This leads to the low relative molecular mass products low bp accumulating near the top of the tower and high relative molecular mass constituents high bp collecting near the bottom Figure 5. Figure 9 The fractional distillation of crude oil. The high boiling point residue from the crude oil is then transferred to another column and distilled under vacuum; lowering the pressure reduces the boiling point and ensures constituents distil at temperatures below their decomposition temperature. From this process, lubricating oils and waxes are obtained.
The final residue from the process is bitumen. Details of the fractionation are given in Table 1. The constituents in crude oil vary from one oil field to another for example, the proportion of naphtha from North Sea oil is considerably greater than that from Middle East oil so the numbers given are approximate.
Save Save. The Essential Chemical Industry - online. The chemical industry. Catalysis in industry Chemical reactors Cracking and related refinery processes Distillation Extracting crude oil and natural gas Green chemistry Recycling in the chemical industry. Polymers: an overview Degradable plastics Methanal plastics Formaldehyde plastics Polyamides Polycarbonates Poly chloroethene Polyvinyl chloride Polyesters Poly ethene Polyethylene Poly methyl 2-methylpropenoate Polymethyl methacrylate Poly phenylethene Polystyrene Poly propene Polypropylene Poly propenoic acid Polyacrylic acid Poly propenonitrile Polyacrylonitrile Poly tetrafluoroethene Polytetrafluoroethylene Polyurethanes Silicones.
Distillation of crude oil Crude oil is a mixture of many hundreds of liquid hydrocarbons. Figure 2 Trays in a fractionating column. Figure 3 Valve trays. Distillation is used to produce a variety of alcoholic beverages, such as whiskey, rum and brandy.
When fruit and plant materials ferment, a dilute version of ethyl alcohol is produced. Distilling the fermented material purifies and concentrates the ethanol. A variety of other components, such as water, esters and other types of alcohol, are also collected during the distillation process, which accounts for the unique flavor of each alcoholic spirit. A number of products can be produced from crude oil. Because each of these products has a unique boiling point, a process known as fractional distillation is used to refine oil into separate materials.
These include:. One of the earliest uses of distilling was to make perfume, which began around B. The aroma from various plants and herbs is contained in what are known as essential oils, which can be extracted through distillation. In those instances, steam is passed through the plant material to draw out the essential oils without burning the mixture. The steam is then captured and condensed just as in normal distillation.
Steam distillation is also used to create natural food flavorings. The most common are citrus oils and liquid extracts of various herbs and spices. Mike Maxfield began writing professionally in After earning his BA in communications from California State Fullerton, he spent the next 26 years providing public affairs and media relations services for several local government agencies.
The reduced pressure in the apparatus causes the solvent to boil at a lower temperature than normal. Lisa Nichols Butte Community College. Complete text is available online.
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