Octane number Motor

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. 

Regarding product characteristics, European specifications were established in 1992. They concern mainly the motor octane number (MON) that limits the olefin content and which should be higher than 89, and the vapor pressure, tied to the C3/C4 ratio which should be less than 1550 mbar at 40°C (ISO 4256). On the other hand, to ensure easy vehicle start-ups, a minimum vapor pressure for winter has been set which is different for each country and depends on climatic conditions. Four classes. A, B, C, and D, are thus defined in Europe with a minimum vapor pressure of 250 mbar, respectively, at -10°C (A), -5 C (B), 0°C (C) and -t-10°C (Z)). France has chosen class A. 

RON = research octane number MON = motor octane number. 

The CER engine is operated at two conditions to simulate typical on-road driving conditions. The less severe condition measures research octane number (RON) the more severe one measures motor octane number (MON). Table 1 summarizes the operating conditions for each test. 

Parameter Research octane number (ASTM D2699) Motor octane number (ASTM D2700)... 

Polymer Gasoline. Refinery trends tend to favor alkylation over polymerisation. Unlike the alkylation process, polymerisation does not require isobutane. The catalyst is usually phosphoric acid impregnated on kieselghur pellets. Polymerisation of butylenes is not an attractive alternative to alkylation unless isobutane is unavailable. The motor octane number of polymer gasoline is also low, and there is considerable shrinkage ia product volume. The only commercial unit to be built ia recent years is at Sasol ia South Africa. The commercial process was developed by UOP ia the 1940s (104). 

Saturation of olefins other than reactive olefins usually is not desired. The added hydrogen is often expensive or useful elsewhere, and it does not provide any real improvement in product quality. Acmally, product quality may be reduced in the case of gasolines. Research octane number losses may be correlated with increasing olefin saturation. So in many cases, hydrodesulfurization conditions are selected with an eye toward minimizing olefin saturation over and above that needed for product quality improvement. There is one exception saturation of certain olefins shows substantial improvements in Motor octane number. This is true for iso- and n-pentenes and to a lesser extent for higher boiling isoolefins. The higher n-olefins show octane losses upon saturation. 

Volume of olefin/(volume of ionic liquid.hour). i-C = 2,2- and 2,3-dimethylbutanes, i-Cg = isooctanes, TMP trimethylpentanes, = hydrocarbon products with more than eight carbon atoms, Light ends = hydrocarbon products with fewer than eight carbon atoms, RON = research octane number, MON = motor octane number... 

Two octane numbers are routinely used to simulate engine performance the research octane number (RON) simulates gasoline performance under low severity ( 600 rpm and 120°F (49°C) air temperature), whereas the motor octane number (MON) reflects more severe conditions ( 900 rpm and 300°F (149°C) air temperature). At the pump, road octane, which is the average of RON and MON, is reported. 

Motor Octane Number (MON) is a quantitative measure of a fuel to knocking, simulating the fuel s performance under severe operating condition.s (at 900 rpm and at 300°F). 

The motor octane number jc7 was a function of the external isobutane-to-olefin ratio jc8 and the acid strength by weight percent x6 (for the same reactor temperatures and acid strengths as for the alkylate yield x4)... 

The last dependent variable is the F-4 performance number jc10, which was expressed as a linear function of the motor octane number jc7... 

Fig. 14 Hydrogenolysis on metal catalysts product from ring opening reactions of Cl ring contraction compounds and their corresponding research octane number and motor octane number. Adapted from ref. 100.

Table 12.2 Research and motor octane numbers (RON, MON) of C5-C7 alkane isomers.

IPE increment preparation error MON motor octane number... 

Now there are two octane scales, a research octane number (RON) and a motor octane number (MON). RON values reflect performance at 600 rpm, 125°F, and low speed. MON is a performance index of driving with 900 rpm, 300°F, and high speed. Before 1973 RON values were the ones usually... 

Deactivation Energy, Kcal/mole Fraction of ZSM-5 in inventory Catalyst Inventory, tons Deactivation Rate Constant Pre-Exponential Term of Kp Water Partial Pressure Effect Makeup Rate of Base Catalyst, tons/min Makeup Rate of ZSM-5 Catalyst, tons/min Motor Clear Octane Number Base Motor Octane Number Deactivation Order... 

World-Wide there is approximately 1000 tons of fluid cracking catalyst manufactured each day. Of this, about 35% contains some form of aluminum deficient zeolite Y, one whose SiOz/AlaOa ratio exceeds 5.5 1, and whose performance is generally characterized by enhanced olefin formation and higher gasoline research and motor octane number. The aluminum deficient... 

To the extent that motor octane is dependent on aromatic and isoparaffin content, motor octane increases in an FCC unit will be difficult to achieve. Thermodynamics does not allow the production of highly branched isoparaffins in an FCC unit, and blending studies show that motor octane is relatively insensitive to the aromatic content of an FCC gasoline in the range of 35-507e aromatics. However, a more aromatic gasoline may have better blending characteristics in that less aromatics from other sources will be required to achieve the same motor octane number increase. 

Research Octane Number Motor Octane Number... 

Isomerization of paraffins using current octane catalysts under current conditions is favorably away from equilibrium. Additional isomerization activity would make more normal paraffins and a lower octane at FCC temperatures. A much more olefinic gasoline is a possibility. However, additional olefins above the current olefin levels of 10-30% would have decreased effectiveness, especially on the motor octane number. 

FCC Gasoline. The produced light FCC gasoline typically contains a mixture of paraffins, olefins, and aromatic compounds in a ratio of around 5 3 2. This ratio will often vary depending upon feedstock, catalyst quality, and reactor parameters. The research octane number of FCC gasoline will typically be much higher than the motor octane number. 

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. 

TABLE 3-3. Research Octane Number and Motor Octane Number Test Parameters... 

This rating is termed the aviation octane rating (F-3) and is used to simulate lean fuel/air conditions experienced during aircraft cruise operation. The number is determined by ASTM D-2700 MON (motor octane number) procedure and converted to the aviation rating. 

Both motor octane number (MON) and research octane number (RON) values of finished fuel blends are measured using the whole fuel, not individual fuel fractions. However, the octane number contribution of the various fuel fractions can influence the overall knock resistance. Finished fuels with identical RON values may contain fractions with either very similar or widely different octane number values. 

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