1. Biofuel is a renewable and sustainable energy source, while crude oil is non-renewable. Food crops like palm oil or sugarcane can be replenished in a relatively short period of time. Food wastes are readily available and in abundance in big, populated cities. Biofuel made from these sources is renewable and sustainable.
In contrast, crude oil reserves are depleting fast and are projected to run out in decades.
2. Biofuel from food crops is a cleaner source of energy as the carbon dioxide released during its combustion will be offset by the carbon dioxide absorbed during photosynthesis carried out over the food crops’ lifetime.
Crude oil, when combusted, produces air pollutants like sulfur dioxide, and releases carbon dioxide which is not offset by carbon dioxide absorption during photosynthesis.
Category: Fractional Distillation of Crude Oil
Fractional Distillation of Crude Oil
(a) Fractional distillation
(b) In the furnace at the bottom of the fractionating tower, petroleum is heated to 400 oC.
The oil vaporizes and enters the fractionating tower at the bottom.
The temperature of the fractionating tower is highest at the bottom and the temperature decreases going up the tower.
As the hot vapour rises up the column, they cool and condense into the trays at various heights depending on their boiling points.
Lighter fractions with the lowest boiling points are distilled over at the top of the fractionating column.
Heavier fractions with the highest boiling points are collected at the bottom of the fractionating column.
(c) Petroleum gas, petrol, naphtha, paraffin, diesel, lubricating oil, bitumen.
(d) (i) Cracking is the breaking of long chain alkanes into shorter chain hydrocarbons.
(d) (ii) There is lower demand for the longer chain alkanes like lubricating oil, and higher demand for shorter chain alkanes like petrol and naphtha. Cracking allows the conversion of the longer chain alkanes into shorter chain alkanes in order to meet the demand for these shorter chain alkanes.
Explain how crude oil is separated in a fractionating tower.
In the furnace at the bottom of the fractionating tower, petroleum is heated to 400 deg C.
The oil vaporizes and enters the fractionating tower at the bottom.
The temperature of the fractionating tower is highest at the bottom and the temperature decreases going up the tower.
As the hot vapour rises up the column, they cool and condense into the trays at various heights depending on their boiling points.
Lighter fractions with the lowest boiling points are distilled over at the top of the fractionating column.
Heavier fractions with the highest boiling points are collected at the bottom of the fractionating column.