Catalytic Reforming Unit ( CRU)

DISTILLATIONOverviewWhat is Distillation?Types of Distillation Applications of DistillationHow is the Distillation important to Petrotrin?Different types of Distillation processes SummaryQuestions and Answers What is Distillation?Separating the components in a liquid mixture by continuous evaporation and condensation Separation is based on differences in the volatility of the components within the mixture i.e. differences in the boiling points of the componentsApplications of DistillationImportance to RefinerySplitting of light and heavy naphtha with benzene precursors specificationsHeavy naphtha must contain < 2wt% total of precursorsLPG productionBenzene saturationIsomerate contains 600F (5) Oxygen Removal Phenols + H2 Alkyl Benzene + H2O

Naphtha Hydro-treating Unit

PENEX UnitPENEX throughput is 7400 BPDHydro-treated naphtha (low octane) combines with recycle Isomerate (final product) & go through the Feed Driers to remove moistureMake-up H2 goes to Make-up Compressor and then to the Chloride Treaters & Gas Driers Dried Feed & H2 combine and heated with Reactor Effluent and steam Chloride promoter is injected and stream enters PENEX ReactorsPENEX UnitPENEX Reactors consist fixed bed catalyst (I-8 catalyst) and a sulphur guard bedOperating Conditions: 450psig/260FOnly Reactor A in use while Reactor B acts as a spare/backup Reactor effluent goes to Stabiliser Column to remove light ends (due to hydro-cracking) and hydrogen chloride gas (HCl) produced Stabiliser Bottoms is Isomerate (high octane gasoline)PENEX UnitOff-gas is rich in HCl and goes to the Net Gas Scrubber which utilises NaOH for treating NaOH + HCl NaCl + H2OAny H2S formed is also removed H2S + 2NaOH Na2S + 2H2OTreated Off-gas goes to the Refinerys Fuel Gas SystemPENEX Unit

PENEX UnitCritical Reactions:(1) Paraffin Isomerisation (a) Normal Hexane (RON = 24.8) 3-Methyl Pentane (RON = 74.5) 2,2-Dimethyl Butane (RON = 91.8)(b) Normal Pentane (RON = 61.8) Iso-Pentane (RON = 93.0)

PENEX Unit(2) Naphthene Ring Opening three (3)important naphthenes which areconverted to paraffins are:Cyclopentane (CP)Methyl Cyclopentane (MCP)Cyclohexane (CH) These ring opening reactions increasewith increasing temperature

PENEX Unit(3) Naphthene Isomerisation the MCP& CH exist in equilibrium. MCP productionincreases as the temperature increases:CH (RON = 84.0) MCP (RON = 89.3) (4) Benzene Saturation benzene issaturated to CH (exothermic reaction). Hencethe limit on the feed is 5% benzene byvolume. BENZENE + 3H2 CH

Catalyst Management Removal of PENEX catalyst contaminants (sulphur, nitrogen, metals and water) in the Hydro-treating section These contaminants deactivate the active sites of the catalyst permanentlyAs the catalyst deactivates, the reactor inlet temperature must be increased to maintain product octaneCatalyst Management The addition of perchloroethylene to the process stream is to maintain acid function of the catalyst It decomposes to hydrogen chloride (HCl) in the present of the I-8 catalyst C2Cl4 + 5H2 4HCl + C2H6The HCl is then removed in the Net Gas ScrubberSummaryIsomerisation results in higher octane gasoline used for pool blending Total benzene saturation is achieved Isomerisation complex consists of three sections:Fractionation splitting of light and heavy naphthaHydro-treating removal of PENEX catalyst poisons PENEX production of higher octane gasolineEnd of PresentationThank you!!

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