PET-CBM-24-01-09-CBM

Petrochemical : 

Petrochemical Nuzhat Khan Visiting Faculty Institute of Business Management nuzhatk@gmail.com

Slide 2: 

Petrochemicals are chemical products made from raw materials of petroleum or other hydrocarbon origin. Although some of the chemical compounds that originate from petroleum may also be derived from coal and natural gas, petroleum is the major source.

Out line of the lecture : 

Out line of the lecture Characteristics of crude oil Hydrocarbon types and chemistry Major refinery products and by-products Common refinery processes

Petrochemical Industry : 

Petrochemical Industry Only about 5% of the oil and gas consumed each year is needed to make all petrochemical products Petrochemical have had a dramatic impact on our daily life

Crude oil : 

Crude oil Crude oils are complex mixtures containing many different hydrocarbon compounds that vary in appearance and composition from one oil field to another. Crude oils range in consistency from water to tar-like solids Color from clear to black An "average" crude oil contains about 84% carbon, 14% hydrogen, 1%-3% sulfur and less than 1% each of nitrogen, oxygen, metals, and salts Crude oils are generally classified as paraffinic, naphthenic, or aromatic, based on the predominant proportion of similar hydrocarbon molecules Mixed-base crudes have varying amounts of each type of hydrocarbon.

Slide 6: 

Fractional distillation of crude oil Petroleum Kerosene (C12-C16) Bpt (200-250 ºC) Heating oil (C15-C18) Bpt (250-300 ºC) Natural Gas (C1-C4) Gasoline (C4-C12) Bpt (40-200 ºC) Straight-chain alkanes are a pure fuel, because of engine knock. n-Heptane has an octane rating = 0 2,2,4-trimethylpentane has an octane rating = 100 Catalytic cracking

Most products of oil processing are : 

Most products of oil processing are Petrochemicals (Plastic) Asphalt Diesel fuel Fuel oils Gasoline Kerosene Liquefied petroleum gas (LPG) Lubricating oils Paraffin wax Tar

Slide 9: 

The largest petrochemical industries are to be found in the USA and Western Europe Major growth in new production capacity is in the Middle East and Asia. There is a substantial inter-regional trade in petrochemicals of all kinds. World production of ethylene is around 110 million tons per year, of propylene 65 million tons, and of aromatic raw materials 70 million tons.

Classification of petrochemical : 

BASICS OF HYDROCARBON CHEMISTRY. Crude oil is a mixture of hydrocarbon molecules, which are organic compounds of carbon and hydrogen atoms that may include from one to 60 carbon atoms. The properties of hydrocarbons depend on the number and arrangement of the carbon and hydrogen atoms in the molecules. The simplest hydrocarbon molecule is one carbon atom linked with four hydrogen atoms: methane. All other variations of petroleum hydrocarbons evolve from this molecule. Classification of petrochemical

Classification of petrochemical : 

Hydrocarbons containing up to four carbon atoms are usually gases, those with 5 to 19 carbon atoms are usually liquids, and those with 20 or more are solids. The refining process uses chemicals, catalysts, heat, and pressure to separate and combine the basic types of hydrocarbon molecules naturally found in crude oil into groups of similar molecules. The refining process also rearranges their structures and bonding patterns into different hydrocarbon molecules and compounds. Therefore it is the type of hydrocarbon (paraffinic, naphthenic, or aromatic) rather than its specific chemical compounds that is significant in the refining process. Classification of petrochemical

Primary Petrochemical : 

Primary Petrochemical Series of Hydrocarbon Compounds that Occur Naturally in Crude Oil Paraffin. Aromatic

Intermediated and Derivatives : 

Intermediated and Derivatives Generally produced by chemical conversion of P.Pch to form more complicated derivative Petrochemical derivatives produced by variety of ways Chlorine Nitrogen Oxygen others Plastic, fibers and synthetic rubber

Products : 

Products Some typical petrochemical intermediate are Vinyl acetate: paint, paper and textile Vinyl chloride: PVC, resin manufacturing ethylene glycol: Polyester, textile fiber Styrene: rubber and plastic manufacturing

Other Hydrocarbons : 

Other Hydrocarbons Alkenes are mono-olefins with the general formula CnH2n and contain only one carbon-carbon double bond in the chain. The simplest alkene is ethylene, with two carbon atoms joined by a double bond and four hydrogen atoms. Olefins are usually formed by thermal and catalytic cracking and rarely occur naturally in unprocessed crude oil.

Type of petrochemical : 

Type of petrochemical ethylene (or IUPAC name ethane) is the chemical compound with the formula C2H4. It is the simplest alkenes. Because it contains a carbon-carbon double bond, ethylene is called an unsaturated hydrocarbon or an olefin. It is extremely important in industry and also has a role in biology as a hormone. Ethylene is the most produced organic compound in the world; global production of ethylene exceeded 75 million metric tonnes per year in 2005.

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propylene - used as a monomer and a chemical feedstock isopropyl alcohol - 2-propanol; often used as a solvent or rubbing alcohol acrylonitrile - useful as a monomer in forming Orlon, ABS polypropylene - polymerized propylene propylene oxide propylene glycol - sometimes used in engine coolant glycol ethers - from condensation of glycols isomers of butylene - useful as monomers or co-monomers isobutylene - feed for making methyl tert-butyl ether (MTBE) or monomer for copolymerization with a low percentage of isoprene to make butyl rubber

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1,3-butadiene - a diene often used as a monomer or co-monomer for polymerization to elastomers such as polybutadiene or a plastic such as acrylonitrile-butadiene-styrene (ABS) synthetic rubbers - synthetic elastomers made of any one or more of several petrochemical (usually) monomers such as 1,3-butadiene, styrene, isobutylene, isoprene, chloroprene; elastomeric polymers are often made with a high percentage of conjugated diene monomers such as 1,3-butadiene, isoprene, or chloroprene higher olefins polyolefins such poly-alpha-olefins which are used as lubricants alpha-olefins - used as monomers, co-monomers, and other chemical precursors. For example, a small amount of 1-hexene can be copolymerized with ethylene into a more flexible form of polyethylene. other higher olefins detergent alcohols acrylic acid acrylic polymers allyl chloride - epichlorohydrin - chloro-oxirane; used in epoxy resin formation epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some amine

Aromatic : 

benzene - the simplest aromatic hydrocarbon ethylbenzene - made from benzene and ethylene styrene made by dehydrogenation of ethylbenzene; used as a monomer polystyrenes - polymers with styrene as a monomer cumene - isopropylbenzene; a feedstock in the cumene process phenol - hydroxybenzene; often made by the cumene process acetone - dimethyl ketone; also often made by the cumene process bisphenol A - a type of "double" phenol used in polymerization in epoxy resins and making a common type of polycarbonate epoxy resins - a type of polymerizing glue from bisphenol A, epichlorohydrin, and some amine polycarbonate - a plastic polymer made from bisphenol A and phosgene (carbonyl dichloride) solvents - liquids used for dissolving materials; examples often made from petrochemicals include ethanol, isopropyl alcohol, acetone, benzene, toluene, xylenes Aromatic

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cyclohexane - a 6-carbon aliphatic cyclic hydrocarbon sometimes used as a non-polar solvent adipic acid - a 6-carbon dicarboxylic acid which can be a precursor used as a co-monomer together with a diamine to form an alternating copolymer form of nylon. nylons - types of polyamides, some are alternating copolymers formed from copolymerizing dicarboxylic acid or derivatives with diamines caprolactam - a 6-carbon cyclic amide nylons - types of polyamides, some are from polymerizing caprolactam nitrobenzene - can be made by single nitration of benzene aniline - aminobenzene methylene diphenyl diisocyanate (MDI) - used as a co-monomer with diols or polyols to form polyurethanes or with di- or polyamines to form polyureas polyurethanes alkylbenzene - a general type of aromatic hydrocarbon which can be used as a presursor for a sulfonate surfactant (detergent) detergents - often include surfactants types such as alkylbenzenesulfonates and nonylphenol ethoxylates chlorobenzene toluene - methylbenzene; can be a solvent or precursor for other chemicals

Slide 21: 

benzene toluene diisocyanate (TDI) - used as co-monomers with diols or polyols to form polyurethanes or with di- or polyamines to form polyureas polyurethanes - a polymer formed from diisocyanates and diols or polyols benzoic acid - carboxybenzene caprolactam nylon

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mixed xylenes - any of three dimethylbenzene isomers, could be a solvent but more often precursor chemicals ortho-xylene - both methyl groups can be oxidized to form (ortho-)phthalic acid phthalic anhydride para-xylene - both methyl groups can be oxidized to form terephthalic acid dimethyl terephthalate - can be copolymerized to form certain polyesters polyesters - although there can be many types, polyethylene terephthalate is made from petrochemical products and is very widely used. purified terephthalic acid - often copolymerized to form polyethylene terephthalate polyesters

Alkanes/Paraffin : 

Alkanes/Paraffin general formula CnH2n+2  either straight chains (normal) or branched chains (isomers) of carbon atoms. The lighter, straight-chain paraffin molecules are found in gases and paraffin waxes. Examples of straight-chain molecules are methane, ethane, propane, and butane (gases containing from one to four carbon atoms) Pentane and hexane (liquids with five to six carbon atoms). The branched-chain (isomer) paraffins are usually found in heavier fractions of crude oil and have higher octane numbers than normal paraffins. These compounds are saturated hydrocarbons, with all carbon bonds satisfied, that is, the hydrocarbon chain carries the full complement of hydrogen atoms.

Alkanes/Paraffin (CnH2n+2) : 

Alkanes/Paraffin (CnH2n+2) consist of only carbon and hydrogen bonded by single covalent bonds single Skeletal structure of only carbon atoms C1 – C4 n-alkanes are all gases Methane main component of natural gas Propane and butane often stored as compressed gases

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Physical Properties of Alkanes Non-polar molecules, which are less dense than water. Alkanes are immiscible with water making two layers. Van-der Waals or dipole-dipole attractive forces, and not H-bonding (as in polar molecules) are the main intermolecular forces Alkanes show regular increases in bpt and mpt as molecular weight increases down the homolgous series These weak intermolecular forces operate over small distances, arising because the electron distribution within molecules at any given instance is not uniform. Resulting in tiny electrical attractions between molecules. These temporary dipoles hold alkanes as liquids or solids, and must be overcome in order to vaporize a liquid or melt a solid (wax)

Isomers – the have the same molecular formula, but a different structuresStructural Isomers – same molecular formula, but atoms are bonded in different orders. : 

Isomers – the have the same molecular formula, but a different structuresStructural Isomers – same molecular formula, but atoms are bonded in different orders. Has the same molecular formula as n-pentane, C5H12 Have different Physical Properties, Mpt, Bpt, densities, C4H10 – has two isomers, n-butane and isobutane (2-methylpropane) (2,2-dimethylpropane) (2-methylbutane)

Slide 27: 

Physical Properties of Alkanes Non-polar molecules, which are less dense than water. Alkanes are immiscible with water making two layers. Van-der Waals or dipole-dipole attractive forces, and not H-bonding (as in polar molecules) are the main intermolecular forces Alkanes show regular increases in bpt and mpt as molecular weight increases down the homolgous series These weak intermolecular forces operate over small distances, arising because the electron distribution within molecules at any given instance is not uniform. Resulting in tiny electrical attractions between molecules. These temporary dipoles hold alkanes as liquids or solids, and must be overcome in order to vaporize a liquid or melt a solid (wax)

Isomers – the have the same molecular formula, but a different structuresStructural Isomers – same molecular formula, but atoms are bonded in different orders. : 

Isomers – the have the same molecular formula, but a different structuresStructural Isomers – same molecular formula, but atoms are bonded in different orders. Has the same molecular formula as n-pentane, C5H12 Have different Physical Properties, Mpt, Bpt, densities, C4H10 – has two isomers, n-butane and isobutane (2-methylpropane) (2,2-dimethylpropane) (2-methylbutane)

Use : 

Use As alkenes can be formed in somewhat straightforward reaction mechanisms, they form useful compounds such as Polyethylene and polyvinyl chloride (PVC): commercial products, such as piping, insulation and packaging. Polymers such as PVC are generally referred to as "singular" polymers as they consist of repeated long chains or structures of the same monomer unit, whereas polymers that consist of more than one molecule are referred to as "co-polymers".

Aromatics : 

Aromatics Unsaturated ring-type (cyclic) compounds Highly reactive because they have carbon atoms that are deficient in hydrogen. All aromatics have at least one benzene ring (a single-ring Three double bonds alternating with three single bonds between six carbon atoms) as part of their molecular structure. Naphthalenes are fused double-ring aromatic compounds. The most complex aromatics, polynuclears (three or more fused aromatic rings), are found in heavier fractions of crude oil.

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Cycloalkanes Cyclopropane CnH2n Cyclobutane Cyclopentane

Slide 32: 

Angle Strain in Cyclopropane and Cyclobutane – weaker “Bent” C-C bonds C-C Bond angles 60 and 88o respectively Eclipsed hydrogens – Torsional Angle Reduced in Cyclobutane by folding or bending Pentane has C-C bond angles of 108o C-C bonds slightly bent out of planarity in order to reduce torsional strain The most stable cycloalkane with 109.5o C-C bond angles Cycloalkanes have higher bpt/mpt than straight chain alkanes with the same number of carbon atoms

Slide 33: 

How to draw Cyclohexane ? put in axial H’s put in equitorial H’s

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Reactions of Alkanes Combustion Dehydrogenation Halogenation – radical substitution reactions

Slide 35: 

p-bond lobes represent areas of high electron density E+ Therefore, the p-bond is susceptible to attack by electron deficient molecules, called electrophiles, E+ ADDITION REACTIONS Alkyl Halides Alkyl hydrogen Sulfate Alcohols Dihaloalkanes

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Polymers are large molecules containing many identical repeating units (100-1000000) Polymerisation reaction is a repetition reaction which combines many small molecules of monomer (alkene) to form a polymer Addition polymer is a polymer in which the monomer simply add together with no other products formed besides polymer

Benzenes & Aromatic : 

Benzenes & Aromatic

Slide 38: 

Benzene An Aromatic Hydrocarbon is a cyclic compound that does not readily undergo addition reactions Reactivity is different to other unsaturated compounds-Substitution rather than Addition is favoured. C6H6 Resonance Structure - Rearrange the bonding electrons Delocalised or Conjugated System – p-bonding electrons can move within the molecule Delocalisation, Resonance -Stabilise molecules, so make them less reactive High Carbon content – burn with a smoky flame

Slide 39: 

In aromatic compounds the C atoms are sp2 hybrids, so that each C atom has one remaining p-electron involved in p-bonding Kekul? said that he dreamt the structure of benzene – so called Kekul? structure of benzene Three sp2 hybrid orbitals arrange themselves as far apart as possible - which is at 120° to each other in a plane. The remaining p orbital is at right angles to them. Each carbon atom uses the sp2 hybrids to form sigma bonds with two other carbons and one hydrogen atom. Each carbon atom uses the sp2 hybrids to form s-bonds with two other carbons and one hydrogen atom. This extensive sideways overlap produces a system of p-bonds which are spread out over the whole carbon ring. Because the electrons are no longer held between just two carbon atoms, but are spread over the whole ring, the electrons are said to be delocalised.

Slide 40: 

Flat (Planar) Molecule Regular Hexagon p-Electron Density Rings above and below the plane of the ring – Susceptible to electrophilic attack Benzene is a colourless odourless liquid that is a suspected carcinogen Benzene and its derivatives are said to be aromatic - a term coined because of the strong fragrance of some of the derivatives of benzene Non-aromatic compounds are said to be aliphatic Michael Faraday first isolated benzene in 1825

Slide 41: 

Flat (Planar) Molecule Regular Hexagon Delocalised or Conjugated System – p-bonding electrons can move within the molecule

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Must be cyclic Must be planar Each atom of the ring must have a p orbital and these p orbitals must be perpendicular to the plane of the ring Must contain 4n+2 p-electrons (where n = 0, 1, 2, ...) –Hückel Rule 10 p 14 p Rules for Aromaticity

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1 2 3 4 O m p Vinyl group

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Naming Aromatic Hydrocarbons Fluorobenzene Ethylbenzene Toluene Aniline Phenol Benzoic Acid 1,2-Dichlorobenzene 1,3-Dichlorobenzene -meta -ortho -para 1,4-Dichlorobenzene 2,4,6-Trinitrotoluene (TNT) o-Xylene m-Bromostyrene

Slide 45: 

Electrophilic Aromatic Substitution Electrophilic attack – Slow Rate Determining Step Delocalised Cyclohexadienyl cation Transition State or Wheland Intermediate

Slide 46: 

Fast Step is the loss of a proton Sir Christopher Ingold's ideas (1930s), terminology and nomenclature for reaction mechanisms (e.g. electrophilic, nucleophilic, inductive, mesomeric, SN1, SN2 etc) were generally accepted and employed everywhere. E.g. Nitration of benzene ---rapid re-aromatization

Slide 47: 

The Nitration of Benzene

ALCOHOLS, PHENOL and ETHERS : 

ALCOHOLS, PHENOL and ETHERS

Slide 49: 

Alcohols and Ethers Alcohols and Ethers can be regarded as derivatives of water in which one or two of the H atoms has been replaced by an alkyl group Electronegativity of oxygen causes an unsymmetrical distribution of charge Saturated molecules are sp3 hybridized

Slide 50: 

Alcohols are found to have much higher bpt than those of alkanes or haloalkanes of comparable size, e.g. Methanol (65 oC), Chloromethane and Methane are gases ; Ethanol (78.5 oC), Chloroethane (12 oC) and Ethane is a gas Methanol and Ethanol are classed as Polar Molecules (Hydrophilic) – They are Infinitely Soluble in Water Why? Answer – Hydrogen Bonding H-bonds weaker than covalent bonds, although these bonds can be continually broken and reformed – a highly ordered structure results – H-Bonding to water can also occur Water (mw = 18) is a liquid, bpt 100oC – otherwise a gas

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As R-group increases in size, so does the solubility in non-polar solvents As the number –OHs increases so does solubility in water Bpt increase with chain length and number of –OHs Methanol, CH3OH Solvent in varnishes, paint Racing Car Fuel (easy to put out flames) Highly Toxic – “Blindness” - Formaldehyde Ethanol, CH3OH Drinking Alcohol 50% Ethanol is flammable

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Preparation of Ethanol - Fermentation of Sugar – Break down of sugar to CO2 and Ethanol by Yeast Enzymes - Industrial Process – Hydration of Ethene Ethanol content; Beer, 3-9% ; Wine, 11-13% ; Whisky, 40-45% ; Vanilla Extracts, 35% ; Night Nurse, 25% ; Listerine, 25% Naming Alcohols Methyl alcohol (methanol) Ethyl alcohol (ethanol) Propyl alcohol (propanol) Isopropyl alcohol 2-Ethyl-1-butanol

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Naming Alcohols Polyhydroxy alcohols are alcohols that possess more than one hydroxyl group 1,2-Ethanediol (ethylene glycol) 1,2-Propanediol (propylene glycol) 1,2,3-Propanetriol (glycerol) Extremely Toxic Calcium Oxalate crystallises in the kidney leading to renal problems Harmless

Slide 54: 

Alcohols are very weak Acids

Slide 55: 

Naphthenes are saturated hydrocarbon groupings with the general formula CnH2n, arranged in the form of closed rings (cyclic) and found in all fractions of crude oil except the very lightest. Single-ring naphthenes (monocycloparaffins) with five and six carbon atoms predominate, with two-ring naphthenes (dicycloparaffins) found in the heavier ends of naphtha.

Other Hydrocarbons : 

Other Hydrocarbons Alkenes are mono-olefins with the general formula CnH2n and contain only one carbon-carbon double bond in the chain. The simplest alkene is ethylene, with two carbon atoms joined by a double bond and four hydrogen atoms. Olefins are usually formed by thermal and catalytic cracking and rarely occur naturally in unprocessed crude oil.

Slide 57: 

thylene (or IUPAC name ethene) is the chemical compound with the formula C2H4. It is the simplest alkene. Because it contains a carbon-carbon double bond, ethylene is called an unsaturated hydrocarbon or an olefin. It is extremely important in industry and also has a role in biology as a hormone.[2] Ethylene is the most produced organic compound in the world; global production of ethylene exceeded 75 million metric tonnes per year in 2005.[3]To meet the ever increasing demand for ethylene, sharp increases in production facilities have been added globally, particularly in the Gulf countries.

major commercial petrochemicals and their derivatives: : 

ethylene - the simplest olefin; used as a ripening hormone, a monomer and a chemical feedstock polyethylenes - polymerized ethylene ethanol - made by hydration (chemical reaction adding water) of ethylene ethylene oxide - sometimes called oxirane; can be made by oxidation of ethylene ethylene glycol - from hydration of ethylene oxide or oxidation of ethylene engine coolant - contains ethylene glycol polyesters - any of several polymers with ester linkages in the backbone chain glycol ethers - from condensation of glycols major commercial petrochemicals and their derivatives: