Hydrocarbons In Exhaust Gases Research Articles

Adsorption and desorption properties of toluene on an Ni-encapsulated Beta zeolite catalyst

Hydrocarbon trap (HCT) catalysts are promising automotive catalysts for purifying hydrocarbons in exhaust gas. Zeolites are suitable for use in these catalysts because of their high durability under hydrothermal conditions. Ni-encapsulated Beta zeolite (Ni@Beta) was obtained with Ni phyllosilicate as the Ni precursor. Ni@Beta exhibited higher toluene adsorption and desorption capabilities than those of Ni-impregnated Beta (Ni/Beta), and the Ni@Beta structure was stable after thermal aging at 900 °C. Moreover, Ni@Beta chemically adsorbed toluene after aging owing to the encapsulated Ni particles, which functioned as adsorption sites. In addition, the introduction of Ga into Ni@Beta improved the structural stability, and thus, the specific surface area was maintained at 80% after thermal treatment. Thus, this study provides an effective strategy for synthesizing HCT catalysts.

Detection of Ammonia and Deuterated Hydrocarbons in Exhaust Gas by Infrared Absorption Spectroscopy during Wall Conditioning

Detection of Ammonia and Deuterated Hydrocarbons in Exhaust Gas by Infrared Absorption Spectroscopy during Wall Conditioning

Use of Hot Hydrocarbons in a Plasma Installation for Application of Wear-Resistant Coatings

Results of comprehensive research on the use of exhaust gases from an internal combustion engine (ICE) as the source of hot hydrocarbons instead of propane-butane or natural gas to reduce oxidative processes are presented. Introduction of hot hydrocarbons in exhaust gases from an ICE is shown to reduce significantly the redox potential of a plasma-torch plasma jet with respect to the sprayed material. An experimental mobile multifunctional plasma installation is developed and enables air-plasma spraying and melting of applied wear-resistant coatings. In this case, the exhaust gases from an ICE are used as the plasma-forming gas.

Analysis of Nitrogen-Containing Hydrocarbons in Exhaust Gas of a SI Engine

Analysis of Nitrogen-Containing Hydrocarbons in Exhaust Gas of a SI Engine

Modelling and simulation of electrochemical analysis of hybrid spark-ignition engine using hydroxy (HHO) dry cell

Nowadays the high consumption rates of fossil fuel and pollution of unburned hydrocarbons in exhaust gases are the major problems that face the world. Using HHO dry cell is suggested for solving these problems at the engines. Experimenting with an actual HHO dry cell is more expensive, and consumes more time and effort. So modelling HHO dry cell usage is very important to save costs and efforts. Different parameters were modelled and evaluated for using HHO dry cell. The experimental tests were performed at the Faculty of Engineering, Suez Canal University on a gasoline engine (Chevrolet Lanos 1.5, model 2012). Beta cell was designed, fabricated and connected to said engine. The cell performance can easily be controlled and adjusted using different parameters. Many different factors were taken into consideration, such as; the cell design, the free space in the car engine, and the plates' overall dimensions. There is a lack in the study of modelling and simulation of hybrid spark-ignition engine using (HHO) dry cell with complete parameters. Therefore, the main objectives of this study are to perform and evaluate the modelling of different parameters that affect the performance of the hybrid spark-ignition engine. Also in this study, two different modelling techniques were used according to the available experimental data; MATLAB code and fuzzy logic modelling. The experimental and modelled results were compared and evaluated according to different statistical methods, such as the coefficient of determination (R2). The results showed that there is strong agreement between the experimental and the modelled fuzzy data, with R2 equaling 0.915 for the hydroxy rate.

ChemInform Abstract: Toxicity and Protective Effects of Cerium Oxide Nanoparticles (Nanoceria) Depending on Their Preparation Method, Particle Size, Cell Type, and Exposure Route

AbstractReview: 82 refs.

Toxicity and Protective Effects of Cerium Oxide Nanoparticles (Nanoceria) Depending on Their Preparation Method, Particle Size, Cell Type, and Exposure Route

AbstractNanoceria (cerium oxide nanoparticles) toxicity is currently a concern because of its use in motor vehicles in order to reduce carbon monoxide (CO), nitrogen oxides (NOx), and hydrocarbons in exhaust gases. In addition, many questions arise with respect to its biomedical applications exploiting its potential to protect cells against irradiation and oxidative stress. Indeed, toxicology studies on nanoceria report results that seem contradictory, demonstrating toxic effects in some studies, protective effects in others, and sometimes little or no effect at all. The variability in the experimental setups and particle characterization makes these studies difficult to compare and the toxicity of newly developed nanoceria materials challenging to predict. This microreview aims to compare the toxicity of nanoceria in terms of preparation method, particle size, concentration, host organism, and exposure method.

Determination of Carbon Oxide in Exhausts of Vehicles by Thermocatalytic Method

Selective methods of thermocatalytic determination of carbon oxide and hydrocarbons in exhaust gases of vehicles are based on measurement of different thermo effects of oxidation of a combustible mixture, obtained from two identical thermosensible elements...

Investigation and analysis into the impact of rapeseed methyl ester biodiesel on the diesel oxidation catalyst performance

The term ‘biodiesel’ refers, in this paper, to the fatty acid alkyl esters derived from vegetable, animal or waste oil feedstocks. Numerous economic and environmental drivers, such as the need for fuel security, the requirement to reduce global carbon dioxide emissions and the volatile price of crude oil, are leading to the production of alternative transport fuels such as biodiesel, and their consumption, in increasing quantities. Most published research has focused on the impact of biodiesel on the engine performance and the emissions and, to a lesser degree, on the intention of understanding the impact on after-treatment systems. Where the after-treatment systems have been considered, studies have mainly concentrated on diesel particulate filters and nitrogen oxide reduction systems. To date, no detailed studies in the open literature have addressed the performance of the diesel oxidation catalyst and, subsequently, this work presents the first thorough examination in this area. This study investigated the relative impacts of thermal and chemical factors, when using rapeseed-based biodiesel, on the performance of a diesel oxidation catalyst. The oxidation reaction intensity inside the catalyst brick was examined and used to identify any possible effects caused by different hydrocarbon speciation when using biodiesel compared with that when using baseline diesel fuel. It was found that the carbon monoxide catalyst conversion efficiency over a legislative driving cycle decreased as the biodiesel percentage increased, with conversion reduced by 10% and 16% for 25% biodiesel fuel blend and 50% biodiesel fuel blend respectively compared with baseline diesel. The reduction in the spatial and temporal average catalyst brick temperature between baseline diesel and 50% biodiesel fuel blend over the New European Drive Cycle was found to be up to 15.5 °C. Catalyst light-off curves showed very similar responses when the engine-out emissions of carbon monoxide and hydrocarbons were closely matched to those of baseline diesel fuel. No statistically significant difference between the light-off temperatures of 50% biodiesel fuel blend and baseline diesel was found, indicating that exhaust gas hydrocarbon speciation did not have a significant impact on the catalyst performance. The results show that the exhaust gas temperature and the energy released during the exothermic reactions within the catalyst are the most significant causes of the variations in the catalyst performance when using biodiesel blends. These findings indicate that the increased use of biodiesel could require after-treatment design and control optimisation to negate an adverse impact on the catalyst light-off time and the catalyst performance.

Combustion Efficiency Impacts of Biofuels

The term biofuel is referred to as liquid fuels for the transport sector that are predominantly produced from biomass. Biofuels are important because they replace petroleum fuels. There are many benefits for the environment, economy, and consumers in using biofuels. The advantages of biofuels such as biodiesel, vegetable oil, bioethanol, biomethanol, and biomass pyrolysis oil as engine fuel are liquid nature-portability, ready availability, renewability, higher combustion efficiency, lower sulfur and aromatic content, and biodegradability. The biggest difference between biofuels and petroleum feedstocks is oxygen content. Biofuels have oxygen levels from 10–45% while petroleum has essentially none making the chemical properties of biofuels very different from petroleum. Oxygenates are just pre-used hydrocarbons having structure that provide a reasonable antiknock value. Also, as they contain oxygen, fuel combustion is more efficient, reducing hydrocarbons in exhaust gases. The only disadvantage is that oxygenated fuel has less energy content.

Hydrocarbon oxidation and three-way catalytic activity on a single step directly coated cordierite monolith: High catalytic activity of Ce0.98Pd0.02O2−δ

Catalytic activity of cordierite honeycomb by a completely new coating method for the oxidation of major hydrocarbons in exhaust gas is reported here. The new coating process consists of (a) dipping and growing γ-Al2O3 on cordierite by combustion of monolith dipped in the aqueous solution of Al(NO3)3 and oxalyldihydrazide (ODH) (or glycine) at 600 °C and active catalyst phase Ce0.98Pd0.02O2−δ on γ-Al2O3-coated cordierite again by combustion of monolith dipped in the aqueous solution of ceric ammonium nitrate, ODH and 1.2 × 10−3 M PdCl2 solution at 500 °C. Weight of active catalyst can be varied from 0.02 wt% to 2 wt% which is sufficient but can be loaded even up to 12 wt% by repeating dip dry combustion. Adhesion of catalyst to cordierite surface is via oxide growth, which is very strong. ‘HC’ oxidation over the monolith catalyst is carried out with a mixture having the composition, 470 ppm of both propene and propane and 870 ppm of both ethylene and acetylene with the varying amount of O2. Three-way catalytic test is done by putting hydrocarbon mixture along with CO (10 000 ppm), NO (2000 ppm) and O2 (15 000 ppm). Below 350 °C full conversion is achieved. In this method, handling of nano-material powder is avoided.

An investigation into the traffic-related fraction of isoprene at an urban location

Continuous hourly measurements of isoprene and 30 other hydrocarbons were performed at an urban centre site in Lille, France, from May 1997 to April 1999. Parallel mass emissions of the same hydrocarbons from in-service passenger vehicles were determined from measurements made on a chassis dynamometer using the European MVEG driving cycle. On the one hand, descriptive statistics and principal component analysis revealed the strong traffic origin of isoprene in winter months and its double biogenic and anthropogenic origin during the summer. On the other hand, the emission measurements of individual hydrocarbons in exhaust gases confirmed the presence of isoprene in petrol fuelled (with or without catalytic converters) and diesel car exhausts. Finally, the isoprene/acetylene ratios, both of them derived from ambient concentrations and emission factors, were compared. No statistically significant difference was found in winter, indicating the strict traffic origin of isoprene during that period. For the winter period, a simple regression analysis was performed on daily isoprene concentrations vs. those of acetylene and three other exhaust gases tracers—propene, ethylene and 1,3-butadiene. The established regression equations, together with the four tracer concentrations, were used to estimate the vehicle exhaust fractions of isoprene. From November to March, vehicle exhaust explained the totality of isoprene levels. While traffic remained the major source of isoprene with a contribution greater than 50% during the growing season, it still constituted a non-negligible source of isoprene in summer, anti-correlated to temperature and fluctuating between 10% and 50%. The application with 1,3-butadiene gives the greatest estimation of the anthropogenic fraction of isoprene. Other sources of 1,3-butadiene, acetylene, ethylene and propene were suspected in addition to their known traffic origin.

Quick sampling GC system for analyzing specific hydrocarbons in exhaust gas

Quick sampling GC system for analyzing specific hydrocarbons in exhaust gas

Adsorbents for hydrocarbons in exhaust gas

Adsorbents for hydrocarbons in exhaust gas

Adsorbents for hydrocarbons in exhaust gases

Adsorbents for hydrocarbons in exhaust gases

A solid electrolyte sensor as an alarm device to detect chlorinated hydrocarbons in exhaust gas

The concept of the combination of an amperometric sensor, based on an Ag 6I 4WO 4 pellet with an ultraviolet decomposition unit, suitable to detect hydrocarbons in the ppmv range is presented. The photolytic breakdown of chlorinated hydrocarbons partially produces chlorine, which can be detected on the sensor element. The mechanism of chlorine detection at the surface of the sensor element is discussed and the detection limits for perchloroethene, trichloroethene and trichloromethane are presented. The t 90 time was found to be in the range of 20 s for all gases tested in the laboratory. The first results obtained suggest the application of this sensor as an alarm device in the control of emission gases.

Flame Photographs of Light Load Combustion Point the Way to Reduction of Hydrocarbons in Exhaust Gas

An investigation to determine why the hydrocarbon content of automobile exhaust gas increases abruptly during deceleration and how this can be prevented is described in this paper. High-speed motion pictures of the flame, taken through a quartz-window cylinder head, show incomplete combustion under these conditions. Additional experiments established that excess residual-gas dilution is the major cause of the incomplete combustion. The concentration of hydrocarbons in the exhaust can be reduced either by admitting extra air and fuel to the intake manifold to limit vacuum attained during deceleration or by shutting off the fuel during deceleration.

Some Effects of Engine-Fuel Variables on Exhaust Gas Hydrocarbon Content

Some Effects of Engine-Fuel Variables on Exhaust Gas Hydrocarbon Content