Rail Direct Injection Diesel Engine Research Articles

Effect of Hydrogen Energy Share on a Hydrogen Diesel Dual Fuel Mode using a Common Rail Direct Injection System

This research work was aimed to investigate the maximum possible utilization of hydrogen energy in CI engine with diesel fuel replacement on energy share basis in hydrogen diesel dual fuel (HDDF) mode using common rail direct injection diesel engine. In HDDF mode, experiments were performed at two load conditions such as 3 and 5 bar of brake mean effective pressures (BMEPs). At a BMEP of 3 bar, the maximum hydrogen energy share (HES) could be reached to 50.1% without erratic engine operation, the level of NO, HC, CO and CO2 emissions were decreased up to 18%, 62%, 56% and 45% as compared with neat diesel case. However, there was no significant change in brake thermal efficiency (BTE) and smoke at high HES. At a BMEP of 5 bar, the maximum possible hydrogen energy share was nearly 40%, beyond this energy share severe knocking was noticed. NO emission was raised by 48%, whereas smoke and CO2 emission were decreased up to 20% and 24%. The brake specific HC emission was increased by 42% and there was no significant variation in CO emission with HES.

Influence of Fuel Injection Pressure on the Emissions Characteristics and Engine Performance in a CRDI Diesel Engine Fueled with Palm Biodiesel Blends

This experiment investigates the combustion and emissions characteristics of a common rail direct injection (CRDI) diesel engine using various blends of pure diesel fuel and palm biodiesel. Fuel injection pressures of 45 and 65 MPa were investigated under engine loads of 50 and 100 Nm. The fuels studied herein were pure diesel fuel 100 vol.% with 0 vol.% of palm biodiesel (PBD0), pure diesel fuel 80 vol.% blended with 20 vol.% of palm biodiesel (PBD20), and pure diesel fuel 50 vol.% blended with 50 vol.% of palm biodiesel (PBD50). As the fuel injection pressure increased from 45 to 65 MPa under all engine loads, the combustion pressure and heat release rate also increased. The indicated mean effective pressure (IMEP) increased with an increase of the fuel injection pressure. In addition, for 50 Nm of the engine load, an increase to the fuel injection pressure resulted in a reduction of the brake specific fuel consumption (BSFC) by an average of 2.43%. In comparison, for an engine load of 100 Nm, an increase in the fuel injection pressure decreased BSFC by an average of 0.8%. Hydrocarbon (HC) and particulate matter (PM) decreased as fuel pressure increased, independent of the engine load. Increasing fuel injection pressure for 50 Nm engine load using PBD0, PBD20 and PBD50 decreased carbon monoxide (CO) emissions. When the fuel injection pressure was increased from 45 MPa to 65 MPa, oxides of nitrogen (NOx) emissions were increased for both engine loads. For a given fuel injection pressure, NOx emissions increased slightly as the biodiesel content in the fuel blend increased.

Optimization of palm oil biodiesel blends and engine operating parameters to improve performance and PM morphology in a common rail direct injection diesel engine

In this paper, the characteristics of five palm oil biodiesel blends (B0, B10, B20, B30, and B100) have been tested in a common rail direct injection (CRDI) diesel engine with various EGR rates and pilot injection timings under 25% and 75% engine loads. The following were evaluated: combustion characteristics, including in-cylinder pressure, heat release rate (HRR), and mass fraction burned (MFB); engine performance parameters, including brake specific fuel consumption (BSFC) and coefficient of variation of the indicated mean effective pressure (COVimep); and emission characteristics, including CO, HC, NOx, PM and its morphology. By considering the combustion and emission characteristics, we found that the diesel engine fueled with B30 blend fuel with a 10% EGR rate, or with a pilot injection timing of 24° CA BTDC, can effectively reduce PM emissions and simultaneously keep NOx emissions at a low level. In addition, we found that the variations of the engine load and EGR rate, as well as the biodiesel blend ratio, have direct impacts on the PM particle diameter, shape, and other morphology.

Optimisation of nozzle geometry in the modified common rail direct injection biodiesel-fuelled diesel engine

The study of the experimental work focused on the optimisation nozzle geometry in the modified common rail direct injection (CRDI) diesel engine powered with palm oil methyl ester (POME) fuel. The CRDI diesel engine modified in terms of the toroidal re-entrant combustion chamber (TRCC) shape and nozzle geometry. The experiments are conducted with POME and diesel fuels (DF) at 80% and 100% loads, respectively. The parameters, such as compression ratio (CR) 17.5, speed 1500 RPM, fuel injection timing (IT) 10° BTDC and 900 bar injection opening pressure (IOP), are maintained constant. The selected fuel IT and IOP were optimised in our previous research. The experiments results revealed that the 7-hole nozzle injector improved in break thermal efficiency (BTE) by 1.5% and 1.3% for diesel and POME, respectively, as compared to the 6-hole injector. The average percentages of emissions are reduced up to 7.24% and 7.81% for diesel and POME fuels, respectively, except oxides of nitrogen (NOx). The peak pressure (PP) and heat release rate (HRR) are improved by 2.40% and 3.65%, respectively, for DF. The similar increased trend of PP and HRR is 2.53% and 4.10%, respectively, for POME in the modified CRDI diesel engine.

An experimental analysis of performance and exhaust emissions of a CRDI diesel engine operating on mixtures containing mineral and renewable components

The manuscript presents a comparative analysis of the performance and emission characteristics of a compression ignition engine equipped with a Common Rail injection system. The engine is fueled with diesel-biodiesel mixtures containing 25% and 50% share (by volume) of renewable components. Conventional diesel is used as a reference. Turkey lard and rapeseed oil are used as raw materials and subjected to the single-stage transesterification process to obtain methyl esters. The experiments are performed on a medium-duty, turbocharged, inter-cooled, Common Rail Direct Injection (CRDI) diesel engine. This study concentrates on one engine speed of 1500 rpm, typical for gen-set applications, and mid-load range from 100 Nm to 200 Nm. The scope of measurements covers the analysis of exhaust gasses concentration and engine efficiency parameters. In addition, the in-cylinder pressure measurements are performed in order to provide insight into the differences in combustion characteristics between examined fuel mixtures. The study reveals that the addition of the renewable component to fuel mixture positively affects a number of examined performance parameters as well as decreases the concentration of the examined toxic exhaust components, in the majority of cases.

An integrated effort of medium reactivity fuel, in-cylinder, and after-treatment strategies to demonstrate potential reduction in challenging emissions of reactivity controlled compression ignition combustion

Previous studies on reactivity controlled compression ignition combustion indicated that, reducing the hydrocarbon and carbon monoxide emissions at low load conditions still remains a challenge because of lower in-cylinder temperatures due to lower global reactivity gradient and reduced oxidation process. Research in this direction has not been reported so far and with this motivation, an attempt has been made to increase the global reactivity gradient and oxidation of fuel–air mixture by converting the low reactivity fuel methanol into medium reactivity fuel. This is achieved by mixing high octane oxygenated fuel, methanol (Octane Number: 110), with an oxygenated better cetane and volatility fuels like polyoxymethylene dimethyl ether (Cetane Number: 78) and isobutanol (Cetane Number: 15). The medium reactivity fuel with multiple direct injection of diesel fuel timed the combustion of dual fuel–air mixture to avoid too late or too advanced combustion which are the prime factors in controlling the unburnt emissions in a low temperature combustion process. Four medium reactivity fuel samples, M80IB20, M60IB40, M90P10, and M80P20, on percentage volume basis have been prepared and tested on the modified on-road three-cylinder turbocharged common rail direct injection diesel engine to demonstrate higher indicated thermal efficiency and potential reduction in unburnt and oxides of nitrogen/particulate matter emissions from reactivity controlled compression ignition combustion. Experimental results show that, use of medium reactivity fuel with optimized diesel injection strategy resulted in 66% decrease in hydrocarbon emission and 74% decrease in carbon monoxide emission by enhancing the oxidation of fuel–air mixture at lower temperatures which is evidently noticed in the combustion characteristics. Further reduction in hydrocarbon and carbon monoxide emission of about 90% has been achieved by integrating the diesel oxidation catalyst with the engine.

Investigation on pilot injection with low temperature combustion of Calophyllum inophyllum biodiesel fuel in common rail direct injection diesel engine

The present research work emphasises on the utilization of Calophyllum inophyllum biodiesel and preparation of 20% blend sample to explore the effects of variation of multiple injection strategies and amount of exhaust gas recirculation in a common-rail direct injection engine. In this aspects, the pilot injection quantity of B20 blend has been varied from 5 to 15% for the improvement of diesel engine characteristics. Among the tested results, an optimum pilot injection quantity has been identified and the same experimental work is extended for the addition of 10% and 20% exhaust gas recirculation under same operating conditions. The experimental study revealed that the increase in pilot injection rate from 5% to 15% at same operating conditions has shown higher brake thermal efficiency of 36.8% and the same improvement has not observed during exhaust gas recirculation addition. In terms of emissions point of view, the 15% pilot injection quantity of B20 fuel has resulted lowest hydrocarbon and carbon monoxide emissions when compared to diesel fuel by about 54.4% and 45.9% respectively. However, the implementation of 10% EGR rate at 15% pilot injection quantity reduced the oxides of nitrogen emission by 10.04%. On the other hand, the combustion characteristics are enhanced during increase in pilot injection rate and it decreased to lower level at higher concentration of EGR addition. Thus, the combined effect of 15% pilot injection rate and 10% EGR rate would be a best possible option for obtaining an improved performance and emission characteristics. Further, the study can be extended to vary the pilot injection, main and post injection timings with suitable EGR addition successful running of biodiesel blend.

Effects of Fuel Injection Pressure on Combustion and Emission Characteristics under Low Speed Conditions in a Diesel Engine Fueled with Palm Oil Biodiesel

In this study, the effect of injection pressure on combustion and emission characteristics was evaluated on a common rail direct injection diesel engine fueled with palm oil biodiesel. Recently, many studies have been conducted to utilize biodiesel produced from various sources to prevent environmental pollution and the depletion of petroleum resources. The oxygen content and high cetane number of biodiesel can reduce the production of exhaust pollutants by improving the combustion, but its high viscosity deteriorates the atomization of the injected fuel. Particularly at low engine speed conditions like idle, poor atomization and low airflow in the cylinder deteriorates the combustion efficiency. Increasing the fuel injection pressure is one of the effective methods to improve the atomization of biodiesel without mechanical modification of the current diesel engine. In this study, combustion characteristics and emission levels of pollutants were measured by varying the fuel injection pressure applying palm oil biodiesel. As a result, it was confirmed that increasing the injection pressure to apply palm oil biodiesel at low engine speed can reduce ignition delay and improve combustion efficiency so that nitrogen oxides (NOx) is increased but soot formation is reduced. Carbon monoxide (CO) and hydrocarbon (HC) are slightly reduced but these are increased again when using 100% palm oil biodiesel. The increased NOx due to increased injection pressure can be reduced by applying exhaust gas recirculation (EGR).

Performance, combustion and emission analysis of microalgae Spirulina in a common rail direct injection diesel engine

In the present work, a numerical investigation has been performed on the engine characteristics of a compression ignition (C.I.) engine using D100 (diesel) and AB100 (Algae-biodiesel) as fuels at various compression ratios (16.5–18.5). A commercial numerical software Diesel-RK was used for the simulation work of a direct injection diesel engine. The fluid flow inside the combustion chamber of engine plays a significant role in conducting the performance of an internal combustion engine. Experiments were conducted on the test engine with the optimum compression ratio of 17.5 at full load conditions and the results were compared with the numerical model. The numerical results were found to have respectable treaty against the experimental results. The simulation was carried out for predicting the parameters such as cylinder pressure, exhaust gas temperature, brake thermal efficiency, specific fuel consumption along with the emissions of carbon dioxide, nitrogen oxide, particulate matter at a constant engine speed under 100% load condition. The results indicated that the use of AB100 reduced brake thermal efficiency by 2.73%, torque by 6.66%, exhaust gas temperature by 1.6%, carbon dioxide by 6.1%, nitrogen oxide by 0.5% and particulate matter by 60%. However, the specific fuel consumption at CR 17.5 was increased by 6.4% as compared to diesel.

Influences of biodiesel fuels produced from highly degraded waste animal fats on the injection and emission characteristics of a CRDI diesel engine

In the current study, biodiesel fuels produced from waste chicken fat and waste fleshing oil with high free fatty acid were tested in a four stoke, four-cylinder, water-cooled, turbocharged-intercooled, common rail direct injection (CRDI) diesel engine. Their effects on the injection and exhaust emission characteristics of the test engine were determined and compared with those of petroleum-based diesel fuel (DF) as the reference fuel. Engine tests were performed at different engine loads and constant engine speed of 2000 rpm. Injection characteristics showed differences with respect to engine load and fuel type. However, the effects of biodiesel fuels on the injection profiles were more dominant for main injection characteristics such as the start of main injection, end of the main injection, injection amount and injection rate and these effects became more pronounced with increasing engine load. Compared to DF, animal fat based biodiesels had better total hydrocarbon (THC) and carbon monoxide (CO) emissions, but their carbon dioxide (CO2) and especially nitrogen oxides (NOx) emissions were higher. In addition, waste fleshing oil-based biodiesel fuel emitted lower emissions than waste chicken fat-based biodiesel.

Investigation of diesel engine performance and exhaust emissions of microalgae fuel components in a turbocharged diesel engine

Microalgae are a promising feedstock for alternative fuel for compression ignition engines due to their positive contribution to reducing greenhouse gas emissions. Microalgae are gaining significant interest as they can produce more oil than any oilseed plants. Unlike some other plant oils, the use of microalgae as an alternative to fossil fuels, can overcome food versus fuel conflict. In the current investigation, five different chemical components of microalgae hydrothermal liquefaction (HTL) biocrude paraffin, xylene, cyclo-pentanone, dioctyl-phthalate and butanol were mixed in equal volumes. Commercial diesel fuel was used as a reference fuel. The first blend consisted of 5 vol% of each of the 5 components was mixed with 75 vol% diesel. The blend is called as B1. The second blend consisted of 10 vol% of each of the 5 components was mixed with 50 vol% of diesel. This blend is called B2. The neat diesel (100% pure diesel) is called as 100D. The engine used in this study was a six-cylinder high-pressure common rail direct injection diesel engine fitted with a turbocharger. This study deals with engine performance, combustion and exhaust emission characteristics comparing diesel, B1 and B2 blends. The experimental results indicated a general reduction in both particle mass (PM) and total particle number (PN) emissions with both blends compared to those of diesel. Increase in nitrogen oxides (NOx) emissions at all four engine loads were found with both B1 and B2 blends. It was realised that the drop or rise of emissions was mainly a function of fuel-bound oxygen.

Investigation of Waste Animal Fat Based Biodiesel Fuels’ Usage in a Common Rail Direct Injection Diesel Engine: Performance and Combustion Characteristics

Investigation of Waste Animal Fat Based Biodiesel Fuels’ Usage in a Common Rail Direct Injection Diesel Engine: Performance and Combustion Characteristics

Optimization of Multiple Injection Strategy in Modified Common Rail Direct Injection Diesel Engine Powered with Palm Oil Methyl Ester

In this investigation, the common rail direct injection (CRDI) single cylinder four stroke diesel engine has made to modify in terms of toroidal reentrant combustion chamber (TRCC) shape and 7 holes CRDI nozzle injector. The current experimental study objective is to optimization of multiple injection strategy (MIS) in modified CRDI diesel engine powered with palm oil methyl ester (POME) B100 and diesel fuels. In the first phase of work, experiment results showed that slightly improved in brake thermal efficiency (BTE) and reduced emissions except oxides of nitrogen (NO_x) for POME fuelled engine operates under optimized MIS, fuel injection timing (IT) of -10° before top dead center (BTDC) and 600 bar injection pressure (IOP) in modified CRDI diesel engine. In the second phase of work, the performance of modified CRDI diesel engine is improved by increasing IOP from 600 bar to 900 bar at same MIS and fuel IT. The second phase of experiment results showed that percentage of increase in BTE by 2.47%, peak pressure (PP) by 13.69%, heat release rate (HRR) by 17.64%, NO_X by 11.70% and percentage of decreased in ignition delay (ID) by 29.62%, combustion duration (CD) by 13.79%, unburnt hydrocarbon (UBHC) by 19.04%, carbon monoxide (CO) by 14.28%, smoke level by 20.93% as compared to first phase of work in modified CRDI diesel engine fuelled with POME.

Investigation of Waste Animal Fat Based Biodiesel Fuels’ Usage in a Common Rail Direct Injection Diesel Engine: Performance and Combustion Characteristics

Investigation of Waste Animal Fat Based Biodiesel Fuels’ Usage in a Common Rail Direct Injection Diesel Engine: Performance and Combustion Characteristics

Combustion and performance evaluation of a common rail DI diesel engine fueled with ethyl and methyl esters

Biodiesel is a renewable fuel for diesel engines and it can be produced from different feedstocks via different types of alcohols and catalysts. Alcohol type directly affects the fuel properties of the produced biodiesel. The difference in the fuel properties may cause different performance, combustion and injection characteristics in diesel engines. In the present study, a common rail direct injection (CRDI) diesel engine was operated with waste vegetable frying oil based ethyl and methyl esters. The engine was operated under the conditions of three different engine speeds (1500, 2000 and 2500 rpm) and four engine loads (BMEP: ∼ 3.3, 5.0, 6.6 and 8.3 bar). According to the results of comprehensive combustion and performance tests, ethyl and methyl esters showed higher brake specific fuel consumption, higher peak heat release rate and cylinder pressure values compared to pure diesel fuel on average. Ethyl and methyl esters showed similar performance and combustion characteristics. Pilot injection and main injection durations of the ester fuels were higher than those of diesel fuel. The relationship between the determined and the calculated combustion and injection values of the test fuels changed with respect to engine operating parameters.

Combustion characteristics of a common rail direct injection engine using different fuel injection strategies

Fuel injection parameters such as fuel injection pressure (FIP) and start of injection (SOI) timing significantly affect combustion, performance, emission and durability of a common rail direct injection (CRDI) diesel engine. In this study, a state-of-the-art single cylinder research engine was used to investigate the effects of FIP and SOI timings on engine combustion characteristics, which affects heat transfer and soot formation as well. The experimental setup consisted of an instrumented single cylinder engine with provision to vary the fuel injection parameters along with online high speed combustion data acquisition and analysis system. Experiments were conducted at constant engine speed (1500 rpm) at four different FIPs (300, 500, 750 and 1000 bar), four different SOI timings and different fuel injection quantities. Combustion characteristics of the engine were analyzed using exhaustive heat release analysis based on in-cylinder pressure data. In direct injection compression ignition (DICI) engines, fuel vaporization and heat transfer characteristics affect fuel-air mixing, which is also influenced by the FIP and SOI timings. These injection parameters significantly control the rate of pressure rise (ROPR), and heat release rate (HRR), which in-turn affect the heat transfer from the engine cylinder as well as the engine power output. Therefore, it is necessary to optimize the fuel injection parameters to develop efficient and clean combustion diesel engines.

A novel study on the effect lemon peel oil as a fuel in CRDI engine at various injection strategies

Lemon peel oil is one of the renewable and biodegradable biofuel for diesel engine applications due to its low viscous nature. This study aims to observe the performance and emission characteristics of a common rail direct injection diesel engine at various fuel injection strategies under different loading conditions. An open type electronic control unit is used to control the fuel injection timing, injection rate and split injection at various injection pressures. In this research work, 20% lemon peel oil-diesel blend (by volume) is injected at a pressure of 400 bar, 500 bar and 600 bar with 10% pilot injection by volume and the results are compared with diesel fuel at same injection conditions. Further, pilot injection quantity of lemon peel oil blend is varied by 20% and 30% of total volume of fuel injected at 600 bar injection pressure. Finally, the experimental work is carried out in common rail direct injection diesel engine fuelled with lemon peel oil blend under 10% cooled exhaust gas recirculation condition. The study reveals that the brake thermal efficiency is improved with increase in injection pressures and pilot injection rates. However, this trend has been changed during 10% EGR addition for lemon peel oil blend operation at 30% pilot injection rate. The combustion characteristics are improved for lemon peel oil blend for 600 bar injection pressure with 20% and 30% pilot injection rates compared to 10% pilot injection rate. The higher pilot injection rate has shown significant reductions in carbon monoxide, hydrocarbon and smoke emissions. However, the emission results are reversed with 10% exhaust gas recirculation at 600 bar injection pressure of lemon peel oil blend. There is a significant reduction in NOx emission for low injection pressure of lemon peel oil blend at 10% pilot injection rate.

Evaluation of Fuel Injection Strategies for Biodiesel-Fueled CRDI Engine Development and Particulate Studies

Fuel injection parameters such as fuel injection pressure (FIP) and start of main injection (SoMI) timings significantly affect the performance and emission characteristics of a common rail direct injection (CRDI) diesel engine. In this study, a state-of-the-art single cylinder research engine was used to investigate the effects of fuel injection parameters on combustion, performance, emission characteristics, and particulates and their morphology. The experiments were carried out at three FIPs (400, 700, and 1000 bar) and four SoMI timings (4 deg, 6 deg, 8 deg, and 10 deg bTDC) for biodiesel blends [B20 (20% v/v biodiesel and 80% v/v diesel) and B40 (40% v/v biodiesel and 60% v/v diesel)] compared to baseline mineral diesel. The experiments were performed at a constant engine speed (1500 rpm), without pilot injection and exhaust gas recirculation (EGR). The experimental results showed that FIP and SoMI timings affected the in-cylinder pressure and the heat release rate (HRR), significantly. At higher FIPs, the biodiesel blends resulted in slightly higher rate of pressure rise (RoPR) and combustion noise compared to baseline mineral diesel. All the test fuels showed relatively shorter combustion duration at higher FIPs and advanced SoMI timings. The biodiesel blends showed slightly higher NOx and smoke opacity compared to baseline mineral diesel. Lower particulate number concentration at higher FIPs was observed for all the test fuels. However, biodiesel blends showed emission of relatively higher number of particulates compared to baseline mineral diesel. Significantly lower trace metals in the particulates emitted from biodiesel blend fueled engine was an important finding of this study. The particulate morphology showed relatively smaller number of primary particles in particulate clusters from biodiesel exhaust, which resulted in relatively lower toxicity, rendering biodiesel to be more environmentally benign.

An experimental investigation on the usage of waste frying oil-diesel fuel blends with low viscosity in a Common Rail DI-diesel engine

In this study, waste frying oil (WFO) was blended with mineral diesel fuel (MDF) (without converting biodiesel) in the ratios of 2%, 7%, 15% and 25% (v/v) on the condition that the viscosities of all WFO-MDF blends were lower than viscosity upper limit given in European Biodiesel Standard, EN 14214. It was aimed to determine the influences of the direct usage of WFO-MDF blends with low viscosity on the performance, injection, combustion, and emission characteristics of a Common Rail Direct Injection (DI) diesel engine. Engine tests were performed at constant engine speed of 2000 rpm and five different engine loads (50 Nm, 75 Nm, 100 Nm, 125 Nm and 150 Nm). WFO blends’ brake specific fuel consumption values were higher than those of MDF. The brake thermal efficiencies of MDF are better than WFO-MDF blends. Slightly higher cylinder gas pressures were attained with the neat MDF but the crank angles where the peak pressures obtained were close to each other. Injection timings did not show significant differences, but fuel quantities injected during pilot and main injection were higher for WFO blends. Excluding 50 Nm engine load, ignition delay and combustion durations were consistent with each other. Compared to MDF as the reference fuel, the use of WFO caused to increase in all exhaust emission types measured, especially THC emissions. The deterioration in performance and emission characteristics increased with increasing engine load and WFO content of the fuel blend.

Effects of triglyceride gasoline blends on combustion and emissions in a common rail direct injection diesel engine

This study presents the combustion and emission results using a blend of unrefined triglycerides (straight vegetable oils) and regular unleaded gasoline in a compression ignition engine typically used in farming machinery. Most farm equipment is powered by diesel engines. A sizable cost of producing a crop on a farm can be attributed to fuel—diesel in such cases. Farmers and researchers have been interested in the use of alternative fuels, especially triglycerides, which could potentially bring down the fuel cost portion of the farm input costs. One of the major drawbacks of using unrefined triglycerides is poor cold flow properties due to high density and viscosity. To overcome this, the triglycerides can be blended with gasoline to lower the density and viscosity. This blend has been used in existing diesel engines without the need for any modification to the engine or its control system. The experiments were conducted on a 4.5-L Tier 3 engine. The fuel used was a blend of unrefined canola triglyceride and regular unleaded gasoline (10% by volume). Measurements include mass fraction burned combustion pressure, fuel consumption and pollutant emissions. The fuel consumption of TGB10 was lower than most straight vegetable oils found in the literature, but higher than diesel. The peak pressure of TGB10 was slightly higher than diesel and occurred earlier than diesel. The brake-specific NOx was lower than diesel at lower and no load points. Particulate matter emissions of TGB10 were higher than diesel at rated speed. Total hydrocarbon emissions were generally higher than diesel. CO emissions were lower than diesel except at low or no load points where they were significantly higher.