Fundamentals of Petrochemicals Presented by Umar Raja 25th May 2011 NOTES:

Introduction Mr Umar Raja, Principal Process Engineer Umar has over 20 years experience in developing concept and detail design with an ability to see them through start-up, operations and operations management. The goal of today's workshop is to quickly and effectively bring you up to speed with the language, concepts and key issues in the petrochemical industry. It has been designed for managers, engineers, graduates, operators and other personnel who are new or are requiring insight into the Refining and Petrochemicals industry. The workshop will provide an excellent overview for people from technical, non-technical and commercial backgrounds, who have limited experience and wish to improve their familiarity with some of the systems and technologies involved. NOTES:

Summary Chemical Industry Oil Refineries & Petrochemical Refineries Feed Stocks & Products Basic Building Block Chemicals Process Flow Configuration Hands-on Session - Constructing simplified flow-schemes Major Processes: Separation, Reaction, Equipment and Environment The Petrochem business? Role of Engineers Challenges in the Chemical Industry Where can I get more information Workshop Summary & Questions NOTES:

The Chemical Industry Chemical products made from gas and crude oil (~70000 products) End products include plastics, soaps, detergents, solvents, paints, drugs, fertilizer, pesticides, explosives, synthetic textile fibres and rubbers, flooring and insulating materials and much more. The largest petrochemical manufacturing industries are to be found in the United States, Western Europe, Asia and the Middle East. In 2007, 2,980 operating plants worldwide 10 Million direct employees, 50 million indirect employees Annual growth rate 2.4 %. Global enterprise valued at $2.2 Trillion …… and growing! NOTES:

Refining -The Mother Industry 5-6% NOTES:

Petrochemical Refinery THE PURPOSE OF A PETROCHEM REFINERY IS TO TRANSFORM RELATIVELY LOW VALUE PRODUCTS FROM OIL REFINERY INTO HIGH VALUE PRODUCTS AS EFFICIENTLY, PROFITABLY AND ENVIRONMENTALLY SOUND A WAY AS POSSIBLE NOTES:

Petrochemical Refinery NOTES:

Feed Stocks & Products NOTES:

Feed Stocks & Products Chemical Industry- Product Pattern NOTES:

Basic Building Blocks The term ‘aromatics’ is typically used to describe Benzene Toluene Xylenes These are commonly referred to as BTX aromatics and are produced in a refinery or petrochemicals complex The term ‘olefins’ is used to describe molecules with a C double bond Ethylene Propylene Butenes or Butadiene These are commonly referred to as light olefins and are also produced in a refinery or petrochemicals complex Olefins and aromatics are very high-value products Prices have reached over 1,000 $ / tonne for Paraxylene and benzene Ethylene and propylene. Compared to naphtha at 40-60% of this value NOTES:

Basic Building Blocks- Aromatics Benzene, C6H6 , colourless and highly flammable liquid Carcinogen, additive in gasoline now limited Building block for over 250 products e.g.. Ethyl benzene (for styrene), Cumene (for phenol), Cyclohexane NOTES:

Basic Building Blocks- Aromatics NOTES:

Basic Building Blocks- Aromatics Toluene (Methylbenzene), C7H8 or C6H5CH3, is a clear, water-insoluble liquid Produces benzene and xylenes Toluene for toluene diisocyanate (TDI), manufactures polyurethane Produces phenol, caprolactam, nitrobenzene, benzoic acid . Octane booster in gasoline 50% produces benzene and xylenes, 25% in solvents and 10% in the TDI. Around 15% of demand is by gasoline. NOTES: [1] www.icis.com

Basic Building Blocks- Aromatics Paraxylene (p-Xylene), C8H10, is colourless and a flammable liquid Isomers are O-xylene and M-xylene One of the fastest growing petrochemicals p-Xylene is used for PTA, DMT and PET for polyester High purity needed for polymerisation process NOTES:

Basic Building Blocks- Aromatics NOTES:

Basic Building Blocks - Olefins Ethylene, C2H4, is a gaseous organic compound Simplest Olefin Chemical feedstock Most produced organic compound 90% used to produce three chemical compounds ethylene oxide ethylene dichloride ethylbenzene polyethylene NOTES:

Basic Building Blocks - Olefins NOTES:

Basic Building Blocks - Olefins LDPE produces containers, dispensing bottles, tubing, plastic bags. Other products made from it include: Food storage and laboratory containers Parts that require flexibility, for which it serves very well Parts of computer hardware, such as hard disk drives, screen cards, and optical disc drives NOTES:

Basic Building Blocks - Olefins HDPE is resistant to solvents and has a wide variety of applications, including: Plastic lumber Folding tables/chairs Storage sheds Chemical-resistant piping systems Water pipes, for domestic water supply Refillable bottles Bottle Caps NOTES:

Basic Building Blocks - Olefins Butadiene, C4H6 Main intermediate for polymer production Product of steam cracking Light feeds, give primarily ethylene and heavier feeds form heavier olefins, butadiene, and aromatic hydrocarbons. Most butadiene is used in styrene-butadiene rubber (BDR) production for the tyre industry (~28%) Other polymers include Polybutadiene (PB), styrene-butadiene latex (SBL), acrylonitrile-butadiene-styrene (ABS) NOTES:

Basic Building Blocks - Olefins shoe heels and soles, gaskets and even chewing gum. NOTES: Musical instruments golf club heads (due to its good shock absorbance), automotive trim components, automotive bumper bars, enclosures for electrical and electronic assemblies, protective headgear, whitewater canoes, buffer edging for furniture and joinery panels, luggage, small kitchen appliances, and toys, eg. Lego bricks

Basic Building Blocks - Olefins Propylene, C3H6 Converts to acetone and phenol via the cumene process Produces isopropanol (propan-2-ol), acrylonitrile. Separated by distillation from hydrocarbon mixtures. Products include plastic items for medical/laboratory, kettles, food containers, clear bags and ropes. NOTES:

Petrochemical Refinery – Flow Configuration NOTES:

Major Processes – Aromatics Complex & Naphtha Cracker • Catalytic reformer for aromatics ̶ Feeds are heavy naphtha ̶ 60-70% yield of aromatics ̶ Up to 5% benzene, more in dedicated ‘benzene reformers’ • Steam cracker for olefins ̶ Feeds are ethane, propane, C4s, naphtha ̶ 50-80% yield of olefins, 2–13% yield of BTX Toluene 0 Kta Paraxylene 1400 Kta Benzene 932 Kta Aromatics Complex Heavy Aromatics 26 Kta Medium/Heavy Naphtha 2923 Kta Tail Gas 85 Kta Propylene 720 Kta DeC5’d Pygas 440 Kta Naphtha Cracker Ethylene 1440 Kta C2/C3 Cut 162 Kta LPG 291 Kta L.t Naphtha 308 Kta Butene 1 54 Kta Light Naphtha 3489 Kta NOTES: MTBE 185 Kta H2 92 Kta H2 35 Kta Butadiene 200 Kta H2 Export 127 Kta

Aromatics Complex - Overview The following processes recover aromatic compounds from mixture Distillation Extraction Purification The following processes convert lower-value aromatics into higher value aromatics Xylene isomerisation Toluene conversion C9+ aromatics conversion NOTES:

Aromatics Complex - Overview Distillation won’t separate aromatics from non-aromatics due to the similar boiling points Aromatic are extracted from non-aromatic using either Solvent extraction (liquid-liquid extraction) Extractive distillation Hybrid extraction (combination of the two) Purification of paraxylene from other C8 aromatics when not achieved by distillation uses following two techniques Crystallisation exploits wide differences in freezing points Adsorption exploits differences in molecular shapes NOTES:

Aromatics Complex - Production Processes NOTES:

UDEX Process (UOP Dow Extraction) Aromatics Complex - Production Processes Catalytic Reformer Operation with high catalyst activity to increase reformate aromatic yields from 50% to 75% UDEX Process (UOP Dow Extraction) Aromatic rich feed with solvent removes non Aromatics in raffinate stream and aromatics in extract stream. SulfolaneTM Process similar to the UDEX but uses internal recycle streams to enhance separation and aromatic recovery Sulfolane by Shell Oil Company in the early 1960s is still the most efficient solvent available for the recovery of aromatics. NOTES:

Aromatics Complex - SulfolaneTM Process NOTES:

Aromatics Complex - Chemical Transformations Toluene conversion into xylenes or benzene can be classified into 3 categories depending on the feed: 100% toluene feed Toluene together with C9 and heavier aromatics Toluene plus methanol Toluene Hydrodemethylation to convert toluene to benzene Highly exothermic, hydrogen atmosphere to suppress coke formation Demethylation of occurs at about 650°F and 82barg NOTES:

Aromatics Complex - Chemical Transformations Toluene hydro de-alkylation Toluene methylation: Toluene and methanol + benzene CH4 + H2 + P-xylene H2O + CH3OH NOTES:

Aromatics Complex - Chemical Transformations NOTES:

Aromatics Complex - Chemical Transformations Toluene Disproportionation to convert toluene to benzene and xylene 2 moles of toluene into 1 mole of benzene and 1 mole of xylene Catalyst transfers methyl group from one methylbenzene ring to another methylbenzene ring Expensive than hydrodemethylation. Involves hydrogen as reaction mixture is equilibrium limited. 2 + Mixed xylene Benzene NOTES:

Aromatics Complex - Chemical Transformations NOTES:

Aromatics Complex - Chemical Transformations Process in which mixed C8 aromatics depleted in paraxylene are isomerised to produce more paraxylene There are two types of xylene isomerisation Ethylbenzene (EB) isomerisation Ethylbenzene (EB) dealkylation The reaction path is dependent on catalyst used C2H5 + H2 Mixed xylenes C2H5 NOTES: + C2H6 + H2 Benzene

Aromatics Complex - Chemical Transformations Xylene Isomerisation Process Feed and hydrogen are preheated to reaction temperature Isomerisation reactor is a fixed bed down flow vessel operating at temperatures of 450C and 31barg Deheptanizer separates isomerised product as the bottoms stream NOTES:

Aromatics Complex – Selective Adsorption Parex process to separate Paraxylene from Xylene mixtures Isomers boil closely and conventional distillation is not practical. Parex process simulates a moving bed of adsorbent Separation takes place in the adsorbent chambers. 99.9 wt-% pure para-xylene at 97 wt-% recovery per pass NOTES:

Naphtha Steam Cracking – olefins The feedstock is heated to the point that the energy transfer from heat is enough to ’crack’ the molecule into two or more smaller molecules. High heat input Mixture HC and steam passed through tubes inside a furnace Very Short Residence Time <1s Rapid Quench of reaction followed by distillation. 50-80% yield of olefins, 2–13% yield of BTX NOTES:

Naphtha Steam Cracking – Overview NOTES:

Hands on Session The petrochemicals may be olefins or their precursors, or various types of ________ petrochemicals. 2) An ________ _______ is a combination of process units which are used to convert _________, from a variety of sources, and ___________ into the basic petrochemical intermediates: ______, ______, and ______. 3) Aromatics can be produced from variety of different feedstocks, including ______, _______, ________, and ___________. 4) Fill in the missing components for polystyrene production ______________ _______________ Polystyrene NOTES:

Fill in the missing process link Hands on Session Fill in the missing process link Traditional _________ won’t separate aromatics from non-aromatics due to _____ _____ ______. Aromatic components can be extracted from non-aromatic components using ____ _____ or _______ _______. The two processes used to purify paraxylene from other C8 aromatics are ___________ and ___________. _____________ exploits wide differences in freezing points and adsorption exploits differences in _________ ___________. Toluene via ____________ or __________with C9-aromatics can produce _____ and an equilibrium mixture of xylenes. ? Naphtha (80-110 C) Ethylene, propylene, Butenes & butadiene NOTES:

O-xylene / M-xylene separation Hands on Session Fill in the missing processes and components for the aromatic complex block flow below: ? ? Gas ? Toluene TADP Separation ? C9 Aromatics O-xylene / M-xylene separation ? ? ? NOTES: ? Metaxylene Isomerisation O- xylene

Hands on Session The petrochemicals may be olefins or their precursors, or various types of ________ petrochemicals. 2) An ________ _______ is a combination of process units which are used to convert _________, from a variety of sources, and ___________ into the basic petrochemical intermediates: ______, ______, and ______. 3) Aromatics can be produced from variety of different feedstocks, including ______, _______, ________, and ___________. 4) Fill in the missing components for polystyrene production Aromatic Aromatics Complex Naphtha Py Gas Benzene Toluene Xylene Naphtha LPG Condensate Py Gas ______________ _______________ Polystyrene NOTES: Benzene Ethylbenzene Styrene Ethylene

extraction distillation Hands on Session Fill in the missing process link Traditional _________ won’t separate aromatics from non-aromatics due to _____ _________. Aromatic components can be extracted from non-aromatic components using ____ _____ or _______ _______. The two processes used to purify paraxylene from other C8 aromatics are ___________ and ___________. _____________ exploits wide differences in freezing points and adsorption exploits differences in _______________. Toluene via _____________ or ___________with C9-aromatics can produce _______and an equilibrium mixture of xylenes. Naphtha (80-110 C) cracking Ethylene, propylene, Butenes & butadiene distillation similar boiling points solvent extraction extraction distillation crystallisation adsorption crystallisation molecular shapes NOTES: disproportionation transalkylation benzene

Hands on Session Fill in the missing processes and components for the aromatic complex block flow below: naphtha Benzene Gas Benzene Toluene Separation Toluene TADP Separation Hydrotreating C9 Aromatics O-xylene / M-xylene separation Paraxylene Separation Reformer P-xylene NOTES: Metaxylene Isomerisation O- xylene Orthoxylene Separation

- Metabolic Processes in Living Organisms Reaction and Reactor Reaction- Process leading to transformation of one set of chemical substances to another. Reactor- Confines within which reaction occurs. Principal is not just confined to industrial reactors; but; - Metabolic Processes in Living Organisms - Atmospheric Chemistry.

Ideal, Batch and Flow Reactor Ideal Reactor- has uniform temperature, pressure and composition. - In practice reactor temperature, pressure and composition are not uniform. Batch Reactor- Where reactor mass is not exchanged with surroundings Flow Reactor- Where reactor mass is exchanged with surroundings.

Adiabatic and Isothermal Reactor Adiabatic Reactor- Where Reactor does not exchange heat with surrounding. Isothermal Reactor- Where Reactor has good contact with surrounding but held at constant temperature (in both time and position within reactor).

CSTR or MFR CSTR or MFR Continuous Flow Stirred Tank Reactor OR Mixed Flow Reactor. Reaction occurs at constant pressure, constant temperature; and composition inside reactor is assumed to be that of effluent.

Tubular Reactor Ideal Tubular or Plug Flow Reactor Reactor operating isothermally and at constant pressure and at steady-state with unique residence time. Fluid fills the tube and moves like a plug down the length of the tube. Fluid properties are uniform over cross-section normal to direction of flow.

Industrial Reaction What is expected from a Reaction? Product of Choice What is a Catalyst? - Substance that enhances reaction without being consumed

Ammonia Synthesis N2 + 3H2 Catalyst Reactants Products

Reaction and Catalyst How long should a reaction take? Fast to be economical What is Economical? Good value in relation to money, time and effort Ammonia is a cheap commodity, so catalyst must be cheap and durable! Lasts longer and produces 2000 times its value.

Industrial Reaction If conversion is less what comes to mind? How to dramatically improve it? What are the factors? - Catalysts - Thermodynamics Which of above is a primary Consideration? - Thermo is Primary- Catalyst is Secondary

Elementary and Stoichiometric Reaction H2+Br2 2HBr Kinetics Identification of Reaction Elementary and Stoichiometric Reaction H2+Br2 2HBr Multi-step arrangement in Network (sequence/intermediates) Br+H2 → HBr + H H+Br2 → HBr + Br Break or Make a single chemical bond. Must be written the way it takes place.

Petrochemical Refinery environmental impacts on Water: Environment - Water Petrochemical Refinery environmental impacts on Water: process wastewater from desalting, distillation, cracking, and reforming operations about 24% of total emissions is released to wastewater large quantities of cooling water NOTES:

Petrochemical Refinery environmental impacts on Air: Environment - Air Petrochemical Refinery environmental impacts on Air: volatile hydrocarbons from crude oil SOx from crude oil and process heat NOx  and particulates from process heat H2S from sulfur recovery operations about 75% of total emissions by weight are released to air NOTES:

Environment – Waste & Global Warming Solid Waste Petrochemical plants generate significant amounts of solid waste and sludge , some of which is hazardous because of organics and heavy metals. Contribution to Global warming energy-intensive operation most of the energy is consumed as process heat thus, little prospect for replacement of process energy by renewable or non-CO2-intensive sources Of great concern are accidental discharges as a result of abnormal operation. NOTES:

Environment - Minimising Pollution Operate Furnaces Efficiently Waste Material to Flare Avoiding Spills and Accidental Releases Water Treatment NOTES:

Petrochemical Business Price and quality of feedstock and products is constantly changing. Government regulations add additional constraints. Not much differential between price of feedstock’s and products. HOW DO I KEEP IN BUSINESS? NOTES:

I NEED ENGINEERS! Petrochemical Business I need to design and revamp the plant utilizing the latest technology to be more efficient I need to make the plant more flexible and responsive I need to operate (control) the plant in the most efficient manner possible I need to keep the equipment running all the time I NEED ENGINEERS! NOTES:

Operations & Maintenance Engineers Control Systems Engineer Role of Engineers Operations & Maintenance Engineers Control Systems Engineer Design Engineer Health & Safety Environmental Impacts Planning & Scheduling Reliability Engineer Plant Manager NOTES:

Chemical Industry- The Challenges Feedstock availability and increasing cost Environmental controls e.g. increasing constraints on emissions Energy Savings Process Efficiency Catalyst Development Increasing demand for products NOTES:

NOTES:

Workshop Summary Presented only some of the main processes in petrochemicals, others downstream are polymers, plastics, fibres and resins is extensive. A petrochemical refinery is made up of a combination of highly integrated processes such as distillation, extraction, and various separation operations. Olefins and aromatics are the building blocks for a wide range of materials and products Aromatic complexes is a general term for a combination of process units that produce the three basic chemicals Crackers convert feed-stocks into ethylene, propylene, butane, butadiene via cracking.  NOTES:

Further Information Books: Speight, James. G. 2002, Chemical Process and Design Handbook John Wiley & Sons. 2007 , Wiley Critical Content - Petroleum Technology, Volume 1-2 Chenier, P. 2002, Survey of Industrial Chemistry, Third Edition Internet: Google Search, Online Books, Articles NOTES:

Q & A NOTES: QUESTIONS

Summary Keywords –Language, Concept, Key Issues Petrochemicals- Petrochemical Refineries are a combination of highly integrated processes involving Reaction, Separation; and Extraction Aromatics Complex- A combination of Process units that converts Naphtha and Pygas into basic chemical intermediates. Simplest configuration produces Benzene, Toluene and Xylene. Basic Building Block Chemicals. Process Flow Configuration Hands-on Session - Constructing simplified flow-schemes Major Processes: Separation, Reaction, Equipment and Environment The Petrochem business? Role of Engineers Challenges in the Chemical Industry Where can I get more information Workshop Summary & Questions NOTES: