FORENSIC INVESTIGATION OF PETROLEUM COMPONENTS OF MIXED MOTOR GASOLINES

The main types of petroleum components that are used in the manufacture of mixed motor gasolines are considered. For the manufacture of mixed motor gasolines, a low-octane base is used, to which high-octane components are added. In many cases, reformate (catalytic reforming gasoline) and isopentane (isopentane fraction) are used as high-octane components of mixed motor gasolines. Straight-run gasoline and stable gasoline are often used as the low-octane gasoline base of blended automobile gasolines. Reformate is a liquid mixture of aromatic and saturated hydrocarbons used as a high-octane component of automobile (aviation) gasolines and raw materials in the production of aromatic hydrocarbons (arenas). The reformate is obtained by catalytic reforming of straight-run gasoline fractions. Isopentane (2-methylbutane (CH3)2CHCH2CH3) is a colorless, flammable liquid. The technical product is a mixture of isomeric pentanes and boils within 24 - 34°C. The isopentane fraction can be isolated from gas gasoline, from gasoline direct distillation of oil and gasoline catalytic cracking. Straight-run gasoline (nefras) is obtained from the processing of crude oil or gas condensate, oil shale or coal, natural gas or oil and gas. Straight run gasoline contains light gasoline fractions of direct distillation of oil with a boiling range of 35 - 180°C. Gas gasoline (gas stable gasoline) is obtained from natural and petroleum gases containing vapors of gasoline hydrocarbons. To separate them, the gases are compressed and cooled (compression method) or absorbed with oil or activated carbon. Gas gasoline is similar in chemical composition to straight-run gasoline, but contains lighter hydrocarbon fractions. The article discusses the results of a study of the listed petroleum components of mixed gasoline by gas-liquid chromatography. This method allows you to establish the qualitative and quantitative composition of mixed motor gasolines and their components. It is shown that from readily available petroleum components (isopentane fraction, aromatic hydrocarbons and gas stable gasoline) without the use of sophisticated technological equipment, a gasoline mixture with high detonation resistance, which is falsified automobile gasoline, can be obtained by mixing method. When mixed in certain proportions of reformate, isopentane fraction and gas stable gasoline, it is possible to obtain marketable gasoline that will meet the requirements of regulatory documents for gasoline. The considered technology allows, when mixing commodity gasolines A-92 (A-95) with reformate, isopentane fraction and gasoline gas stable in the calculated proportions, to improve the operational characteristics (detonation resistance) of the obtained gasoline mixture or to increase the volume of the obtained gasoline mixture without improving its performance.

Research on the effects of idling start-stop function on light vehicles fuel consumption and emission under different cycle conditions

The idling distribution characteristics of NEDC, WLTC and CLTC conditions were analyzed, and the exhaust emissions and fuel consumption of three light gasoline vehicles when the idling start-stop function was turned on and off under different cycle conditions were measured. The effects of idling start-stop function on light vehicle fuel consumption and emissions under different cycle conditions were analyzed. The results show that the vehicle fuel saving rate of the idling start-stop function in three cycle conditions is WLTC, NEDC and CLTC conditions from low to high. The idling start-stop function has little effect on vehicle gaseous pollutant emissions. On the whole, the the activation of idling start-stop function increases the THC and CO emissions and reduces NOx emissions.

Hydro-catalytic isomerization of light gasoline fraction of Zhanazhol field’s oil

The purpose of the present work is to show that light straight-run gasoline fraction can be used as feedstock for hydro-catalytic isomerization process, and the isomerized product can serve as a component for obtaining pure ecological commercial gasoline brand Euro-4 and Euro-5. Transformation of n-alkanes of Zhanazhol oil’s light gasoline fraction with boiling temperature 180°C was studied. Isomerization was carried out in a flow unit with a stationary layer of modified sample of industrial aluminum-platinum catalyst at 200-300°C and 2.0-4.0 MPa, with volume feed rate of 1.0-3.0 h-1 and circulation ratio of hydrogen containing gas circulation 1000-1500 m3/m3 of catalyst feed. Light gasoline fraction are subjected to a number of chemical transformations: n-paraffins isomerization, five-membered and six-membered cycloalkanes dehydroisomerization and hydrocracking. n-Alkanes are isomerized in iso-alkanes, naphthenic hydrocarbons are first subjected to hydrocracking with opening the cycle and forming n-alkanes, which are then isomerized into iso-alkanes. Thus, the reaction products contain isopentane, 2,3-dimethylbutane with octane number 92 and 104 correspondingly, and other iso-paraffinic hydrocarbons that lead to raise of gasoline octane number. By study of individual hydrocarbon composition of feedstock and isomerizate it is possible to establish some regularities hydrocarbons in the process of hydro-catalytic isomerization of light gasoline fraction.

Non-Regulated Emissions and PN of Two Passenger Cars with Diesel-Butanol Blends

Biofuels represent one of the alternatives to obtain the CO2-neutral propulsion of IC-engines. Butanol, which can be produced from biomass, is considered and was investigated in the last years due to the very advantageous characteristics of this alternative fuel. Butanol can be easily and irreversibly blended both with light (gasoline) and heavier (Diesel) fuels. Comparing with ethanol it has the advantages of: higher calorific value, lower hygroscopicity and lower corrosivity. It can replace the aviation fuels. This paper presents the emission results obtained on two Diesel passenger cars with different technology (Euro2 and Euro6c) and with addition of Butanol to Diesel fuel, as a part of the research project DiBut (Diesel and Butanol). Interesting results are given about some non-legislated (non-regulated) components, Acetaldehyde (MeCHO) and Formaldehyde (HCHO) and about the PN-emissions with/without DPF.

Formic Acid as a Hydrogen Donor for Catalytic Transformations of Tar

Specific features of the catalytic tar cracking in the presence of formic acid, BEA zeolite and 8% Ni-2.5% Mo/Sibunit catalyst were studied at 350 °C and 1.0 MPa pressure. The obtained results evidenced that formic acid can be used as a hydrogen donor during catalytic reactions. The formic acid addition made it possible to perform efficient hydrocracking of heavy feed such as tar. It was found that both the tar conversion and selectivity to light (gasoline-diesel) fractions grew in the sequence: tar < (tar - formic acid) < (tar - formic acid - BEA zeolite) < (tar - formic acid - BEA zeolite - 8% Ni-2.5% Mo/Sibunit catalyst). Furthermore, significantly lower concentrations of impurities containing sulfur and nitrogen were observed for the (tar - formic acid - BEA zeolite - 8% Ni-2.5% Mo/Sibunit catalyst) system. For example, the sulfur and nitrogen concentrations in the tar precursor were 1.50% and 0.86%, respectively. Meanwhile, their concentrations in the liquid products after the catalytic cracking were 0.73% and 0.18%, respectively.

N-METHYLPYRROLIDONE – SELECTIVE SOLVENT FOR OXIDATIVE DESULFURIZATION OF LIGHT GASOLINE FRACTIONS

The extraction of various sulfur-containing compounds occurring in the oil and condensate fractions using solutions based on N-methylpyrrolidone was studied. The extracts can later be used in the organic/electrochemical synthesis of valuable organosulfur compounds. By the example of a model mixture, the solvent is shown to be selective to various classes of organic sulfur compounds: thiols, mono-, di-, and trisulfides. It is established that the solvent exhibits the greatest affinity to aromatic sulfur compounds. The extraction degree increases from mono- to di- and trisulfide. In the case of aliphatic thiols, a decrease in the degree of extraction is observed with an increase in the length of the hydrocarbon group. The optimal parameters of extraction with mixtures based on N-methylpyrrolidone for light gasoline fractions BPT-90 °C and BPT-120 °C were set: the temperature – 35 °C, the ratio solvent - feedstock is 1 to 1. In the series of different mixtures of solvents, a selective solvent based on dimethyl carbonate (5% by weight) showed the highest efficiency. At the same time, the highest raffinate yield with a moderate total sulfur content is observed for the solvent with H2O (5% by weight). A multi-stage extraction of sulfur components from gasoline fractions using the mixture N-methylpyrrolidone with H2O allowed reducing the content of organic sulfur compounds by 7-10 times. A combined process based on the extraction of thiols from model mixtures and its oxidation by o-benzoquinones is proposed. Unlike the more aggressive oxidizing agents o-benzoquinones depending on the structure ensure the utilization of thiols to thioethers or disulfides.

Modelling organic aerosol over Europe in summer conditions with the VBS-GECKO parameterization: sensitivity to secondary organic compound properties and IVOC emissions

The VBS-GECKO parameterization for secondary organic aerosol (SOA) formation was integrated in the chemistry-transport model CHIMERE. Concentrations of organic aerosol (OA) and SOA were simulated over Europe for the July–August 2013 period. Simulated concentrations with the VBS-GECKO were compared to results obtained with the former H2O parameterization implemented in CHIMERE and to observations from EMEP, ACTRIS and other observations available in the EBAS database. The model configuration using the VBS-GECKO parameterization slightly improves the performances compared to the model configuration using the former H2O parameterisation. The VBS-GECKO model configuration performs well for stations showing a large SOA concentration from biogenic sources, especially in northern Europe but underestimate OA concentrations over stations close to urban areas. Simulated OA was found to be mainly secondary (~ 85 %) and from terpene oxidation. Simulations show negligible contribution of the oxidation of mono-aromatic compounds to SOA production. Tests performed to examine the sensitivity of simulated OA concentrations to hydro-solubility, volatility, ageing rates and NOx regime have shown that the VBS-GECKO parameterization provides consistent results, with a weak sensitivity to changes in the parameters provided by the gas phase mechanism included in CHIMERE (e.g. HOx or NOx concentrations). Different emission scenarios (from heavy diesel to light gasoline fleet) were tested to examine the contribution of S/IVOC oxidation to SOA production. At the continental scale, these simulations show a weak sensitivity of OA concentrations to the vehicle fleet. At the local scale, accounting for IVOC emission was found to lead to a substantial increase of OA concentrations in the plume from urban areas, especially if diesel fleet case is assumed. This additional OA source remains too small to explain the gap between simulated and measured values at stations where anthropogenic sources are dominant.