量硫化物,其排放量与进气系统、燃油系统、曲柄连杆机构、冷却系统、柴油的品质、柴油机的转速与负荷等有关。这些有害成分不仅污染环境,而且严重危害人体健康,应采取技术措施对其进行严格控制。     

Energy consumption and exhaust emissions in mechanized timber harvesting operations in Sweden

The study presents an estimation of the energy input and the amount of emissions to air due to fuel, chainsaw and hydraulic oil consumption by heavy duty diesel engine vehicles operating in forest logging operations in Sweden. Exhaust concentrations are given for carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons and particulate matter. Three fuel types (rapeseed methyl ester, environmental class 1 and environmental class 3 diesel fuels) and two types of lubricating base oil (mineral- and vegetable-based) were examined. Energy input per unit of timber production (m3ub) was 82 MJ, 11% of which was due to energy consumption during the production phase of the fuel. Emissions during the whole life cycle of the fuels and the base oils are included in the study. The highest CO2 and NOx emissions occurred when rapeseed methyl ester was used as fuel together with rapeseed as base oil for chainsaw and hydraulic oil. The highest HC and CO emissions occurred when environmental class 3 diesel fuel was used.     

Bio-ethanol additive effect on direct injection diesel engine performance,emission and combustion characteristics – an experimental examination

ABSTRACT

The present investigation explores the effect of dairy scum oil methyl ester (DSOME) blends and ethanol additive on TV1 Kirloskar diesel engine performance, combustion and emission characteristics. From the experimental study, it is concluded that DSOME-B20 (20% dairy scum biodiesel?+?80% diesel) has shown appreciable performance and lower HC and CO emissions among all other blends. Hence DSOME-B20 is optimised as best fuel blend and it is carried for further investigations to study the effect of bio-ethanol additive on diesel engine performance. From the study it apparent that diesel engine operated with ethanol additive and 20% dairy scum biodiesel blended fuels shown the satisfactorily improved emission characteristics when compared to petroleum diesel fuel operation. Finally, from the experimental investigation, it concludes that addition of ethanol shown the slightly higher HC, CO emission and improved BTE, BSFC, NOx and CO₂ than sole B20 biodiesel blend. Among all three (3%, 6% and 9%) ethanol additive ratios, E6% (6%-ethanol with B20) ethanol additive exhibits slightly better BTE, BSFC, cylinder pressure and heat release rate hence 6% ethanol additive with B20 biodiesel blend would furnish beneficial effects in the diesel engine.     

Effects of physical activity on the deposition of traffic-related particles into the human lungs in silico

Traffic-related particle emissions have been a great concern over a number of years due to their adverse health effects. In this research project, traffic-related particle deposition in the human lungs is studied using lung deposition estimates based on the ICRP 66 model. This study covers four human groups, i.e. adult males, adult females and two groups of children aged 5 and 10 years. The study examines particle deposition in the human lungs in relation to four different physical exercise levels, i.e. sleeping, sitting, light exercise and heavy exercise. To conduct the study, the particle size distributions of diesel and compressed natural gas (CNG) busses were monitored in field laboratory conditions. The study indicates that the total number of diesel particles measured is greater than the total number of CNG particles. The results further display that most of the diesel particles measured are smaller than 0.2 μm, whereas the CNG particles are smaller than 0.05 μm in aerodynamic diameter. The level of physical exercise, as well as the age and gender of a person affects the deposition of particles in the lungs. An increase in the physical activity results in larger amounts of small-size particles penetrating deeper into the respiratory system. The lung deposition of particles in males was substantially different compared to that of females and children. The deposited dose of particles was generally lower for females than for males and further lower for children than for females. This article argues that these groups should be discussed separately when conducting exposure assessments and that the level of physical activity should be taken into account when assessing potential health consequences.