Jun 28, 2017 distillation is a unit operation physical process while catalysts are used to change the rate of a chemical process in unit processes. At 200 degrees, kerosene is produced and at 150 degrees, gasoline is produced. Alkanes alkanes are saturated hydrocarbons saturated. Stuff that boils at the lowest temperature is vaporized first and is condensed at a corresponding. Organic chemistry starters 1618 resource rsc education. Browse 500 sets of distillation organic chemistry flashcards. The initial process, thermal reforming, was developed in the late 1920s. Catalytic cracking high impact list of articles ppts journals 1870. The octane number of gasoline may also be improved by adding tetraethyl lead tel pbc 2 h 5 4 which is a knock inhibitor. Mar 23, 2016 learn complete crude oil refining process from distillation to cracking. Therefore, molecules with strong intermolecular forces will have higher boiling points.
The main difference between fractional distillation and cracking is that fractional distillation involves the separation of compounds through distillation according to their boiling points whereas cracking involves the breakdown of large molecules into smaller molecules. The purpose of the thermometer is to follow the progress of the distillation. Feb 28, 2016 fractional distillation and refining of petroleum 1. History of refining year process name purpose byproducts, etc. The main feedstock is vacuum gas oil, a heavy fraction of petroleum. In fact, we cannot meet this demand through the products of fractional distillation alone. While they succeeded in providing a small increase in gasoline yields, it was the commercialization of the fluid catalytic cracking process in. Chemistry edexcel paper 11 term 2 cherry hill tuition. Crude oil distillation an overview sciencedirect topics. Reforming is described as the processing of straightchain hydrocarbons into branchedchain alkanes and cyclic hydrocarbons for efficien gcse. The general formula of the alkenes is cnh2n most alkenes are formed when fractions from the fractional distillation of crude oil are cracked. Learn about the process of oil distillation in order to create fuels and plastics with bbc bitesize gcse chemistry.
Oct 31, 2016 fractional distillation separates and collects from a mixture of chemicals those that differ in their vapour pressure, at a series of temperatures. Petroleum crude oil is a complex mixture of thousands of substances, the majority of which are. The word petroleum is composed of two latin words petra means rock and oleum means oil. Chemical processing how oil refining works howstuffworks. The fractional distillation of crude oil carries out several steps. Crude oil processing starts with fractional distillation. Select three advantages of cracking from the list below. You can change one fraction into another by one of three methods. The mixtures of products obtained from cracking and reforming are separated by fractional distillation. Making crude oil useful fractional distillation and cracking. Fortunately, we have much more of the larger fractions than are needed. Catalytic cracking is the breakdown of large hydrocarbon compounds into small hydrocarbon molecules with the use of moderate temperatures and pressures in the presence of catalysts. Whats the difference between fractional distillation and. Petroleum is a complex mixture of hydrocarbons and a number of different compounds whose composition varies according to its place of occurrence.
The cracking products, such as ethene, propene, buta1,3diene and c 4 alkenes, are used to make many important chemicals. Cracking larger molecules are broken down into smaller ones reforming large molecules are formed from smaller ones these chemical processes are needed because fractional distillation does not produce enough of the hydrocarbons that are in demand i. In most cases, the distillation is operated at a continuous steady state. The mixture of c 5c 10 hydrocarbons obtained directly from the distillation of crude oil contains a high proprtion of straightchain alkanes. Reforming uses heat and pressure to convert unbranched fractions into cycloalkanes e. Learn complete crude oil refining process from distillation to cracking. Petrol gasoline contains a mixture of hydrocarbons, with 5 to 10 carbon atoms. The feed for the catalytic cracking is distillates obtained from crude oil distillation. Difference between catalytic cracking and catalytic reforming.
The fractional distillation process does an efficient job in breaking down crude oil into useful products. Cracking is conducted at high temperatures, by two processes. What is the catalyst use in fractional distillation of crude oil. Oil fractions cracking, isomerisation, reforming 1. To solve this supply and demand problem, we use a process called catalytic cracking to break the long chain hydrocarbons into shorter, more useful, hydrocarbons. Catalytic cracking and catalytic reforming are two processes used in the conversion of crude oil into useful products. Then, the vapor goes into the bottom of a fractionating column. Ludwigs applied process design for chemical and petrochemical plants fourth edition, volume 2, 2010. Molecules which strongly interact or bond with each other through a variety of intermolecular forces cannot move easily or rapidly and therefore, do not achieve the kinetic energy necessary to escape the liquid state.
Chen, in computer aided chemical engineering, 2016. The hydrocarbons are mixed with a very fine catalyst powder. Specific hydrocarbons are separated out of crude oil by. The use of thermal cracking units to convert gas oils into naphtha dates from before 1920. Fractional distillation is the most common form of separation technology used in petroleum refineries, petrochemical and chemical plants, natural gas processing and cryogenic air separation plants. Useless, longchain compounds are converted into more useful shorter chain compounds. Cracking and reforming of crude oil fractions when crude oil is separated into its various fractions through farctional distillation, there is usually a greater demand for specific components which cannot be simply obtained through fractional distillation alone. The most widespread process for rearranging hydrocarbon molecules is naphtha reforming. The source of the large hydrocarbon molecules is often the naphtha fraction or the gas oil fraction from the fractional distillation of crude oil petroleum. The main fractions or cuts obtained have specific boilingpoint ranges and can be classified in order of decreasing volatility into gases, light distillates, middle distillates. Fractional distillation of crude oil often produces more of the larger hydrocarbons than can be sold, and less of the smaller hydrocarbons than customers want.
These fractions are obtained from the distillation process as liquids, but are revaporised before cracking. Fossil fuels fractional distillation fractional distillation how it works cracking reforming combustion of fuels problems. The catalytic reforming includes the rearrangement of hydrocarbons in order to form different products. In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby. Reforming reforming is a similar process to catalytic cracking that is used in addition to cracking to. Therefore, the large hydrocarbon chains have to be broken down into smaller and. Bio refinery bioremediation catalytic cracking distillation downstream operations ethane fractionation gasoline. Fractional distillation is the separation of a mixture into its component parts, or fractions. Fractional distillation is the main activity of oil refineries, and is done in a large fractionating column known as a fractionation tower. Compared to thermal cracking, catalytic cracking occurs at lower temperatures and pressures, is more selective and flexible, and incorporates a catalyst. The first step in the refining process is the separation of crude oil into various fractions or straightrun cuts by distillation in atmospheric and vacuum towers.
Atmospheric and fractional distillation of crude oil swf vacuum distillation fluid catalytic cracking, together with function in diesel and propylene markets catalytic reforming aromatics restoration for btx petrochemical feedstocks isomerization, alkylation, and polymer gasoline. Cracking crack means break, burst is a process that involves breakdown of long carbon chains into shorter ones. Making crude oil usefulfractional distillation and cracking. This is the first and most basic step in the refining process, and is the precursor to cracking and reforming. Crude oil distillation is a large energy consumer and a large waste generator, so refiners need to balance the economics of processing crude oil to viable fractions. Thermal cracking is a free radical chain reaction which determines the product distribution during thermal cracking a significant feature of such reactions is the resistance of hydrocarbon free radicals to isomerization.
Reforming to benzene derivatives is not required in this module. Fractional distillation simple english wikipedia, the free. Since world war ii the demand for light products e. Were talking about hydrocarbons, that is, substances with molecules made up of hydrogen and carbon atoms. During petroleum refining, catalysts play an extremely important role during the. The products from steam cracking include a mixture of c1 c4 hydrocarbons and are separated by fractional distillation. That it why it is produced in the processing of hard coal or synthesis gas, or in cracking cracking from the highest fractions obtained during fractional distillation of crude oil. New feed is always being added to the distillation column and products are. The following minilecture presents each phase of the crude oil refining process and the various products that are extracted from each barrel of oil. Fractional distillation separates and collects from a mixture of chemicals those that differ in their vapour pressure, at a series of temperatures. Reforming converts straightchained alkanes to branched. Petroleum refining petroleum refining catalytic cracking.
Bitumen is obtained from bottom and other useful products like gasoline, kerosene and diesel are obtained from different stages of distillation tower. Difference between fractional distillation and cracking. Petroleumrefining of petroleumknockingoctane number. These products are used in petrol and as a feedstock for a wide range of organic chemicals including many pharmaceuticals and. Cracking involves breaking up heavy molecules into lighter and more valuable hydrocarbons. Fractional distillationcrude oil is heated and passed into a fractionating tower. Alkenes the members of this series contain a double bond. Cracking and alkenes crude oil, hydrocarbons and alkanes. These are treated in several ways including cracking, isomerisation and reforming. The fractional distillation process starts by heating up the material to over 400 degrees celsius in order to vaporize it. Thus the various fractions obtained from the distillation of crude oil and the. Thermal reforming employed temperatures of 510565 c 9501,050 f at moderate pressuresabout 40 bars 4 mpa, or 600 psito obtain gasolines petrols with. Distillation involves the separation of materials based on differences in their volatility.
Reforming reforming uses heat and pressure to convert unbranched fractions into cycloalkanes e. To solve this supplyanddemand problem, we use a process called catalytic cracking to break the long chain hydrocarbons into shorter, more useful, hydrocarbons. Fuels and thermochemistry the various types of fuel mentioned on the syllabus are the fossil fuels coal, gas, oil, and hydrogen. They are obtained from the crude oil in the order of fractional distillation, cracking and reformation of crude oil alkanes are used as fuels.
Petroleum cracking reforming fractional distillation petrol. Octane ratings the quality of a fuel is indicated by its octane rating, which is a measure of its ability to burn in a combustion engine without knocking or pinging. Why is cracking an important process in oil refining answers. In this article, a comparison between fractional and simple distillation has been presented, which will identify the prime differences between the two processes. Reforming is described as the processing of straightchain hydrocarbons into branchedchain alkanes and cyclic hydrocarbons for efficien. Ali shaerinioeciransimulationthecontinuouscatalytic reforming octanizerunitofarakrefinerygasolineproductioncomplexwithpetrosimsoftware. Crude oil can be separated into different fractions using fractional distillation. Catalytic cracking takes place in a reactor and can convert a majority of heavy hydrocarbons to useful lighter ones. Fractional distillation is a process by which components in a chemical mixture are separated into different parts called fractions according to their different boiling points. Others such as branched and cyclic alkanes are added to the gasoline fraction obtained from the distillation of crude oil to enhance the octane rating. In the process of fractional distillation, a mixture of different liquids is evaporated followed by condensation. The most widely used method of conversion, catalytic cracking is the process of breaking heavy fractions down into lighter ones using a combination of pressure, high heat and a catalyst to quicken the process. Distillation involves the separation of materials based on differences in their.
Products from crude oil scool, the revision website. Photo courtesy phillips petroleu m company catalysts used in catalytic cracking. Main difference catalytic cracking vs catalytic reforming. Sep 11, 2017 the difference between fractional distillation and cracking is that fractional distillation involves the separation of compounds through distillation according to their boiling points whereas cracking involves the breakdown of large molecules into smaller molecules. How to make better use of the chemical feedstock from the fractional distillation of crude oil, thermalcatalytic cracking, use of zeolite catalysts. Cracking hydrocarbons in liquid paraffin with a catalyst. The physical and chemical components of nigerian crude oil. The most common method of refining crude is the process of fractional distillation. What is difference between reforming and cracking answers. These units produced small quantities of unstable naphthas and large amounts of byproduct coke.
Catalytic cracking involves taking a heavy oil and heating it to a high temperature in the presence of a catalyst. What are the differences between reforming and cracking in. Different liquids are evaporated according to their boiling point and they are collected in different chambers of distillation tower. Reforming, in chemistry, processing technique by which the molecular structure of a hydrocarbon is rearranged to alter its properties.
Cracking takes large hydrocarbons and breaks them into smaller ones. What is left at this point of the fractional distillation process emerges at the top of the column in gas form. A knowledge of how these processes are carried out, including the names and nature of the fractions obtained, is expected. There isnt any single unique reaction happening in. The refining of crude oil requires separation, distillation, reforming, cracking and related processes to resolve the mixture of components into products. Catalytic cracking processes have evolved over the years, and are an exemplary display of che.
Reforming involves changing the chemical nature of hydrocarbons to achieve. Petroleum as a source of hydrocarbons by fractional distillation and cracking. Petrol and other fuels are produced from it using fractional distillation. The majority of our fuels and plastics are derived from oil. Petroleum refining petroleum refining visbreaking, thermal cracking, and coking. Jul, 2012 distillation, cracking and catalyzing are key parts of the process. Fractional distillation is used to purify chemicals and to separate mixtures to obtain their components.
Reforming is a process similar to cracking, which converts nalkanes into branched alkanes. Cracking fractional distillation gcse chemistry single science. Pdf distillation process of crude oil researchgate. Fractional distillation involves separating the crude oil into its different parts. Jun 15, 2016 in fact, we cannot meet this demand through the products of fractional distillation alone.
Petroleum refining petroleum refining naphtha reforming. Industrially, crude oil is heated and sent up along the fractionating column that has decreasing temperatures with height and several platforms at different levels to collect the condensate. These products are used in petrol and as a feedstock for a wide range of organic chemicals including many pharmaceuticals and dyes. Alkanes alkanes are saturated hydrocarbons contain single. There isnt any single unique reaction happening in the cracker. Petroleum refining visbreaking, thermal cracking, and coking. Cracking is used to convert long alkanes into shorter, more useful hydrocarbons.
See how crude oil is converted in useful different fractions and how long. Chemical compounds are separated by heating them to a temperature at which one or more fractions of the mixture will vaporize. Distillation is the standard process used for separation of chemical mixtures. Crude oil and its uses, hydrocarbons and fuel, processing, fractional distillation, cracking, reforming, exam style question, summary. Oil chemistry involves the main processes that occur in an oil refinery fractional distillation, cracking and reforming. Theres no use of catalyst in distillation of crude oil. Thermal you heat large hydrocarbons at high temperatures sometimes high pressures as well until they break apart. Learn vocabulary, terms, and more with flashcards, games, and other study tools. See how crude oil is converted in useful different fractions and how long chain hydrocarbons are converted in branched. Catalytic cracking list of high impact articles ppts. Furthermore, many of the new sources of crude petroleum california, alaska, venezuela, and mexico have yielded heavier crude oils with higher. The feed for the catalytic reforming is naphtha feedstock. When the process is done, a heavy, almost pure carbon residue is left coke.