This document discusses chemical reactors and reaction engineering. It begins by classifying reactions as reversible or irreversible, and homogeneous or heterogeneous based on the phases involved. It then covers approaches to performing material balances on reactive processes using conversion, extent of reaction, or yield. Reaction kinetics models like power law and Langmuir-Hinshelwood-Hougen-Watson are also introduced. The document concludes by describing different reactor blocks in Aspen Plus that can be used to model and simulate reactive processes based on stoichiometry, equilibrium, kinetics, and Gibbs energy minimization.
This document outlines the course contents, objectives, and topics for a Chemical Reaction Engineering course. The course will cover topics such as kinetics of homogeneous and heterogeneous reactions, reactor design including batch, mixed flow, plug flow, and catalytic reactors. Students will learn how to develop rate expressions and design industrial reactors by applying principles of thermodynamics and reaction kinetics. The objective is to provide an in-depth understanding of commonly used chemical reactor designs.
These slides may be used for a part of Advanced level course in Chemical Reaction Engineering. I taught this course to Masters level students covering 1.5 credit hours.
heat capacity of sitric acid0c96051e8eb63eea58000000Tika Ningsih
This document summarizes thermodynamic properties of the citric acid-water binary system determined through various experimental methods. Key findings include:
- The phase diagram exhibits eutectic and peritectic behavior with solid-liquid and vapor-liquid equilibria measured.
- Enthalpies of formation for citric acid monohydrate, solution, transition, and vaporization were determined via calorimetry and vapor pressure measurements.
- Specific heat capacity and solubility data were also collected to characterize the phase behavior and thermodynamic functions of citric acid and its monohydrate over a range of temperatures.
This document provides instructions for an experiment to determine the heat of neutralization (ΔH) for acid-base reactions using calorimetry. It discusses key concepts like enthalpy, Hess' Law, and heat capacity. The procedure involves first calibrating thermometers and determining the heat capacity of the calorimeter. Then neutralization reactions between acids and bases are carried out in the calorimeter, and the temperature change is used to calculate the heat of reaction (ΔH) based on the calorimeter's heat capacity.
This slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
Partial gibbs free energy and gibbs duhem equationSunny Chauhan
Partial gibbs free energy and gibbs duhem equation,relation between binary solution,relation between partiaL properties,PARTIAL PROPERTIES,PARTIAL PROPERTIES IN BINARY SOLUTION,RELATIONS AMONG PARTIAL PROPERTIES,Maxwell relation,Examples
1. The document discusses slow reactions, their rates, and various methods to measure reaction rates including observing changes in partial pressure, concentration, color, spectrophotometry, conductance, and calorimetry.
2. It also covers molecularity and order of reactions, chain reactions involving initiation, propagation, termination and retardation steps, and using the steady state approximation to derive rate laws.
3. An example is given for determining the rate of the chain reaction between H2 and Br2 and the thermal decomposition of acetaldehyde is discussed as a specific example of a three-halves order reaction.
This document outlines the course contents, objectives, and topics for a Chemical Reaction Engineering course. The course will cover topics such as kinetics of homogeneous and heterogeneous reactions, reactor design including batch, mixed flow, plug flow, and catalytic reactors. Students will learn how to develop rate expressions and design industrial reactors by applying principles of thermodynamics and reaction kinetics. The objective is to provide an in-depth understanding of commonly used chemical reactor designs.
These slides may be used for a part of Advanced level course in Chemical Reaction Engineering. I taught this course to Masters level students covering 1.5 credit hours.
heat capacity of sitric acid0c96051e8eb63eea58000000Tika Ningsih
This document summarizes thermodynamic properties of the citric acid-water binary system determined through various experimental methods. Key findings include:
- The phase diagram exhibits eutectic and peritectic behavior with solid-liquid and vapor-liquid equilibria measured.
- Enthalpies of formation for citric acid monohydrate, solution, transition, and vaporization were determined via calorimetry and vapor pressure measurements.
- Specific heat capacity and solubility data were also collected to characterize the phase behavior and thermodynamic functions of citric acid and its monohydrate over a range of temperatures.
This document provides instructions for an experiment to determine the heat of neutralization (ΔH) for acid-base reactions using calorimetry. It discusses key concepts like enthalpy, Hess' Law, and heat capacity. The procedure involves first calibrating thermometers and determining the heat capacity of the calorimeter. Then neutralization reactions between acids and bases are carried out in the calorimeter, and the temperature change is used to calculate the heat of reaction (ΔH) based on the calorimeter's heat capacity.
This slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
Partial gibbs free energy and gibbs duhem equationSunny Chauhan
Partial gibbs free energy and gibbs duhem equation,relation between binary solution,relation between partiaL properties,PARTIAL PROPERTIES,PARTIAL PROPERTIES IN BINARY SOLUTION,RELATIONS AMONG PARTIAL PROPERTIES,Maxwell relation,Examples
1. The document discusses slow reactions, their rates, and various methods to measure reaction rates including observing changes in partial pressure, concentration, color, spectrophotometry, conductance, and calorimetry.
2. It also covers molecularity and order of reactions, chain reactions involving initiation, propagation, termination and retardation steps, and using the steady state approximation to derive rate laws.
3. An example is given for determining the rate of the chain reaction between H2 and Br2 and the thermal decomposition of acetaldehyde is discussed as a specific example of a three-halves order reaction.
The document discusses the appropriateness of using the Arrhenius equation for kinetic analysis of solid state reactions from thermal analysis data. While the Arrhenius equation can be justified for homogeneous reactions, its application to heterogeneous solid state reactions is more complex due to factors like immobilized species, possible multi-step mechanisms, and variations in activation energy with reaction progress. The values of activation energy and pre-exponential factor derived also often lack clear physical meaning for solid state reactions.
Chemistry zimsec chapter 8 chemical equilibriaalproelearning
(1) This document discusses chemical equilibria, including reversible reactions, factors that affect equilibrium, and acid-base theories.
(2) It describes how reversible reactions reach equilibrium when the rates of the forward and reverse reactions are equal. Le Chatelier's principle states that if a stress is applied to a system at equilibrium, it will shift in a way to counteract the stress.
(3) Equilibrium constants Kc and Kp are introduced, which do not depend on concentration or pressure changes. The Brønsted-Lowry acid-base theory defines acids as proton donors and bases as proton acceptors.
Elementary and non elementary reaction(no-18) - copyPrawin Ddy
The document discusses the differences between elementary and non-elementary reactions. Elementary reactions occur in a single step, while non-elementary reactions occur through a series of steps. For elementary reactions, the order is the same as the stoichiometric coefficient, but for non-elementary reactions the order does not necessarily match the stoichiometry. Non-elementary reactions are represented by rate equations that may have fractional orders, unlike elementary reactions which always have integer orders.
Chemical reaction engineering introduction by Er sohel R sheikhEr Sohel R Sheikh
This document provides an introduction to chemical reaction engineering (CRE). CRE studies the rates and mechanisms of chemical reactions and the design of reactors. It discusses various reactor types including batch, continuously stirred tank reactor (CSTR), plug flow reactor (PFR), and packed bed reactor (PBR). The general mole balance equation is presented and applied to these different reactor configurations. Industries that rely heavily on CRE principles include chemical, pharmaceutical, and microelectronics.
Chemical Reaction Engineering (CRE) studies chemical reaction rates and mechanisms and reactor design. It is important for many industries like chemicals, pharmaceuticals, and medicine. The document discusses mole balance equations for batch reactors, continuously stirred-tank reactors (CSTR), plug flow reactors (PFR), and packed bed reactors (PBR). It also covers reaction rates and examples.
1. The document discusses kinetics and factors that affect the rate of chemical reactions such as concentration, temperature, surface area, and catalysts.
2. It explains concepts such as the rate of reaction, instantaneous rate, rate laws, reaction order, molecularity, activation energy, and the Arrhenius equation.
3. Examples of zero-order, first-order, and second-order reactions are provided along with explanations of pseudo-first order and pseudo-second order reactions that can occur when one reactant is in excess.
Production of-n-propyl-acetate-by-reactive-distillation-experimental-and-theo...Josemar Pereira da Silva
This document summarizes the first steps in developing a catalytic reactive distillation process for producing n-propyl acetate. Kinetic experiments were conducted to determine the reaction rates for homogeneous and heterogeneous catalysis. Pilot plant experiments were also performed using a homogeneous strong acid catalyst in a packed column with a top-column decanter. Simulation results matched experimental data well when accounting for non-ideal thermodynamics. Several process configurations were identified that could dramatically increase alcohol conversion and n-propyl acetate purity by adding a stripping section. The best startup strategy was determined to involve an initial charging of the two-phase top product to achieve steady-state conditions most quickly.
The document summarizes an experiment that studied the kinetics of a reaction between sodium hydroxide and ethyl acetate in batch and continuous stirred-tank reactors (CSTR). The objectives were to determine the reaction rate constant (k) and activation energy (Ea). For the batch reactor, k and fractional conversion were calculated from concentration data over time. For the CSTR, conductivity measurements at steady states were used to calculate k and Ea based on how they relate to temperature according to the Arrhenius equation. While some results agreed with expectations, the calculated k and Ea values differed substantially from literature values, suggesting issues with temperature control, flow rate calibration, or reactor volume measurement that need addressing in future experiments.
Concept of rate of reaction.
Factors effecting rate of reaction.
Concept of order of reaction.
Methods for the determination of order of reaction.
Pharmaceutical importance and applications of rate and order of reaction.
This document discusses chemical equilibrium in homogeneous systems. It defines chemical equilibrium as a state where the concentrations of reactants and products remain constant over time, despite reactions continuing on a molecular level. The chemical equilibrium constant K is introduced, which relates the concentrations of products and reactants at equilibrium. Factors that can influence chemical equilibrium such as concentration, temperature, pressure, and catalysis are described. Equations for calculating the equilibrium constant Kc in terms of molar concentrations and Kp in terms of partial pressures are also provided.
Lecture 3 kinetics of homogeneous reactionsUsman Shah
This slide completely describes you about the stuff include in it and also everything about chemical engineeringThis slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
This document discusses the topics of entropy and spontaneity in chemistry. It defines entropy as a measure of disorder or randomness in a system. Reactions that increase disorder have a positive change in entropy. The standard entropy change of a reaction can be calculated from standard entropy values. A spontaneous process is one that can occur without outside intervention. The Gibbs free energy change (ΔG) determines if a reaction is spontaneous - a negative ΔG means the reaction proceeds spontaneously. Temperature can affect spontaneity through the entropy term in the ΔG equation.
1. The document discusses chemical kinetics, which is the study of reaction rates and their mechanisms. It defines the average and instantaneous rates of reactions in terms of changes in reactant or product concentrations over time.
2. Reaction rates depend on factors like concentration, temperature, and catalysts. The rate law expresses how the rate of a reaction varies with changes in concentration. Generally, reaction rates increase with higher reactant concentrations and decrease over time as concentrations decrease.
3. For reactions where stoichiometric coefficients are not equal to one, the rates of appearance/disappearance must be divided by the appropriate coefficients to make the rates equal. This allows rates to be expressed consistently in terms of changes in concentrations of
Influence of temperature on the liquid liquid equilibria of methanol benzene ...Josemar Pereira da Silva
This document summarizes a study on the liquid-liquid equilibria of the ternary system composed of methanol, benzene, and hexane at temperatures of 278.15 K, 283.15 K, and 293.15 K. Equilibrium data including component mass fractions in each phase are reported for the three temperatures. The data are compared to literature data and correlated using various models including Othmer and Tobias, NRTL, and UNIFAC. The results show that temperature influences the liquid-liquid equilibrium behavior of the system.
The document discusses various topics related to chemical kinetics including:
- Rate of reaction is defined as the change in concentration of reactants or products over time. Rate laws relate the rate of reaction to the concentrations of reactants.
- Reaction order refers to the sum of powers in the rate law. Molecularity is the actual number of reacting species. Pseudo-orders occur when one reactant is in excess.
- Rate constants have different units for different reaction orders. Integrated rate laws and the half-life method can be used to determine the order of a reaction experimentally.
- Collision theory states that molecules must collide with sufficient energy and correct orientation to react. Physical factors like temperature, solvent, and
Chemical kinetics is the study of reaction rates and mechanisms. The rate of a reaction describes how quickly reactants are converted to products and is affected by factors like concentration, temperature, catalysts, and surface area. The rate law expresses the reaction rate in terms of reactant concentrations and can be used to determine the order of a reaction. Integrated rate laws relate concentration over time and are used to calculate quantities like half-life, the time for half the reactants to be consumed.
Chemical reaction engineering is that engineering activity which is concerned with the exploitation of chemical reactions on commercial scale.
The areas of different fields of science like:
Oil Refining
Pharmaceuticals
Biotechnology
Chemical Industries
Sustainable Development
This document discusses concepts related to chemical kinetics and stability testing, including:
- Reaction order determination through substitution, graphical, and half-life methods
- Zero-order, first-order, and pseudo-first-order reactions
- Factors that affect reaction rates such as temperature, solvent properties, catalysis, and pH
- Accelerated stability testing methods that use exaggerated storage conditions to increase degradation rates for evaluation.
A complete introduction to all things chemical kinetics designed specifically for non-chemists to understand. Fair warning: The presentation is very rigorous in its mathematical treatment, which is makes it a useful reference for looking up equations, but this can unfortunately make it less polished and flowing then a typical presentation. I tried my best to spell everything out clearly, but despite my best efforts it's still pretty dense.
Fedunik hofman 2019. kinetics of solid-gas reactions and their carbonatosMayliSanchezAlcocer
This document reviews methods for analyzing the kinetics of solid-gas reactions and applies them to carbonate looping systems. It discusses common kinetic analysis methods like model-fitting and model-free approaches. For carbonate looping, calculated kinetic parameters can vary significantly depending on the experimental conditions, material properties, and kinetic method used. The document recommends isoconversional techniques for calcination kinetics and material characterization before choosing an analysis method for carbonation kinetics. It aims to analyze disparities in results and provide guidance on applying kinetic methods to these important solid-gas reactions.
FUZZY LOGIC Control of CONTINUOUS STIRRED TANK REACTOR ProfDrDuraidAhmed
This document describes the use of fuzzy logic control for a continuous stirred tank reactor (CSTR). It begins with an abstract that summarizes modeling the CSTR system using mass and energy balances, and designing a fuzzy logic controller to control the reactor temperature. It then provides more details on mathematical modeling of the CSTR, the basic operations of fuzzy set theory, and the design of the fuzzy logic controller. The controller design involves choosing membership functions to classify the error signal and change in error, then developing fuzzy rules relating the error terms to the control output. Simulation results showed the fuzzy logic controller provided better tracking and regulation than a traditional PID controller.
The document discusses the appropriateness of using the Arrhenius equation for kinetic analysis of solid state reactions from thermal analysis data. While the Arrhenius equation can be justified for homogeneous reactions, its application to heterogeneous solid state reactions is more complex due to factors like immobilized species, possible multi-step mechanisms, and variations in activation energy with reaction progress. The values of activation energy and pre-exponential factor derived also often lack clear physical meaning for solid state reactions.
Chemistry zimsec chapter 8 chemical equilibriaalproelearning
(1) This document discusses chemical equilibria, including reversible reactions, factors that affect equilibrium, and acid-base theories.
(2) It describes how reversible reactions reach equilibrium when the rates of the forward and reverse reactions are equal. Le Chatelier's principle states that if a stress is applied to a system at equilibrium, it will shift in a way to counteract the stress.
(3) Equilibrium constants Kc and Kp are introduced, which do not depend on concentration or pressure changes. The Brønsted-Lowry acid-base theory defines acids as proton donors and bases as proton acceptors.
Elementary and non elementary reaction(no-18) - copyPrawin Ddy
The document discusses the differences between elementary and non-elementary reactions. Elementary reactions occur in a single step, while non-elementary reactions occur through a series of steps. For elementary reactions, the order is the same as the stoichiometric coefficient, but for non-elementary reactions the order does not necessarily match the stoichiometry. Non-elementary reactions are represented by rate equations that may have fractional orders, unlike elementary reactions which always have integer orders.
Chemical reaction engineering introduction by Er sohel R sheikhEr Sohel R Sheikh
This document provides an introduction to chemical reaction engineering (CRE). CRE studies the rates and mechanisms of chemical reactions and the design of reactors. It discusses various reactor types including batch, continuously stirred tank reactor (CSTR), plug flow reactor (PFR), and packed bed reactor (PBR). The general mole balance equation is presented and applied to these different reactor configurations. Industries that rely heavily on CRE principles include chemical, pharmaceutical, and microelectronics.
Chemical Reaction Engineering (CRE) studies chemical reaction rates and mechanisms and reactor design. It is important for many industries like chemicals, pharmaceuticals, and medicine. The document discusses mole balance equations for batch reactors, continuously stirred-tank reactors (CSTR), plug flow reactors (PFR), and packed bed reactors (PBR). It also covers reaction rates and examples.
1. The document discusses kinetics and factors that affect the rate of chemical reactions such as concentration, temperature, surface area, and catalysts.
2. It explains concepts such as the rate of reaction, instantaneous rate, rate laws, reaction order, molecularity, activation energy, and the Arrhenius equation.
3. Examples of zero-order, first-order, and second-order reactions are provided along with explanations of pseudo-first order and pseudo-second order reactions that can occur when one reactant is in excess.
Production of-n-propyl-acetate-by-reactive-distillation-experimental-and-theo...Josemar Pereira da Silva
This document summarizes the first steps in developing a catalytic reactive distillation process for producing n-propyl acetate. Kinetic experiments were conducted to determine the reaction rates for homogeneous and heterogeneous catalysis. Pilot plant experiments were also performed using a homogeneous strong acid catalyst in a packed column with a top-column decanter. Simulation results matched experimental data well when accounting for non-ideal thermodynamics. Several process configurations were identified that could dramatically increase alcohol conversion and n-propyl acetate purity by adding a stripping section. The best startup strategy was determined to involve an initial charging of the two-phase top product to achieve steady-state conditions most quickly.
The document summarizes an experiment that studied the kinetics of a reaction between sodium hydroxide and ethyl acetate in batch and continuous stirred-tank reactors (CSTR). The objectives were to determine the reaction rate constant (k) and activation energy (Ea). For the batch reactor, k and fractional conversion were calculated from concentration data over time. For the CSTR, conductivity measurements at steady states were used to calculate k and Ea based on how they relate to temperature according to the Arrhenius equation. While some results agreed with expectations, the calculated k and Ea values differed substantially from literature values, suggesting issues with temperature control, flow rate calibration, or reactor volume measurement that need addressing in future experiments.
Concept of rate of reaction.
Factors effecting rate of reaction.
Concept of order of reaction.
Methods for the determination of order of reaction.
Pharmaceutical importance and applications of rate and order of reaction.
This document discusses chemical equilibrium in homogeneous systems. It defines chemical equilibrium as a state where the concentrations of reactants and products remain constant over time, despite reactions continuing on a molecular level. The chemical equilibrium constant K is introduced, which relates the concentrations of products and reactants at equilibrium. Factors that can influence chemical equilibrium such as concentration, temperature, pressure, and catalysis are described. Equations for calculating the equilibrium constant Kc in terms of molar concentrations and Kp in terms of partial pressures are also provided.
Lecture 3 kinetics of homogeneous reactionsUsman Shah
This slide completely describes you about the stuff include in it and also everything about chemical engineeringThis slide completely describes you about the stuff include in it and also everything about chemical engineering. Fluid Mechanics. Thermodynamics. Mass Transfer Chemical Engineering. Energy Engineering, Mass Transfer 2, Heat Transfer,
This document discusses the topics of entropy and spontaneity in chemistry. It defines entropy as a measure of disorder or randomness in a system. Reactions that increase disorder have a positive change in entropy. The standard entropy change of a reaction can be calculated from standard entropy values. A spontaneous process is one that can occur without outside intervention. The Gibbs free energy change (ΔG) determines if a reaction is spontaneous - a negative ΔG means the reaction proceeds spontaneously. Temperature can affect spontaneity through the entropy term in the ΔG equation.
1. The document discusses chemical kinetics, which is the study of reaction rates and their mechanisms. It defines the average and instantaneous rates of reactions in terms of changes in reactant or product concentrations over time.
2. Reaction rates depend on factors like concentration, temperature, and catalysts. The rate law expresses how the rate of a reaction varies with changes in concentration. Generally, reaction rates increase with higher reactant concentrations and decrease over time as concentrations decrease.
3. For reactions where stoichiometric coefficients are not equal to one, the rates of appearance/disappearance must be divided by the appropriate coefficients to make the rates equal. This allows rates to be expressed consistently in terms of changes in concentrations of
Influence of temperature on the liquid liquid equilibria of methanol benzene ...Josemar Pereira da Silva
This document summarizes a study on the liquid-liquid equilibria of the ternary system composed of methanol, benzene, and hexane at temperatures of 278.15 K, 283.15 K, and 293.15 K. Equilibrium data including component mass fractions in each phase are reported for the three temperatures. The data are compared to literature data and correlated using various models including Othmer and Tobias, NRTL, and UNIFAC. The results show that temperature influences the liquid-liquid equilibrium behavior of the system.
The document discusses various topics related to chemical kinetics including:
- Rate of reaction is defined as the change in concentration of reactants or products over time. Rate laws relate the rate of reaction to the concentrations of reactants.
- Reaction order refers to the sum of powers in the rate law. Molecularity is the actual number of reacting species. Pseudo-orders occur when one reactant is in excess.
- Rate constants have different units for different reaction orders. Integrated rate laws and the half-life method can be used to determine the order of a reaction experimentally.
- Collision theory states that molecules must collide with sufficient energy and correct orientation to react. Physical factors like temperature, solvent, and
Chemical kinetics is the study of reaction rates and mechanisms. The rate of a reaction describes how quickly reactants are converted to products and is affected by factors like concentration, temperature, catalysts, and surface area. The rate law expresses the reaction rate in terms of reactant concentrations and can be used to determine the order of a reaction. Integrated rate laws relate concentration over time and are used to calculate quantities like half-life, the time for half the reactants to be consumed.
Chemical reaction engineering is that engineering activity which is concerned with the exploitation of chemical reactions on commercial scale.
The areas of different fields of science like:
Oil Refining
Pharmaceuticals
Biotechnology
Chemical Industries
Sustainable Development
This document discusses concepts related to chemical kinetics and stability testing, including:
- Reaction order determination through substitution, graphical, and half-life methods
- Zero-order, first-order, and pseudo-first-order reactions
- Factors that affect reaction rates such as temperature, solvent properties, catalysis, and pH
- Accelerated stability testing methods that use exaggerated storage conditions to increase degradation rates for evaluation.
A complete introduction to all things chemical kinetics designed specifically for non-chemists to understand. Fair warning: The presentation is very rigorous in its mathematical treatment, which is makes it a useful reference for looking up equations, but this can unfortunately make it less polished and flowing then a typical presentation. I tried my best to spell everything out clearly, but despite my best efforts it's still pretty dense.
Fedunik hofman 2019. kinetics of solid-gas reactions and their carbonatosMayliSanchezAlcocer
This document reviews methods for analyzing the kinetics of solid-gas reactions and applies them to carbonate looping systems. It discusses common kinetic analysis methods like model-fitting and model-free approaches. For carbonate looping, calculated kinetic parameters can vary significantly depending on the experimental conditions, material properties, and kinetic method used. The document recommends isoconversional techniques for calcination kinetics and material characterization before choosing an analysis method for carbonation kinetics. It aims to analyze disparities in results and provide guidance on applying kinetic methods to these important solid-gas reactions.
FUZZY LOGIC Control of CONTINUOUS STIRRED TANK REACTOR ProfDrDuraidAhmed
This document describes the use of fuzzy logic control for a continuous stirred tank reactor (CSTR). It begins with an abstract that summarizes modeling the CSTR system using mass and energy balances, and designing a fuzzy logic controller to control the reactor temperature. It then provides more details on mathematical modeling of the CSTR, the basic operations of fuzzy set theory, and the design of the fuzzy logic controller. The controller design involves choosing membership functions to classify the error signal and change in error, then developing fuzzy rules relating the error terms to the control output. Simulation results showed the fuzzy logic controller provided better tracking and regulation than a traditional PID controller.
This document discusses the implementation of kinetic models into process simulators to simulate heterogeneous catalytic processes. It provides examples of kinetic modelling for methanol synthesis and bioethanol conversion reactions. Kinetic models like the Langmuir-Hinshelwood-Hougen-Watson model are preferred over simple power law models as they account for adsorption/desorption steps. The document outlines how to implement kinetic parameters from literature into simulators like Aspen Plus, including converting units and specifying temperature dependence and rate expressions. It emphasizes that accurate thermodynamic and transport property models are also needed for reliable process simulation.
New chm-152-unit-1-power-points-sp13-140227172047-phpapp01Cleophas Rwemera
This document discusses chemical kinetics and reaction rates. It defines key concepts such as reaction rate, reaction mechanism, rate laws, and rate constants. It explains how temperature, concentration, and catalysts can influence reaction rates. Graphs and equations are provided to illustrate first-order, second-order, and zero-order reactions. Methods for determining reaction order experimentally and calculating reaction rates are also described.
This document discusses the design of batch and semi-batch reactors. It describes the key characteristics of ideal batch reactors, including that no material enters or leaves during the reaction, the composition is a function of time only, and the concentration and temperature are uniform throughout the reactor volume. It provides equations for calculating reaction time based on conversion for batch reactor design. It also discusses considerations for non-isothermal reactors, including how temperature changes can affect the rate constant and integration of design equations. Heat effects on batch reactors are examined, including approaches for isothermal and non-isothermal operation.
This experiment involves conducting a saponification reaction between sodium hydroxide (NaOH) and ethyl acetate (Et(Ac)) in a continuous stirred tank reactor (CSTR) to determine the effect of residence time on conversion. A calibration curve will be prepared to relate conductivity measurements to conversion values for the 0.1M NaOH and 0.1M Et(Ac) reaction. The objectives are to determine conversion, the reaction rate constant, and the effect of residence time on conversion.
TEMPERATURE AND PRESSURE EFFECTS ON CHEMIOCAL RESCTIONvarshabhi27
1) Temperature and pressure affect reaction equilibrium, rates, and product distribution. The optimal temperature progression minimizes reactor size by maintaining the maximum rate.
2) For reversible reactions, the equilibrium constant and conversion vary with temperature based on thermodynamics. Irreversible reactions proceed best at the maximum temperature allowed.
3) Reactor designs aim to approximate the optimal temperature-conversion profile. This involves determining heat effects and using techniques like heat exchange, multi-staging, and recycle to control temperatures.
Assignment chemical equilibrium_jh_sir-4168NEETRICKSJEE
This document provides information about chemical equilibrium. It begins with defining types of chemical reactions as irreversible or reversible. For reversible reactions, the document states that the reactants and products can interconvert under equilibrium conditions. Several examples of homogeneous and heterogeneous equilibrium reactions are given. The key characteristics of chemical equilibrium are then outlined, including the dynamic nature of equilibrium and the role of Le Chatelier's principle in affecting the equilibrium position. The concepts of equilibrium constants Kp and Kc are introduced, along with how to use them to predict reaction direction and extent. Factors that influence the equilibrium position like concentration, pressure, temperature and catalysts are also discussed.
This document provides information on various topics related to chemical reaction engineering:
- It discusses types of reactors, how materials behave within reactors, and how to process and interpret data from chemical reactors.
- It explains the concepts of reversible and irreversible reactions, and the three ways a species may lose its chemical identity: decomposition, combination, and isomerization.
- Rate of reaction is discussed, including how it can be expressed as the rate of disappearance of reactants or formation of products.
- Other topics covered include mass/energy balances, Laplace transforms, psychrometric charts, pump curves, and pipe friction tables.
Pink and Green Doodle Hand drawn Science Project Presentation.pdfravrodriguez1632
1. Kinetics is the area of chemistry concerned with the speed or rate of chemical reactions. Reaction rate depends on factors like the nature of reactants, concentration, temperature, catalysts, and surface area.
2. Rate laws show the dependence of reaction rate on reactant concentration. Common orders are zero order, where rate is constant, first order where rate depends on concentration, and second order where rate depends on concentration squared.
3. The half-life of a reaction is the time for the concentration of a reactant to reduce to half its initial value. Half-life equations depend on the reaction order. Integrated rate laws relate concentration over time for different orders.
This document discusses methods for determining the order of a chemical reaction. It defines key terms like rate of reaction, order of reaction, molecularity, and half-life. It describes several methods to determine the order of a reaction:
1) The substitution method involves substituting concentration data into integrated rate equations for zero, first, and second order reactions to determine which gives a constant rate constant.
2) The graphical method plots concentration data versus time in different ways depending on the suspected order to identify linear relationships.
3) The half-life method examines how half-life depends on initial concentration to infer order.
4) Ostwald's isolation method determines partial orders with respect to each reactant by
This document discusses enzyme kinetics and the Michaelis-Menten model of enzyme kinetics. It defines key terms like reaction rate, elementary reactions, rate laws, and transition state theory. It then introduces the Michaelis-Menten equation, defines terms like Km, Vmax, and kcat. It discusses steady state kinetics and how the Michaelis-Menten equation was derived. It explains the meaning and uses of Km and Vmax and concludes by discussing the Lineweaver-Burk double reciprocal plot.
This document discusses kinetics and factors that affect reaction rates. It defines kinetics as how quickly reactions occur and the factors that influence reaction rates, such as temperature, concentration, and the presence of catalysts. Reaction rates are linked to reaction mechanisms - the step-by-step processes by which reactions take place. Increasing temperature leads to more collisions between reactant particles and faster reaction rates, as described by the Arrhenius equation. Catalysts lower the activation energy of reactions, speeding up reaction rates without being consumed.
The document discusses chemical kinetics and reaction rates. It provides information on:
- The study of rates of chemical reactions and reaction mechanisms (chemical kinetics).
- How reaction rates are expressed in terms of changes in reactant/product concentrations over time.
- Factors that influence reaction rates such as concentration, temperature, and surface area.
- Collision theory and how effective collisions between reactant particles lead to reactions.
- Reaction orders, rate laws, and how to determine the order of reactions based on experimental rate data.
kinetics of stability Molecular pharmaceuticsMittalGandhi
This document discusses kinetics of stability and reaction order. It defines key terms like rate, order of reaction, and molecularity. The main types of reaction order discussed are zero order, first order, pseudo first order, and second order. Graphs and equations to determine the rate constant and half-life are provided for each order. Methods for determining the experimental order of a reaction are outlined. Factors that can influence the reaction rate are also summarized. Tables listing the key equations for zero, first, and second order kinetics are included.
Biomass is considered as a potential source of energy production.Gasification can be employed to convert
dilute biomass energy source in to gaseous products holding concentrated form of energy. A steady state model for fluidized
bed biomass gasifier is developed based on reaction kinetics and hydrodynamic aspects of fluidization. The presence of
sorbent for absorption of carbon dioxide from the product gas is also incorporated in the model.The developed model
predicts the variation of syngas composition, temperature, pressure and velocity along the height of gasifier. Experiments
were carried out in a lab scale fluidized bed biomass gasifier and the results were used to validate the model.An increase of
50.35% in H2 mole fraction and a decrease of 50.88 % in CO2 mole fraction were observed when CaO was used as the
sorbent.
The document discusses kinetics and reaction rates. It defines kinetics as the branch of chemistry that studies the speed or rate of chemical reactions. It explains that reaction rates can be measured by changes in concentration, temperature, or pressure over time. The rate depends on factors like the nature of reactants, concentration, temperature, catalysts, surface area, and pressure. Reactions may occur in multiple steps through reaction intermediates rather than a single step. The collision theory and concept of activation energy are introduced to explain why certain collisions result in reactions. Reaction coordinate diagrams are used to illustrate the energy changes in reactions.
This document provides information about dimensional analysis and model studies in fluid mechanics. It defines dimensional analysis as a technique that uses the study of dimensions to help solve engineering problems. Buckingham π theorem is discussed, which states that physical phenomena with n variables can be expressed in terms of n-m dimensionless terms, where m is the number of fundamental dimensions. Several model laws are defined, including Reynolds, Froude, Euler, and Weber laws. Hydraulic models are classified as undistorted or distorted, and scale effects are discussed.
This document provides information about fluid flow through pipes, including definitions and equations. It defines types of fluid flow such as steady/unsteady, uniform/non-uniform, laminar/turbulent. It also defines compressible/incompressible flow and rotational/irrotational flow. Bernoulli's equation and its assumptions are described. Darcy-Weisbach and Hagen-Poiseuille equations for head loss due to friction are given. Reynolds number range for laminar and turbulent flow is provided. Shear stress, velocity distribution, and average velocity equations are listed. Factors affecting frictional head loss are also mentioned.
The document provides information about the unit II of the course CE6303 - Mechanics of Fluids. It includes topics like fluid statics and kinematics, Pascal's law, hydrostatic equation, buoyancy, meta centre, pressure measurement, fluid mass under relative equilibrium, fluid kinematics, stream, streak and path lines, classification of flows, continuity equation, stream and potential functions, flow nets, and velocity measurement techniques. It also lists 2 marks and 16 marks questions with answers related to these topics at the end.
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This document contains 31 questions regarding boundary layer concepts and fluid mechanics. It covers topics such as the range of Reynolds numbers for laminar and turbulent flow, Hagen-Poiseuille formula, velocity distribution formulas, boundary layer thickness definitions, and equations for major and minor head losses in pipes. The document also provides definitions for terms like boundary layer, laminar sublayer, displacement thickness, and momentum thickness.
This document contains a series of logic and reasoning puzzles with the answers provided. Some examples include:
1) The name of the fifth son would be Fifty.
2) After taking away 2 apples from the original 3 apples, you would have 1 apple remaining.
3) Dividing 30 by 1/2 and then adding 10 would give the answer of 60.
4) The number that does not belong in the series 1,1,2,3,4,5,8,13,21 is 5 because it is not the result of adding the previous two numbers.
Fracture mechanics is concerned with studying crack propagation in materials. There are three modes of applying force to a crack: Mode I is opening, Mode II is sliding parallel to the crack plane and crack front, and Mode III is tearing parallel to the crack plane and front. Ductile fractures are characterized by plastic deformation, dull and fibrous fracture surfaces not related to principal stress direction, and cup-and-cone shapes from microvoid formation and 45 degree shear lips. Brittle fractures occur suddenly with little plasticity and no necking, often due to low temperatures making steel more brittle.
This document provides information on the B.E. Mechanical Engineering program at MEPCO Schlenk Engineering College in Sivakasi, India. It outlines the department vision and mission, which are to educate students to become professional mechanical engineers and serve society. The program educational objectives are for students to develop self-learning abilities, a breadth of engineering knowledge, analytical reasoning skills, and strong communication skills. The program outcomes cover imparting technical knowledge and developing skills in areas such as problem solving, design, tools/software usage, and professional/social responsibilities. The document also provides course details across 8 semesters, including required courses, electives, labs, and a project work component in the final year.
The document provides an overview of the history and evolution of lean manufacturing. It discusses key figures and developments that influenced lean thinking from the 1850s through the 1990s. These include Eli Whitney and interchangeable parts, Frederick Taylor's time and motion studies, Henry Ford's assembly line, and Eiji Toyoda and Taiichi Ohno's Toyota Production System. The core principles of lean focus on removing waste and only producing what is needed when it is needed to maximize value for the customer.
This document is the preface to a textbook on reactor shielding. It discusses how shielding technology has advanced in recent decades with new computational tools and measurement techniques. It aims to cover the fundamentals of neutron and gamma-ray transport in the first semester and special topics like Monte Carlo techniques and shield design in the second semester. It is intended for advanced undergraduate or graduate students in nuclear engineering and assumes familiarity with calculus, differential equations, and nuclear physics. The author acknowledges contributions from many reviewers and thanks the late E. P. Blizard for his influence on the field of shielding technology.
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The document discusses geometric modeling techniques used in manufacturing. It describes wireframe, surface, and solid modeling and their advantages and limitations. Wireframe models represent objects with edges only, while surface and solid models contain additional geometric and topological information. Parametric and non-parametric representations are used to mathematically define curves and surfaces. Geometric modeling is important for design analysis, manufacturing, inspection, and other applications.
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detection in smart grids. The proposed approach is a combination of the Convolutional Neural Network
(CNN) and the Long-Short-Term Memory algorithms (LSTM). We employed a recent intrusion detection
dataset (DNP3), which focuses on unauthorized commands and Denial of Service (DoS) cyberattacks, to
train and test our model. The results of our experiments show that our CNN-LSTM method is much better
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Generative AI leverages algorithms to create various forms of content
247447699 reactors
1. 95
Reactors
Reactions are usually the heart of the chemical processes in which relatively cheap raw materials
are converted to more economically favorable products. In other cases, reactions play essential
safety and environmental protection roles. In any case, proper design and operation of the reactor
is required to provide the desired outcome. Such design is usually based on thermodynamics,
chemical kinetics, and transport studies coupled with experience and economic considerations.
When studying chemical reactions we need to determine what are the reactants and products
needed, to what extent will the reaction proceed, and how fast it will proceed. The study of such
factors in addition to the detailed design of the reactor consist the chemical reaction engineering
field in which process simulation can be of great help.
Aspen Plus provides several libraries to model reactive processes. The selection of the model
depends on the amount of information available and the type of simulation.
Reaction Classifications
There are several ways to classify a chemical reaction. For example, reactions can be classified
as reversible and irreversible reactions. In reversible reactions, the reactants are converted to
products at a certain rate while the products are converted to reactants at a different rate. At
equilibrium, the two rates become equal. An example of reversible reaction is the formation of
ammonia from hydrogen and nitrogen:
In irreversible reactions, on the other hand, the rate of conversion of products to reactants is zero.
For example, the hydration of calcium oxide to form calcium hydroxide is an irreversible
reaction:
( )
Another classification of reactions is based on the phase(s) involved. In this classification, a
homogeneous reaction is defined as a reaction which occurs in one phase. On the other hand, a
heterogeneous reaction requires the presence of two or more phases for the reaction to take place
(regardless of where the reaction is occurring). For example, the burning of methane is a
homogeneous reaction since it occurs in the gas phase only. On the other hand, burning coal is a
heterogeneous reaction since the presence of oxygen (gas) and coal (solid) are needed to
complete the reaction.
When considering the phase of the reaction, it is important to distinguish between the phases
present during a reaction and the phases in which the reaction occurs. For example, an oxygen
scavenging system such as sodium sulfite (Na2SO3) solution when used to remove oxygen from a
gas stream, the gas will have to dissolve in the solution for the oxygen to be removed. Thus,
2. Dr. YA Hussain 96
while the reaction is heterogeneous (requires the presence of gas and liquid phases), the reaction
occurs in the liquid phase only.
Material Balance on Reactive Processes
For the general reaction:
(28)
occurring in the process shown in Figure 67. The amount of each component entering the system
is known, and the objective is to determine the outlet composition. One approach to solve this
material balance is to use the fractional conversion of one of the materials. The fraction
conversion is defined as:
(29)
Of course, ranges from 0 to 1. Then, the outlet of component can be determined by
rearranging Equation (29) to give:
(30) ( )
Using stoichiometry, the outlet for other components can be calculated.
In the example in Figure 67, if the conversion of is known ( ), then the outlet flow rates can
be written as:
Alternatively, the extent of reaction can be used. The extent of reaction can be viewed as a
hypothetical product for which one molecule (or mole) is produced each time a reaction event
occurs. The extent of reaction ( ) is used to define the output from the reaction using the
following expression:
(32)
Reactor
nAo
nBo
nCo
nDo
nIo
nA
nB
nC
nD
nI
Figure 67. Simple reactor block.
(31)a ( )
(31)b ( )
(31)c ( )
(31)d ( )
3. 97
where a summation is used to account for the presence of multiple reactions (denoted by the
subscript ), and denotes the stoichiometric coefficient of component in reaction . Thus, for
the above system, the outlet flow rates can be written as:
Both the conversion and extent of reaction are based on stoichiometry and requires knowledge of
the exact reaction(s) taking place.
In some cases, detailed information about the reaction is available and different approaches need
to be taken that does not require exact knowledge of the reaction. For example, reactions
involving non-conventional materials, such as crude oil and food stuffs, it can be difficult to
write a set of chemical reactions describing the system. In such cases, general knowledge of the
reactants and products present and quantities produced can be employed. The reaction yield,
defined as:
(34)
Since the stoichiometry is unknown, yield must be provided for each product. If, however, yield
is used with reaction where stoichiometry is determined, the yields can all be related through the
stoichiometric coefficients.
In all of the above analysis information is needed about the final product (conversion, , or
yield). If such information is not available a different approach may be followed. Consider for
example the reversible reaction in Equation (28), with an equilibrium constant . The
equilibrium constant is defined from thermodynamics as:
(35) ∏ (
̂
)
where refers to the fugacity of component , and is equal to:
(36) ( )
and:
(37) ∑
which is the stoichiometric weighted difference between the products and reactants. Thus, once
the reaction stoichiometry is known, we can calculate the equilibrium constant and the
equilibrium conversion (i.e., material balance) of each species. Notice here that the equilibrium
(33)a
(33)b
(33)c
(33)d
4. Dr. YA Hussain 98
constant is affected by the temperature based on the value of and in the denominator of
the exponential argument in Equation (36).
In cases where information on the stoichiometry is unknown and, especially, if phases changes
accompany the reaction an approach based on minimizing the Gibbs free energy of the whole
mixture can be used. In this approach, the total Gibbs energy of all components (reactants,
products, and inerts) is minimized. For example, the Gibbs energy for an ideal mixture is given
by:
(38) ∑ ∑
which, for two components system, is minimized as:
(39) ( )
This derivative is set to zero to find the minimum . A similar approach can be applied for
more complex systems with multiple phases.
Reaction Kinetics
Reactors are usually designed based on rate considerations. Two commonly used reactors are the
CSTR (continuous stirred tank reactor) and the PFR (plug flow reactor). These reactors provide
enough residence time for the reaction to take place with satisfactory conversion. In such
reactors, the reaction rate expression must be known determined.
One of the most common reaction rates is the power law expression. This law can be written as:
(40)
( ) * ( )+
⏟
∏( )
⏟
Where the concentration is multiplied by a temperature dependent factor ( ), which represents
a weighing factor for the dependence of the reaction rate on the different components
concentrations. The exponent ( ) can be equal to the stoichiometric coefficient, and in such
case the rate is termed an elementary, or it can differ.
In many cases, a catalyst is used to enhance the reaction. In such cases, the adsorption of the
different materials on the catalyst can be an important process that affects the reaction rate. In
such cases, the reaction rate of Equation (40) must be modified to take into account the
adsorption effect. One of the most commonly used reaction rates for such cases is the Langmuir-
Hinshelwood-Hougen-Watson (LHHW). The reaction rate with the LHHW model is similar to
that in Equation (40) except for the addition of an adsorption term as a denominator, i.e:
(41)
( )( )
The adsorption term is given by:
5. 99
(42) ∑ ∏( )
Once the kinetics is known, the reactor design can be made based on material balance. For an
ideal CSTR reactor, the residence time ( ) required for the reaction is given by:
(43)
For an ideal PFR reactor, the residence time is given by:
(44) ∫
Heat of Reaction
Energy balances on reactors are coupled with material balances to determine the heating or
cooling requirements. Here, the energy balance is similar to that for non-reactive system except
for the addition of the heat of reaction term. The heat of reaction is defined as:
(45) ∑
where is the heat of formation for the reactants and products and is the stoichiometric
coefficient (negative for the reactants and positive for the products). For example, the energy
balance for CSTR with a single reaction is given by:
(46) ∑ ( ) ̇
where is the concentration of component and ̇ is the external heating or cooling to the
reactor. Similar expression can be written for the PFR.
Reactor Modeling in Aspen Plus
There are seven blocks for reaction modeling in Aspen that can perform calculations based on
the stoichiometry, yield, equilibrium, and Gibbs minimization, plus the kinetics models for
CSTR and PFR. In addition, a batch model is available for batch reactors.
RStoic
When the reaction stoichiometry is known but
information on kinetics is not available (or not
important). The block must have one or more feed
streams, one required output stream. Optional
connections are the water decant and input and output
heat streams. The connectivity for this block is shown
in the figure to the right.
The input form for this block is shown in Figure 68. Two specifications must be made either to
the outlet stream conditions or the heat duty of the reactor. The form allows specification of the
valid phases inside the reactor. The reactions can be defined in the Setup | Reactions tab by
6. Dr. YA Hussain 100
defining a New reaction and entering the reactants and products with their stoichiometric
coefficients as shown in Figure 69. In this figure, an example has been input for the reaction:
C6H6 + Cl2 → C6H5Cl + HCl
The stoichiometric coefficients are automatically adjusted to be negative for the reactants and
positive for the products. The form also defines the completion of the reaction through either the
extent of reaction or the fractional conversion of any reactant.
Multiple reactions can be defined in the Reactions form. The option "Reactions occur in series",
if checked, will cause the calculations to proceed in the order the reactions are entered. If the
option is not selected, the reactions will be taken to occur in parallel.
If the reaction involved is a combustion reaction, the Setup | Combustion tab can be used. In
this case, no reaction needs to be defined, and the simulation will assume complete combustion
of all carbon, hydrogen, sulfur, and nitrogen. Components containing atoms other than C, H, S,
or N will be ignored. When the combustion is selected, make sure to add the combustion
Figure 68. Input form for the RStoic block.
Figure 69. Edit Stoichiometry form used for entering the reaction information.
7. 101
products (CO2, H2O, SO2, and NO or NO2).
The heat of reaction can be calculated or input in the Setup | Heat of Reaction tab. The heat of
reaction will not be used in the calculations but will be presented in the Results sheet. The heat
of reaction will be calculated based on the reaction of 1 mole of a reference component
(reactant). The temperature, pressure, and phase for the calculations must be specified.
Other options are available in the RStoic Setup form such as the calculations of the selectivity
for multiple reactions and options for working with non conventional streams.
Consider for example the benzene chlorination reaction shown previously. If 100 kmol/hr of an
equimolar amounts of chlorine and benzene at 70 o
C and 2 bar are fed to an RStoic reactor in
which 80% conversion of benzene is achieved. No pressure drop and no temperature changes
occur. The Results form gives information about the outlet stream conditions and heat duty of
the reactor, phase equilibrium, heat of reactions (if selected).
RYield
The second block in the Reactors library, RYield, performs
the calculations based on the yield. The block takes similar
streams as that for the RStoic block, as shown in the figure to
the right. This block does not require exact information about
the stoichiometry or kinetics. Similar input to that of RStoic
is needed here for the exit stream. The output of the reaction
is defined based on the yield in the Setup | Yield form shown
in Figure 70. The yield is defined as mole or mass of each component per total mass input to the
block. Inert components can be defined in the same form and will not be included in the yield
calculations. No heat of reaction can be calculated here because the stoichiometry of the reaction
is not known. Another option to enter the yield is through the component mapping option. If this
option is selected in the Yield form, the Setup | Comp. Mapping from becomes available. In
this form, the combination (lumping) or breaking (de-lumping) of reactants (with their weight
fraction) to form products is input for each material.
8. Dr. YA Hussain 102
If we want to repeat the previous example, we can define the yield as shown in Figure 70.
Similar results to that obtained in the RStoic is displayed in the Results form.
REquil
When one or more reactions involved are equilibrium reaction, the REquil block can be used.
The block requires knowledge of the reaction
stoichiometry, and performs chemical and phase
equilibrium reactions. Unlike the previous blocks,
the REquil block has a vapor and liquid phase
product streams (both are required). The only
required information for this block is the output stream and the reaction. With this input, all the
required calculations are made based on thermodynamics calculations as described in page 97.
The equilibrium constant for the reaction will be calculated and presented in the Results | Keq
form. The constant will be calculated at the outlet stream conditions. If the equilibrium constant
needs to be estimated at a different temperature than the that of the reactor, input can be made in
the Temperature approach field of the Edit Stoichiometry window show in Figure 71. If the
extent of a reaction is known and no equilibrium calculations are need the Molar extent can be
defined directly in the Edit Stoichiometry window as well.
Figure 70. Defining the yield for RYield reactor.
Figure 71. Edit Stoichiometry window.
9. 103
The previous example can be repeated with the REquil block. The results show that most of the
reactants are consumed in this system. The equilibrium constant for the reaction at 70 o
C is
2.16×1019
showing a large favorability of the forward reaction as indicated by the consumption
of the reactants.
RGibbs
The fourth block provides reaction calculations
without the need for detailed stoichiometry or
yield. The calculations are based on minimizing
the Gibbs energy for the system as discussed in
page 98. The block takes one or more input and
one or more output streams, and an optional heat
input and/or output streams. The input form requires two variable specifications. The block can
be used to calculate phase and/or chemical equilibrium, and allows constraining the equilibrium
value with specific heat duty and/or temperature approach in the Setup | Specifications form. If
restricted equilibrium is selected, reactions can be defined for the system. The block also allows
specifying the number of phases, which components present in each phase, and how to distribute
the phase on the outlet streams (when multiple output streams are used) in the Setup | Products
and Setup | Assign Streams forms. Inert components can be defined in the Setup | Inerts form.
The setup form for the RGibbs block is shown in Figure 72.
Repeating the previous example with the RGibbs block gives close results to that in the previous
examples. The Results form gives information on the outlet conditions and reactor duty, and
information on the outlet phases and compositions as defined in the Setup form.
RCSTR and RPlug
When rigorous simulation of reactors is needed, the RCSTR and RPlug are used. These two
blocks perform simulation of ideal reactors operated under specific conditions. For the CSTR,
two design variables are needed (pressure and temperature or heat duty), specification of the
valid phases, and a reactor specification. For the plug reactor, a specification is needed for the
type of the reactor (specific temperature, adiabatic, or cooled). Depending on the type choice, the
required specification will vary: temperature or temperature profile, no specifications are needed,
Figure 72. The RGibbs Setup form.
10. Dr. YA Hussain 104
or heat transfer coefficient. The configuration for the reactor is input in the Setup |
Configuration form which includes the reactor geometry. The pressure drop can be specified in
the Setup | Pressure form.
In both the RCSTR and RPlug, specifications for the catalyst can be made in the Setup |
Catalyst form. Catalyst specification will be used to calculate species generation when the basis
for the reaction rate is given in weight catalyst. In addition, pressure drop calculations will
depend on the catalyst specifications when Ergun's equation is used.
Unlike the previous blocks, detailed information on the reaction and its kinetics must be input for
these blocks. The reactions are defined in the Reactions folder. Two types of reactions present:
chemistry (used for ions forming systems) and reactions (for reactions in general). Only the
second type will be discussed here. New reactions can be defined by going the Reactions |
Reactions folder and click the New… button. The Create new ID window appears where you
can input a reaction name and select its type. The available reaction types cover a wide range of
kinetics expression for general reactions, polymerization reactions, and reactive distillation
applications. The General type provides options for common reaction kinetics including power
law, equilibrium, and LHHW.
For example, the benzene chlorination reaction described in the previous examples have a
kinetics of the form:
(47)
where and are the concentrations in kmol/m3
, and the rate is given in kmol/m3
·s. The
reacting phase is the liquid phase. Define a new reaction (named CLBZ) as a general reaction of
the power law type, and input the information as shown in Figure 73.
To use the reaction in the RCSTR and RPlug reactions, go back to the Setup | Reactions form
and add the reaction to the Selected reaction sets.
For example, define a CSTR with 0.5 m3
volume where the reaction is taking place in the liquid
phase only. Once the simulation is executed, the Results page gives about the reactor duty,
phases, and residence time. We can also use the same reaction with a RPlug block for a PFR
having a specified exit temperature of 70 o
C, zero pressure drop, 5.22 m length, 0.35 m diameter,
and reaction in liquid phase only. The Results page gives similar information to that of the
RCSTR.
12. Dr. YA Hussain 106
Exercise 1: Toluene Production
A fresh feed of 20 lbmol/hr of pure n-heptane at 77 o
F and 1 atm is combined wih a solvent
recycle from an extractor and heated to 425 o
F at 1 atm. The hot stream is fed into a reactor in
which the following reaction occurs:
C7H16 → C7H8 + 4H2
The conversion based on n-heptane is 15%. The products of reaction are cooled to 180 o
F, after
which the hydrogen is completely separated from the reactor products in the first separator. A
feed of 100 lbmol/hr of benzene at 180 o
F and 1 atm is combined with the remaining products
of reaction to extract the toluene. All of the toluene and benzene leave a s the product of the
process. The unreacted n-heptane is recycled to the mixer. A sketch of the process is given
below. Use the RStoic model for the reactor, and Chao-Seader property method.
Questions:
14. What is the overall conversion of the process?
B CFEED
RCYCL
A
G
D
E
F
PROD
RSTOIC
REACT
MIXER
MIX
HEATER
HEAT1
SEP
SEP1
SEP
EXTRCT
HEATER
HEAT2
13. 107
Exercise 2: Different Reactor Types
Using the conditions listed below and in the figure to prepare your simulation: the reactor
conditions are 70 o
C and 1 atm. The reaction taking place is:
Ethanol + Acetic Acid ↔ Ethyl Acetate + Water
Which has a first order with respect to each of the reactants in the reaction (second order
overall). The reaction rate is expressed with an Arrhenius type relation: k = ko∙e-E/RT
with a
forward Reaction pre-exp. factor of 1.9 x 108
, and activation energy of 5.95 x 107
J/kmol. The
reverse reaction has a pre-exp. factor of 5.0 x 107
and activation energy of 5.95 x 107
J/kmol.
The reactions occur in the liquid phase, and composition basis is Molarity. (Hint: Check that
each reactor is considering both Vapor and Liquid as Valid phases.) Setup a simulation as shown
in the flowsheet below.
RGIBBS
RSTOIC
RPLUG
RCSTR
V = 0.14 m3
L = 2 m
D = 0.3 m
70% conversion
of EtOH
Feed:
Temp = 70 C
Pres = 1 atm
Water: 8.892 kmol/hr
Ethanol: 186.59 kmol/hr
Acetic Acid: 192.6 kmol/hr
Use NTRL-RK
Questions:
1. What is the kmol/hr of ethyl acetate from each reactor:
RSTOIC: RGIBBS:
RPLUG: RCSTR:
2. Calculate the conversion of ethanol for each reactor:
RSTOIC: RGIBBS:
RPLUG: RCSTR:
3. Plot the composition profile for each component in the PFR reactor as a function of
distance.