PC Unit 1 HW PDF
Document Details
Uploaded by UnparalleledZombie4881
Tags
Summary
These notes cover the basics of chemical engineering, including historical perspectives, scope, and the role of chemical engineers, along with discussion of different processes like reactors and distillation. It touches upon various chemical industries and different types of materials like polymers and composites.
Full Transcript
# Unit 4 ### Introduction to Chemical Engineering ### HISTORY: Historical Development - **Scope of Chemical Engineering:** - Almost every industry requires chemical processing. - **Air/water pollution**: cosmetics industry, food industry. - **Pharmaceutical industry**: semiconductor....
# Unit 4 ### Introduction to Chemical Engineering ### HISTORY: Historical Development - **Scope of Chemical Engineering:** - Almost every industry requires chemical processing. - **Air/water pollution**: cosmetics industry, food industry. - **Pharmaceutical industry**: semiconductor. - **Dying & textile industry**. - **Role of Chemical Engineers in Industry & Society:** - Control chemical reactions while they are processing. - **Reactor:** Where "R" gets mixed * **Requirements:** vol. size, shape, speed, arrangements * **Agitator**: R mixing * **Heating & Cooling** R * **Thermo couples**: measure temp of inside & outside of reactor * **Adding catalyst and zeolites** * **Cleaning:** * **Manual:** by hand * **Mechanical:** high-pressure pump (e.g. water servicing) * **Chemical:** by using appropriate solvent - **Distillation:** mass transfer operation (thermal energy), heating - vapours * Primary operation involves diffusion * Aim to get almost 100% pure product in single step. * Seperation of solute & solvent: * **Low BP + volatility:** seperation of liquid mixture into its components at its BP (e.g. benzene) * **High BP + volatility:** (e.g. water) * **History:** (around 19th century), ayurveda, pottery, alcohol making. * **Use for:** fake tooth making, eye lens, bone joints - **History, Evolution, & Scope of Chemical Engg.** - Developed industrial chemistry in the late 19th century. - **Role of Chemical Engineers in Industry & Society**: - **Syllabus Overview**: * Process Engineering * Biochemical Engineering * Polymer/Plastics Engg, composites, blends etc. - **Introduction to Various Different Chemical Industries** * **Solid - Liquid Extraction (leaching):** * A + C → Feed Solvent → B - Extract (or extracting solvent) → C - Solute. * A + B + C → B + C + A. * B + C → B + C * **Distillation** * **Crystallisation/Supersaturation:** * Evaporation/cooling/adding substance ### Chemical Engineering - The production and manufacturing of products through chemical processes. This includes equipment designs, new systems, processes of refining raw materials for mixing, compounding, and processing chemicals. - Chemical Engineering is the study and application of chemistry, physics, biology, and other sciences to manufacturing processes. - It focuses on using the safest and most efficient ways to make products. - **Father of Chemical Engg**: George Edward Davis (1850-1907). He is regarded as the founding father of the discipline of chemical engineering. - **What is the Role of Chemical Engineering?** - Chem Engg deals with the application of chemistry, physics, biology, and other natural sciences to manufacturing processes. - It focuses on using the safest & most efficient ways to make products. - Chem Engg may be applied to any product that involves chemicals or chem. R's, including food, medicine, cosmetics, perfumes, colours, paints coating, plastic polymers, pharmaceuticals - **Chem Engg Operations**: * **Mechanical** crushing, grinding, sedimentation, (use of mech force) agitation. * **Chemical** hydrolysis, drying, absorption, distillation, extraction, and solid, liquid. - **What is Chem Engineer?** - A chem engineer is an engineer who focuses on making industrial & consumer products through chem. methods. - **Materials:** * **Plastic:** The material being molded under pressure. * **Fiber** (strongest material among these) * **Melt Spinning** * **Dry Spinning = Solution Spinning** * **Wet Spinning**: gives bath & solvent remove other dissolvent * **Rubber is elastically strong but: less strong than plastic & fiber** * **SBR** is copolymer due to having two monomers. * **Impact Strength** - Butadene is responsible for strong Impact Strength. ### Discuss preparation properties application Metal & Non Metal - **TOPIC** - Material Engineering, Polymer, Metal & Non-metal * **Metal** gold, silver, aluminium, copper, mild steel. * **Non-Metal** plastic, rubber, polymer, composing lead. - **POLYMER:** many parts/units, plastics, rubber, fibre * **Natural** * e.g. cis-polyisoprene (man-made), SBR (styrene butadine rubber) * PBR, Nitrile Rubber, butyl rubber * ABS-PVC, ABS-PS. * **Synthetics** * **Monomer** > **polymer** - **Oil/Naptha/Monomer/Polymer** * **Petrochemical** Organic substance derived from petroleum * **Petroleum** obtain from many dissimilar mineral oil. * **Composite** material or combination of dissimilar material. * **Natural composites:** bones, hair, skinwood * **Synthetic composites:** plywood. * **Strongest Material**: Fiber > Plastic > Rubber. - **Equimolar Counter Diffusion:** A ↔ B (bidirectional diffusion) - **Unidirectional Diffusion**: A → B (gas absorption) ### Mass Transfer - **Transfer of molecules from high to low concentration to minimize temp. diff or gradient becoming zero. - **What is Mass Transfer? What is driving force of MT?** - **Types of Mass Transfer Operations**: * **Diffusion Mass Transfer**: * **Ordinary Diffusion**- occurs in all types of Mass Transfer (to calculate rate of diffusion/MT coeff) * **Thermal Diffusion** * **Pressure Diffusion** * **Forced Diffusion** * **Convective Mass Transfer:** randomess (zigzag) speed/manner. - **What is Mass Transfer? What is driving force of Mass Transfer?** - Mass transfer occurs due to conc. or density diff. - There is a natural tendency for mass to be transferred, minimizing the conc diff. within the mixture. - MT is strongly affected by molecular spacing. - **Diffusion Mass Transfer:** * **Diffusion MT is classified into 4 types:** * **Liquid - Liquid Diffusion:** (preforated pot) H2O2, NaDH * **Liquid - Gas Diffusion:** Diffusion apparatus (T-tube) - to calculate volatile rate of diffusion/MT coeff * **Solid - Gas Diffusion:** (napthalene ball or camphor) * **Gas - Liquid Diffusion:** Ammonia-air (mixture). Water (salvent) + Ammonia water mixture. (to separate - distillation) * **Gas - Gas Diffusion:** Oxygen in carbon dioxide. - **DMI can occur either by molecular diffusion or Eddy diffusion in gases or liquids.** * **In mol. diffu. the transfer of matter occurs on a microscopic level as a result of diffusion from the zone of higher conc. to a zone of lower conc. in gas of liq. or a mixture of gaser & liquid.** * **Various egs of mol diffusion are:** * **Humidification of air in coolers, cooling towers.** * **FA dissolution of sugar or salt & uniform spreading in water.** * **Spreading of fragrance of perfume or flowers in surrounding.** * **Drying or clothes or timber.** * **Evaporation of petrol inengine corporator.** * **Diffusion of neutron in nudecor reactor.** * **Diffu. of smoke from chimney into atmospheric air.** **In Eddy diffusion, one of the diffusing fluids needs to be in turbulent motion; due to turbulence, rate of diffy increases as a result - rate of MT increases.** ### What is Mass transfer? - **Factors affecting rate of Mass Transfer:** * **Molar concentration:** * No of moles of A per unit volume. * PV=nRT = P = n/v = CA * **Mass Concentration:** * CA = MA/V * S = CA * MA * **Factors affecting rate of mass transfer:** * **Concentration Difference** * **Temperature Difference** * **Degree of Turbulence** * **Pressure Difference** - **Physical Properties:** * **Viscosity** * **Density** * **Diffusion Coefficient** - **Interphase & Interphase Mass transfer** * Mass/molecule transfer takes place from one phase to another phase across a boundry is called interphase. This process is called Mass Transfer. * **Some common terms used in mass transfer process:** * **Mass Concentration (C):** * In a gas of liq mixture contains one or more components, then conc. is defined as mass of spacies of specific component per unit vol. of mixture. It is also called as density in kg/m³. So mass conc. (SA)or((A) * **Mass Conc= S(A) = mass of component A/vol of mixture.** * **Mass conc is denoted by (C)** * **Molar Concentration**: * It is defined as no of moles of a specific component per unit vol. of the mixture. It is also called as molar density. * **Molar conc = No. of moles of component A/vol. of mixture.** * **No. of moles of A = mass of comp A/mol weight of component A.** * **Therefore, molar conc= Mass of comp A x 1/vol of Mixture.** * **Molar conc. = S(A)/MA = density of A/mol wt.of A.** * **Mass Fraction**: It is defined as conc. of comp A to the total mass conc. * **Mass fraction = CA/C = conc of A/total conc.** * **Mole Fraction**: * The no. of motes of comp A to the total no. of moles in the mixture. * **Mole-fraction = NA/(NA + NB)** ### Chemical Engineering Operations - **Liquid - Liquid Extraction (L.L.E):** - **A:** Feed solvent. - **B:** Extracting Solvent - **C:** Solute - **F:** Feed * **A+C → F** * **B+C → Pair 1 (P1) (extract phase)** * **A+C → P2 (Raffinate Phase)** * **A+B → P3** * **Ultimate Aim - Recovery of Solute** * Always lighter phase * Always heavier phase - **Drying:** - Removal of moisture into the atmosphere due to diffusion.