In this note, we will learn a topic called “What is Cracking of Petroleum in Chemistry?” and Types of Cracking. Welcome to Poly Notes Hub, a leading destination for Engineering Notes for Diploma and Degree Engineering Students.
Author Name: Arun Paul.
What is Cracking of Petroleum in Chemistry?
Petroleum Cracking is a chemical process used in crude oil refining that breaks down large, complex hydrocarbon molecules into smaller, more usable ones. This process is essential for transforming heavy portions of crude oil into valuable products including gasoline, diesel, kerosene, and other petrochemicals.
Types of Cracking in Petroleum
There are three types of cracking in Petroleum –
- Thermal Cracking: Thermal cracking is the use of high temperatures and pressure to break carbon-carbon bonds in heavy hydrocarbons. This process yields lighter fuels and valuable alkenes like ethylene and propylene, which are important feedstocks in the petrochemical sector. Thermal cracking has two common subtypes: steam cracking and visbreaking. Steam cracking, for example, is commonly used to create ethylene from hydrocarbons such as naphtha. Visbreaking, on the other hand, lowers the viscosity of heavy oil residues, resulting in lighter goods like furnace oil. For example, hexadecane (C16H34) can be thermally cracked to provide octane (C8H18) and octene (C8H16).
- Catalytic Cracking: Catalytic cracking, unlike thermal cracking, breaks hydrocarbons at lower temperatures and pressures. This process increases efficiency and produces higher-quality goods, such as gasoline and diesel. Fluidized Catalytic Cracking (FCC) is a popular technique in this category that uses a powdered catalyst to speed up chemical processes. For example, vacuum gas oil, a heavy crude oil fraction, can be transformed into lighter products such as gasoline and olefins using FCC.
- Hydro Cracking: Hydrocracking combines the cracking process with hydrogenation, which occurs when hydrogen gas and a catalyst work together under high pressure. This process is particularly successful for creating ultra-clean fuels such as diesel, jet fuel, and kerosene with low sulfur content. Heavy crude oil fractions, such as vacuum residue, are transformed into lighter hydrocarbons, such as diesel, using hydrocracking.
The importance of petroleum cracking in chemistry stems from its capacity to maximize crude oil utilization, eliminate waste, and fulfill global energy demands efficiently. Thermal cracking, for example, is essential for converting heavy oils into lighter fractions, whereas catalytic cracking enhances fuel quality. In contrast, hydrocracking ensures the creation of ultra-clean fuels by eliminating contaminants.