Introduction to Process Engineering - BE4254 PDF

1. Introduction into Process Engineering 1.1 Chemistry vs. Biotechnology (Process Engineering vs. Bioprocess Engineering) ▪ Uses raw material ▪ Uses living organisms ▪ Up to very high temperatures (1300°C) ▪ Upper limit...

1. Introduction into Process Engineering 1.1 Chemistry vs. Biotechnology (Process Engineering vs. Bioprocess Engineering) ▪ Uses raw material ▪ Uses living organisms ▪ Up to very high temperatures (1300°C) ▪ Upper limit of temperature due to degradation of enzymes of death of cell ▪ High pressures not unusual ▪ Usually, ambient pressure ▪ Yields (amount) sometime more important ▪ Selectivity (purity) might beat Yields (amount) than selectivity (purity) e.g. for pharmaceutical products ▪ Reactions can be very fast ▪ Reactions very often slow ▪ Heterogeneous catalyst very often metal ▪ Catalytic enhancement based on enzymes based BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 9 1. Introduction into Process Engineering 1.1 Chemistry vs. Biotechnology Crude Oil 1800 1850 1900 1950 2000 ? 2050 Natural Gas Renewable Resources Coal https://www.vci.de/presse/mediathek/infografiken/anteil -industrieller-biotechnologie-an-der-chemieproduktion- in-europa.jsp BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 10 1. Introduction into Process Engineering 1.1 Chemistry vs. Biotechnology fibers silicones dyes solvents insecticides cosmetics cleaning ceramics adhesives agents Consumer Products construction pharmaceutics materials fertilizer plastics formaldehyde methanol urea ethanol vinyl chloride styrene ethylene oxide acetic acid Intermediate Chemicals acrylic acid acrylonitrile ENERGY ethylene oxide acetaldehyde vinyl chloride ethane chlorine benzene xylene ammonia butadiene propene toluene Base Chemicals synthesis gas caustic soda sulfuric acid nitric acid natural water oxygen gas metal Raw Materials oxides crude oil biomass sodium phosphates coal nitrogen chlorides BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 11 1. Introduction into Process Engineering 1.2 Scope of Process Engineering ▪ „Unit Operations“ ▪ Distillation ▪ Filtration ▪ Extraction ▪ Crystallization ▪ Chemical Reactor (compared to unit operations) ▪ Larger heat effects ▪ More pronounced property changes ▪ Greater sensitivity to operating parameters ▪ A process engineer should be good in ▪ Inorganic and organic chemistry ▪ Physical Chemistry ▪ Physics ▪ Mathematics BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 12 1. Introduction into Process Engineering 1.2 Scope of Process Engineering Inflow (Reactants) Outflow (Products) Outflow = f(Inflow; Kinetics, Cooling/Heating, Mixing behavior) „How fast is the reaction?“ „How do the substances flow through the reactor?“ ▪ Kinetics ▪ Where and when do the substances ▪ Equilibrium come in contact? ▪ Heat- and mass transport ▪ How easy can they be mixed? BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 13 1. Introduction into Process Engineering 1.2 Scope of Process Engineering AB A A B B AB C B B AB A A B D A A C A A B B A D B B B BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 14 1. Introduction into Process Engineering Process Engineering is Flow + Conversion BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 15 1. Introduction into Process Engineering 1.2 Scope of Process Engineering No mixing (plug flow) Laminar flow Intensive mixing BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 16 1. Introduction into Process Engineering 1.2 Scope of Process Engineering Ammonia Synthesis stoichiometric coefficients i 3 H2 + (1) N2 2 NH3 “One mole of Nitrogen and three moles of Hydrogen react to two moles of Ammonia” ▪ A stoichiometric correct equation for reaction does not violate the conservation of mass (atoms are neither destroyed nor created) ▪ The equations are independent of temperature or pressure ▪ Stoichiometry does help to find reasonable equations describing a reacting system ▪ Stoichiometry does not tell if a reaction takes place at all or even how fast it take place BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 17 1. Introduction into Process Engineering 1.2 Scope of Process Engineering 𝑏𝑦 𝑐𝑜𝑛𝑣𝑒𝑛𝑡𝑖𝑜𝑛 stoichiometric coefficients 𝑖 = 1…𝑁 𝜈𝑖 < 0 𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡 for one equation 𝜈𝑖 > 0 𝑝𝑟𝑜𝑑𝑢𝑐𝑡𝑠 𝜈𝑖 = 0 𝑖𝑛𝑒𝑟𝑡 BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 18 1. Introduction into Process Engineering 1.3 Co product, by product, value product Value product Benzene Chlorine Chlorobenzene Co-product Hydrogen chloride consecutive reaction By-product Chlorobenzene BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 19 1. Introduction into Process Engineering 1.4 Conversion, Yield, Selectivity Conversion X = parameter for quantifying the fractional consumption of the (limiting) reactant A in the reaction reacted component Ai 𝑁𝑖,0 − 𝑁𝑖 0 = 𝑛𝑜 𝑟𝑒𝑎𝑐𝑡𝑖𝑜𝑛 Xi = = Xi = ቐ … component in feed Ai,0 𝑁𝑖,0 1 = 𝑐𝑜𝑚𝑝𝑙𝑒𝑡𝑒 𝑟𝑒𝑎𝑐𝑡𝑖𝑜𝑛 0 1 0 1 BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 20 1. Introduction into Process Engineering 1.4 Conversion, Yield, Selectivity Yield Y = parameter for quantifying the amount of desired product formed with respect to the (limiting) reactant A supplied taking the reaction stoichiometry into account reacted to Ak 𝑁𝑘 − 𝑁𝑘,0 𝜈𝑖 Yki = =− component in feed Ai,0 𝑁𝑖,0 𝜈𝑘 BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 21 1. Introduction into Process Engineering 1.4 Conversion, Yield, Selectivity Selectivity S = parameter for quantifying the amount of product formed with respect to quantity of (limiting) reactant A consumed, taking reaction stoichiometry into account to Ak reacted Ai 𝑁𝑘 − 𝑁𝑘,0 𝜈𝑖 𝑌𝑘𝑖 Sk,i = =− = reacted Ai (𝑁𝑖,0 −𝑁𝑖 ) 𝜈𝑘 𝑋𝑖 BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 22 1. Introduction into Process Engineering 1.4 Conversion, Yield, Selectivity 𝑛ሶ 1,0 = 4.0 𝑚𝑜𝑙/ℎ 𝑛ሶ 1,1 = 0.5 𝑚𝑜𝑙/ℎ 𝑖) 𝐴1 + 𝐴2 = 2 𝐴3 𝑛ሶ 2,1 = 1.5 𝑚𝑜𝑙/ℎ 𝑛ሶ 2,0 = 6.0 𝑚𝑜𝑙/ℎ 𝑖𝑖) 𝐴1 + 2 𝐴2 = 3 𝐴4 𝑛ሶ 3,0 = 0.1 𝑚𝑜𝑙/ℎ 𝑛ሶ 3,1 = 5.1 𝑚𝑜𝑙/ℎ 𝑛ሶ 4,0 = 0.2 𝑚𝑜𝑙/ℎ 𝑛ሶ 4,1 = 3.2 𝑚𝑜𝑙/ℎ 𝑁𝑖,0 − 𝑁𝑖 4.0 − 0.5 Xi = ⟹ 𝑋1 = = 0.875 = 𝟖𝟕. 𝟓 % 𝑁𝑖,0 4.0 𝑁𝑘 − 𝑁𝑘,0 𝜈𝑖 (5.1 − 0.1) −1 3.2 − 0.2 −1 Yki = − ⟹ 𝑌31 =− = 0.625 = 𝟔𝟐. 𝟓 % ⟹ 𝑌41 = − = 𝟐𝟓. 𝟎 % 𝑁𝑖,0 𝜈𝑘 4.0 2 4.0 3 Y𝑘𝑖 62.5 % 25.0 % Ski = ⟹ 𝑆31 = = 𝟕𝟏. 𝟒 % ⟹ 𝑆41 = = 𝟐𝟖. 𝟔 % Xi 87.5 % 87.5 % BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 23 1. Introduction into Process Engineering 1.4 Conversion, Yield, Selectivity 𝑛ሶ 1,0 = 4.0 𝑚𝑜𝑙/ℎ 𝑛ሶ 1,1 = 0.5 𝑚𝑜𝑙/ℎ 𝑖) 𝐴1 + 𝐴2 = 2 𝐴3 𝑛ሶ 2,1 = 1.5 𝑚𝑜𝑙/ℎ 𝑛ሶ 2,0 = 6.0 𝑚𝑜𝑙/ℎ 𝑖𝑖) 𝐴1 + 2 𝐴2 = 3 𝐴4 𝑛ሶ 3,0 = 0.1 𝑚𝑜𝑙/ℎ 𝑛ሶ 3,1 = 5.1 𝑚𝑜𝑙/ℎ 𝑛ሶ 4,0 = 0.2 𝑚𝑜𝑙/ℎ 𝑛ሶ 4,1 = 3.2 𝑚𝑜𝑙/ℎ Yield Selectivity BE 4254, Process Engineering, Prof. Dr.-Ing. Platte 24