Liquefied Petroleum Gas Fuels Research Articles

Computational and Chemical Kinetics Analysis of Hydrogen-Blended LPG for Domestic Cook Stove Burners

The penetration of liquefied petroleum gas (LPG) is much faster due to its wide range of applications, from industry to domestic usage. Hydrogen-blended LPG (H2-LPG) fuels offer benefits such as reduced emissions and increased fuel efficiency, and hydrogen is a promising option due to its clean-burning properties and easy transportation through pipelines. The present work investigated the combustion performance of blended fuels of hydrogen and LPG for commercial cooking burners (CCBs). SolidWorks was used to create a model of the CCB, which was then analysed using a non-premixed combustion approach with a compressible k-ε turbulent flow model in Ansys Fluent. The chemical kinetic mechanisms were employed to analyse the impact of fuel blends and combustion conditions on the burner's emissions and efficiency. The study found that blending hydrogen with LPG up to 50% can significantly enhance combustion performance, reduce CO and CO2 emissions, and increase economic viability through fuel conservation.

Life Cycle Assessment of LPG Engines for Small Fishing Vessels and the Applications of Bio LPG Fuel in Korea

This study aimed to evaluate the environmental impact of using liquefied petroleum gas (LPG) in small fishing vessels by conducting a life cycle assessment (LCA) in Korea. For the first time in the country, LPG engines designed for small fishing ships were utilized in this study. In addition, this research examined the potential benefits of employing Bio LPG, a renewable LPG produced from two distinct raw materials (crude palm oil (CPO) and refined, bleached, and deodorized (RBD) palm oil), instead of conventional LPG. The LCA findings reveal that utilizing LPG fuel in small fishing vessels can reduce greenhouse gas (GHG) emissions by more than 30% over conventional gasoline and diesel fuels. During the life cycle of vessels that use LPG fuel instead of gasoline and diesel fuels, there is a reduction of 2.2 and 1.2 million tons of GHG emissions, respectively. Moreover, substituting conventional fossil fuels with Bio LPG can result in over 65% reduction in GHG emissions. For the life cycle of boats that use Bio LPG fuel in place of gasoline and diesel fuels, the reduction of GHG emissions was 4.9 million tons and 2.5 million tons for CPO and 5.2 million tons and 2.7 million tons for RBD, respectively. This study not only underscores the substantial advantages of using Bio LPG over conventional fossil fuels but also presents conventional LPG as a way to reduce GHG emissions and promote sustainable practices in the fishing industry.

Performance and Emission Analysis of Modified Compression Ignition Engine from Diesel Engine to Variable Load using Petrol and LPG Fuel

Even though diesel and petrol fuels are utilized largely in various fields it also emits a substantial amount of particulate matter that results in environmental pollution. Several research scholars have worked on modifying an IC engine as a dual fuel mode. But a pilot fuel is required to start the working of alternate fuel. This paper analyzes the modified single-cylinder diesel engine working on a dual fuel mode without pilot fuel. The emission analysis and the performances of the modified engine are working on dual fuel (petrol and liquefied petroleum gas (LPG)) at a constant speed and compression ratio of 7.5. In addition to this, four different emission parameters namely hydrocarbons, carbon monoxide, carbon dioxide as well as nitrogen oxide are computed in this study. Also, the performance analysis is carried out for various engine parameters like total fuel consumption (TFC), Brake specific fuel consumption (BSFC) and Brake thermal efficiency (BTE) for various load conditions. The experimental analysis is performed and it is evident that the LPG fuel performs well with a BTE of about 50.36%; whereas in petrol and diesel the BTE achieved is 18.36% and 27%. Finally, the emission analysis is carried out and the analysis demonstrates that LPG fuel outperforms petrol and diesel with minimum emission rates.

Effect of fuel composition and EGR on spark-ignited engine combustion with LPG fueling: Experimental and numerical investigation

This paper presents an experimental and numerical investigation of a spark-ignited (SI) cooperative fuel research (CFR) engine fueled with different liquefied petroleum gas (LPG) fuels and exhaust gas recirculation (EGR). The effects of LPG fuel composition on engine combustion characteristics are initially evaluated at two different compression ratios (CR). Results show normal combustion at CR 7 and heavy knocking combustion at CR 10 for all the tested fuels, with a more substantial impact for the LPG fuel with high proportions of n-butane species. The Livengood-Wu (LW) integral method is then used to analyze the knock occurrence risk of individual fuel based on the reactivity of the tested fuels. The introduction of EGR then demonstrates the potential of knock intensity reduction below the borderline knock limit. A zonal-based kinetic interactions study is also performed to understand the knock mitigation effectiveness of EGR over the pressure–temperature domain relevant to SI engine operation. Finally, a multidimensional, computational fluid dynamics (CFD) simulation model is shown to predict the LPG combustion characteristics and presents the evolution of in-cylinder temperature and chemical species to demonstrate the development of end-gas autoignition events without and with EGR.

Particle Number Emissions of Gasoline, Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) Fueled Vehicles at Different Ambient Temperatures

Compressed natural gas (CNG) and liquefied petroleum gas (LPG) are included in the group of promoted transport fuel alternatives for traditional fossil fuels in Europe. Both CNG and LPG fueled vehicles are believed to have low particle number and mass emissions. Here, we studied the solid particle number (SPN) emissions >4 nm, >10 nm and >23 nm of bi-fuel vehicles applying CNG, LPG and gasoline fuels in laboratory at 23 °C and sub-zero (−7 °C) ambient temperature conditions. The SPN23 emissions in CNG or LPG operation modality at 23 °C were below the regulated SPN23 limit of diesel and gasoline direct injection vehicles 6×1011 1/km. Nevertheless, the limit was exceeded at sub-zero temperatures, when sub-23 nm particles were included, or when gasoline was used as a fuel. The key message of this study is that gas-fueled vehicles produced particles mainly <23 nm and the current methodology might not be appropriate. However, only in a few cases absolute SPN >10 nm emission levels exceeded 6×1011 1/km when >23 nm levels were below 6×1011 1/km. Setting a limit of 1×1011 1/km for >10 nm particles would also limit most of the >4 nm SPN levels below 6×1011 1/km.

Influence of the Use of Liquefied Petroleum Gas (LPG) Systems in Woodchippers Powered by Small Engines on Exhaust Emissions and Operating Costs

The use of alternative fuels is a contemporary trend in science aimed at the protection of non-renewable resources, reducing the negative impact on people and reducing the negative impact on the natural environment. Liquefied petroleum gas (LPG) is an alternative fuel within the meaning of the European Union Directive (2014/94/UE), as it is an alternative for energy sources derived from crude oil. The use of LPG fuel in low-power internal combustion engines is one of the currently developed scientific research directions. It results from the possibility of limiting air pollutant emissions compared to the commonly used gasoline and the lower cost of this fuel in many countries. By “gasoline 95” the Authors mean non-lead petrol as a flammable liquid that is used primarily as a fuel in most spark-ignited internal combustion engines, whereas 95 is an octane rating (octane number). This article presents the results of research on fuel consumption, toxic exhaust gas emission, and operating costs of a woodchipper used for shredding branches with a diameter of up to 100 mm in real working conditions. The woodchipper, powered by a 9.5 kW internal combustion engine, fueled by gasoline and LPG was tested. Liberal regulations of the European Union (Regulation 2016/1628/EU) on the emission of harmful exhaust compounds from small spark-ignition engines (up to 19 kW) and non-road applications contribute to the low technical advancement level of these engines. The authors researched a relatively simple and cheap LPG fueling system, as in their opinion, such a system has the best chance of being implemented for use. In the study, the branches of cherry plum were shredded (Prunus cerasiferaEhrh. Beitr. Naturk. 4:17. 1789 (Gartenkalender4:189-204. 1784)). Their diameter was ca. 80 mm, length 3 m, and moisture content ca. 25%. The system was tested during the shredding of the branches in real working conditions (the frequency of supplying the branches about 4 min−1 and the mass productivity of about 0.73 t/h). Based on the recorded results, it was found that the LPG fueled engine was characterized by higher carbon monoxide (CO) and nitrogen oxides (NOx) emissions by 22% and 27%, respectively. A positive effect of using LPG was the reduction of fuel consumption by 28% and carbon dioxide (CO2) and hydrocarbons (HC) emissions by 37% and 83%, respectively. The results of the research show that the use of alternative fuels can bring benefits in terms of CO2 and HC emissions, but at the same time be characterized by an increase in CO and NOx emissions. Further research should be conducted on innovative alternative fuel supply systems, such as in the automotive industry. At the same time, legislators should limit the use of low-quality fuel supply systems with the limits of pollutant emissions in exhaust gases, contributing to the development and economic competitiveness of new fuel injection systems.

Comparison of Spark Ignition Engine Performance and Emission Analysis Using Gasoline, LPG and Mixture Fuels

Emissions of higher amount of pollutants are a major concern in the use of conventional fuels such gasoline and diesel. Exhaust emissions such as nitrogen oxides (NOx), carbon monoxides (CO) and sulphur dioxides (SO2) affect the human body adversely. The problem of emission of higher amount of harmful pollutants can be diluted by use of alternate fuels such as liquefied petroleum gas (LPG), gasoline and their mixtures. The emission level can be brought down to safer level set by international agencies. In this work the engine was tested using LPG, gasoline and with gasoline and LPG-air mixture; so that comparative study of the emissions of pollutants gases and engine performance can be made. The results of the experiments have shown improvement in efficiency of LPG mode engine in comparison to gasoline and mixture fuel engine. Simultaneously, there was a reduction in HC and CO emissions of LPG and mixture fuel engines with reference to gasoline mode engines. On the other hand, the pure LPG fuel system showed a tremendous reduction in emissions, delivered a comparable torque as compared to gasoline and mixture fuel engine. The fuel consumption rate of LPG fuel mode is slightly higher than the gasoline mode. LPG mode is more economical but in most of the cases it results in about 10 -15% power loss.

LPG Cookstove Use and Fuel Subsidies in the Cuzco Region of Peru

2.8 billion people around the globe continue to use open fires and biomass stoves for cooking and heating. Household air pollution is a serious health hazard, especially for women and children. A solution involves promoting so-called clean fuels such as liquefied petroleum gas (LPG). The purpose of this research is to examine the use of LPG cookstoves in the Cuzco Region of Peru. A specific focus is on the Peruvian government’s FISE gas subsidy program. Surveys were administered to seventy-seven households in four indigenous agriculturalist communities over two different years. The results show the widespread use of gas stoves, but only as a supplement to wood and other biomass. We concluded that FISE is well organized, easy to use, and properly targets low income households. However, while the LPG subsidy program does promote the use of some gas, it is insufficient to prompt a complete fuel switch given current prices and resource availability. This research critiques the energy ladder model for fuel switching, and the results reveal that the use of multiple fuels, or fuel stacking, continues to be the norm. Furthermore, the data suggest an increase in eucalyptus and pine reforestation efforts, which will impact the relative scarcity of fuels, fuel choice, and health in the rural areas of the Cuzco Region.

Exposures to PM2.5 Associated with LPG Stove and Fuel Interventions in Four Countries: Pilot Results from the HAPIN Trial

Background: The Household Air Pollution Intervention Network (HAPIN) Trial is a multi-country effort to demonstrate the effects of a liquefied petroleum gas (LPG) stove and fuel distribution interv...

A new model for predicting antiknock quality of hydrocarbon fuel blends

A procedure for predicting the Critical Compression Ratio (CCR) and the Octane Number (ON) of hydrocarbon fuel blends is presented in this work. Compositional data as well as antiknock characteristics and thermo-physical properties of the constituent hydrocarbons are taken as input parameters for this calculation. The proposed methodology was developed by considering single-step kinetics for the pre-flame reactions taking place within the combustion chamber of the CFR engine, which is the standard apparatus used in ON evaluation tests. Furthermore, a thermodynamic model was used to describe the relevant processes the in-cylinder fuel-air mixture undergoes prior to the occurrence of knock. In order to validate the proposed method, CCRs of Primary Reference Fuel (PRF) mixtures; Motor ONs (MONs) of paraffinic fuels; and Research ONs (RONs) of Liquefied Petroleum Gas (LPG) fuels were computed and compared with experimental data reported in literature. The maximal absolute error and the root mean square deviation found were, respectively, 0.084 and 0.047 for the CCR of PRF mixtures; 1.6 and 0.60 for the MONs of paraffinic fuels; and 1.45 and 0.70 for the RONs of LPG fuels.

Investigation of in-cabin volatile organic compounds (VOCs) in taxis; influence of vehicle's age, model, fuel, and refueling

The air pollutant species and concentrations in taxis' cabins can present significant health impacts on health. This study measured the concentrations of benzene, toluene, ethylbenzene, xylene (BTEX), formaldehyde, and acetaldehyde in the cabins of four different taxi models. The effects of taxi's age, fuel type, and refueling were investigated. Four taxi models in 3 age groups were fueled with 3 different fuels (gas, compressed natural gas (CNG), and liquefied petroleum gas (LPG)), and the concentrations of 6 air pollutants were measured in the taxi cabins before and after refueling. BTEX, formaldehyde, and acetaldehyde sampling were actively sampled using NIOSH methods 1501, 2541, and 2538, respectively. The average BTEX concentrations for all taxi models were below guideline values. The average concentrations (±SD) of formaldehyde in Model 1 to Model 4 taxis were 889 (±356), 806 (±323), 1144 (±240), and 934 (±167) ppbv, respectively. Acetaldehyde average concentrations (±SD) in Model 1 to Model 4 taxis were 410 (±223), 441 (±241), 443 (±210), and 482 (±91) ppbv, respectively. Refueling increased the in-vehicle concentrations of pollutants primarily the CNG and LPG fuels. BTEX concentrations in all taxi models were significantly higher for gasoline. Taxi age inversely affected formaldehyde and acetaldehyde. In conclusion, it seems that refueling process and substitution of gasoline with CNG and LPG can be considered as solutions to improve in-vehicle air concentrations for taxis.

Impact of cleaner fuel use and improved stoves on acute respiratory infections: evidence from India.

The use of cleaner fuel and improved stoves has been promoted as a means to lower harmful emissions from solid fuels. However, little is known about how exclusive use of cleaner fuels, mixed fuel use and improved stoves influences children's health. We compared the impact of using liquefied petroleum gas (LPG) exclusively with mixed fuel use (LPG plus polluting fuels) and with exclusive use of polluting fuels on acute respiratory infections (ARI) among 16 157 children 0-4 years of age from households in the 2012 Indian Human Development Survey. Inverse probability weighting (IPW) procedures for multiple treatments were used for this evaluation. Children from households using LPG had a 5.0% lower probability of reporting ARI relative to exclusive users of polluting fuels, with larger effects (10.7%) in rural households. The probability of ARI in households using improved stoves and mixed fuel use was also lower in rural households, by 2.9% and 2.8%, respectively. The magnitude of effect varied across population subgroups, with the highest effects for children living in households living in kachha (low quality material) houses households identified as poor. Use of LPG and improved stoves lowered the probability of ARI among children younger than 5 years.

A comparison of performance and exhaust emissions with different valve lift profiles between gasoline and LPG fuels in a SI engine

In this study, a single-cylinder, four-stroke, single overhead camshaft (SOHC), spark ignition (SI) gasoline engine was converted to run with liquefied petroleum gas (LPG) fuel. To improve the volumetric efficiency, the camshaft of the engine was re-designed using classical spline method for different valve lifts. The variations of engine brake torque, power, brake specific fuel consumption (BSFC), HC, CO, CO2 and NOx emissions and exhaust gas temperature were investigated with unleaded gasoline and LPG fuels for different valve lifts. The experiments were conducted at 1700–3200rpm engine speeds range at wide open throttle (WOT) and λ=1. Engine torque and power decreased and BSFC increased with LPG fuel for the 7mm valve lift. Brake engine torque decreased by 8.82% and BSFC increased by 7.25% with LPG fuel compared to gasoline for 7mm valve lift at 2600rpm engine speed. However, HC and CO emissions decreased, NOx emissions increased with the usage of LPG fuel. HC and CO emissions decreased by 18.24% and 5.3%, respectively, and NOx emissions increased by 7.67%, with LPG fuel at 2600rpm engine speed. An improvement was observed on engine torque, BSFC, HC and CO emissions with the increase of the valve lift to 8mm and LPG fuel. At the low engine speeds, engine performance and exhaust emissions deteriorated with the increase of valve lift for gasoline fuel, while improvements were found at middle and higher engine speeds.

새로운 비황분계 부취제 혼합 LPG 연료의 엔진성능과 배출가스 특성에 관한 연구

일반적으로 황분계 부취제는 연료가스에 인한 가스중독, 발화, 폭발 등의 사고를 방지하고, 배출가스에 의해 연료 가스 누출의 즉각적으로 손쉽게 검출할 수 있도록 LPG, LNG 그리고 도시가스와 같은 연료가스에 첨가 사용하고 있다. 본 연구에서는 새로운 비황분계 부취제(K-Petro S-Free)를 사용한 LPG 혼합연료의 엔진 성능과 배출가스(CO, THC, <TEX>$CO_2$</TEX>, <TEX>$NO_x$</TEX>, <TEX>$SO_2$</TEX> ) 특성을 살펴보았다. 새로운 비황분계 부취제를 40mg/kg를 혼합한 LPG 연료(여름용, 겨울용)와 현재 사용 중인 황분계 부취제 (EM, ethyl mercaptan)를 혼합한 LPG 연료의 엔진 성능과 배출가스 특성을 실험하였다. 비황분계 부취제를 혼합한 LPG 연료의 엔진 성능은 황분계 부취제를 혼합한 LPG 연료와 비교할 때 비슷한 결과를 보여 주었다. 한편, 비황분계 부취제를 혼합한 LPG 연료의 엔진 배출가스 중 CO, THC, <TEX>$CO_2$</TEX>, <TEX>$NO_x$</TEX>은 황분계 부취제를 혼합한 LPG 연료와 비교할 때 비슷한 특성을 보였다. 그러나 2,000rpm에서 배출가스 중 <TEX>$SO_2$</TEX>은 비황분계 부취제를 혼합한 LPG 연료가 황분계 부취제를 혼합한 LPG 연료보다 83% 감소하는 우수한 결과를 보였다. In general, odorants are added to fuel gases, such as LPG, LNG and city gas, to prevent gas poisoning, ignition, explosion, or other accident caused by fuel gases, and to enable immediate and easy detection of fuel-gas leakage by emitting an offensive smell. This study describes a study on the performance and exhaust emissions (CO, THC, <TEX>$CO_2$</TEX>, <TEX>$NO_x$</TEX>, <TEX>$SO_2$</TEX>) characteristics of liquefied petroleum gas (LPG) engine using LPG fuel with new sulfur free odorant (K-Petro S-Free). New sulfur free odorant (40 mg/kg) was added to 2 type LPG fuels for summer, and winter and it was used in performance and exhaust emissions, compare to LPG fuel with sulfur containing odorant (EM, ethyl mercaptan). Engine performance using LPG with sulfur free odorant was similar to LPG with sulfur-containing odorant. Exhaust emissions (CO, THC, <TEX>$CO_2$</TEX>, <TEX>$NO_x$</TEX>) of LPG with sulfur free odorant were also similar characteristics, compare with sulfur containing odorant. Especially, <TEX>$SO_2$</TEX> emission using LPG with K-Petro S-Free odorant was more reduced 83 % than LPG with sulfur containing odorant(EM) at 2000 rpm.

Experimental Study on the Combustion and NOx Emission Characteristics of DME/LPG Blended Fuel Using Counterflow Burner

Dimethyl ether (DME) continues to be considered as an alternative fuel to conventional hydrocarbon fuels. Specifically, DME has been considered as a substitute fuel for liquefied petroleum gas (LPG) because the physical and chemical characteristics of DME are similar to those of LPG. However, the combustion performance for DME has not yet been established. In this study, the combustion and NOx-emission characteristics of LPG, DME, and an LPG/DME-blended fuel were experimentally investigated in a counterflow nonpremixed flame. The flame structure, flame temperature, NOx concentration, and distribution of OH radicals are reported. In this experimental study, the types of LPG used were butane 100%, butane 80% + propane 20%, and butane 75% + propane 25% by mass with DME mole fraction varied from 0 to 100 mole%. The experimental results indicated that the combustion and NOx emission characteristics of LPG fuels varied with the DME mole fraction. As the DME mole fraction increased, the flame thickness increased, but the flame length decreased. Also, the flame became wider, and its origin moved closer to the oxidizer nozzle with increasing DME mole fraction. In addition, as the DME mole fraction increased, the maximum flame temperature increased due to fast pyrolysis of DME as a result of the high oxygen content (∼35% by mass) in DME. Moreover, NOx concentration decreased with increasing DME mole fraction in all LPGs.

Hydrotreatment of Vegetable Oils to Produce Bio-Hydrogenated Diesel and Liquefied Petroleum Gas Fuel over Catalysts Containing Sulfided Ni–Mo and Solid Acids

Biohydrogenated diesel (BHD) and liquefied petroleum gas (LPG) fuel were produced by the hydrotreatment of vegetable oils over Ni–Mo-based catalysts in a high-pressure fixed-bed flow reaction system at 350 °C under 4 MPa of hydrogen. Because triglycerides and free fatty acids underwent the hydrogenation and deoxidization at the same time during the reaction, various vegetable oils (jatropha oil, palm oil, and canola oil) were converted to mixed paraffins by the one-step hydrotreatment process although they contained quite different amounts of free fatty acids. Ni-Mo/SiO2 formed n-C18H38, n-C17H36, n-C16H34, and n-C15H32 as predominant products in the hydrotreatment of jatropha oil. These long normal hydrocarbons had high melting points and thus gave the liquid hydrocarbon product over Ni-Mo/SiO2 a high pour point of 20 °C. Either Ni-Mo/H-Y or Ni-Mo/H-ZSM-5 was not suitable for producing BHD from jatropha oil because a large amount of gasoline-ranged hydrocarbons was formed on the strong acid sites of zeol...

Burst Pressure Determination of Vehicle Toroidal Oval Cross-Section LPG Fuel Tanks

This study addresses the prediction of the burst pressures and burst failure locations of the vehicle toroidal liquefied petroleum gas (LPG) fuel tanks using both experimental and finite element analysis (FEA) approaches. The experimental burst test investigations were carried out hydrostatically in which the cylinders were internally pressurized with water. The FEA modeling processes of these LPG fuel tanks subjected to incremental internal uniform pressure were performed in the nonlinear field. Two different types of nonlinear models, plane and shell, were developed and evaluated under nonuniform and axisysmmetric boundary conditions. The required actual shell properties including weld zone and shell thickness variations were also investigated and used in the computerized modeling processes. Therefore, the results of the burst pressures and their failure locations were predicted and compared with experimental ones.

Performance and emission investigation of a four-stroke liquefied petroleum gas spark-ignition engine generator used in a Malaysian night market

The objective of this study is to investigate and compare the performance and emission characteristics of the liquefied petroleum gas (LPG)-fuelled engine generator and the conventional gasoline-fuelled engine generator. The approach involves converting a gasoline engine generator, commonly used in Malaysian night markets to generate electricity, to the LPG engine generator. A four-stroke SI single-cylinder engine is equipped with an LPG injection system with minor modifications and then tested with both LPG and gasoline fuels. A venturi mixer (carburettor) was designed and in house constructed and then installed to deliver a proper A/ F ratio to the combustion chamber. The commercial computational fluid dynamics software FLUENT was used for simulation of air flow inside the mixer. The converted engine was tested at constant speed for its brake-specific fuel consumption (BSFC), efficiency, exhaust temperature, and exhaust gas emissions. The results show that the performance and emission characteristics of the LPG-fuelled engine are well suited for use in night markets. Average BSFC and average efficiency for the LPG engine over a range of loads were quite similar to those for the gasoline engine: the average BSFC was 0.95 kg/kWh for the LPG engine and 1 kg/kWh for the gasoline engine. The use of LPG as fuel in a gasoline engine causes only a slight reduction in efficiency as a 17 per cent reduction in average efficiency was recorded over the entire load range; however, the LPG engine fared better at higher loads than the gasoline engine for which only as low as a 4 per cent reduction was recorded at high loads. Emission tests seem to verify the minimal pollution products; there are significant reductions in the emission concentration results when LPG is used. Average decreases of 32 per cent for nitrogen oxide, 10 per cent for carbon dioxide, and 40 per cent for carbon monoxide were recorded. Although higher values of hydrocarbon (HC) were recorded, a 50 per cent reduction in HC was found for loads higher than 700 W. The study verified the more favourable features of LPG compared to gasoline as it is one of the best alternative fuels to gasoline for spark-ignition engine generators to solve the air pollution problem in night markets.

Influence of fuel composition on polycyclic aromatic hydrocarbon emissions from a fleet of in-service passenger cars

The composition of exhaust emissions from eight in-service passenger cars powered by liquefied petroleum gas (LPG) and unleaded petrol (ULP) were measured on a chassis dynamometer at two driving speeds (60 and 80 km h −1) with the aims of evaluating their polycyclic aromatic hydrocarbon (PAH) contents and investigating the effects of the type of fuel on vehicle performance, ambient air quality and associated health risks. Naphthalene, fluorene, phenanthrene, anthracene, pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene were the most prominent PAHs emitted by both ULP and LPG powered cars. The total emission factors of PAHs from LPG cars were generally lower than (but statistically comparable with) those of ULP cars. Similarly, the total BAP eq of the PAHs emitted by LPG cars were lower than those from ULP cars. Multi-criteria decision making (MCDM) methods showed that cars powered by LPG fuel performed better than those powered by ULP fuel in term of PAH levels. The implications of these observations on the advantages and disadvantages of using ULP and LPG fuels are discussed.

Exhaust Emissions From In-Use Alternative Fuel Vehicles

Abstract This study examines exhaust emissions from 11 vehicles tested on compressed natural gas, liquefied petroleum gas, methanol, ethanol, and reformulated gasoline fuels (22 vehicle/ fuel combinations). The paper highlights ozone precursor and toxic emissions. Emission rates from some of the presumably well-maintained, low-mileage test vehicles were higher than expected, but fuel effects were consistent with findings of similar studies. Aggregate toxic and non-methane organic emission rates from the variable/flexible fuel vehicles were higher with alcohol fuels than with reformulated gasoline. Lower specific reactivities for emissions with the alcohol fuels offset this negative trait. Specific reactivities of the organic emissions with the alternative fuels were consistently lower than those with the gasoline blends. Compressed natural gas and liquefied petroleum gas fuels had the lowest values. Although specific reactivities were expected to vary from fuel-to-fuel, they also varied considerably from vehicle-to-vehicle.