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Btx Separation

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Group Members Syed Muhammad Obaid Ur Rehman

CH-018 Hosh Muhammad Shiekh CH-025 Syed Muhammad Shaheer Fayyaz CH-042 Syed Zaki Haider Naqvi CH-061

BTX SEPARATION

BENZENE Benzene is an organic chemical compound. It is composed

of 6 carbon atoms in a ring, with 1 hydrogen atom attached to each carbon atom, with the molecular formula C6H6. Benzene is a natural constituent of crude oil, and is one of the most basic petrochemicals. Benzene is an aromatic hydrocarbon and the second [n]-annulene ([6]-annulene), a cyclic hydrocarbon with a continuous pi bond. It is sometimes abbreviated PhH. Benzene is a colorless and highly flammable liquid with a sweet smell. Because it is a known carcinogen, its use as an additive in gasoline is now limited, but it is an important industrial solvent and precursor to basic industrial chemicals including drugs, plastics, synthetic rubber, and dyes.

STRUCTURE OF BENZENE

TOLUENE Toluene, formerly known as toluol, is a clear, water-

insoluble liquid with the typical smell of paint thinners. It is a mono-substituted benzene derivative, i.e., one in which a single hydrogen atom from the benzene molecule has been replaced by a univalent group, in this case CH3. It is an aromatic hydrocarbon that is widely used as an industrial feedstock and as a solvent. Like other solvents, toluene is sometimes also used as an inhalant drug for its intoxicating properties; however, inhaling toluene has potential to cause severe neurological harm.[1][2] Toluene is an important organic solvent, but is also capable of dissolving a number of notable inorganic chemicals such as sulfur.

STRUCTURE OF TOLUENE

XYLENE Xylene encompasses three isomers of dimethylbenzene.

The isomers are distinguished by the designations ortho- (o), meta- (m-), and para- (p-), which specify to which carbon atoms (of the benzene ring) the two methyl groups are attached. Counting the carbon atoms from one of the ring carbons bonded to a methyl group, and counting towards the second ring carbon bonded to a methyl group, the oisomer has the IUPAC name of 1,2-dimethylbenzene, the m- isomer has the IUPAC name of 1,3-dimethylbenzene, and the p- isomer has the IUPAC name of 1,4dimethylbenzene. The mixture is a slightly greasy, colourless liquid commonly encountered as a solvent. Several million tons are produced annually.

STRUCTURE OF XYLENE

World Wide Applications

World Wide ApplicationsToluene Adhesives Manufacture Carpet adhesive solvents Electroplating Cold-cleaning Solvents Vapor Degreasing Solvents Laboratory ChemicalsSolvents Dilution Laboratory Chemicals Solvents

Metal DegreasingPaint Manufacture Hydrocarbon Solvents Paint StrippingSolvents Paint Stripping Paper Coating Solvents Pesticide Mfg (Insecticides) Solvents Insecticide Manufacture Pharmaceuticals MfgSolvents PharmaceuticalsPrinting Solvents for Flexograph Solvents

World Wide ApplicationsApplications (xylene) Terephthalic acid and related derivatives Solvent applications Laboratory uses Precursor to other compounds

BTX Production Methods 1) Sulfolane process 2) Tatory process 3) Parex process 4) Toulene de-alkylation unit 5) Mixed xylene separation by crystallization

process

Process Flow Diagram

Feed or Raw Material Naphtha

Cracked naphtha feeds such as FCC naphtha and coker naphtha are upgraded to produce chemical grade BTX (benzene, toluene, xylene with ethylbenzene) while co-producing a low sulfur gasoline of relatively high octane number. The cracked, sulfurcontaining naphtha is processed by hydrodesulfurization followed by treatment over an acidic catalyst, preferably a zeolite such as ZSM-5 or zeolite beta with a hydrogenation component, preferably molybdenum. The treatment over the acidic catalyst in the second step restores the octane loss which takes place as a result of the hydrogenative treatment and results in a low sulfur gasoline product to permit a low sulfur gasoline of blending quality to be obtained with the BTX. The BTX can be extracted from the second stage effluent, preferably from a C6 -C8 fraction of this effluent.

Process DescriptionThe key process technologies include: Reforming The process selectively reforms naphtha to

aromatics (BTX) and high purity hydrogen. Para-xylene Separation The Parex process separates high

purity para-xylene from mixed C8 aromatics isomers. Isomerization The Isomar process re-establishes an

equilibrium mixture of isomers via xylene isomerization and conversion of ethyl benzene to benzene or xylenes. Toluene and Heavy Aromatics Conversion The UOP

Tatoray Process disproportionates toluene and transalkylates toluene with C9/C10+ aromatics to produce benzene and xylenes.

Process Description Toluene Selective Disproportionation The PX

Plus Process selectively disproportionates toluene to produce benzene and xylenes with near 90% paraxylene content, significantly above the equilibrium. process extracts benzene and toluene from the reformate using an extractive distillation flow scheme. converts toluene and heavier aromatics to benzene.

Extractive Distillation The Sulfolane

Thermal Hydro-Dealkylation The THDA process

Aromatic Petrochemical Complex Naphtha and gas oil is also catalytically

reformed at high temperatures in the presence of catalysts to yield aromatic intermediate chemicals, such as benzene, toluene and xylene . These are liquids at ordinary temperatures and pressures and can be easily transported to desired locations where they are used as raw materials in the production of a variety of secondary chemical products as shown in Fig.

Products and By Products

Industries Producing and Consuming BTXProducers National Refinery Under Development of BTX plant BYCO Refinery Attock Refinery Consumers Tufail Chemicals

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