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The similarities between the small scale lab work and the large scale industrial productions are very similar in practice. However there are differences. In order to measure a boiling point, the lab measures the temperature of vapors with a thermometer in a fractional distillation apparatus. The refineries use thermocouples and they use radio to transmit the information to a control tower. In order to remove vapors, snorkel hoods are used in lab. The snorkel hood vacuums the any dangerous vapors and circulates the air. Also, in lab, in order to purify chemicals, refluxing is used. Refluxing essentially evaporates the materials at different levels with heat, and then it's possible to get the pure chemical. In oil refineries enclosed systems with streams that go to incinerators to keep the product from escaping and harming the workers. The large scale refineries reflux with temperature or fire heaters to keep the oil from becoming explosive. In order to cool the chemicals, labs circulate water to cool. BP uses air cooling since the water is dirtier then the substance the company is trying to purify. In lab, the process is simply acid and base reactions. The oil production demineralized water recycles resins by washing them with acids and bases then combines them to neutralize the solution.
Fractional and simple distillation, chromatography paper and gas, vacuum filtration precipatitation, acidification for precio, scaping crystals out of vessels, iodine in turpentine
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The large scale production utilized insulated tanks with vicious liquids that keeps viscosity low.
machinery and processes
A floating liquid such as oil sits on the top. Acetic acid is used to stir. Has methonal and CO in the bottom of the reactor with an iridium catalyst. Demineralized water is used to cool in the heating towers. BP separates para xylene from meta a"nd ortho by recrystallization
Fractional Distillation. Fractional distillation "refers to a distillation process involving concurrent vaporization-condensation cycles. During fractional distillation, the distillate is collected in several separation fraction collectors (receivers), the contents of each being a different fraction." (book 691, ch 29) Essentially, by taking advantage of the different boiling point, the liquid mixture is heated, separated into fractions then it is vaporized, and it condenses thus separating the two components of the mixtures. However, oil refinery and lab aren't necessarily the same.
In A&M's organic chemistry lab, students separate the components of cyclohexane and toluene by using fractional distillation. Then, the students assess the efficiency of the separation by measuring the fractions' compositions. In order to measure said composition, the scientists use gas chromatography. According to http://www.wfu.edu/chem/courses/organic/GC/index.html "Gas Chromatography (GC) is used to separate volatile components of a mixture.Â A small amount of the sample to be analyzed is drawn up into a syringe.Â The syringe needle is placed into a hot injector port of the gas chromatograph, and the sample is injected.Â The injector is set to a temperature higher than the components' boiling points.Â So, components of the mixture evaporate into the gas phase inside the injector.Â A carrier gas, such as helium, flows through the injector and pushes the gaseous components of the sample onto the GC column.Â It is within the column that separation of the components takes place.Â Molecules partition between the carrier gas (the mobile phase) and the high boiling liquid (the stationary phase) within the GC column."
From the peaks, the students then measure the HETP (height equivalent to theoretical plate). Height of column divided by number of theoretical plates. A heat source is placed closely to the round bottom flask. Then the fractional distillation apparatus is supported by a steel rod and a microclamp. Boiling chips are placed in the flask. The flask is attacked to a condenser, which is attached to a Hickman Still. A thermometer is then placed in the Hickman still to read the temperature of the boiling point in the second column. This is how scientist measures the temperature.
"A simple distillation apparatus consists of a boiling flask attached to an adapter holding a thermometer. The adapter connects to a condenser into which cold water is constantly passed through. The condenser leads into a collection flask for the purified liquid." http://www.chemhelper.com/distillation.html
First the scientists distilled the cyclohexane and toluene by heating the mixture in a 10-mL round-bottom flask, with a stir bar in it to speed up the process, in order to separate the mixture. The liquid with the lower boiling point evaporates first. A thermometer in the second stage tells the students what temperature the substance boils at. Then the gas enters a water-cooled condenser column, as its name suggest, the gas is then turned back into a liquid (condensation) where it will be collected away from the other liquid with the higher boiling point in a Hickman still. This process is called reflux. Water cooling systems stops the vapor from getting out of the reaction. "The vapors contact the cool, inside surface of the tube and condense into the liquid phase, dripping down the inside of the tube and returning to the reaction mixtureâ€¦circulating cold tap water through an outer glass jacket. "(http://academic.evergreen.edu/b/barlowc/microscale%20glassware.htm Water flows in the lower connector and it goes out of the higher connect so air is not trapped in the water jacket.
A PVC insulating jacket, which is filled with a round glass tunnel, separates the condenser and the flask. The round glass tunnel "provide(s) 'theoretical plates' on which the refluxing liquid can condense, re-evaporate, and condense again, essentially distilling the compound over and over. " (http://www.chemhelper.com/distillation.html). The liquid with a higher boiling point will stay in the round bottom flask.
Another difference in how labs measure temperature and separate substances is determining the melting point. Melting point helps identify substances by comparing the melting point to an official value.
"A sample having the same melting point as the authentic is mixed with the authentic, melted, and solidified by cooling. If the sample thus obtained has the same melting point as that of the original, it become reliable identification." http://science.wonderhowto.com/how-to/measure-melting-point-chemistry-lab-269384/
The fractional distillation processes in oil refineries are different than the process in the lab. "The first step in petroleum refining is the separation of petroleum into different hydrocarbons fractions by distilling it through huge fractionating columns called distillation towers." (how stuff works) Crude oil is heated inside the tower to become a mixture of gases. The components have different amounts of carbon atoms. The different amount of carbon atoms means that the components have boiling points that are different. By abusing this property, it is possible to isolate the components of oil in fractions "containing hydrocarbons of similar carbon content". Inside the tower, the hydrocarbon gases go through bubble caps. The temperature at each tray is controlled to be at the exact temperature the specific hydrocarbon will condense and become a liquid. Different hydrocarbons condense out of the gas cloud when the temperature goes below their specific boiling point the hydrocarbons will go out the tower. This is how oil refineries reflux. The hydrocarbons with the lowest boiling point are evaporated to the highest part of the tower which is the coolest part of the tower. The gasses are condensed and "collected as 'top fractions' .The hydrocarbons in top fractions are chemically modified and used in gasoline." (The book page 64)
Paper Chromatography, Paper chromatography is a process used to isolate substances and to determine the purity of compounds. The substances are dispersed among a mobile phase (the solution of cake dyes and foods die that go up paper) and a stationary phase (the paper). When placed in a solvent the samples disperse from each other. When the solvent diffuses, it dissolves some of the sample's molecules. This is based on the molecules and the polarity. The differences in the solubility makes the water and dye move to various places up on the places. If the sample is not polar there will be little to no movement on the paper.
Vacuum filtration. In lab to change chemicals into chemicals and separate them acid and base reactions are used to make mixtures soluble and insoluble. Separating solids from liquids by vacuum filtration is used. Vacuum filtration isolates a solid from a liquid solid mixture and removes solid impurities from the liquid. In lab, the apparatus is assembled for vacuum filtration. Then the filter paper is moistened and positioned. The vacuum is then turned on. The mixture to be filtered is added to the Hirsch funnel. The solid is washed on a filter with solvent. Then on filter paper, the solid is dried by air. Finally, the solid is transferred to a container and possibly put in an oven to dry further.
Centrifuge. Centrifuge is used to separate different states of matter by centrifugal force. "When is mixture is a centrifuge tube is whirled around a circular path at high speed, the denser phaseâ€¦ is forced to the bottomâ€¦ leaving the other phase on top."(601 book) Centrifuging is also use to collect crystallized solids. It can be used to separate solids from liquids or two polar liquids. In lab this is done by transferring the mixture into a centrifuge tube. Then the tubes are placed in the machine for 3-5 minutes. Finally, the lab separated the liquid layer from a solid or a second liquid layer. In order to remove vapors, snorkel hoods are used in lab. The snorkel hood vacuums any dangerous vapors and circulates the air.
The lab adds 40g of sodium benzonate in a small beaker and then adds 3 mL of diluted water to dissolve the solid. Then hydrochloride is added. The mixture is then chilled on ice. rbons are mixed to make the pH less than 2. hydrochloric acid to sodium benzonate to me a new substance.
A cicle of filter paper is laid flat on a perforated plate inside a special funnel, attached by a connector to a fliter flask. A Hirsch funnel 598
Melting Point (oC)
Boiling Point (oC)
Table of Hydrocarbons. This table shows that the longer the carbons in a chain, the higher the melting and boiling point is. This property can be exploited by heating the hydrocarbons and then separated. From: http://www.elmhurst.edu/~chm/vchembook/501hcboilingpts.html
In order to measure the temperature of the boiling points the refineries use thermocouples "A thermocouple is a sensor for measuring temperature. It consists of two dissimilar metals, joined together at one end. When the junction of the two metals is heated or cooled a voltage is produced that can be correlated back to the temperature. The thermocouple alloys are commonly available as wire." (http://www.omega.com/prodinfo/thermocouples.html) The data is then transmitted by radio into a control room.
However, the separation does not mean the components can be sold yet, they are impure. , "oil companies chemically process some other fractions from the distillation column to make gasoline; this processing increases the yield of gasoline from each barrel of crude oil." (how oil is made website). The oil must be refined.
Chemical Processing. Scientist and oil refiners want to make different products, they can do this by using chemical processing. Chemical processing is when a chemical or chemical compound is changed often by a chemical reaction. In the lab this is done by acid base reactions In oil refineries, chemically processing is changing the composition of the oil using technology. Chemical Processing in oil refinery can be done by cracking, unification, or alteration.
Cracking. Cracking is breaking long hydrocarbon chains into small pieces. There are different types of cracking and they produce different substances. However, most produces a mix of saturated and unsaturated hydrocarbons.
Thermal cracking is heating and/or pressurizing long chains until they break. Thermal is the simplest method. Ethene and propene are created. Steaming cracking is using steam to break butane ethance and naptha into smaller components of benzene and ethylene. Visbreaking is using the left behind products from the distillation tower and reheating them. Then, "cooled with gas oil and rapidly burned (flashed) in a distillation tower. This process reduces the viscosity of heavy weight oils and produces tar." Coking is similar except the residual is broken down into gas, oil, and naptha. This process leaves a coke residue which is sold to third world countries cheaply.
A catalyst is a substance that allows a reaction to proceed quicker or at lower temperatures. Catalytic cracking "uses a catalyst to speed up the cracking reaction. Catalysts include zeolite, aluminum hydrosilicate, bauxite and silica-alumina." This makes the components of liquid petroleum gas. Fluid catalytic cracking is using a catalyst that is an extremely hot liquid which cracks gas oil into gasoline and diesel. Hydrocracking is virtually the same, except a different catalyst is used, the pressure is higher, and the temperature is lower. This produces gasoline and kerosene. There are 5-10 carbon atoms in the chains: pentane, hexane, heptane, octane, nonane, and decane.
After the different hydrocarbons have been cracked into smaller chains, they are separated in another fractional distillation column.
After various hydrocarbons are cracked into smaller hydrocarbons, the products go through another fractional distillation column to separate them.
Unification. Unification is the opposite of cracking; converting small carbon chains into larger chain. There are different processes, but the most important is catalytic reforming. It "uses a catalyst (platinum, platinum-rhenium mix) to combine low weight naphtha into aromatics, which are used in making chemicals and in blending gasoline. A significant by-product of this reaction is hydrogen gas." (how stuff works) The oil refineries then sell the hydrogen gas or use the product for hydrocracking.
Rearranging. Oil refiners will take some of the broken down hydrocarbon chains and rearranges them to produce other chains. In order to accomplish this, BP uses alkylation. Compounds that have a low molecular weight are mixed with the impure by-products to make octane hydrocarbons. It's used to reduce knocking in gasoline.
Purifying. The fractions are treated to make the substances pure. This is done by sending the fraction through:" a column of sulfuric acid - removes unsaturated hydrocarbons (those with carbon-carbon double-bonds), nitrogen compounds, oxygen compounds and residual solids (tars, asphalt); an absorption column filled with drying agents to remove water; (and )sulfur treatment and hydrogen-sulfide scrubbers to remove sulfur and sulfur compounds" (how stuff works)
BP then air cools the fractions. . BP uses air cooling to condense the vapor. BP uses air cooling instead of water cooling because the water is dirtier then the substance the company is trying to purify. After being cooled, the vapors are blended together to make other products like gasoline, jet fuel, lube, kerosene, diesel, heating oil, plastics, etc.