An Introduction to Chemical Process Technology

1. An Introduction to Chemical Process Technology Paul Ashall & Muhammad Said, M.T. Paul Ashall, 2008

2. Aspects of Industrial Chemical Processes • Products • Types of process • Flowsheets • Mass and Energy balances • Heat transfer and heat exchangers • Reactor design and operation • Separation and purification processes Paul Ashall, 2008

3. Aspects of chemical processes cont. • Process instrumentation and process control • Materials handling • Process economics • Safety and environmental issues • Quality etc Paul Ashall, 2008

4. Industrial Chemical Processes Chemical processes are used to produce chemical products and are by definition processes which include chemical transformation(s). Specific products produced by the chemical and pharmaceutical industry include: aspirin, ibuprofen, paracetamol, naproxen, labetalol, etc These active pharmaceutical ingredients (APIs) are produced by chemical reactions involving organic chemicals (organic chemistry). Paul Ashall, 2008

5. Chemical processes cont. • Route (materials, steps, operations etc) • ‘Recipe’(materials, quantities, steps) • Plant equipment (operations) • Process operating conditions Paul Ashall, 2008

6. Many chemicals are mixed with other chemicals to produce formulations suitable for consumer use. These include consumer products such as paints, fragrances, pesticides and medicinal products. For example ibuprofen is the active pharmaceutical ingredient (API) in the OTC product ‘Nurofen’, which contains other ingredients called excipients. Paul Ashall, 2008

7. Specific processes have been developed to produce specific chemicals. Particularly well established processes are given names. For example the process used to manufacture sulphuric acid is called the ‘Contact’ process. In some cases a chemical may be produced by more than one process. Paul Ashall, 2008

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9. The chemical industry consists of many different sectors (or product groups), each with their own characteristics. For example pharmaceuticals, pesticides, fertilisers, petrochemicals, dyestuffs etc The type of chemical produced will determine the particular characteristics of the process (or processes) used to produce the product. For example compare the processes used to manufacture ammonia and aspirin. Paul Ashall, 2008

10. The production of hard aspirin tablets requires only four ingredients: the active ingredient (acetylsalicylic acid), corn starch, water, and a lubricant. Paul Ashall, 2008

11. Classification of chemical products • Bulk chemicals e.g. sulphuric acid • Fine chemicals e.g. ‘ibuprofen’ • Speciality chemicals e.g. adhesives • Inorganic/organic Paul Ashall, 2008

12. Bulk chemicals are characterised by a combination of two parameters – large volume production, which is supported by market demand, and lower unit costs, where the principle of economy of scale is important. Fine chemicals are produced on a relatively smaller scale in more versatile (less dedicated generally) production units using batch operations. Product specifications may be more exacting and unit cost is relatively higher. Fine chemicals may be used as ingredients in formulations or as intermediates in the production of more complex chemicals. For example bulk pharmaceuticals. Paul Ashall, 2008

13. Characteristics of fine versus bulk chemicals Paul Ashall, 2008

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15. Speciality chemicals These are chemically formulated products manufactured from basic chemicals which are used by industry and domestic consumers for specific purposes. For example: coatings, adhesives, pharmaceutical products, pesticides, cosmetics, disinfectants etc Paul Ashall, 2008

16. Chemical & pharmaceutical companies in Indonesia • PT Abbot Indonesia • PT Bayer Indonesia Tbk • PT Bintang Toedjoe • PT Bio Farma • Boehringer Ingelheim • PT Bristol Myers Squibb Indonesia Tbk • PT Bristol Myers Squibb Indonesia Tbk Paul Ashall, 2008

17. Integration of the chemical industry with manufacturing industry For example the manufacture of polyester textiles. crude oil naphtha terephthalic acid/ethylene glycol PET polyester fibres textiles Discuss production of ibuprofen. Paul Ashall, 2008

18. Choice of process Examples include: • Ibuprofen (Boots route and Hoechst-Celanese route) • Acetic acid, Adipic acid, Ethylene oxide • Vinyl chloride (ethyne and ethene based routes) • Titanium dioxide (‘sulphate process’, ‘chloride process’) • Ethanol, etc Paul Ashall, 2008

19. General factors to be considered • Yield, conversion, selectivity/mass balances • Energy usage/energy balances • Kinetics/rates and productivity (kg/hr) • Number of synthetic reaction steps/reaction chemistry • Scale of operation, Manufacturing costs • Separations required, Operating conditions • Environmental factors – waste, environmental impact, emissions, effluent, solid waste, hazardous waste • Health and safety factors – process safety/operating conditions, use of hazardous materials • Material availability, Quality issues • By products and co products, etc Paul Ashall, 2008

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21. Ammonia is made from natural gas which is imported by pipeline from the North Sea. • Some ammonia is used to make nitric acid. • Ammonia and nitric acid are used to make the fertilizer, ammonium nitrate. • Ammonia is also converted into hydrogen cyanide. • Hydrogen cyanide is used in the process to make methyl 2-methylpropenoate, a key monomer for the manufacture of various acrylic polymers. • The stream of ‘waste’ sulfuric acid and ammonium sulfate from the process to make methyl 2-methylpropenoate is converted to pure sulfuric acid, which can then be reused in the process. • The tank farm stores imported reactants and products prior to export Paul Ashall, 2008

22. Process obsolescence - case study • Routes to ibuprofen (see EP0284310A1) Paul Ashall, 2008

23. Product obsolescence • Sulphonamide drugs Paul Ashall, 2008

24. Choice of route Case study: 3, 3-dimethylindoline Paul Ashall, 2008

25. System model of a chemical process Inputs: reactants, solvents, catalysts, energy etc Outputs: product, by-products, co-products, spent catalyst, solvents, waste, energy etc Paul Ashall, 2008

26. “Two-or more products separated in the course of the same processing operation, usually requiring further processing, each product being in such proportion that no single product can be designated as major product”. • In oil industry kerosene, gasoline, fuel oil, lubricants etc. are all produced from the same product, crude petroleum. They are of equal important; hence they are called joint products. Paul Ashall, 2008

27. By-product is defined as “a product which is recovered incidentally from the material used in the manufacture of recognised main products, such a by­product having either a net realisable value or a usable value which is relatively low in comparison with the saleable value of the main products. By-product may be further processed to increase their realisable value.” • (a) In soap-making industry—in the process of mixing and boiling ingredients many rejections take place. These rejections are collected for recovery as by-product. • (b) In coke ovens—gas and tar are treated as by-products. Paul Ashall, 2008

28. Co-products are such products which are produced simultaneously with the main product but not necessarily from the same raw material. • In lumbering operations, it is possible to obtain oak, pine and walnut boards at the same time but from different trees. Paul Ashall, 2008

29. Chemical process operations are of two basic types: • Batch processes, which operate according to batch cycles, • Continuous processes, which operate continuously under steady conditions. Paul Ashall, 2008

30. Chemical processes Chemical processes consist of a number of sequential and integrated operations carried out in appropriate equipment. For example chemical reaction carried out in a chemical reactor. The precise operations, sequence of operations and equipment specifications depend on the nature of the process, operating conditions, materials used and product produced. Paul Ashall, 2008

31. Chemical processes Operationequipment Chemical reaction reactor Distillation distillation column Filtration filter units Drying dryers (various types) Fluid transport pipes, valves, pumps etc Process controlmeasurement devices, controllers, control valves etc Evaporation evaporators Centrifugation centrifuges Heat transfer heat exchangers Granulation granulator etc Paul Ashall, 2008

32. Multi-purpose/product plant for bulk active pharmaceutical ingredients • Batch reactors (stainless steel, agitator, glass-lined, reflux condenser, jacket etc) • Material feed system to reactors • Separation and purification equipment ( crystallisers, filtration, centrifuges, dryers, distillation unit etc) • Material storage • Process support services/Utilities (incl. heat transfer fluids) • Waste treatment • Emissions control Paul Ashall, 2008

33. Equipment • Batch reactors • Filter driers e.g Cogeim Nutsche • Crystallisers • Double cone vacuum driers • Mixers and granulators • Fluid bed driers • centrifuges • etc Paul Ashall, 2008

34. Separation and purification processes Why do we need separation and purification processes in the production of chemicals? Paul Ashall, 2008

35. Separation processes A typical sequence of separation processes used in the production of bulk pharmaceutical products is: crystallisation (from mother liquour), filtration or centrifugation and drying. Paul Ashall, 2008

36. Separation processes Factors to be considered in choosing separation/purification process(es): • Quantity of material to be separated • Rate of separation required • Feasibility, Selectivity • Economics, Quality • Equipment • Mode of operation Paul Ashall, 2008

37. Process support services/Utilities (or plant services) • Steam, Oksigen • Cooling water, Chilled water • Other heat transfer fluids • Inert gases, Compressed air • Electricity, • Demineralised water/deionised water • UP water, Distilled water • Effluent treatment, etc Paul Ashall, 2008

38. Purified Water/Water for Injection • Obtained from potable water • Specified in pharmacopoeias • Storage • Depth filter • Organic trap • Carbon filter • DI • Filtration (0.45 micron)/UV (254 nm) • UF (0.22 micron) • Distillation/RO Paul Ashall, 2008

39. WFI distribution • Sealed storage • Ring main (loop) circulation under turbulent flow conditions at 85 deg cent • No ‘dead legs’ in pipe distribution system • UV irradiation Paul Ashall, 2008

40. Material storage • Reactants • Products • Intermediates • Solvents • Catalysts • Reagents • etc Paul Ashall, 2008

41. Flowsheets Flowsheets are used to describe the operating details of chemical processes. There are a number of basic types: Flowcharts (or block diagrams), Process flowsheets (or Process Flow Diagram), Piping and Instrumentation Diagrams (PID). Paul Ashall, 2008

42. Flowsheets • Schematic representations • Arrangement of equipment • Interconnections • Movement of material • Stream connections • Stream flows/quantities • Stream compositions • Operating conditions etc Paul Ashall, 2008

43. Flowcharts Simple flowcharts can be used to show the main material routes through the process (lines and arrows) and to depict the main operations (blocks). Paul Ashall, 2008

44. Process flowsheet • Symbols • Stream information • Layout Paul Ashall, 2008

45. P and I Diagram • Equipment details and arrangement (item no., name, dimensions, materials of construction, rate or capacity, occupation time, T, P, materials handled, heat duty, power) • Pipe details • Valves • Ancillary fittings • Pumps • Instrumentation and control loops • Services (utilities) • Symbols • Layout Paul Ashall, 2008

46. For a large chemical plant a large number of such flowsheets will be required to specify the process. These will be grouped into individual plant operating areas. Paul Ashall, 2008

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49. Exercise 1.Construct a process flowsheet for a batch esterification reaction from the information given. 2.Construct a process flowsheet for a batch process to produce aspirin from the information given Paul Ashall, 2008

50. Exercise cont. Choose a chemical product and from the information sources given below write a process description and draw a block flow diagram of the reaction and separation steps. Examples: aspirin, penicillin, paracetamol. Paul Ashall, 2008