What is thermal cracking and catalytic cracking?

Definition. Thermal Cracking: Thermal cracking is the process of breaking down large compounds into small compounds at high temperatures and high pressures. Catalytic Cracking: Catalytic cracking is the breakdown of large compounds into small hydrocarbons using an acid catalyst.

What is meant by catalytic cracking?

Catalytic cracking is an important process in the oil industry where petroleum vapor passes through a low-density bed of catalyst, which causes the heavier fractions to 'crack' producing lighter more valuable products. In the petrochemicals industry they are used for producing polyolefins on a very large scale.

What is thermal cracking reaction?

Cracking is a reaction in which greater saturated hydrocarbon molecules are broken down into smaller, more functional hydrocarbon molecules, some of which are unsaturated: alkanes are the initial starting hydrocarbons.

What are the 2 types of cracking?

Why is catalytic cracking better than thermal cracking?

Furthermore, sulfur compounds are changed in such a way that the sulfur content of catalytically cracked naphtha is lower than in thermally cracked naphtha. Catalytic cracking produces less cracked residuum and more of the useful gas oils (which can be used as hydrocracker feedstocks) than thermal cracking.

A Level Chemistry Revision "Thermal Cracking and Catalytic Cracking of Alkanes"

What are the advantages of thermal cracking?

One advantage of thermal cracking for fuels production, which is apparent from eq 3, is that the cracking rate decreases with decreasing carbon chain length. It thereby suppresses the overcracking of naphtha and distillate to lighter products and explains why thermal cracking inherently has a low gas make.

What are the products of thermal cracking?

In thermal cracking, high temperatures (typically in the range of 450 °C to 750 °C) and pressures (up to about 70 atmospheres) are used to break the large hydrocarbons into smaller ones. Thermal cracking gives mixtures of products containing high proportions of hydrocarbons with double bonds - alkenes.

What are the types of catalytic cracking?

The three types of catalytic cracking processes are fluid catalytic cracking (FCC), moving-bed catalytic cracking, and Thermofor catalytic cracking (TCC). The catalytic cracking process is very flexible, and operating parameters can be adjusted to meet changing product demand.

What is catalytic cracking in organic chemistry?

Catalytic cracking is an important process in the oil industry where petroleum vapor passes through a low-density bed of catalyst, which causes the heavier fractions to 'crack' producing lighter more valuable products. In the petrochemicals industry they are used for producing polyolefins on a very large scale.

What is a catalyst in chemistry?

A catalyst is a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction. Catalysis is the process of adding a catalyst to facilitate a reaction.

What is produced from catalytic cracking?

The catalyst promotes breaking of the large molecules in a certain way that maximizes the yield of gasoline. Ideally, all of the “cat-cracked” product would be in the gasoline range, but the technology is not that capable. Cat cracking produces a full range of hydrocarbons, from methane to residue.

How many catalysts are there?

Catalysts are primarily categorized into four types. They are (1) Homogeneous, (2) Heterogeneous (solid), (3) Heterogenized homogeneous catalyst and (4) Biocatalysts. 1) Homogeneous catalyst: In homogeneous catalysis, reaction mixture and catalyst both are present in the same phase.

What are thermal and catalytic cracking of petroleum?

The use of thermal cracking units to convert gas oils into naphtha dates from before 1920. These units produced small quantities of unstable naphthas and large amounts of by-product coke.

Why cracking is a thermal decomposition?

There is a much greater demand for shorter hydrocarbon than there is for the longer hydrocarbons. Long chain hydrocarbons can be broken into smaller hydrocarbons, by heating with a catalyst. This is a thermal decomposition reaction known as cracking.

What is the temperature of thermal cracking?

In thermal cracking, high temperatures (typically in the range of 450°C to 750°C) and pressures (up to about 70 atmospheres) are used to break the large hydrocarbons into smaller ones. Thermal cracking gives mixtures of products containing high proportions of hydrocarbons with double bonds - alkenes.

Which gas is known as cracking gas?

This process employs hydrogen gas to improve the hydrogen-carbon ratio in the cracked molecules and to arrive at a broader range of end products, such as gasoline, kerosene (used in jet fuel), and diesel fuel.

What is cracking explain with example?

The decomposition of a compound by heat in the absence of air is called Pyrolysis. When pyrolysis occurs in alkanes, the process is termed as cracking. For example: Alkanes on heating under high temperature or in the presence of a catalyst in absence of air broken down into lower alkanes, alkenes and hydrogen.

What are the example of thermal cracking?

Thermal cracking remains important, for example in producing naphtha, gas oil, and coke, and more sophisticated forms of thermal cracking have been developed for various purposes. These include visbreaking, steam cracking, and coking.

What is the difference between catalytic cracking and thermal cracking of vacuum distilled crude oil residue?

Compared to thermal cracking, catalytic cracking occurs at lower temperatures and pressures, is more selective and flexible, and incorporates a catalyst. Catalytic cracking processes have evolved over the years, and are an exemplary display of chemical engineering.

Who discovered thermal cracking?

The first thermal cracking process for breaking up large nonvolatile hydrocarbons into gasoline came into use in 1913; it was invented by William Merriam Burton, a chemist who worked for the Standard Oil Company (Indiana), which later became the Amoco Corporation.

Which catalyst is used during catalytic cracking of petroleum?

Catalytic cracking

Modern cracking uses zeolites as the catalyst. These are complex aluminosilicates, and are large lattices of aluminium, silicon and oxygen atoms carrying a negative charge. They are, of course, associated with positive ions such as sodium ions.

What are 3 types of catalyst?

Catalysts can be categorized as homogeneous, heterogeneous, or enzymatic. Homogeneous catalysts exist in the same phase as the reactants, whereas heterogeneous catalysts exist in a different phase than the reactants.

What are the two types of catalyst?

What is a FCC unit?

An FCC unit is a fluid catalytic cracking unit, which is a type of process that is used in refining crude oil into gasoline. The expansion joints used for the service are called stand pipe expansion joints.