Showing papers on "Gasoline published in 2018"

Selective conversion of CO 2 and H 2 into aromatics

Abstract: Transformation of greenhouse gas CO2 and renewable H2 into fuels and commodity chemicals is recognized as a promising route to store fluctuating renewable energy. Although several C1 chemicals, olefins, and gasoline have been successfully synthesized by CO2 hydrogenation, selective conversion of CO2 and H2 into aromatics is still challenging due to the high unsaturation degree and complex structures of aromatics. Here we report a composite catalyst of ZnAlOx and H-ZSM-5 which yields high aromatics selectivity (73.9%) with extremely low CH4 selectivity (0.4%) among the carbon products without CO. Methanol and dimethyl ether, which are synthesized by hydrogenation of formate species formed on ZnAlOx surface, are transmitted to H-ZSM-5 and subsequently converted into olefins and finally aromatics. Furthermore, 58.1% p-xylene in xylenes is achieved over the composite catalyst containing Si-H-ZSM-5. ZnAlOx&H-ZSM-5 suggests a promising application in manufacturing aromatics from CO2 and H2. Selective conversion of CO2 and H2 into aromatics remains challenging due to the high unsaturation degree and complex structure of aromatics. Here the authors report a composite catalyst of ZnAlOx and H-ZSM-5 which promotes the formation of aromatics with high selectivity while inhibiting CO and CH4 formation in CO2 hydrogenation reactions.

Alcohol and ether as alternative fuels in spark ignition engine: A review

Abstract: Energy security and global warming concern are the two main driving forces for the global alcohol development that also have the effort to animate the agro-industry. Generally, alcohol and ether fuels are produced from several sources and can be produced locally. Almost all alcohol fuels have similar combustion and ignition characteristics to existing known mineral fuels. Mainly the ether fuels (MTBE and DME) are used as additives at low blending ratio to enhance the octane number and oxygen content of gasoline. The addition of alcohol and ether fuels to gasoline lead to a complete combustion due to the higher oxygen content, thereby leads to increased combustion efficiency and decreased engine emissions. The objectives of this paper are to systematically review the use of alcohols and ethers including butanol, methanol, ethanol, and fusel oil, MTBE, and DME as fuels in SI engine. Also, the current study has investigated the effects of performance (brake torque, brake power, BSFC, effective efficiency, and EGT), emissions (CO, CO2, NOx and HC) and combustion characteristics of SI engine with alcohol and ether. The increase in engine performance could be attained with an increased compression ratio along with the use of alcohol fuels which have a higher-octane value. Furthermore, alcohol and ether burn very cleanly than regular gasoline and produce lesser carbon monoxide (CO) and nitrogen oxide (NOx). On the other hand, the energy value of alcohol and ether fuels is approximately 30% lower than gasoline; thereby the specific fuel consumption (SFC) will increase simultaneously when using alcohol and ether as a fuel. Finally, this paper also discusses the impacts of alcohol on engine vibration, engine noise, and potential to be used as a gasoline octane enhancer. Alcohol can be used as a pure fuel in spark ignition engine, but it requires some modifications to the engine.

Life cycle environmental impact assessments and comparisons of alternative fuels for clean vehicles

Abstract: In this study, a comparative life cycle assessment of internal combustion engine-based vehicles fueled by various fuels, ranging from hydrogen to gasoline, is conducted in addition to electric and hybrid electric vehicles. Three types of vehicles are considered, namely; internal combustion engine vehicles using gasoline, diesel, liquefied petroleum gas, methanol, compressed natural gas, hydrogen and ammonia; hybrid electric vehicles using 50% gasoline and 50% electricity; and electric only vehicles for comprehensive comparison and environmental impact assessment. The processes are analyzed from raw material extraction to vehicle disposal using process-based life cycle assessment methodology. In order to reflect the sustainability of the vehicles, seven different environmental impact categories are considered: abiotic depletion, acidification, eutrophication, global warming, human toxicity, ozone layer depletion and terrestrial ecotoxicity. The primary energy resources are selected based on currently utilized options to indicate the actual performances of the vehicles. The results show that electric and plug-in hybrid electric vehicles result in higher human toxicity, terrestrial ecotoxicity and acidification values because of manufacturing and maintenance phases. In contrast, hydrogen vehicles yield the most environmentally benign option because of high energy density and low fuel consumption during operation.

Gasoline compression ignition approach to efficient, clean and affordable future engines:

Abstract: The worldwide demand for transport fuels will increase significantly but will still be met substantially (a share of around 90%) from petroleum-based fuels. This increase in demand will be significantly skewed towards commercial vehicles and hence towards diesel and jet fuels, leading to a probable surplus of lighter low-octane fuels. Current diesel engines are efficient but expensive and complicated because they try to reduce the nitrogen oxide and soot emissions simultaneously while using conventional diesel fuels which ignite very easily. Gasoline compression ignition engines can be run on gasoline-like fuels with a long ignition delay to make low-nitrogen-oxide low-soot combustion very much easier. Moreover, the research octane number of the optimum fuel for gasoline compression ignition engines is likely to be around 70 and hence the surplus low-octane components could be used without much further processing. Also, the final boiling point can be higher than those of current gasolines. The potential a...

Overview of the oxygenated fuels in spark ignition engine: Environmental and performance

Abstract: Oxygenated fuels such as alcohols and ethers have the potential to provide reliable sources, and environmentally friendly fuel to world's increasing future energy demands. Oxygenated fuels have a promised future since are renewable and produced from several sources, also can be produced locally. The first objective of this paper is to systematically review of oxygenated fuels including alcohol and ether regarding the production, environmental impacts and potential using as octane booster of gasoline that used in spark ignition SI) engine. Another objective of this paper is to review the effects of oxygenated fuels on performances and emissions characteristics of spark ignition engine. Alcohol and ether burn very cleanly than regular gasoline and produce lesser carbon monoxide (CO) and nitrogen oxides (NOx). Mainly the ether fuels (methyl tertiary butyl ether MTBE and Dimethyl Ether DME) are used as additives at low blending ratio to enhance the octane number and oxygen content of gasoline. Furthermore, alcohols and ethers have significant impacts on the environment, greenhouse gas and human health. In addition to this, application of oxygenated fuel on SI engines can decrease environmental pollution, strengthen agricultural economy and decrease gasoline fuel requirements. The increase in engine performance could be attained with an increased compression ratio along with the use of alcohol fuels which have a higher-octane value. Overall, oxygenated fuels have been found to be a very promising alternative fuel for SI engines, capable of providing high thermal efficiency, and lower NOx levels.

Comprehensive organic emission profiles for gasoline, diesel, and gas-turbine engines including intermediate and semi-volatile organic compound emissions

Abstract: . Emissions from mobile sources are important contributors to both primary and secondary organic aerosols (POA and SOA) in urban environments. We compiled recently published data to create comprehensive model-ready organic emission profiles for on- and off-road gasoline, gas-turbine, and diesel engines. The profiles span the entire volatility range, including volatile organic compounds (VOCs, effective saturation concentration C * = 10 7 – 1011 µ g m −3 ), intermediate-volatile organic compounds (IVOCs, C * = 10 3 – 106 µ g m −3 ), semi-volatile organic compounds (SVOCs, C * = 1 – 102 µ g m −3 ), low-volatile organic compounds (LVOCs, C * ≤ 0.1 µ g m −3 ) and non-volatile organic compounds (NVOCs). Although our profiles are comprehensive, this paper focuses on the IVOC and SVOC fractions to improve predictions of SOA formation. Organic emissions from all three source categories feature tri-modal volatility distributions (“by-product” mode, “fuel” mode, and “lubricant oil” mode). Despite wide variations in emission factors for total organics, the mass fractions of IVOCs and SVOCs are relatively consistent across sources using the same fuel type, for example, contributing 4.5 % (2.4 %–9.6 % as 10th to 90th percentiles) and 1.1 % (0.4 %–3.6 %) for a diverse fleet of light duty gasoline vehicles tested over the cold-start unified cycle, respectively. This consistency indicates that a limited number of profiles are needed to construct emissions inventories. We define five distinct profiles: (i) cold-start and off-road gasoline, (ii) hot-operation gasoline, (iii) gas-turbine, (iv) traditional diesel and (v) diesel-particulate-filter equipped diesel. These profiles are designed to be directly implemented into chemical transport models and inventories. We compare emissions to unburned fuel; gasoline and gas-turbine emissions are enriched in IVOCs relative to unburned fuel. The new profiles predict that IVOCs and SVOC vapour will contribute significantly to SOA production. We compare our new profiles to traditional source profiles and various scaling approaches used previously to estimate IVOC emissions. These comparisons reveal large errors in these different approaches, ranging from failure to account for IVOC emissions (traditional source profiles) to assuming source-invariant scaling ratios (most IVOC scaling approaches).

Production and application of ABE as a biofuel

Abstract: The increasing energy demand and more stringent legislation for engine pollutant emissions with the use of carbon-neutral fuels have forced to use alcohol. ABE, a combination of acetone, butanol, and ethanol, is a potentially fuel that can be produced from waste biomass via fermentation. Recently, this fuel has attracted researchers’ attention due to its better performance and less emission as a diesel blend when compared to ethanol. First, this article addresses past and recent research conducted in the field of biofuel (ABE) production from lignocellulosic materials. Second, the development in ABE production efficiency is reviewed and various methods of improving ABE production are presented. ABE from lignocellulosic materials (a green energy re- source) can be improved through metabolic engineering of the fermenting yeast (Clostridia) and/or pre-treat- ment techniques. Furthermore, the application of ethanol, butanol and ABE as biofuel blends is compared and summarised considering three aspects (1) combustion characteristics; (2) as an additive blend of diesel fuel in compression engines; and (3) as an additive blend of gasoline in spark ignition engines related to engine per- formance and emission levels. This study shows that ABE has the potential to become an important second-generation biofuel that can be blended with diesel and gasoline for the following reasons: it is cheaper to produce compared to butanol, it is possible to improve engine performance and it reduces exhaust gas emissions. Moreover, engine power is comparable to diesel, and at the same time ABE releases fewer emissions such as CO and NOx than other fuel blends.

Secondary Organic Aerosol Production from Gasoline Vehicle Exhaust: Effects of Engine Technology, Cold Start, and Emission Certification Standard.

Abstract: Secondary organic aerosol (SOA) formation from dilute exhaust from 16 gasoline vehicles was investigated using a potential aerosol mass (PAM) oxidation flow reactor during chassis dynamometer testing using the cold-start unified cycle (UC). Ten vehicles were equipped with gasoline direct injection engines (GDI vehicles) and six with port fuel injection engines (PFI vehicles) certified to a wide range of emissions standards. We measured similar SOA production from GDI and PFI vehicles certified to the same emissions standard; less SOA production from vehicles certified to stricter emissions standards; and, after accounting for differences in gas-particle partitioning, similar effective SOA yields across different engine technologies and certification standards. Therefore the ongoing, dramatic shift from PFI to GDI vehicles in the United States should not alter the contribution of gasoline vehicles to ambient SOA and the natural replacement of older vehicles with newer ones certified to stricter emissions s...

The Effect of Using Ethanol-Gasoline Blends on the Mechanical, Energy and Environmental Performance of In-Use Vehicles

Abstract: The use of ethanol in gasoline has become a worldwide tendency as an alternative to reduce net CO2 emissions to the atmosphere, increasing gasoline octane rating and reducing dependence on petroleum products However, recently environmental authorities in large urban centers have expressed their concerns on the true effect of using ethanol blends of up to 20% v/v in in-use vehicles without any modification in the setup of the engine control unit (ECU), and on the variations of these effects along the years of operation of these vehicles Their main concern is the potential increase in the emissions of volatile organic compounds with high ozone formation potential To address these concerns, we developed analytical and experimental work testing engines under steady-conditions We also tested carbureted and fuel-injected vehicles every 10,000 km during their first 100,000 km of operation We measured the effect of using ethanol-gasoline blends on the power and torque generated, the fuel consumption and CO2, CO, NOx and unburned hydrocarbon emissions, including volatile organic compounds (VOCs) such as acetaldehyde, formaldehyde, benzene and 1,3-butadiene which are considered important ozone precursors The obtained results showed statistically no significant differences in these variables when vehicles operate with a blend of 20% v/v ethanol and 80% v/v gasoline (E20) instead of gasoline Those results remained unchanged during the first 100,000 km of operation of the vehicles We also observed that when the vehicles operated with E20 at high engine loads, they showed a tendency to operate with greater values of λ (ratio of the actual air-fuel ratio to the stoichiometric air-fuel ratio) when compared to their operation with gasoline According to the Eco-Indicator-99, these results represent a minor reduction (<13%) on the impact to human health, and on the deterioration of the ecosystem However, it implies a 129% deterioration of the natural resources Thermal equilibrium analysis, at the tailpipe conditions (~100 °C), showed that ethane, formaldehyde, ethylene and ethanol are the most relevant VOCs in terms of the amount of mass emitted The use of ethanol in the gasoline reduced 20–40% of those emissions These reductions implied an average reduction of 17% in the ozone formation potential

Gasoline Particulate Filters—a Review

Abstract: To improve ambient air quality, several countries have adopted regulations setting stringent limits on vehicular tailpipe emissions of particulates. The issue of high particulate emissions has been mostly addressed for diesel vehicles with the widespread adoption of diesel particulate filters (DPFs). Attention is now turned to gasoline direct injection (GDI) technology, which provides improved fuel economy and performance, but also increased particulate emissions, as compared to the port fuel injection (PFI) engines. Europe has set a particle number (PN) limit on emissions from GDI vehicles, while China has expanded that to include all gasoline vehicles. In the USA, these are regulated through particle mass (PM) limits. To meet these regulations, it is anticipated that gasoline particulate filters (GPFs) will be widely applied to gasoline exhaust after-treatment. GPF technology has rapidly advanced, and already a wide range of pore size distribution and cell geometries are being offered to minimize back pressure and offer high ash storage capacity, high filtration efficiency, and, in the case of filters combined with three-way catalytic functionality, high conversion of gas-phase criteria pollutants. This review summarizes representative studies on particulate emissions from gasoline engines, the nature of the particulates, and the advances in GPF technology.

Dimethyl Carbonate as a Promising Oxygenated Fuel for Combustion: A Review

Abstract: Energy shortage and environmental problems are two dominant subjects. Dimethyl carbonate (DMC) is one of the oxygenated fuels with increasing interest as the alternative to diesel fuel or additive for conventional hydrocarbon fuels. In the last decade, comprehensive studies on DMC have been carried out in terms of synthesis, use, and oxidation and combustion mechanism. DMC synthesis from greenhouse gas such as carbon dioxide can achieve the carbon circulation between air and fuel. Ethylene carbonate route is one of the most promising ways to utilize carbon dioxide and synthesize DMC in terms of particle efficiency, energy consumption per one unit of product, and net carbon dioxide emission. In addition, the results show that pure DMC in compression ignition (CI) engines or DMC addition in diesel/gasoline could decrease emissions significantly. Moreover, DMC pyrolysis form carbon dioxide before carbon monoxide which is different from other oxygenated fuels. However, DMC can produce formaldehyde during oxidation process in high concentration, which is harmful to the environment and human health as well. The present DMC kinetic model needs to update the major reactions constant through recognizing the initial decomposition routes and low-temperature oxidation. In addition, further studies on the DMC/hydrocarbon fuels mixtures for the interaction chemistry are needed.

Indian scenario of ethanol fuel and its utilization in automotive transportation sector

Abstract: About 85% of petroleum oil need of India is being met through imports. Indian economy is growing steadily resulting in rapid increase of vehicular population and demand for transportation fuels. Indian Government has already mandated blending of ethanol in gasoline by 10% to reduce the oil import. Bureau of Indian Standards is finalizing the specification of 20% ethanol blended gasoline for use as vehicular fuel. In this context, this review presents the current and future scenario of Indian transportation, petroleum oil and bio-fuel sectors including global progress on utilization of ethanol as an alternative transportation fuel in spark ignition vehicles. The data from various standard reference sources were compiled, analyzed and is presented. The review indicates that the gasoline demand would be around 44 billion liters by the year 2020 and India has a potential to produce ethanol to the tune of 30 billion liters per annum in addition to existing capacity. Apart from augmenting production of first generation ethanol, the second generation ligno-cellulosic ethanol and thermo-chemical conversion of carbon-rich agricultural/petroleum residues are seen as alternative options. The potential of such alternative feed stocks and ethanol conversion technologies need to be exploited to increase ethanol availability for blending. The review indicates that ethanol is most suitable fuel for spark ignition engines due to its higher octane number. Ethanol blending reduces sulphur, aromatics, olefin and benzene content in gasoline and can reduce vehicular emissions such as hydrocarbon, carbon monoxide and particulate matter.