Cracking is done in the absence of oxygen and in the presence of a catalyst. It is widely used to convert the highboiling, highmolecular weight hydrocarbon fractions of petroleum crude oils into more valuable gasoline, olefinic gases, and other products. After fractional distillation there are a large number of longchain hydrocarbons left. When hydrocarbons burn they are reacting with oxygen in the air. Burning hydrocarbons burning hydrocarbons is the main source of energy that the world uses today thus making it the most valuable energy resource. Hydrocracking catalysts consist of active metals on solid, acidic supports and have a dual function, specifically a cracking function and a hydrogenation function. Ppt hydrocarbons powerpoint presentation free to view. When the hydrocarbon molecules are broken up in a random way as a product a mixture of shorter hydrocarbons chains is expected. The simplest alkanes are hydrocarbons compounds that contain only carbon and hydrogen. The factors responsible for the formation of products during cracking are. Download hires image download to mspowerpointcite this.
Depending on the end product, the oils can go directly into fuel blending, or they can be routed through further cracking reactions or other. Petroleum and natural gas are the major sources of aliphatic hydrocarbon while coal is an important source of aromatic hydrocarbons. Saturated hydrocarbons contain carboncarbon and carbonhydrogen single bonds. Generally, the rate of cracking and the final products. Ppt alkanes and alkenes powerpoint presentation free. Fluid catalytic cracking fcc is one of the most important conversion processes used in petroleum refineries. Most of the pahs with low vapour pressure in the air are adsorbed on particles. Naming an organic compound by interprating the formula. C 3 h 7 oh the following is an alcohol as we can see a oh group is attached to it, with three. The process of breaking higher hydrocarbons with high boiling points into a variety of lower hydrocarbons that are more volatile low boiling, is called cracking or pyrolysis. In this unit, you will learn more about hydrocarbons. During the refining process, crude oil is separated into fractions having similar boiling points. Understanding the kinetics and mechanisms of hydrocarbon thermal cracking. Boost engagement with internal communication videos.
Alkanes and alkenes 1 organic chemistry alkanes and alkenes 2 pure hydrocarbons. They are, of course, associated with positive ions such as sodium ions. Use of a catalyst acts under much less severe operating conditions than in thermal cracking. If different carbon atoms are joined together to form open chain of carbon atoms with single bonds, they are termed as alkanes as you have already studied in unit 12. In cracking, the hydrocarbon molecules randomly break into smaller hydrocarbon compounds. In general, the smaller the molecule the better it will mix and then react with the air.
Thermal cracking thermal cracking is used for conversion of residues and higher mol. First, crack the vapour of liquid paraffin by passing it over a heated catalyst to produce and collect a mixture of gaseous shortchain hydrocarbons. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby. Cracking of petroleum hydrocarbons was originally done by thermal cracking, which has been almost. Over a million stunning new images at your fingertips. Since catalyst speed upretard the rate of reaction, if cracking is carried out in the presence of catalyst the rate of desired reactions cracking of heavy hydrocarbons into gasoline range hydrocarbons can be. Steam cracking process ethylene is almost exclusively produced by thermally cracking petroleum hydrocarbons in the presence of steam over 97% of the annual volume, in a process known as steam cracking or pyrolysis 7, whose simplified flowsheet is shown in figure1. C 5 h 10 the following formula satisfies the general formula of alkene and consists of 5 carbon atoms.
They have a relatively low solubility in water, but are highly lipophilic. Catalytic cracking large hydrocarbons are broken into smaller molecules using heat and a catalyst. In addition to breaking heavier hydrocarbons into molecules of the size range. For example, a higher hydrocarbon c 1 0 h 2 2 splits according to the reaction. Steam cracking adopted produce large amounts of ethene, propene and butene for making plastics cracking plants in jurong island and pulaubukom in the singapore context steam cracking plant in singapore jurong island pulaubukom. Catalytic cracking is similar to thermal cracking except. Thus, you can well understand the importance of hydrocarbons in your daily life.
Other compounds in crude oil contain not only carbon and hydrogen, but also small but important amounts of other hetero elements most notably sulfur, as well as nitrogen and certain metals e. Fluid catalytic cracking, or fcc, is the last step in the evolution of cat cracking processes also introduced in 1942, just like tcc or thermafor cat cracking, during the second world war in an effort to make highoctane number gasoline. Hydrocarbons main idea hydrocarbons are carboncontaining organic compounds that provide a source of energy and raw materials. Catalytic cracking of hydrocarbons in a crec riser simulator using a yzeolite based catalyst. Fundamentals of chemical technology and chemicals management laboratory.
Minimal cracking minimal conversion 10% to 20% typical products suitable for further processing or final blending reforming, catalytic cracking, hydrocracking hydrocracking severe form of hydroprocessing break carbon. C7c9 hydrocarbons a tmospheric gas oil kerosene diesel fuel heavy fractions lubricating oil residual or heavy fuel oil asphalt or resid boiling point range below 701400c 175275ec above above comments similar to natural gas. The result is that the hydrocracking products are essentially free of sulfur and nitrogen impurities and consist mostly of paraffinic hydrocarbons. C 3 h 8 the following formula satisfies the general formula of alkane, and consists of 3 carbon atoms.
Hydrocarbons cracking is important industrial process for olefins largescale production. Worlds best powerpoint templates crystalgraphics offers more powerpoint templates than anyone else in the world, with over 4 million to choose from. Download in free pdf hydrocarbons are composed of carbon and hydrogen. Model the industrial process of cracking larger hydrocarbons to produce smaller alkanes that can be converted into petrol. Cracking is the most important process for the commercial production of gasoline and diesel fuel. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or longchain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking of carboncarbon bonds in the precursors. Cracking of petroleum yields light oils corresponding to gasoline, middlerange oils used in diesel fuel, residual heavy oils, a solid carbonaceous product known as coke, and such gases as methane, ethane, ethylene, propane, propylene, and butylene. Realworld reading link if you have ridden in a car or a bus, you have used hydrocarbons. Cracking reactions involving heavy molecules contribute to lowering the specific gravity and forming light products, such as gas and light naphtha, in the hydrocracker products. Best igcse organic chemistry notes complete breakdown. Steam cracking, ethane, propane, naphtha, kinetics, feed characterisation ix. The gasoline and diesel fuel that are used in cars, trucks, and. Catalytic cracking presentation free download as powerpoint presentation.
Hydrocarbons are used mainly as fuels, solvents and lubricants. Long residence time also favours the yield of the light hydrocarbon products. The calculations of the elementary reactions involved in the overall cracking of paraffin molecules agree. Catalytic cracking of hydrocarbons uniwersytet warszawski.
The products of this process are saturated hydrocarbons. Ethane, liquefied petroleum gas lpg and gasoline represents usual feedstock of the process, however. Generally, any light hydrocarbon fuel that must be compressed to keep it from boiling away. These topics contain content suitable for separate chemistry students only. The gasoline and diesel fuel that are used in cars, trucks, and buses are hydrocarbons. Cracking of crude oil crude oil is a mixture of hydrocarbons called fractions to separate the oil into its component fractions we first boil it. Theyll give your presentations a professional, memorable appearance the kind of sophisticated look that todays audiences expect. Cracking hydrocarbons in liquid paraffin with a catalyst. The cracking reaction is highly endothermic, therefore, high energy rates are. Lesson with option of differentiated resources for cracking hydrocarbon. University of zagreb petroleum refining and petrochemical. Apparatus delivery tube and bung bunsen burner boiling tube containing mineral wool porous pot liquid paraffin clamp and stand. These fractions are then modified by cracking, condensation, polymerization, and.
Steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. Winner of the standing ovation award for best powerpoint templates from presentations magazine. Hydrocracking is a catalytic cracking process assisted by the presence of an elevated partial pressure of hydrogen. It is the principal industrial method for producing the lighter alkenes or commonly olefins, including ethene or. Today ethylene is primarily produced by thermal cracking of hydrocarbons in the presence of steam. Pdf study on the feasibility of plasma dbd reactor cracking of. If these are to be used as fuels or feedstock for the chemical industry then they have to be cracked into smaller molecules. Hydrocarbon cracking is the process whereby large and heavy hydrocarbon molecules longchain hydrocarbons are broken down up into simpler and smaller bits as light hydrocarbons shortchain hydrocarbons by the breaking a carboncarbon bonds in cracking stock. There are 5 worksheets, 5 homework tasks, and an examinationstyle assessment test, each with answers included in this unit. Pdf hydrocarbons cracking in the presence of alcohol. In addition except, catalytic cracking reactions of isomeryzation, cyclization, polymerization, dehydrogenation and others are also possible. Hydrocarbons hydrocarbons hydrocarbons hydrocarbons hydrocarbons iupac system of naming organic compounds iupac system of naming organic compounds naming branches as groups naming. It is the principal industrial method for producing the lighter alkenes or commonly olefins, including ethene or ethylene and propene or propylene. Because the main use of hydrocarbons is as a fuel there is no point in going to the effort to separate them into individual hydrocarbons.
Also obtained from catalytic cracking and catalytic reforming. Such a decomposition reaction into smaller fragments by the application of heat is called pyrolysis or cracking. Lesson with option of differentiated resources for cracking hydrocarbon fuelsfractions. Balasubramanian viswanathan, in energy sources, 2017. Process of steam cracking steam cracking is a petrochemical process in which saturated hydrocarbons are broken down into smaller, often unsaturated, hydrocarbons. Chemistry of catalytic cracking print as opposed to thermal cracking governed by free radicals, catalytic cracking proceeds through the formation of ionic species on catalyst surfaces, and produces shorter, but branchedchain not straightchain alkanes by cracking the long straightchain alkanes. The rate of cracking and the end products are strongly dependent on the temperature and presence of catalysts. Understanding the kinetics and mechanisms of hydrocarbon. The large hydrocarbons are generally obtained during the fractional distillation of crude oil petroleum. Steam cracking plants figures 1 and 2 use a variety of feedstocks, for example. Cracking hygdrocarbons presentation teaching resources. It is the principal industrial method for producing lighter alkenes olefins, including ethene or ethylene and propene or propylene figure 3.
Index termsheavy oil, hydrocarbons cracking, lubricating. Alkenes ppt slides share and discover knowledge on. The mechanism of catalytic cracking of hydrocarbons is ionic. They are also used as the starting materials for manufacture of many dyes and drugs. Catalytic cracking advantages of catalytic cracking over thermal cracking. High reaction temperature and heating rate can significantly promote the production of light hydrocarbons. Plant capacities are up to 11,5 million tyr ethylene. As hydrocarbons burn, it creates an immense amount of energy and heat which is utilized in heating, transport, or electricity generation around the world. Some compounds obtained from cracking have carboncarbon double bonds. This website and its content is subject to our terms and conditions. Hydrocarbon cracking reactions occur in the presence of steam inside the furnace in the radiant coil. It is, however, possible to obtain pure hydrocarbons by very careful distillation. Other processes are also available or under development.
To make use of excess larger hydrocarbons and to supply demand for shorter ones, longer hydrocarbons are cracked. Pdf catalytic cracking of hydrocarbons in a crec riser. Catalytic cracking in which a catalyst is employed and which produces high yields of branched and cyclic alkanes. Catalytic cracking presentation cracking chemistry zeolite. These are complex aluminosilicates, and are large lattices of aluminium, silicon and oxygen atoms carrying a negative charge.