Chapter 68, Problem 1RQ

What is the difference between summer-blend and winter-blend gasoline?

To determine

Difference between summer-blend and winter-blend gasoline.

Explanation of Solution

Gasoline:

Gasoline is the mixture of various hydrocarbons. Gasoline is refined from the crude petroleum oil. Gasoline is combusted along with air in the cylinder of the engine to produce required power output.

Volatility:

It is one of the properties of the gasoline to become vaporize. Gasoline should be vaporized to mix with air for proper combustion. Thus, the gasoline should possess good volatile property. The pressure and temperature of the atmosphere play a significant role in vaporizations of gasoline. The unit RVP (Reid vapor pressure) measures the volatility of a gasoline. RVP is the pressure of the vapor that is present above the fuel level when temperature of the fuel is 100°F (38°C).

Seasonal blending:

To normalize the pre or post vaporization of gasoline, blending is introduced into gasoline, depending on the seasonal pressure and temperature. It is classified into two types as follows:

1. 1. Summer-blending – Do not vaporize at low temperatures.
2. 2. Winter-blending - Vaporize at low temperatures.

Both the summer and winter blended gasolines are specially formulated gasolines to achieve proper and complete combustion depending on the season.

Difference between summer and winter blended gasoline:

The significant difference between the summer and winter blended gasoline is volatility. The volatility of summer-blended gasoline should be 7 PSI RVP and the volatility of winter blended gasoline should be 15 PSI RVP. The volatility of summer-blended gasoline should not exceed 10.5 PSI RVP.