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The growing demand for transportation fuels and the global emphasis on reducing greenhouse gas (GHG) emissions have led to increased interest in analyzing transport GHG emissions from the life-cycle perspective. Methanol, a potentially carbon-neutral fuel synthesized from CO2 and H2, has emerged as a promising candidate. This paper conducts a comprehensive life-cycle analysis (LCA) of the GHG emissions associated with the methanol production process, utilizing data inventory from China in 2019. To simulate the synthesis and distillation process of methanol, Aspen Plus is employed, using parameters obtained from actual plants. GHG emissions are then calculated using the GREET model, incorporating updated industry statistics and research findings. The CO2 necessary for methanol production is captured from factory flue gas.

Ethanol fuel blends with gasoline for spark ignition (SI) internal combustion engines are widely used on account of their advantages in terms of fuel economy and emissions reduction potential. The focus of this paper is to study the effects of these blends on combustion characteristics such as in-cylinder pressure profiles, gas-phase emissions (e.g., unburned hydrocarbons, NOx) and particulates (e.g., particulate matter and particle number) using both measurement campaigns and digital engineering workflows. Nineteen load-speed operating points in a 1L 3-cylinder GDI SI engine were measured and modelled. The measurements for in-cylinder pressure and emissions were repeated at each operating point for three types of fuel: gasoline (E0, 0% by volume of ethanol blend), E10 (10 % by volume of ethanol blend) and E20 (20% by volume of ethanol blend).

Wide Distillation Fuel (WDF) refers to the fuels with a distillation range from Initial Boiling Point (IBP) of gasoline to Final Boiling Point (FBP) of diesel. Polyoxymethylene Dimethyl Ethers (PODEn) have high oxygen content and cetane number, are promising green additive to diesel fuel. In this paper, WDF was prepared by blending diesel and gasoline at ratio of 1:1, by volume; the mass distribution of oligomers in the PODE3-4 product was 88.9% of PODE3 and 8.46% of PODE4. Diesel fuel (Diesel), WDF (G50D50) and WDF (80%)-PODE3-4 (20%) (G40D40P20) were tested in a light-duty single-cylinder diesel engine, combustion characteristic, fuel consumption and exhaust emissions were measured. The results showed that: at idling condition, G40D40P20 has better combustion stability, higher heat release rate, higher thermal efficiency compared with G50D50.

A study of Multiple Premixed Compression Ignition (MPCI) with mixtures of gasoline and diesel is performed on a light-duty single cylinder diesel engine. The engine is operated at a speed of 1600rpm with the same fuel mass per cycle. By keeping the same intake pressure and EGR ratio, the influence of different blending ratios in gasoline and diesel mixtures (90vol%, 80vol% and 70vol% gasoline) is investigated. Combustion and emission characteristics are compared by sweeping the first (−95 ∼ −35deg ATDC) and the second injection timing (−1 ∼ 9deg ATDC) with an injection split ratio of 80/20 and an injection pressure of 80MPa. The results show that compared with diesel combustion, the gasoline and diesel mixtures can reduce NOx and soot emissions simultaneously while maintaining or achieving even higher indicated thermal efficiency, but the HC and CO emissions are high for the mixtures.

Experimental research were carried out on a compression ignition engine with compression ratio of 17.5 with direct-run Naphtha. Exhaust recirculation ratio sweeps were carried out with three injection strategies. Premixed charge compression ignition, partially premixed combustion and low temperature combustion modes were realized and compared with each other. The first injection strategy is single injection. The injection timing is scanned to form partially premixed combustion and low temperature combustion. The second injection strategy features a large early first injection with fixed timing to form premixed charge and a small second injection near top dead center, which was scanned. The third injection strategy is similar to the traditional diesel injection strategy, which has a small pilot injection with fixed interval before the main injection. Results show that all injection strategies could realize both low NOx and low particulate matter emissions simultaneously.

Unregulated emissions have become an important factor restricting the development of methanol and ethanol alternative alcohols fuels. Using two light-duty vehicles fuelled with pure gasoline, gasoline blend of 10% and 20% volume fraction of ethanol fuels, gasoline blend of 15% and 30% volume fraction of methanol fuels, New European Driving Cycle (NEDC) emission tests were carried on a chassis dynamometer according to ECE R83-05. High performance liquid chromatography (HPLC), Gas chromatography - Mass spectrometry (GC-MS), Fourier transform infrared spectrometer (FTIR) were used to measure methanol, formaldehyde, acetaldehyde, acetone, benzene, toluene, xylene, ethylene, propylene, 1,3-butadiene and isobutene emissions in the exhaust during the NEDC.

The complexity of powertrain calibration has increased significantly with the development and introduction of new technologies to improve fuel economy and performance while meeting increasingly stringent emissions legislation with given time and cost constraints. This paper presents research to improve the model-based engine calibration optimization using an integrated sequential Design of Experiments (DoE) strategy for engine mapping experiments. This DoE strategy is based on a coherent framework for a model building - model validation sequence underpinned by Optimal Latin Hypercube (OLH) space filling DoEs. The paper describes the algorithm development and implementation for generating the OLH space filling DoEs based on a Permutation Genetic Algorithm (PermGA), subsequently modified to support optimal infill strategies for the model building - model validation sequence and to deal with constrained non-orthogonal variables space.

Gasoline engines suffer low thermal efficiency and diesel engines have the emission problem of the trade-off between NOx and soot emissions. Homogeneous Charge Induced Ignition (HCII) is introduced using a port injection of gasoline to form a homogeneous charge and using a direct injection of diesel fuel to ignite. HCII has the potential to achieve high thermal efficiency and low emission combustion. However, HCII combustion mode still has problems of high THC emissions at low load and high pressure rise rate at high load. In order to improve the gasoline reactivity and reduce THC emissions, double injection of diesel was applied in HCII mode. In order to reduce peak pressure rise rate (PPRR), a two-staged high-temperature heat release is achieved at suitable engine condition. The effects of HCII mode on combustion and emission characteristics are studied in a light-duty engine.

In this paper blends of diesel and gasoline (dieseline) fuelled Partially Premixed Compression Ignition (PPCI) combustion and the comparison to conventional diesel combustion is investigated. The tests are carried out using a light duty four cylinder Euro IV diesel engine. The engine condition is maintained at 1800 rpm, 52 Nm (equivalent IMEP around 4.3 bar). Different injection timings and different amounts of EGR are used to achieve the PPCI combustion. The results show that compared to the conventional diesel combustion, the smoke and NOx emissions can be reduced by more than 95% simultaneously with dieseline fuelled PPCI combustion. The particle number total concentration can be reduced by 90% as well as the mean diameter (from 54 nm for conventional diesel to 16 nm for G50 fuelled PPCI). The penalty is a slightly increased noise level and lower indicated efficiency, which is decreased from 40% to 38.5%.

A new combustion mode namely multiple premixed compression ignition (MPCI) for gasoline engines was proposed. The MPCI mode can be realized by two or more times gasoline injections into cylinder with a high pressure around the compression TDC and featured with a premixed combustion after each injection in the cylinder, which is different from the existed gasoline direct injection compression ignition (GDICI) modes such as homogeneous charge compression ignition (HCCI) mode with gasoline injection occurred in intake stroke, and partially premixed compression ignition (PPCI) mode with multiple gasoline injections in intake and compression strokes before the start of combustion (SOC). Therefore the spray and combustion of the MPCI mode are alternatively occurred as "spray-combustion-spray-combustion" near the TDC, rather than "spray-spray-combustion" sequence as traditional PPCI gasoline engines.

In-cylinder spray imaging by Mie scattering has been taken with frame rates up to 27,000 fps, along with high speed video photography of chemiluminescence and soot thermal radiation. Spectroscopic measurements have confirmed the presence of OH*, CH* and C2* emissions lines, and their magnitude relative compared to soot radiation. Filtering for CH* has been used with both the high speed video and a Photo-Multiplier Tube (PMT). The PMT signals have been found to correlate with the rate of heat release derived from in-cylinder pressure measurements. A high power photographic strobe has been used to illuminate the fuel spray. Images show that the fuel spray can strike the ground strap of the spark plug, break up, and a fuel cloud then drifts over and under the strap through the spark plug gap. Tests have conducted at two different spark plug orientations using a single spark strategy.

The effective matching of the exhaust mufflers and engines is an important measure to reduce the noise emission of running vehicles. Currently, the matching is based mainly on the steady state performance of engine. The muffler's influence on a vehicle's noise emission and sound quality under different running conditions is not generally considered. A comprehensive performance evaluation method is proposed to describe the muffler's influence on a commercial vehicle's noise emission, sound quality and exhaust back pressure under multiple working conditions. The weighted insertion loss and linearity coefficient were defined based on the test data of the exhaust noise under different engine loads and speeds. A comprehensive performance evaluation method was defined from the test data analysis of engine exhaust noise with different mufflers. Finally, the simulation results of the exhaust noise of a vehicle with different mufflers were compared with test data.

In the catalyst heating operation for a spray guided DISI (Direct Injection Spark Ignition) engine, split injection has been shown to improve combustion stability which is critical for the trade-off between tailpipe emissions and vehicle idle NVH [ 1 ]. The spray guided DISI engine has a multi-hole injector centrally located in the chamber with the spark plug. For catalyst heating operation, the first injection occurs during induction, which forms a relatively well mixed but lean mixture in the cylinder before ignition, and the second injection occurs close to a retarded ignition, which produces a stratified fuel rich mixture in the central region of the combustion chamber. Combustion initialization is found to be sensitive to spark plug protrusion and orientation, injector orientation and 2 nd injection timing relative to ignition [ 1 ].

In catalyst heating operation for DISI (Direct Injection Spark Ignition) engines, split injection has been generally known to improve combustion stability which is critical for the trade-off between tailpipe emissions and vehicle idle NVH. This is also the case for a spray guided DISI engine employing multi-hole injectors and with both injector and spark plug centrally located in the chamber. There are some special challenges with regard to combustion robustness because of the close proximity between injector and spark plug. Investigations have been carried out through engine testing and CFD simulation to ensure combustion robustness. For catalyst heating operation, the first injection occurs during induction, which forms a relatively well mixed but lean mixture in the cylinder before ignition, and the second injection occurs close to ignition, which produces a stratified fuel rich mixture in the central region of the combustion chamber.

Particulate Emissions from Homogeneous Charge Compression Ignition (HCCI) combustion are routinely assumed to be negligible. It is shown here that this is not the case when HCCI combustion is implemented in a direct injection gasoline engine. The conditions needed to sustain HCCI operation were realized using the negative valve overlap method for trapping high levels of residual exhaust gases in the cylinder. Measurements of emitted particle number concentration and electrical mobility diameter were made with a Cambustion DMS500 over the HCCI operating range possible with this hardware. Emissions of oxides of nitrogen, carbon monoxide and unburned hydrocarbons were also measured. These data are presented and compared with similar measurements made under conventional spark ignition (SI) operation in the same engine. Under both SI and HCCI operation, a significant accumulation mode was detected with particle equivalent diameters between 80 and 100 nm.

Previous work of the authors' group has shown that biodiesel fuels as a replacement for conventional diesel fuel in engine combustion can reduce PM level dramatically while lowering some other regulated emissions as well. It has shown that these fuels have the potential to increase the overall engine performance due to their lower sulphur and/or aromatics content compared with standard diesel fuels. This paper presents a study on a single cylinder naturally aspirated direct injection (DI) diesel engine, equipped with a pump-line-nozzle injection system, operating with varied biodiesel fuel blends (0%, 25%, and 50% of RME by volume) with ultra low sulphur diesel fuel (ULSD). The detailed analysis of the measurement data shows that the ignition delay and exhaust emissions are affected by the proportion of biodiesel due to the effect of different physical and chemical properties of the two fuels.

This paper reports on the cold (below 20°C coolant temperature) characterisation of a Jaguar 4.2 litre supercharged engine using a model based design of experiment approach. Engine responses were modelled and optimised to improve emissions performance under cold operating conditions. Key modelling and optimisation techniques are discussed, and a selection of results is presented.