DOCSLIB.ORG

2007-04-16.Patzek.CE170 Energy Earth Humans.University Of

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
2007-04-16.Patzek.CE170 Energy Earth Humans.University Of Tad W. Patzek Department of Civil and Environmental Engineering The University of California Berkeley First DRAFT Copyright c 2007 by the University of California April 16, 2007 To Joanna, My Patient Wife, And My Children: Lucas, Sophie and Julie Contents 1 Preface 1 1.1 ExecutiveSummary ......................... 2 1.2 PriorKnowledge ........................... 3 1.2.1 UsefulPhysics ........................ 3 1.2.2 UsefulBiology ........................ 3 1.2.3 UsefulChemistry....................... 3 1.2.4 UsefulMathematics . .. .. .. .. .. .. .. .. 4 1.3 WhatisStillMissing......................... 4 2 The Finite Earth 5 3 Energy Primer 13 3.1 WhatAreYouGoingToLearn? . 14 3.2 WhyIsItImportant? ........................ 14 3.3 Preliminaries ............................. 14 3.3.1 UnitsofEnergy........................ 14 3.3.2 BombCalorimeter . 16 3.3.3 HeatingValuesofFuels . 17 3.3.4 HigherorLowerHeatingValues? . 20 3.3.5 Conclusion .......................... 22 3.4 PrimaryEnergyUseinUS . 22 3.4.1 DataSources ......................... 22 3.4.2 Electricity........................... 22 3.4.3 Petroleum........................... 25 3.4.4 Coal.............................. 25 3.4.5 NaturalGas.......................... 25 3.4.6 NuclearEnergy........................ 25 3.4.7 Summary ........................... 26 3.4.8 EnergyCosts ......................... 27 3.4.9 Problems ........................... 27 4 Economics 37 4.1 WhatAreyouGoingtoLearn? . 38 4.2 WhyIsItImportant? ........................ 38 ii CONTENTS 4.3 Background.............................. 39 4.4 ACrashCourseontheSSE . 40 4.5 GlobalPopulation .......................... 41 4.6 USPopulation ............................ 44 4.7 PopulationControl.. .. .. .. .. .. .. .. .. .. .. 44 4.8 Problems ............................... 44 5 Exponential Growth? 49 5.1 WhatAreYouGoingToLearn? . 50 5.2 WhyIsItImportant? ........................ 50 5.3 GrowthRates............................. 50 5.4 KingHubbert............................. 51 5.5 WhatDidHubbertTeachUs?. 53 5.6 WhyDoHubbertCyclesExist?. 56 5.6.1 LogisticGrowth ....................... 57 5.6.2 Logisticvs. GaussianDistribution . 58 5.7 Problems ............................... 61 5.8 Matching the Logistic and Normal Distributions . .. 69 6 Geologic Time Scale on the Earth 73 6.1 WhatAreyouGoingtoLearn? . 74 6.2 WhyIsItImportant? ........................ 74 6.3 GeologicTimeScales. .. .. .. .. .. .. .. .. .. .. 74 7 Basic Thermodynamics 81 7.1 WhatAreyouGoingtoLearn? . 82 7.2 WhyIsItImportant? ........................ 82 7.3 Introduction.............................. 82 7.4 Body,PrimitiveProperty,andState . 82 7.5 TheSystem.............................. 83 7.5.1 ASimpleSystem ....................... 84 7.5.2 Path.............................. 84 7.5.3 ThermodynamicProcess. 84 7.5.4 Cycle ............................. 86 7.6 GeneralDefinitionofaProperty . 86 7.6.1 IndependentProperties . 86 7.7 TheLawofMassConservation . 87 7.8 AllowedStatesofaSystem . 87 7.8.1 PassiveResistances. 87 7.8.2 Constraints .......................... 88 7.8.3 IsolatedSystems .. .. .. .. .. .. .. .. .. .. 89 7.9 Temperature ............................. 90 7.10 EquationofState........................... 91 7.11Problems ............................... 92 CONTENTS iii 8 First Law of Thermodynamics 95 8.1 WhatAreyouGoingtoLearn? . 96 8.2 WhyIsItImportant? ........................ 96 8.3 Background.............................. 96 8.4 DefinitionofWorkInteractions . 96 8.4.1 AdiabaticProcess . 97 8.5 TheFirstLawofThermodynamics . 97 8.5.1 Energy............................. 98 8.5.2 OlderFormulations. 99 8.6 MoreonEnergy............................ 99 8.7 Problems ...............................100 9 Second Law of Thermodynamics 103 9.1 Background.............................. 104 9.2 TypesofStates ............................ 104 9.3 ThermodynamicEquilibrium . 105 9.3.1 StableEquilibrium . 105 9.3.2 Unstable and Neutral and Equilibria . 106 9.3.3 MetastableEquilibrium . 106 9.3.4 MutualEquilibrium . 107 9.3.5 Thermodynamic Propertiesand States . 107 9.4 SecondLawofThermodynamics . 107 9.4.1 StatePrinciple . 108 9.5 DefinitionofHeatInteractions . 108 9.5.1 DefinitionofHeatQuantity . 109 9.6 EnergyChangesin NonadiabaticProcesses . 109 9.6.1 LawofConservationofEnergy . 110 9.6.2 ImportanceofBoundaries . 110 9.7 OlderFormulationsofSecondLaw . 110 9.8 An alternative Modern Formulation of Second Law . 110 9.9 Problems ...............................111 10 Reversibility, Irreversibility, Etc. 113 10.1 WhatAreWeGoingtoLearn? . 114 10.2 WhyIsItImportant? . 114 10.3 EfficiencyofaHeatMachine . 114 10.4 Reversibility. .. .. .. .. .. .. .. .. .. .. .. .. 114 10.5 ThermodynamicTemperature . 114 10.6 Perpetual Motion Machine of the Second Kind . 115 10.7 HeatReservoir ............................ 115 10.8 Irreversibility . 115 10.8.1 ProvingIrreversibility . 115 10.8.2 ExampleofanIrreversibleProcess . 116 10.9 Internal and External Irreversibility . 116 10.10Problems ............................... 118 iv CONTENTS 11 Entropy 119 11.1 WhatAreWeGoingtoLearn? . 120 11.2 WhyIsItImportant? . 120 11.3Background .............................. 120 11.4 ExistenceofEntropy . 120 11.4.1 Entropy Changes in Internally Reversible Systems . 122 11.4.2 Entropy Changes in Irreversible Systems . 122 11.4.3 Entropy and Heat in Irreversible Processes . 123 11.4.4 IsentropicProcess . 124 11.4.5 PrincipleoftheIncreaseofEntropy . 124 11.4.6 EntropyChangefor a Simple System. 125 11.5 Entropy,Order,andProbability . 126 11.6Problems ............................... 128 12 Thermodynamic Functions and Their Differentials 131 12.1 WhatAreYouGoingtoLearn?. 132 12.2 WhyIsItImportant? . 132 12.3 GeneralDefinitions. 132 12.4 Energy Balance for PVT Systems of Variable Composition . 133 12.4.1 LegendreTransformations . 134 12.5 Equilibrium in Closed, Heterogeneous Systems . 135 12.5.1 SpecialFormsofEquation(12.14) . 136 12.6 Gibbs-DuhemEquation . 138 12.7 AvailableFreeEnergy . 138 12.7.1 IntroductiontoExergy. 139 12.7.2 Change of Bth betweenTwoStates. 140 12.7.3 AnIndustrialFlowProcess . 140 12.7.4 Cumulative Exergy Consumption (CExC) . 142 12.8Problems ............................... 142 13 Solar Energy Sequestered by Agriculture 145 13.1 WhatAreWeGoingtoLearn? . 146 13.2 WhyIsItImportant? . 146 13.3 MainAgriculturalCrops . 146 13.3.1 Barley............................. 146 13.3.2 Maize(Corn) . 147 13.3.3 Cotton............................. 148 13.3.4 Potatoes............................ 151 13.3.5 Rapeseed ........................... 153 13.3.6 Rice .............................. 156 13.3.7 Sorghum............................ 157 13.3.8 Soybean............................ 159 13.3.9 Sugarbeets .......................... 161 13.3.10Sugarcane. 164 13.3.11Wheat............................. 165 13.4 Solar Energy Sequestered by US Agriculture . 167 CONTENTS v 13.4.1 LandUseintheUS . 167 13.4.2 CalorificValuesofWholePlants . 169 13.4.3 MainUSCrops. 171 13.5Conclusions .............................. 173 13.6Problems ............................... 181 14 Biomass to Fuels 195 14.1 WhatAreWeGoingtoLearn? . 196 14.2 WhyIsItImportant? . 196 14.3 AvailabilityofUSBiomass . 196 14.4 Second Law Efficiency of Major Biomass Sources . 198 14.4.1 EfficienciesofSolarEnergyCapture . 201 14.4.2 DrivingonSolarPower . 205 14.5Conclusions .............................. 210 14.6Problems ............................... 211 15 Black Body Radiation 217 15.1 WhatAreWeGoingtoLearn? . 218 15.2 WhyIsItImportant? . 218 15.3Background .............................. 218 15.4 Energy and Entropy in Terms of gi’s................220 15.5 ThermodynamicFunctions. 221 15.6 EvaluationofIntegrals . 222 15.7 Stefan-BoltzmannLaw . 222 15.8Problems ............................... 223 16 Solar Power That Drives the Earth 229 16.1 WhatAreWeGoingtoLearn? . 230 16.2 WhyIsItImportant? . 230 16.3Definitions............................... 230 16.4 AveragesofSolarEnergyFlux . 231 16.5 ADetailedBalanceofRadiationFluxes . 233 16.6 AFunctionalPowerBalanceoftheEarth . 235 16.7 SolarRadiation. 235 16.8 GlobalWarming .. .. .. .. .. .. .. .. .. .. .. 235 16.9Problems ............................... 242 17 The Extraordinary Water 245 17.1 WhatAreYouGoingtoLearn?. 246 17.2 WhyIsItImportant? . 246 17.3 HowMuchWaterIsThereontheEarth? . 247 17.4 MolecularStructureofWater . 248 17.4.1 The van der Waals Intermolecular Forces . 248 17.4.2 HydrogenBonds . 249 17.5WaterDensity ............................ 250 17.6 Water Melting and Boiling Points . 252 vi CONTENTS 17.7 WaterHeatCapacity. 253 17.8 WaterLatentHeatsofPhaseChange. 254 17.9 SurfaceTension. 255 17.10WaterAbsorptionSpectrum. 258 17.11WaterasaSolvent . 259 17.11.1Solubility of Salts and Hydroxides . 260 17.11.2Solubility of Polar Substances . 261 17.12Problems ............................... 261 18 Photosynthetic Efficiency of Plants 269 18.1 WhatAreWeGoingtoLearn? . 270 18.2 WhyIsItImportant? . 270 18.3Definitions............................... 270 18.4Background .............................. 270 18.5 Asymptotic Efficiency of Photosynthesis . 270 18.5.1 LightAbsorption . 271 18.6 Real-life Efficiency ofPhotosynthesis . 278 18.6.1 Recordcropin2004 . 282 18.7Problems ............................... 283 19 Water and CO2 Management by Plants 285 19.1 WhatAreWeGoingtoLearn? . 286 19.2 WhyIsItImportant? . 286 19.3LeafStomata ............................. 286 19.3.1 Countercurrent Diffusion of CO2 andWater. 286 19.3.2 H2O and CO2 FluxEstimates. 288 19.4 WaterRequirementsofCrops . 288 19.5Problems ............................... 291
Load more

Recommended publications
  • Appendix a Rate of Entropy Production and Kinetic Implications
    Appendix A Rate of Entropy Production and Kinetic Implications According to the second law of thermodynamics, the entropy of an isolated system can never decrease on a macroscopic scale; it must remain constant when equilib- rium is achieved or increase due to spontaneous processes within the system. The ramifications of entropy production constitute the subject of irreversible thermody- namics. A number of interesting kinetic relations, which are beyond the domain of classical thermodynamics, can be derived by considering the rate of entropy pro- duction in an isolated system. The rate and mechanism of evolution of a system is often of major or of even greater interest in many problems than its equilibrium state, especially in the study of natural processes. The purpose of this Appendix is to develop some of the kinetic relations relating to chemical reaction, diffusion and heat conduction from consideration of the entropy production due to spontaneous processes in an isolated system. A.1 Rate of Entropy Production: Conjugate Flux and Force in Irreversible Processes In order to formally treat an irreversible process within the framework of thermo- dynamics, it is important to identify the force that is conjugate to the observed flux. To this end, let us start with the question: what is the force that drives heat flux by conduction (or heat diffusion) along a temperature gradient? The intuitive answer is: temperature gradient. But the answer is not entirely correct. To find out the exact force that drives diffusive heat flux, let us consider an isolated composite system that is divided into two subsystems, I and II, by a rigid diathermal wall, the subsystems being maintained at different but uniform temperatures of TI and TII, respectively.
    [Show full text]
  • Review of Thermodynamics from Statistical Physics Using Mathematica © James J
    Review of Thermodynamics from Statistical Physics using Mathematica © James J. Kelly, 1996-2002 We review the laws of thermodynamics and some of the techniques for derivation of thermodynamic relationships. Introduction Equilibrium thermodynamics is the branch of physics which studies the equilibrium properties of bulk matter using macroscopic variables. The strength of the discipline is its ability to derive general relationships based upon a few funda- mental postulates and a relatively small amount of empirical information without the need to investigate microscopic structure on the atomic scale. However, this disregard of microscopic structure is also the fundamental limitation of the method. Whereas it is not possible to predict the equation of state without knowing the microscopic structure of a system, it is nevertheless possible to predict many apparently unrelated macroscopic quantities and the relationships between them given the fundamental relation between its state variables. We are so confident in the principles of thermodynamics that the subject is often presented as a system of axioms and relationships derived therefrom are attributed mathematical certainty without need of experimental verification. Statistical mechanics is the branch of physics which applies statistical methods to predict the thermodynamic properties of equilibrium states of a system from the microscopic structure of its constituents and the laws of mechanics or quantum mechanics governing their behavior. The laws of equilibrium thermodynamics can be derived using quite general methods of statistical mechanics. However, understanding the properties of real physical systems usually requires applica- tion of appropriate approximation methods. The methods of statistical physics can be applied to systems as small as an atom in a radiation field or as large as a neutron star, from microkelvin temperatures to the big bang, from condensed matter to nuclear matter.
    [Show full text]
  • Basic Concepts 1 1
    BASIC CONCEPTS 1 1 Basic Concepts 1.1 INTRODUCTION It is axiomatic in thermodynamics that when two systems are brought into contact through some kind of wall, energy transfers such as heat and work take place between them. Work is a transfer of energy to a particle which is evidenced by changes in its position when acted upon by a force. Heat, like work, is energy in the process of being transferred. Energy is what is stored, and work and heat are two ways of transferring energy across the boundaries of a system. The amount of energy transfer as heat can be determined from energy conservation consideration (first law of thermodynamics). Two systems are said to be in thermal equilibrium with one another if no energy transfer such as heat occurs between them in a finite period when they are connected through a diathermal (non-adiabatic) wall. Temperature is a property of matter which two bodies in equilibrium have in common. Hot and cold are the adjectives used to describe high and low values of temperature. Energy transfer as heat will take place from the assembly (body) with the higher temperature to that with the lower temperature, if they two are permitted to interact through a diathermal wall (second law of thermodynamics). The transfer and conversion of energy from one form to another is basic to all heat transfer processes and hence they are governed by the first as well as the second law of thermodynamics. This does not and must not mean that the principles governing the transfer of heat can be derived from, or are mere corollaries of, the basic laws of thermodynamics.
    [Show full text]
  • Considerations for the Measurement of Deep-Body, Skin and Mean Body Temperatures
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Portsmouth University Research Portal (Pure) CONSIDERATIONS FOR THE MEASUREMENT OF DEEP-BODY, SKIN AND MEAN BODY TEMPERATURES Nigel A.S. Taylor1, Michael J. Tipton2 and Glen P. Kenny3 Affiliations: 1Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong, Australia. 2Extreme Environments Laboratory, Department of Sport & Exercise Science, University of Portsmouth, Portsmouth, United Kingdom. 3Human and Environmental Physiology Research Unit, School of Human Kinetics, University of Ottawa, Ottawa, Ontario, Canada. Corresponding Author: Nigel A.S. Taylor, Ph.D. Centre for Human and Applied Physiology, School of Medicine, University of Wollongong, Wollongong, NSW 2522, Australia. Telephone: 61-2-4221-3463 Facsimile: 61-2-4221-3151 Electronic mail: [email protected] RUNNING HEAD: Body temperature measurement Body temperature measurement 1 CONSIDERATIONS FOR THE MEASUREMENT OF DEEP-BODY, SKIN AND 2 MEAN BODY TEMPERATURES 3 4 5 Abstract 6 Despite previous reviews and commentaries, significant misconceptions remain concerning 7 deep-body (core) and skin temperature measurement in humans. Therefore, the authors 8 have assembled the pertinent Laws of Thermodynamics and other first principles that 9 govern physical and physiological heat exchanges. The resulting review is aimed at 10 providing theoretical and empirical justifications for collecting and interpreting these data. 11 The primary emphasis is upon deep-body temperatures, with discussions of intramuscular, 12 subcutaneous, transcutaneous and skin temperatures included. These are all turnover indices 13 resulting from variations in local metabolism, tissue conduction and blood flow. 14 Consequently, inter-site differences and similarities may have no mechanistic relationship 15 unless those sites have similar metabolic rates, are in close proximity and are perfused by 16 the same blood vessels.
    [Show full text]
  • Section 1 Introduction to Classical Thermodynamics
    Section 1 Introduction to Classical Thermodynamics 1.1 Introduction – Macroscopic and microscopic descriptions Any system may be described macroscopically or microscopically (G pp. 1-4, F pp. xi-xii). The macroscopic description considers the system as a whole. The system is characterised, in equilibrium, by a relatively small number of variables e.g. pressure, volume, temperature, internal energy, entropy. The state of a system described in this way is referred to as a macrostate. The macrostate of a system can be changed in two principal ways: we can do work on the system and/or heat can flow in. (The macrostate would also change if particles flowed into or out of the system.) The general rules governing these macroscopic variables and their inter-relationships is the subject of thermodynamics. The microscopic description considers the detailed microscopic nature of the system. At this level the system is characterised by a large number of variable which specify the state of the microscopic entities that make it up. For example, classically the state of a gas is given at any instant by the position and momentum of each particle. So for N particles we need 6N variables. This is a very large number; for 1cm3 of gas at STP, N is of order 1019. The state of a system described in this way is referred to as a microstate. The positions and momenta of the particles, and thus the microstate, evolves with time according to the laws of mechanics. Practically, we could never hope to perform such a calculation! In the quantum mechanical description a microstate will correspond to the system having a given wave function.
    [Show full text]
  • 82218-1A SP.Pdf
    Matter and Molecules Matter and Molecules A Broader and Deeper View of Chemical Thermodynamics First Edition Roberto J. Fernandez-Prini, Ernesto Marceca, and Horacio Roberto Corti Bassim Hamadeh, CEO and Publisher Amy Smith, Project Editor Berenice Quirino, Associate Production Editor Emely Villavicencio, Senior Graphic Designer Sara Schennum, Licensing Associate Natalie Piccotti, Director of Marketing Kassie Graves, Vice President of Editorial Jamie Giganti, Director of Academic Publishing Copyright © 2019 by Cognella, Inc. All rights reserved. No part of this publication may be reprinted, reproduced, transmitted, or utilized in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information retrieval system without the written permission of Cognella, Inc. For inquiries regarding permissions, translations, foreign rights, audio rights, and any other forms of reproduction , please contact the Cognella Licensing Department at [email protected]. This book was originally published in Spanish by The University Editorial of Buenos Aires (EUDEBA) as Materia y Moléculas written by Roberto Fernández-Prini, Horacio Corti, and Ernesto Marceca © 2004 by EUDEBA. Trademark Notice: Product or corporate names may be trademarks or r egistered trademarks, and are used only for identification and explanation without intent to infringe. Cover: Copyright © 2016 iStockphoto LP/Iaremenko. Printed in the United States of America ISBN: 978-1-5165-2754-0 (pbk) / 978-1-5165-2755-7 (br) x Contents List of figures 9 1 Thermodynamic background 13 1.1Introduction................................ 13 1.2Theprinciples............................... 16 1.3 Other thermodynamic state functions . 25 1.4 Qualitative relationships between thermodynamic and molecular properties................................
    [Show full text]
  • The Mathematical Structure of Thermodynamics
    The mathematical structure of thermodynamics Peter Salamon1, Bjarne Andresen2, James Nulton1, Andrzej K. Konopka3,1 1 – San Diego State University Department of Mathematics & Statistics San Diego, CA USA 92182-7720 2 – Niels Bohr Institute Universitetsparken 5 DK-2100 Copenhagen Ø Denmark 3 – BioLinguaSM Reasearch, Inc. CASSA Center 10331 Battleridge Place Gaithersburg, MD USA Introduction Thermodynamics is unique among physical and chemical descriptions of our surroundings in that it does not rely on a detailed knowledge of any interior structure of the systems1 to which it pertains but rather treats such systems as “black boxes” whose equilibrium states are determined by the surroundings with which they can coexist and which can be described by a few parameters. This feature assures that the theory holds true when the system is a collection of molecules, or a beaker of water, or a black hole. Einstein expressed this feature of thermodynamic theory in his classic quote: "Thermodynamics is the only physical theory of universal content which, within the framework of the applicability of its basic concepts, I am convinced will never be overthrown." — Albert Einstein Foremost among these basic concepts is the notion of equilibrium, the situation where the state of the system does not vary noticeably in time. The “noticeably” in the previous sentence has two complications. The first is that if this system were to be cut off from its surroundings the state would remain the same. This distinguishes equilibria from steady states. The second is the fact that the notion of equilibrium is associated with a particular time scale. Over larger periods of time, any system will eventually evolve until the final dead state of 56Fe is reached through nuclear transformations.
    [Show full text]
  • 4. Classical Thermodynamics
    4. Classical Thermodynamics “Thermodynamics is a funny subject. The first time you go through it, you don’t understand it at all. The second time you go through it, you think you understand it, except for one or two small points. The third time you go through it, you know you don’t understand it, but by that time you are used to it, so it doesn’t bother you any more.” Arnold Sommerfeld, making excuses So far we’ve focussed on a statistical mechanics, studying systems in terms of their microscopic constituents. In this section, we’re going to take a step back and look at classical thermodynamics. This is a theory that cares nothing for atoms and microscopics. Instead it describes relationships between the observable macroscopic phenomena that we see directly. In some sense, returning to thermodynamics is a retrograde step. It is certainly not as fundamental as the statistical description. Indeed, the “laws” of thermodynamics that we describe below can all be derived from statistical physics. Nonetheless, there are a number of reasons for developing classical thermodynamics further. First, pursuing classical thermodynamics will give us a much deeper understanding of some of the ideas that briefly arose in Section 1.Inparticular,wewillfocuson how energy flows due to di↵erences in temperature. Energy transferred in this way is called heat.Througharemarkableseriesofargumentsinvolvingheat,onecandeduce the existence of a quantity called entropy and its implications for irreversibility in the Universe. This definition of entropy is entirely equivalent to Boltzmann’s later definition S = kB log⌦but makes no reference to the underlying states.
    [Show full text]
  • Beyond Equilibrium Thermodynamics In
    Beyond equilibrium thermodynamics in the low temperature plasma processor Elijah Thimsena) Interface Research Group, Department of Energy, Environmental and Chemical Engineering, Washington University in Saint Louis, One Brookings Drive, Box 1180, Saint Louis, Missouri 63130 (Received 15 January 2018; accepted 8 May 2018; published 27 June 2018) Low temperature plasmas are open driven thermodynamic systems capable of increasing the free energy of the mass that flows through them. An interesting thing about low temperature plasmas is that different species have different temperatures at the same location in space. Since thermal equilibrium cannot be assumed, many of the familiar results of equilibrium thermodynamics cannot be applied in their familiar form to predict, e.g., the direction of a chemical reaction. From the perspective of classical processing governed by thermal equilibrium, examples of highly unexpected gas-phase chemical reactions (CO2 dissociation, NO, N2H4,O3 synthesis) and solid material transfor- mations (surface activation, size-focusing, and hyperdoping) promoted by low temperature plasmas are presented. The lack of a known chemical reaction equilibrium criterion prevents assessment of predictive kinetics models of low temperature plasmas, to ensure that they comply with the laws of thermodynamics. There is a need for a general method to predict chemical reaction equilibrium in low temperature plasmas or an alternative method to establish the thermodynamic admissibility of a proposed kinetics model. Toward those ends, two ideas are explored in this work. The first idea is that chemical reactions in low temperature plasmas proceed toward a thermal equilibrium state at an effective temperature intermediate between the neutral gas temperature and the electron temperature.
    [Show full text]
  • The Thermodynamic Equilibrium of Gas in a Box Divided by a Piston
    The thermodynamic equilibrium of gas in a box divided by a piston Alberto Herrera-Gomez CINVESTAV-Querétaro. Querétaro, México 76230. The equilibrium conditions of a system consisting of a box with gas divided by a piston are revised. The apparent indetermination of the problem is solved by explicitly imposing the constancy of the internal energy when the Entropy Maximum Principle is applied. The equality of the pressures is naturally concluded from this principle when the piston is allowed to spontaneously move. The application of the Energy Minimum Principle is also revised. I. Introduction The extraction from the thermodynamic principles of the equilibrium conditions for a system consisting of a gas-containing box divided by an adiabatic piston has been an elusive problem.1,2,3, It is clear that the mechanical equilibrium is reached when the pressures in both sides are equal to each other. However, how to extract this condition from the Entropy Maximum Principle has proven to be confusing. Some authors have claimed that the problem is indeterminate.1,4 Some others have even got to the (wrong) conclusion that the equilibrium is reached when the ratio of the pressure to the temperature P T is the parameter that should be equal in both sides.5,6 Many other authors also arrived to this same conclusion but adding the statement that the temperatures should also be equal to each other, thus effectively considering only the case of a diathermal wall.4,7,8 In 1969 Curzon treated this problem and tried to conclude the equality of the pressures from the maximization of the entropy.9 This work is frequently referred as the appropriate approach.1,3,10 However, the argument employed assumes that the increase of entropy is identically equal to zero, which, as discussed below and pointed out earlier,11 is equivalent to assume (not show) that the pressures are equal.
    [Show full text]
  • Introduction to Chemical Engineering: Thermodynamics of Separation Processes Notes for the Class Separation Process Technology
    Introduction to Chemical Engineering: Thermodynamics of Separation Processes Notes for the class Separation Process Technology Marco Mazzotti∗ ETH Zurich, Institute of Process Engineering, Sonneggstrasse 3, CH-8092 Zurich, Switzerland Welcome Welcome to the class Separation Process Technology. What is Chemical En- gineering about? According to the AIChE (the biggest association of chemical engineers) it is the profession in which a knowledge of mathematics, chemistry, and other natural sciences gained by study, experience, and practice is applied with judgment to develop economic ways of using materials and energy for the benefit of mankind. As this is a rather broad definition, quite a few fields do belong to chemical engineering such as chemical reactions, separation processes, biological reactions, research on thermodynamics, energy conversion, solids pro- cessing, fluid dynamics, and construction and design of equipment. Many indus- trial fields apply chemical engineering knowledge such as the chemical-, food-, pharmaceutical-, energy-, or automotive industries. This class aims at giving you a first impression and an overview over these fields by studying the following specific topics: phase equilibrium thermodynamics, liquid-vapor and liquid-solid equilibria, flash evaporation and nucleation of particles and crystals, kinetic gas theory with applications, chemical reaction engineering (including ideal reactor design). ∗Corresponding author: phone +41 44 632 2456; fax +41 44 632 11 41. Email address: [email protected] (Marco Mazzotti) Preprint submitted to Script February 20, 2020 Contents 1 Thermodynamics and Phase Equilibria 4 1.1 Introduction . .4 1.2 An axiomatic approach to thermodynamics . .4 1.2.1 Four Postulates . .4 1.2.2 Entropy Representation .
    [Show full text]
  • Thermodynamics: Clcalor Ime Try, Htheat
    Thermodynamics: ClCalor ime try, HtHeat • Physics 1 Internal Energy Internal energy (also called thermal energy) is the energy an objjpgect or substance is due to the kinetic and potential energies associated with the random motions of all the particles that make it up. The kinetic energy is, of course, due to the motion of the partilicles. T o und erstand dh the potenti ilal energy, i magi ne a solid lidi in which all of its molecules are bound to its neighbors by springs. As the molecules vibrate, the springs are compressed and stretched. (Liquids and gases are not locked in a lattice structure like this.) The hotter something is, the faster its molecules are moving or vibrating, and the high er i ts temperature. Temperature is proportional to the average kinetic energy of the atoms or molecules that make up a substance. Internal Energy vs. Heat The term heat refers is the energy that is transferred from one body or location due to a difference in temperature. This is similar to the idea of work, which is the energy that is transferred from one bdbody to anot her due to forces t hat act between t hem. Heat is internal energy when it is transferred between bodies. Technically, a hot potato does not possess heat; rather it possesses a good deal of internal energy on account of the motion of its molecules. If that potato is dropped in a bowl of cold water , we can talk about heat: There is a heat flow (energy transfer) from the hot potato to the cold water; the potato ’s internal energy is decreased, while the water’s is increased by the same amount.
    [Show full text]