Chemical & Biological Engineering Lecture - NGN110 PDF

Chemical & Biological Engineering Lecture- NGN110 Introduction to Chemical & Biological Engineering What is Chemical & Biological Engineering? ❖Chemical & biological engineers change raw materials into valuable products on an industrial scale ❖Chemical...

Chemical & Biological Engineering Lecture- NGN110 Introduction to Chemical & Biological Engineering What is Chemical & Biological Engineering? ❖Chemical & biological engineers change raw materials into valuable products on an industrial scale ❖Chemical engineers are concerned with PROCESSES and PRODUCTS. 2 Example-Raw Material of Paper Industry  What is a Chemical Process? Raw Chemical Products Materials Process (High value) (Low value) A chemical process converts raw materials of low value into products of high value The chemical process ‘adds value’ by producing something useful/desirable from something relatively useless/undesirable 5  Chemical Processes Petrol, Diesel Crude Oil Oil Refinery Chemicals, Plastics 6  Chemical Processes Electrolytic Bauxite Aluminium Process 7  Introduction to Chemical & Biological Engineering Processes: Process Design: Making chemicals and Inventing a new process pharmaceuticals Designing the equipment for a Processing polymers and foodstuffs process Energy generation Operating a process Wastewater treatment Improving a process Environmental clean-up Products: Product Design: Chemicals - petrol, ammonia, methanol Choosing a product for an Polymers - polythene, PVC, synthetic application fibres Designing the product Consumer products - shampoo, Improving the product washing powder Foodstuffs - ice cream, chocolate, beer Pharmaceuticals - paracetamol, penicillin 8  Introduction to Chemical & Biological Engineering ❖Chemical engineers know how transformations occur at different length scales. Transformations: Length scales: Chemical reactions Molecular level - how molecules Changes in physical state (e.g. behave and react melting, boiling) Process level - how transformations Mixing and separating can be performed Biosynthesis Plant level - how processes can be put together Global level - logistics, management, the environment 9  Introduction to Chemical & Biological Engineering ❖Chemical engineers know about mature and new technologies. Mature technology: New technology: Stirred tanks Membrane separators and reactors Distillation columns Supercritical fluids Heat exchangers Biotechnology Filters Genetic manipulation of organisms 10  Introduction to Chemical & Biological Engineering ❖Chemical & biological engineers have knowledge of many subjects. Subjects: Pure science Management Engineering Entrepreneurship Information technology Safety, health and the environment Economics ❖Chemical & biological engineers are vital in the process industries. 11 Roles of Chemical & Biological Engineers 12  Chemical Process Design Each chemical process involves a series of steps, or ‘unit operations’ Examples are: – Reaction (in a reactor) – Heat transfer (in a heat exchanger) – Distillation (in a distillation column) Chemical engineers design processes to be safe, efficient and economically viable 13  Unit Operations Classification of unit operations – Mass transfer operations – Heat transfer operations – Chemical reaction operations – Fluid flow operations – Mechanical operations 14  Mass transfer operations http://upload.wikimedia.org/wikipedia/commons/thumb/c/cc/Colonne_distillazione.jpg/250px-Colonne_distillazione.jpg Distillation Gas absorption Gas stripping Liquid-liquid extraction Adsorption Leaching Crystallisation 15  Heat transfer operations http://www.7clouds.info/wp-content/uploads/2011/07/heat-exchanger-300x247.jpg Heat exchangers Jacketed cooling/heating Straight-tube heat exchanger 1-pass.PNG Evaporation Condensation 16 Chemical Process Reactor Chemical reaction operations Fixed-bed reactor Stirred tank reactor Fluidised bed reactor http://upload.wikimedia.org/wikipedia/commons/thumb/b/b9/Chemical_reactor_CSTR_AISI_316.JPG/350px-Chemical_reactor_CSTR_AISI_316.JPG 17 Fluid flow operations Piping Valves Solids fluidisation Filtration 18 Mechanical operations Solids transportation Crushing Screening and sieving 19 How do we communicate information about a process? 20 The heart, a hollow muscular pump, is comprised of four chambers, two atria and two ventricles. It is located beneath the sternum, slightly more to the left side, and is composed of cardiac muscle tissue innervated by parasympathetic and sympathetic nerve endings. The ventricles are the lower chambers while the atria reside in the upper portion of the heart. The atria are separated by an interatrial septum, while the ventricles are divided by the interventricular septum. The atria and the ventricle of each side of the heart can communicate via the sheet of connective tissue located between them. Embedded in this tissue is a one-way valve, referred to as the atrioventricular valve (A-V valve). The valve that separates the left atrium and ventricle is known as the bicuspid valve because of the two functioning leaves that it is composed of. The AV valve between the right atrium and ventricle is referred to as the tricuspid valve because it is constructed of three leaves. Another type of valve essential to the function of the heart are the semilunar valves. These serve as a gateway from the ventricles of the heart into both the pulmonary and systemic circulation systems. Can you picture the heart muscle using the above description? 21 The Heart 22  Communication Which mode conveys the structures and processes of the heart most effectively: – Textual description? – Photograph? – Diagram? “A picture is worth a thousand words.” “A diagram is worth ten thousand words!” 23  What is a diagram? A definition: “Diagrams are pictorial, yet abstract, representations of information, and maps, line graphs, bar charts, engineering blueprints, and architects' sketches are all examples of diagrams, whereas photographs and video are not". Diagrams are extremely important in engineering and science to communicate and analyse complex information. 24  Flow Diagrams Diagrammatic representation of a process Each block represents an important step in the process Three main types used by chemical engineers: – Block Flow Diagram (BFD) – Process Flow Diagram (PFD) – Piping and Instrumentation Diagram (P&ID) 25  Block Flow Diagrams (BFD) Gives a clear overview of a production process Each block may represent several unit operations or pieces of equipment Lines used to represent flow streams Useful at the conceptualisation stage Often used as starting point for PFDs 26  Chemical Engineering is Chemical Process Design Example: Production of Ethyl benzene Ethyl benzene can be used to produce styrene It is a valuable product It can be made from benzene and ethylene, which are cheaper So we can make a profit from producing ethyl benzene  Chemical Process Design Example: Production of Ethyl benzene Unfortunate side-reaction: Ethyl benzene (liquid) Diethyl benzene (liquid) Benzene (liquid) Ethylene (vapor)  Ethylene Ethyl benzene Diethyl benzene Benzene Ethylene Benzene Ethylene Ethyl benzene Diethyl benzene  Ethylene Ethyl benzene Diethyl benzene Ethylene Ethylene Process Flow Diagrams (PFD) 38 Piping and Instrumentation Diagrams (P&ID) Much more detailed than PFDs Contains information on all piping and instrumentation for every piece of equipment 39 Chemical Plant-Scale Up Process  Example: A + B → C Plant-scale 1000 kg/hr Mix, heat, and react Separate Chemical Engineers must consider: Cost of production – Raw materials – Energy – Equipment – Maintenance – Labor Things to consider in any chemical process design: Cost of production Value of the product Safety Environment.  Where does a Chemical Engineer work? Petroleum industry ALL Chemical Industries Water Resources Environment Improved Materials  Where does a Chemical Engineer work? Petroleum industry ALL Chemical Industries Water Resources Environment Improved Materials Biomedical Devices Research  Where do AUS CHBE Graduates Work? Petroleum industry Chemicals industry Environmental and water resources Pharmaceutical Industry Biomedical industry Sales Graduate school – 20% – Some are part-time while working – Research! CHBE – AUS Pilot plants Laboratories Unit Operations Instrumentation & Control Laboratory Water Technology Laboratory Fluid Mechanics Laboratory Heat Transfer Laboratory Chemical Reaction Engineering Laboratory Thermodynamics Laboratory Corrosion Laboratory Material Science Laboratory Petroleum Refining Laboratory Energy Systems Laboratory Environmental Research Laboratory Thermochemical Conversion Laboratory Drug Delivery Laboratory Analytical Instrumentation Laboratory  Minor in Safety and Fire Protection Engineering Open to all CEN students (especially CBE, CHE, CVE, INE, MCE)  What do Safety and Fire Protection Engineers do? Conduct safety and fire risk assessments Investigate accidents and near misses Design and implement safety and fire protection systems Train employees on safety procedures Develop and implement emergency response plans Manage safety in buildings and industrial facilities and much more!