How do you increase octane in gasoline

Lead is still used in some aviation fuels. Thanks to coordinated efforts, lead is now absent from gasoline in most of the world. Following the lead phase-out in the United States, the oil refining industry chose to construct additional refining capacity to produce octane from other petroleum products, rather than from renewable sources such as ethanol. RFG has an increased oxygenate content, which helps it burn more completely. As a result, RFG lowers the formation of ozone precursors and other air toxics during combustion.

Petroleum refiners were not required to use any particular oxygenate in RFG, but by the late s, a petroleum product, methyl tertiary butyl ether MTBE , was used in 87 percent of RFG due to its ease of transport and blending.

In the Midwest, ethanol was a more common component of RFG. Despite its success at reducing ozone precursors, MTBE was phased out of the gasoline pool due to concerns over its solubility in water, which resulted in the contamination of water resources in numerous states. Currently, 30 percent of gasoline sold in the United States is reformulated gasoline. Ethanol is providing the additional octane required by RFG. At the time, the U. At the same time, EPA and the U. The BTEX complex is a hydrocarbon mixture of benzene, toluene, xylene and ethyl-benzene.

Commonly referred to as gasoline aromatics, these compounds are refined from low-octane petroleum products into a high-octane gasoline additive. While some volume of BTEX is native to gasoline, it is also added to finished gasoline to boost its octane rating. The total volume of BTEX aromatics in finished gasoline depends on the desired octane value and other desired fuel properties.

When faced with the removal of lead as the primary octane provider in gasoline, refiners had two available alternatives, BTEX and ethanol. The refining industry invested in additional refining capacity to replace lead with BTEX, a high-octane petroleum refining product.

As a result of its substitution for lead, BTEX volume rose from 22 percent to roughly a third of the gasoline pool by In premium gasoline grades, the BTEX volume content was as high as 50 percent. In mandating cleaner fuels, through reformulated gasoline and other programs, EPA has reduced the volume of aromatics to between 25 to 28 percent of the conventional gasoline pool, though some health professionals question the safety of even these levels.

After the lead phase-out, there were early concerns regarding the BTEX complex. Today, health research indeed suggests that even very low-level exposure to the BTEX complex, from gasoline additives and other petroleum products, may contribute to negative developmental, reproductive and immunological responses, as well as cardio-pulmonary effects. Upon incomplete combustion of the BTEX complex contained in gasoline, ultra-fine particulates UFP and polycyclic aromatic hydrocarbons PAHs are formed, which carry their own adverse health impacts even at low levels.

Both UFP and PAHs have also been linked to developmental and neurodegenerative disorders, cancers, and cardio-pulmonary effects. Considerable attention has been given to benzene in fuel, as it is highly toxic.

At the same time, the partial replacement of benzene with other aromatic compounds xylene, ethyl-benzene, toluene may not be sufficient in reducing exposure to BTEX's toxic effects.

The other aromatics, such as toluene and xylene, are not capped. Early automakers expressed interest in plant-based alcohol fuels, such as ethanol. Henry Ford designed the first Model T to run on ethanol. But, at the time, gasoline was a much cheaper fuel. Fuel chemists had not only developed an inexpensive way to raise octane numbers, but also discovered a way to reduce valve seat recession and extend valve life.

Lead substitutes became common on our store shelves, and machine shops saw an increase in requests for hardened valve seat inserts and cylinder head repairs on older vehicles. While lead substitutes are intended for older engines usually without catalytic converters , octane boosters are popular additives among all types of vehicle owners, especially performance enthusiasts.

MMT is a common ingredient in lead substitutes as well as unleaded gasoline, while the others are hydrocarbons derived from gasoline production itself. Ethanol is also a popular ingredient in octane boosters, because on its own, ethanol already has a very high octane rating roughly Supplementing regular 87 octane or mid-grade 89 octane gasoline with a quality octane booster may be beneficial to hard-working, high-compression engines, especially in hot weather.

Octane boosters generally also contain detergents, stabilizers and other chemicals to help maintain a healthy fuel system. The front runners right now for future fuel or alternative fuel are natural gas and propane, due to relatively cheap cost and large amounts available. Bad gasoline is not a myth. These PRFs are used to bracket a given fuel sample to determine the pressure at which similar knock intensities are observed.

To determine the RON, the fuel is tested under engine idle conditions with a low air temperature and slow engine speed. To determine the MON the fuel is tested under the more stressful conditions of higher air temperature and engine speed. Current designs see image below allow the same engine to perform both tests.

Despite this flexibility, many testers still prefer to use more than one machine with each specifically set up and calibrated to perform either RON or MON tests. Gasoline explained. What is energy? Units and calculators.

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