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On-road exhaust emissions from light-duty vehicles are greatly influenced by driving conditions. In this study, two light-duty passenger cars (LDPCs) and three light-duty diesel trucks (LDDTs) were tested to investigate the on-road emission factors (EFs) with a portable emission measurement system. Emission characteristics of carbon monoxide (CO), hydrocarbons (HC) and nitrogen oxides (NOx) emitted from vehicles at different speeds, accelerations and vehicle specific power (VSP) were analyzed. The results demonstrated that road conditions have significant impacts on regulated gaseous emissions. CO, NOx, and HC emissions from light-duty vehicles on urban roads increased by 1.1–1.5, 1.2–1.4, and 1.9–2.6 times compared with those on suburban and highway roads, respectively. There was a rough positive relationship between transient CO, NOx, and HC emission rates and vehicle speeds, while the EFs decreased significantly with the speed decrease when speed ≤ 20 km/h. The emissions rates of NOx and HC tended to increase and then decrease as the acceleration increased and the peak occurred at 0 m/s2 without considering idling conditions. For HC and CO, the emission rates were low and changed gently with VSP when VSP &lt, 0, while emission rates increased gradually with the VSP increase when VSP &gt, 0. For NOx NOx emission rates were lower and had no obvious change when VSP &lt, 0. However, NOx emissions were positively correlated with VSP, when VSP &gt, 0.

The gasoline direct injection (GDI) engine has substantially penetrated light-duty gasoline vehicles to help reduce fleet-wide fuel consumption across the world. However, increased particle emissions from GDI vehicles rather than the conventional multi-port fuel injection (MPFI) vehicles are of great concern. To investigate the particle emissions for these two categories of gasoline engines, we employed a dynamometer and measured the emissions of solid particle number (PN) and black carbon (BC) for four GDI and four MPFI vehicles under various testing cycles and conditions. Under the reference cycle (30 °C and cold-start WLTC), a strong correlation between solid PN and BC emissions is identified for both GDI and MPFI vehicles, although GDI vehicles without particle filters have significantly higher emissions of solid PN and BC than those of MPFI vehicles. Furthermore, varying the testing conditions by including cold start, low temperature, aggressive driving and air conditioning use all increase the emissions of solid PN and BC. These affecting factors pose more significant changes to particle emissions from MPFI vehicles than GDI vehicles. For example, at −7 °C, the solid PN and BC emissions of MPFI vehicles are increased by 4.17 times and 16.5 times relative to the results under 30 °C, and they are comparable to or higher than the emissions of GDI vehicles. Our results indicate that modern gasoline vehicles available in China’s market are likely to fail to comply with the upcoming PN emission limit (China 6), suggesting a serious need to adopt gasoline particle filters (GPF) for both GDI and MPFI vehicles. Advanced after-treatment technologies and stringent regulations to control particle emissions from gasoline vehicles should fully consider varying real-world conditions to guarantee effective environmental benefits.

Abstratct Fuel quality is among the primary reasons for severe vehicle pollution. A limited understanding of the effects of gasoline properties on modern vehicle emissions is one obstacle for the establishment of stricter fuel standards in China. The goal of this study was to evaluate the effects of aromatic and olefin contents and T50 and T90 (defined as the 50%v and 90%v distillation temperatures) on tailpipe emissions from gasoline direct injection (GDI) vehicles compliant with China 4 standards. Both gaseous and particle emissions using different types of gasoline were measured. Changing aromatic and olefin contents had relatively small impacts on fuel consumption. Compared with olefins and T90, the regulated gaseous emissions were impacted more by aromatics and T50. Evident decreases of the particle mass (PM) and particle number (PN) emissions were noticed when the aromatic content and T90 decreased. Reducing the olefin content slightly decreased the PM emissions and increased the PN emissions. With decreasing T50, the PM emissions increased and the PN emissions slightly decreased. These results suggest that aromatic content and T90 should be decreased to reduce particle emissions from GDI vehicles. The information presented in this study provides some suggestions for how to improve gasoline quality in China.

The limited understanding of vehicular emissions in China, especially evaporative emissions, is one obstacle to establishing tighter standards. To evaluate tailpipe and evaporative emissions, two typical China IV vehicles and one Tier 2 vehicle with an onboard refuelling vapour recovery (ORVR) system were selected and tested. One of the China IV vehicles was fuelled with gasoline, E10 and M15, respectively, to investigate the effect of fuel properties on vehicular emissions. For each vehicle, cold-start tailpipe emission tests were conducted first, followed by an evaporation test. Based on the emission factors and real-world vehicle activity data, the annual tailpipe and evaporative hydrocarbon (HC) emissions of each vehicle were calculated and compared. The results show that E10 and M15 significantly reduced the tailpipe CO and particle number (PN) emissions but seriously aggravated the NOx emissions, especially for M15. The hot soak losses (HSLs) and diurnal breathing losses (DBLs) were slightly impacted by the fuel properties. The annual evaporative emissions with E10 and M15 were higher than that with gasoline. The ORVR system effectively controlled the evaporative emissions, especially for DBLs. Evaporative emissions from the China IV vehicles were 1.1–1.4 times the tailpipe HC emissions. Additionally, the evaporative emission factors of the China IV vehicles were almost 50% lower than the standard (2.0 g/test), whereas their annual evaporative emissions were almost 1.8–2.8 times higher than those from the Tier 2 vehicle. Therefore, controlling evaporative emissions currently remains a great need in China, and the ORVR might be a recommended evaporative control technology.

International audience; A composite packing material (CM-5) was prepared in this study, mainly consisting of compost withfunctional microorganisms, calcium carbonate (CaCO3), perlite, cement and plant fiber. To getstronger compressive strength, mass ratios of these components were optimized based onsingle factor experiments, and finally adding amounts of perlite, cement, plant fiber, CaCO3,compost and binder at 18%, 18%, 7%, 13%, 17% and 27%, respectively. According to theoptimum proportion, CM-5 was extruded in cylindrical shape (12 mm in diameter and 20 mm inlength) with a bulk density of 470 kg m−3, a moisture retention capacity of 49% and themicrobial counts of × 105 CFU g−1 of packing material. The cumulative release rates of totalorganic carbon (TOC) and total nitrogen (TN) from CM-5 were 3.1% and 6.5%, respectively, after19 times extraction in distilled water. To evaluate the H2S removal capacity, CM-5 was comparedwith an organic (corncob) and an inorganic (ceramsite) packing material in three biofilters. Theresults showed that CM-5 had higher H2S removal capacity compared with corncob andceramsite. CM-5 could avoid the large fluctuation of pH value and pressure drop during theoperation. The maximum H2S removal capacity of CM-5 was 12.9 g m−3 h−1 and the removalefficiency could maintain over 95.4% when the inlet H2S loading rate was lower than11.3 g m−3 h−1 without any addition of nutrients and pH buffer substances. Besides, only 2–3days were needed for the recovery of biofiltration performance after about two weeks of idleperiod.

Application of renewable energy is an effective way to control the excessive petroleum consumption in transportation sector. However, there is a worthy concern about the applicability of alternative fuel on in-use vehicles and the variation of exhaust emissions when switching from the traditional gasoline to a new fuel. This paper is aimed to investigate the impact of two typical kinds of alcohol gasoline, E10 and M15, on fuel consumption and tailpipe emissions of a late-model multi-port fuel injection (PFI) passenger vehicle over the worldwide harmonized light-duty test cycle (WLTC). The results showed that fuel consumption and CO 2 emissions of the test vehicle with both E10 and M15 were higher than that with gasoline. E10 reduced most of the gaseous and particulate emissions, except NOx, while M15 deteriorated the exhaust emissions seriously, especially for the THC and PN emissions those increased by approximately 3.4 and 4.6 times. The most likely reason was that M15 did not match the configuration of engine and emission control system of this test vehicle. Other studies about fuel consumption and tailpipe emissions after traditional gasoline replaced by alcohol gasoline has also revealed the deterioration when the alcohol gasoline didn't match the vehicle configuration, which would result in some negative impact on the atmospheric environment.

This study discusses development of a mobile fuel laboratory in China, which integrates sulfur content detection device, vapor pressure testing device and fast simulation equipment for detergency detection. The compact mobile fuel lab can test detergency and sulfur content of both gasoline and diesel, and volatilization characteristic of gasoline. The research shows that taking many efficient measures to control influence factors can ensure portable devices providing reliable testing results. The main influence factors such as vehicle vibration, essential resource supply, operating conditions and data quality control have been studied in this work. Building a three dimension dynamic model, consisted of vehicle, absorber and devices, can confirm the influence of vibration. Furthermore, the solution of the model is used for guiding the design and selection of vibration damping unit. Three power supply approaches, including commercial, generator and uninterruptible power supply, can provide sufficient electricity. And split-phase circuit, voltage regulator and filter device are set up for decrease electrical signal interference. Temperature and air circulation are two important elements which should be strictly controlled; thus, automotive air-conditioning system and an additionally onboard roof type air condition work alternatively to keep ambient temperature stable, and gas concentration alarm unit interlocked together with ventilation system ensures the car in a safe gas concentration range. Experiments prove that optimized equipment has good repeatability of results. Additionally, pre-treatment and pre-assessment are effective processes for blind sample analysis.

Vehicle emissions are greatly influenced by various factors that are related to engine technology and driving conditions. Only the fuel injection method and ambient temperature are investigated in this research. Regulated gaseous and particulate matter (PM) emissions from two advanced gasoline-fueled vehicles, one with direct fuel injection (GDI) and the other with port fuel injection (PFI), are tested with conventional gasoline and ethanol-blended gasoline (E10) at both −7 °C and 30 °C. The total particle number (PN) concentrations and size distributions are monitored with an Electrical Low Pressure Impactor (ELPI + ). The solid PN concentrations are measured with a condensation particle counter (CPC) after removing volatile matters through the particle measurement program (PMP) system. The results indicate that decreasing the ambient temperature from 30 °C to −7 °C significantly increases the fuel consumption and all measured emissions except for NO x . The GDI vehicle exhibits lower fuel consumption than the PFI vehicle but emits more total hydrocarbons (THC), PM mass and solid PN emissions at 30 °C. The adaptability of GDI technology appears to be better than that of PFI technology at low ambient temperature. For example, the CO, THC and PM mass emission factors of the PFI vehicle are higher than those of the GDI vehicle and the solid PN emission factors are comparable in the cold-start tests at −7 °C. Specifically, during start-up the particulate matter emissions of the PFI are much higher than the GDI. In most cases, the geometric mean diameter (GMD) of the accumulation mode particles is 58–86 nm for both vehicles, and the GMD of the nucleation mode particles is 10–20 nm. The results suggest that the gaseous and particulate emissions from the PFI vehicle should not be neglected compared to those from the GDI vehicle especially in a cold environment.