Showing papers on "Gasoline published in 2012"

Hydrogen as an energy carrier: Prospects and challenges

Abstract: This paper provides an insight to the feasibility of adopting hydrogen as a key energy carrier and fuel source in the near future. It is shown that hydrogen has several advantages, as well as few drawbacks in using for the above purposes. The research shows that hydrogen will be a key player in storing energy that is wasted at generation stage in large-scale power grids by off-peak diversion to dummy loads. The estimations show that by the year of 2050 there will be a hydrogen demand of over 42 million metric tons or 45 billion gallon gasoline equivalent (GGE) in the United States of America alone which can fuel up 342 million light-duty vehicles for 51 × 1011 miles (82 × 1011 km) travel per year. The production at distributed level has also been discussed. The paper also presents the levels of risk in production, storage and distribution stages and proposes possible techniques to address safety issues. It is shown that the storage in small to medium scale containers is much economical compared to doing the same at large-scale containers. The study concludes that hydrogen has a promising future to be a highly feasible energy carrier and energy source itself at consumer level.

Elucidating secondary organic aerosol from diesel and gasoline vehicles through detailed characterization of organic carbon emissions

Abstract: Emissions from gasoline and diesel vehicles are predominant anthropogenic sources of reactive gas-phase organic carbon and key precursors to secondary organic aerosol (SOA) in urban areas. Their relative importance for aerosol formation is a controversial issue with implications for air quality control policy and public health. We characterize the chemical composition, mass distribution, and organic aerosol formation potential of emissions from gasoline and diesel vehicles, and find diesel exhaust is seven times more efficient at forming aerosol than gasoline exhaust. However, both sources are important for air quality; depending on a region’s fuel use, diesel is responsible for 65% to 90% of vehicular-derived SOA, with substantial contributions from aromatic and aliphatic hydrocarbons. Including these insights on source characterization and SOA formation will improve regional pollution control policies, fuel regulations, and methodologies for future measurement, laboratory, and modeling studies.

Gasoline emissions dominate over diesel in formation of secondary organic aerosol mass

Abstract: Although laboratory experiments have shown that organic compounds in both gasoline fuel and diesel engine exhaust can form secondary organic aerosol (SOA), the fractional contribution from gasoline and diesel exhaust emissions to ambient SOA in urban environments is poorly known. Here we use airborne and ground-based measurements of organic aerosol (OA) in the Los Angeles (LA) Basin, California made during May and June 2010 to assess the amount of SOA formed from diesel emissions. Diesel emissions in the LA Basin vary between weekdays and weekends, with 54% lower diesel emissions on weekends. Despite this difference in source contributions, in air masses with similar degrees of photochemical processing, formation of OA is the same on weekends and weekdays, within the measurement uncertainties. This result indicates that the contribution from diesel emissions to SOA formation is zero within our uncertainties. Therefore, substantial reductions of SOA mass on local to global scales will be achieved by reducing gasoline vehicle emissions.

Integrated hydropyrolysis and hydroconversion (IH2) for the direct production of gasoline and diesel fuels or blending components from biomass, part 1: Proof of principle testing

Abstract: Cellulosic biomass can be directly converted to hydrocarbon transportation fuels through the use of hydropyrolysis or integrated hydropyrolysis plus hydroconversion (IH2). Hydropyrolysis performed in a fast fluidized bed under 14–35 bar of hydrogen pressure with an effective deoxygenation catalyst directly produces a fungible hydrocarbon product with less than 1 total acid number which can either be directly fed to a refinery or polished in an integrated hydroconversion reactor to produce gasoline and diesel with less than 1% oxygen. Experimental data from a 0.45 kg/h semi-continuous IH2 pilot plant is presented. Economics and life cycle analysis data will be presented later in this series, and will show that by employing IH2 technology, biomass can be converted to gasoline and diesel fuels at delivered costs of less and in some cases significantly less than $1.80/gallon with greater than 90% reduction in greenhouse gas emissions. Larger (2.08 kg/h) long-term continuous pilot-scale testing of the IH2 process will commence in the near future. As a biomass-to-fuels conversion technology, IH2 has the potential to substantially reduce US dependence on foreign oil, thereby reducing the price of transportation fuels and significantly lowering worldwide greenhouse gas emissions. © American Institute of Chemical Engineers Environ Prog, 2011

Fluid Catalytic Cracking of Biomass-Derived Oils and Their Blends with Petroleum Feedstocks: A Review

Abstract: To reduce the carbon footprint and greenhouse gas (GHG) emissions associated with heavy crude oil/bitumen upgrading and refining in the production of clean transportation fuels, researchers are targeting the production of fuels from renewable energy resources. These resources are mainly biomass-derived oils, which include oils produced by biomass pyrolysis (bio-oil), edible and inedible vegetable oils, and animal fats. Over the past 2 decades, research has focused on the evaluation of biomass-derived oil processing using conventional fluid catalytic cracking (FCC), a technology responsible for producing the majority of gasoline in a petroleum refinery. The present review summarizes research associated with the FCC of various biomass-derived oil feedstocks as well as studies related to the co-processing of these oils with conventional petroleum feedstocks. The objective of this review is to present a comprehensive perspective of the effects of renewable oil processing on existing FCC technology, operation,...

The Impact of Ethanol Fuel Blends on PM Emissions from a Light-Duty GDI Vehicle

Abstract: This study explores the influence of ethanol on particulate matter (PM) emissions from gasoline direct injection (GDI) vehicles, a technology introduced to improve fuel economy and lower CO2 emissions, but facing challenges to meet next-generation emissions standards. Because PM formation in GDI engines is sensitive to a number of operating parameters, two engine calibrations are examined to gauge the robustness of the results. As the ethanol level in gasoline increases from 0% to 20%, there is possibly a small ( 30%, there is a statistically significant 30%–45% reduction in PM mass and number emissions observed for both engine calibrations. Particle size is unaffected by ethanol level. PM composition is primarily elemental carbon; the organic fraction increases from ∼5% for E0 to 15% for E45 fuel. Engine-out hydrocarbon and NOx emissions exhibit 10–20% decreases, consistent w...

Effects of Gasoline Direct Injection Engine Operating Parameters on Particle Number Emissions

Abstract: A single-cylinder, wall-guided, spark ignition direct injection engine was used to study the impact of engine operating parameters on engine-out particle number (PN) emissions. Experiments were conducted with certification gasoline and a splash blend of 20% fuel grade ethanol in gasoline (E20), at four steady-state engine operating conditions. Independent engine control parameter sweeps were conducted including start of injection, injection pressure, spark timing, exhaust cam phasing, intake cam phasing, and air–fuel ratio. The results show that fuel injection timing is the dominant factor impacting PN emissions from this wall-guided gasoline direct injection engine. The major factor causing high PN emissions is fuel liquid impingement on the piston bowl. By avoiding fuel impingement, more than an order of magnitude reduction in PN emission was observed. Increasing fuel injection pressure reduces PN emissions because of smaller fuel droplet size and faster fuel–air mixing. PN emissions are insensitive to ...

Modeling HCCI combustion of biofuels: A review

Abstract: The ever increasing energy demands coupled with the limited availability of fossil fuels and the detrimental environmental effects resulting from their use, has guided research toward seeking alternative fuels to gradually substitute conventional ones. Among these, biofuels have received increasing attention due to their attractive features of being renewable in nature and reducing the net CO2 emissions. Biofuels have been used in conventional diesel and gasoline engines either as neat fuels or as supplements. Fortunately, a relatively new combustion concept for internal combustion engines, namely homogeneous charge compression ignition (HCCI) combustion, has been evolved in parallel to the biofuel research. HCCI combustion seems to be able to take advantage of the diverse properties of biofuels, since in this combustion mode ignition is not externally instigated, but relies on the compression and subsequent autoignition of a fuel–air mixture. This fact allows the utilization of different fuels or blends thereof, in order to regulate the ignition point and provide adequate operation under diverse operating conditions. This study provides an overview of existing simulation models for the simulation of biofueled HCCI combustion. Simulation models aid and supplement the experimental research conducted on HCCI combustion, providing a fundamental insight into the physicochemical parameters affecting performance and emissions formation. The simulation models include single-zone models, multi-zone models, probability based models, and multi-dimensional models in order of complexity. The vast majority of these models implement chemical kinetics to simulate the combustion process, not only due to the inherent dependence of HCCI combustion on the physicochemical properties of the fuel, but also due to the sometimes complex chemical structure of the biofuels, which include esters, ethers and alcohols. The reaction paths for these homologous series are quite different from the conventional hydrocarbons used to simulate conventional fuels, and provide the ground for current and future research work.

State of the art of the bioliq® process for synthetic biofuels production

Abstract: Synthetic fuels from biomass (also referred to as BTL, biomass to liquids) may contribute to the future motor fuel consumption to a considerable extent. To overcome the logistical hurdles connected with the industrial use of large quantities of biomass, the de-central-centralized bioliq® concept has been developed. It is based on a regional pretreatment of biomass for energy densification by fast pyrolysis. The intermediate referred to as biosyncrude allows for economic long-range transportation. Collected from a number of those plants, the biosyncrude is converted into synthesis gas, which is cleaned, conditioned, and further converted to fuels or chemicals in an industrial plant complex of reasonable size. Gasification is performed in a high-pressure entrained flow gasifier at pressures adjusted to those of the subsequently following chemical syntheses. For increased fuel flexibility and conversion of ash rich feed materials, the gasifier is equipped with a cooling screen operated in slagging mode. At Karlsruhe Institute of Technology (KIT), a pilot plant has been erected for process demonstration along the whole process chain. The two MWth fast pyrolysis plant is already in operation since 2009; the five MWth gasifier, the hot gas cleaning section, and a gasoline synthesis via dimethylether are to be finished in 2011. Commissioning of that plant complex will follow in 2012. The technology applied in the bioliq® process chain and on the state of construction of the pilot plant is presented. © 2012 American Institute of Chemical Engineers Environ Prog, 2012

Are Emissions of Black Carbon from Gasoline Vehicles Underestimated? Insights from Near and On-Road Measurements

Abstract: Measurements of black carbon (BC) with a high-sensitivity laser-induced incandescence (HS-LII) instrument and a single particle soot photometer (SP2) were conducted upwind, downwind, and while driving on a highway dominated by gasoline vehicles. The results are used with concurrent CO(2) measurements to derive fuel-based BC emission factors for real-world average fleet and heavy-duty diesel vehicles separately. The derived emission factors from both instruments are compared, and a low SP2 bias (relative to the HS-LII) is found to be caused by a BC mass mode diameter less than 75 nm, that is most prominent with the gasoline fleet but is not present in the heavy-duty diesel vehicle exhaust on the highway. Results from both the LII and the SP2 demonstrate that the BC emission factors from gasoline vehicles are at least a factor of 2 higher than previous North American measurements, and a factor of 9 higher than currently used emission inventories in Canada, derived with the MOBILE 6.2C model. Conversely, the measured BC emission factor for heavy-duty diesel vehicles is in reasonable agreement with previous measurements. The results suggest that greater attention must be paid to black carbon from gasoline engines to obtain a full understanding of the impact of black carbon on air quality and climate and to devise appropriate mitigation strategies.

Recycling of waste plastics into fuels. LDPE conversion in FCC

Abstract: In order to study the tertiary recycling of waste polymers in standard FCC units low density polyethylene (LDPE) was dissolved into a commercial vacuum gas oil at 2 and 6 wt.% and converted over two equilibrium FCC catalysts of the octane-barrel and resid types in a CREC Riser Simulator laboratory reactor. The reaction temperatures were 500, 525 and 550 °C, the mass catalyst to oil relationship was 6.35 and the contact times were from 3 to 30 s. The study included the effect of the concentration of LDPE over conversion, the various product (dry gas, LPG, gasoline, LCO and coke) yields and selectivities. Results were very similar for the two concentrations. At typical conversions of 70 wt.%, dry gas and gasoline yields increased about 10 wt.%, LPG yields between 9 and 13 wt.%, LCO yields decreased more than 15 wt.% and coke yields were lower than 7.7 wt.% The RON index of gasoline was improved slightly (up to one point), mainly due to significant increases in olefin concentrations, while the fuel quality of the LCO cut was not affected. LDPE is easily converted and seems to be subjected to primary reactions of catalytic cracking, thus increasing the yields of olefins in the LPG and gasoline boiling ranges. It was concluded that recycling waste LDPE by co-processing it as part of conventional feeds to the FCC would not interfere with the standard operation.

Production of Gasoline and Diesel from Coal Tar via Its Catalytic Hydrogenation in Serial Fixed Beds

Abstract: Clean liquid fuel was produced from the catalytic hydrogenation of coal tar using two serial fixed beds. Hydrofining catalyst of MoNi/γ-Al2O3 and hydrocracking catalyst of WNiP/γ-Al2O3-USY were filled in the first and second fixed beds, respectively. In the initial catalyst screening tests, the typical fixed experimental conditions were as follows: hydrogen pressure of 8 MPa, liquid hourly space velocity of 0.8 h–1, hydrogen-to-tar volume ratio of 1600, temperature in first fixed bed at 360 °C, and temperature in second fixed bed at 380 °C. Gasoline (≤180 °C) and diesel (180–360 °C) fractions were then separated from the effluent oil. Their fuel indexes were determined to assess the hydrogenation performance. The effect of pressure (6–10 MPa) on the hydrogenation performance was also investigated by keeping other experimental conditions constant. The catalysts showed good stability in activity in the test of catalyst life. The analysis results of the products indicated that raw coal tar could be promising...

Methane and nitrous oxide emissions affect the life-cycle analysis of algal biofuels

Abstract: Researchers around the world are developing sustainable plant-based liquid transportation fuels (biofuels) to reduce petroleum consumption and greenhouse gas emissions. Algae are attractive because they promise large yields per acre compared to grasses, grains and trees, and because they produce oils that might be converted to diesel and gasoline equivalents. It takes considerable energy to produce algal biofuels with current technology; thus, the potential benefits of algal biofuels compared to petroleum fuels must be quantified. To this end, we identified key parameters for algal biofuel production using GREET, a tool for the life-cycle analysis of energy use and emissions in transportation systems. The baseline scenario produced 55 400 g CO2 equivalent per million BTU of biodiesel compared to 101 000 g for low-sulfur petroleum diesel. The analysis considered the potential for greenhouse gas emissions from anaerobic digestion processes commonly used in algal biofuel models. The work also studied alternative scenarios, e.g., catalytic hydrothermal gasification, that may reduce these emissions. The analysis of the nitrogen recovery step from lipid-extracted algae (residues) highlighted the importance of considering the fate of the unrecovered nitrogen fraction, especially that which produces N2O, a potent greenhouse gas with global warming potential 298 times that of CO2.

A review on removal of sulfur components from gasoline by pervaporation

Abstract: Desulfurization of gasoline has gained growing importance because of tighter limits of less than 10 ppm sulfur in gasoline in recent regulations. On the other hand, preserving octane rating in gasoline is the most concern subject of the manufacturers. This review focuses on the desulfurization of gasoline by means of pervaporation (PV) process. The process as a new technology has drawn increasing attention and provided an efficient approach for eco-friend sulfur removal in petrochemical industries due to its high selectivity, feasible economics, and safety. Theoretical aspects in selection of materials for the applied membranes and their modifications are investigated. The various parameters including the type and concentrations of sulfur and hydrocarbon species, feed temperature, feed flow rate, and permeate pressure, which influence the performance of PV are discussed.