Research Octane Method

Motor octane method a test for determining the knock rating of fuels for use in spark-ignition engines see also Research octane method. 

The feed after hydrotreating and drying in absorber 1 passes to reactor 2. Reactor 2 is a fixed bed reactor. Together with the feed in reactor 2 the promoter (HC1) is within 10 4% of the feed. The liquid product from reactor 3 is separated from the propane fraction in separator 3. The octane number of the product from this unit is approximately 90, according to the research octane method. 

There are two standard procedures for determining the octane numbers Research or FI and the Motor or F2 methods. The corresponding numbers are designated as RON (Research Octane Number) and MON (Motor Octane Number) which have become the international standard. 

Engine knock is measured by two ASTM methods, ASTM D-2699 and D-2700. Method ASTM D-2699 is identified as the research octane number (RON) and method ASTM D-2700 is identified as the motor octane number (MON). The primary differences between these two methods are summarized in TABLE 3-3. 

Aromatic hydrocarbons have exceptionally high engine characteristics. The Research octane numbers of all aromatic hydrocarbons thus far measured are above 100. Those measured by the Motor method are a little lower, but in all cases are above 95. The critical compression ratios at 600 revolutions per minute and 212° F., jacket temper-... 

Several patents discuss the use of Raman spectroscopy to determine the properties of finished products.93 94 For reformulated gasoline, some of these properties include sulfur, olefin, benzene, volatile organic carbon (VOC), nitrogen oxides (NOx), aromatic contents, total air pollutants (TAPs), Reid Vapor Pressure (RVP), distillation properties, motor and research octane numbers, and drivability. For the octane numbers, the accuracy of the Raman method was limited by errors in the reference method. 

Methyl tertiary butyl ether (methyl-r-butyl ether, MTBE boiling point 55°C, flash point -30°C) has excited considerable interest because it is a good octane enhancer for gasoline (it blends as if it had a research octane number of 115 to 135). It also offers a method of selectively removing isobutylene from a mixed C4 stream, thus enabling the recovery of high-purity butene-1. Furthermore, methyl tertiary butyl ether can be isolated, then cracked to yield highly pure iso-butylene and methanol. 

The more severe conditions of the motor method have a greater influence on commercial blends than they do on the reference fuels. Thus, a motor octane number (MON) of a commercial blend often has a lower research octane number (RON). Consequently, blended fuels use an arithmetic average of both ratings—MON and RON—and can be abbreviated as (R + M)/2. 

Considerably more acid had to be added to the reaction mixture however In order to obtain second-step reactions as compared to first-step reactions. Operating procedures and methods of obtaining hydrocarbon samples for analysis were essentially Identical to those used In the first-step investigation. Yields and research octane numbers (RON) were calculated based on the analysis of the hydrocarbon product as reported earlier (2). 

The reactor effluent was analyzed by on-line GC-analysis prior to condensation. Each reactor line was equipped with a HP 5890 GC with flame ionization detector (FID), interfaced with a PC for data handling and storage. The method of analysis, based on HP s PONA analysis, included all important hydrocarbons up to C,. Heavier components than this were only present in trace amounts, and were not analyzed. Research octane numbers (RON) were calculated from GC-analysis based on an adapted version of the method presented by Anderson et al. (5). The hydrogen yield was calculated from GC-analysis as the hydrogen balance over the reactor. 

The original CFR test conditions appear in the second column of Table 7.2. These constitute the Research method and assign the fuel a Research octane number (RON). It was found that typical fuel susceptibility to knock in practical engines did not correlate sufficiently well with this test and one with rather more severe conditions - the Motor method, giving the Motor octane number (MON) - now also is used. These conditions are given in the third column. The inlet manifold temperature and speed have been increased, spark timing advanced, and a shrouded inlet valve fitted to... 

ASTM D2699, Standard Test Method for Research Octane Number of Spark-Ignition Engine Fuel, ASTM International. 

Used as "clear Motor method with the clear Research octane numbers, and as "leaded with the "leaded columns. 

Slightly larger for Research octane numbers and slightly lower for Motor method numbers. 

Measurement of octane numbers is carried out using a reference motor called CFR (Cooperative Fuel Research), referring to a series of studies conducted in 1928 in the United States in order to standardize the methods for characterizing motor fuels. 

R — Research method octane rating, ASTM D2699 M = motor method octaine rating, ASTM D2700. 

The boiling point, refractive index, and density of the olefin derivative of any paraffin were shown, by use of Table III, to stand in the onier of their olefin type. Table X contains the engine data of the olefin derivatives of 2-methylpentane and 3-methylpentane, recorded in the order of their olefin type. No consistent relations between octane numbers or critical compression ratios are obvious—but the blending octane numbers of these branched olefins, as measured by both the research and Motor methods, do generally stand in the order of their type. Two olefins of type III form exceptions, the exceptions being in one case too high and in the other case too low. 

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