Hyogoro Aoyama

Determination of polycyclic aromatic hydrocarbons in diesel exhaust particulate matter and diesel fuel oil

Clean-up procedures were developed for a method for determining the amount of polycyclic aromatic hydrocarbons (PAHs) in diesel exhaust particulate matter and in diesel fuel oils using reversed-phase high-performance liquid chromatography (HPLC). They were based mainly on the elimination of insoluble matter and aliphatic compounds that affect the performance of HPLC, from the dichloromethane extracts of particulate matter or from oils, with the aid of a disposable preparation column containing reversed-phase packings (Sep-Pak C18). Using these procedures, it is possible to detect 1 ng of benzo(a)pyrene in 30 mg of particulate matter with more than a 97% recovery or 0.5 ng in 50 microliters of oil with 91% recovery. Examples of analyses are given for particulate matter emitted from a diesel test engine and for diesel fuel oils, such as gas oil, residual oil and coal-liquefied oil.

Enhancement effect of Mg2+ ion on direct nitric oxide decomposition over supported palladium catalysts

Abstract Direct decomposition of nitric oxide to nitrogen and oxygen was investigated on supported palladium catalysts at 550-750°C. It was found that nitric oxide decomposition activities of Pd/MgAl2O4, Pd/MgO, Pd/Mg2Si3,O8 and Pd/MgZrO3, all of which included Mg2+ ions as the constituent of the oxides, were higher than those of Pd/γ-Al2O3, Pt/γ-Al2O3, and Cu/ZSM-5 in this temperature range. Furthermore, Mg2+ ions doped in Pd/γ-Al2O3 enhanced the catalytic activity. These results led us to conclude that Mg2+ ions on palladium catalysts play an important role in enhancing the decomposition activity.

Application of thin-layer chromatography with flame ionization detection to the characterization of organic extracts from diesel exhaust particulates

Thin-layer chromatography with flame ionization detection has been applied to the analysis of organic extracts of diesel exhaust particulates. Non-volatile organics whose boiling points are higher than ca. 300 degrees C can be analyzed, with a detection limit of ca. 0.03 micrograms and a relative standard deviation of ca. 10%. The organic extracts are separated into aliphatics , aromatics and polars by the development procedure with n-hexane, and the polars can be separated further by using toluene as the solvent. Some examples of application are presented.

Evaluation of gaseous and particulate emission characteristics of a single cylinder diesel engine

Abstract Emission characteristics of a single cylinder diesel engine with a swirl chamber were investigated. Specific fuel consumption, exhaust gas temperature, specific mass emissions of CO, total hydrocarbon (THC), nitrogen oxides (NO x ), and particulates were measured. In addition, contents of carbon, hydrogen, CH 2 Cl 2 soluble fraction (SOF), aliphatic hydrocarbons, polar organics, benzo(a)pyrene (B(a)P), and low temperature combustion fraction in the particulates, and the burnout temperature of the particulates were analyzed. All these results were represented as contour maps on a speed-torque plane. The emission of CO and the particulates increased steeply near the maximum speed and torque investigated, whereas the NO x emission was almost independent of speed, increasing as the torque decreased. Content of hydrogen, SOF, aliphatic hydrocarbons, and low temperature combustion fraction showed similar patterns, having the maximum value at 1500 rpm at 1 4 load and decreasing toward 2500 rpm at full load. Burnout temperature of the particulate matter ranged from 673 to 707°C and correlated with the carbon content.

A Study of an Optical Temperature Monitoring Device Sensitive in the Extended Region to Controlled Regeneration of a Diesel Particulate Filter

A device for monitoring the maximum temperature in an extended region was applied to the control of combustion for regeneration of a diesel particulate filter. The devices main objective is to monitor internal thermal radiation of an optically transparent rod probe at its end. In both the experiments using carbon black and real diesel exhaust particulates, a stable regeneration process was realized by controlling the flow rate of air needed for combustion according to the light intensity from the probe.

Evaluation of Highly Refined, Coal Derived Oils Using Passenger Cars.

To evaluate the feasibility of coal derived oil, we conducted tests on accelerating ability from standstill for a car with a spark-ignition engine and exhaust emissions from a diesel-powered car.Two types of fuels were used. One type of fuel had properties equivalent to motor gasoline (JIS K 2202, Grade 2) and the other to gas oil (JIS K 2204, Grade 2). Two kinds of test fuels (G-A and G-B) equivalent to gasoline were prepared by mixing 20‰ of refined oil (A) and 20‰ of refined oil (B) with usual motor gasoline blend stocks, respectively. The oil A was highly hydrotreated and catalytically reformed naphtha de-rived from brown coal, and the oil B from bituminous coal. Two kinds of test fuels (GO-D and GO-E) equivalent to gas oil were prepared by mixing 20% of refined oil (D) and 20‰ of refined oil (E) with a gas oil, respectivly. The oils D and E were highly hydrotreated oil from brown coal but had different boiling ranges. We also used com-mercial gasoline (G-C) and commercial gas oil (GO-F) for reference. Research octane numbers of G-A, G-B and G-C were 91.2, 90.6 and 90.5, and cetane numbers of GO-D, GO-E and GO-F 48, 50 and 55, respectively.The test car A with a spark-ignition engine used was in conformance with the Japanese emissiom standard for gasoline-fueled passenger cars of 1978, and the test car B with a diesel engine with the Japanese emission standard for diesel-powered passenger cars of 1987. Each car was equipped with an automatic transmission system.In the accelerating ability test from standstill for the test car A, the running time over 400m on a flat and straight test course was measured. Running times of the fuels G-A, G-B and G-C were 18.80, 18.80 and 18.72sec, respectively. From these results, we concluded that there is no difference in accelerating ability among the fuels contain-ing the coal-derived oil and commercial gasoline.The exhaust emissions, CO, HC, NOx, particulate matter (PM) and soluble organic fractin (SOF) in PM from the test car B, fueled with GO-D, GO-E or GO-F, were mea-sured under the condition of the Japanese diesel 10 mode test and of constant engine speeds at idling, 20, 40 and 60km/h. A slight increase in mass emissions of CO, HC and NOx by mixing the coal-derived oil with commercial gas oil was noticed under diesel 10mode condition, but these mass emissions were considerably below allowable limits of emission standard. Therefore, it was concluded that the fuel containing coal derived oil would produce no serious problems in terms of exhaust emissions.

Evaluation of middle distillate derived from Battle River coal as diesel-powered automobile fuels from the point of exhaust emissions.

In order to evaluate the feasibility of coal derived middle distil-lates as diesel-powered automobile fuels, mass emission of CO, HC, NOx and particulate matter, and content of soluble organic fraction (SOF) in the particulate matter were measured by operating two types of automobiles fueled with the middle distillate under 10 mode driving cycle, idle condition and constant speed conditions at 20, 40 and 60km/h. One (A) of the automobiles was conformed to Japanese emission standard for indirect injection type dieselpowered lightduty vehicle in 1988 and the other (B) to standard for dieselpowered passenger car in 1986 which required more stringent permissible limit for NOx. The middle distillate (BHD) was obtained from liquefaction of Battle River coal followed by catalytic hydrogenation and distillation ranged from 180 to 350°C. Test fuels BHD-10 and BHD-25 were prepared by mixing 10 and 25vol% of the distillate (BHD) with the gas oil (F), respectively, and test fuel (BHD-25D) by adding 0.5vol% of a cetane booster to the fuel BHD-25.The mass emission of CO, HC and particulate matter emitted from the automobiles A and B increased with the increase of the middle distillate content in the test fuels, but the mass emission of NOx and the content of SOF did not correlate with the middle distillate content for either automobile. These results were almost the same as the results reported in a previous paper except for SOF. The emission from the automobile B showed stronger dependence on the middle distillate content than the other automobile, but the degree of dependence became very small compared with the previous results. Addition of the cetane booster to the mixed fuel improved the ignition quality, that is, the cetane number was raised from 44 to 53, and it decreased the mass emission of CO, HC and particulate matter in the case of automobile B.Although exhaust emission characteristics of the mixed fuel containing the coal derived middle distillate were highly improved by adding the cetane booster and distilling the middle distillate between 180 to 350°C, the improvement of the middle distillate itself, such as lowering of aromaticity, is necessary to use it under more stringent emission standard.

The evaluation of coal derived naphthas as gasoline-fueled automobile fuels by exhaust emissions.

In order to evaluate the feasibility of coal derived naphthas as gasoline-fueled automobile fuels, mass emissions of several substances in exhaust gas from a test automobile were measured by operating the automobile under 10 mode driving cycle and constant speed conditions at 20, 40 and 60km/h, three kinds of test fuels were prepared by mixing three kinds of coal derived naphtha and iso-octane for setting research octane for numbers at around 90. Two naphthas out of three were produced from Wandoan coal (sub-bituminous coal) by a solvent extraction liquefaction and Victoria coal (brown coal) by a direct coal liquefaction, and the rest was a hydrotreated oil of the latter naphtha.Mass emissions of carbon monoxide, hydrocarbons and nitrogen oxides from the test fuels containing 25 vol% of the coal derived naphtha from sub-bituminous coal and 28 vol% of the hydrotreated oil of the naphtha from brown coal were below permissible limits of 10 mode emission standard, but emissions of carbon monoxide and hydrocarbons from the test fuel containing 70 vol% of the naphtha from brown coal were over the permissible limits. These considerable increases resulted from the large content of naphtha, not the variation in the chemical or physical property.

Combustion Quality and Exhaust Gas Characteristics for Unleaded Gasolines (I)

The effect of variation in fuel composition on combustion quality in a modified-CFR engine has been studied with twelve kinds of unleaded test fuels. The modified-CFR engine at a fixed engine speed and load was mainly used under lean conditions of air-fuel ratios. The combustion quality of the fuels was evaluated by measuring three parameters, maximum temperature of combustion gas (Tmax), maximum pressure (Pmax) and flame propagation time (tImax), which represented the combustion quality.It was found that the parameters were expressed as a f unction of excess air ratio, λ, but at fixed λ values they varied largely from fuel to fuel. The aromatic and olefinic content of the fuels correlated with Tmax over a range of λ varied, Pmax at λ=1.1 and tImax at λ=1.0. Similar results were obtained in terms of atomic hydrogen to carbon ratio of the fuels. It was estimated that an engine power increased with decreasing 50% evaporated-temperatures of the fuels.It was concluded that the fuel of which the aromatic and olefinic content was small and the 50% evaporated-temperature was low was desired in consideration of engine power-up and NO emission control at a lean mixture such as λ=1.2.