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RETROFITTING ANALYSIS TO INTEGRATE THE MIXALCO® PROCESS TO THE CRUDE OIL DISTILLATION PROCESS Thesis By LAURA PATRICIA PRADA VILLAMIZAR Submitted to the Office of Graduate Studies of Universidad de Los Andes In partial fulfillment of the requirements for the degree of M.SC. CHEMICAL ENGINEERING August 2013 Major Subject: Chemical Engineering

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  • RETROFITTING ANALYSIS TO INTEGRATE THE MIXALCO PROCESS

    TO THE CRUDE OIL DISTILLATION PROCESS

    Thesis

    By

    LAURA PATRICIA PRADA VILLAMIZAR

    Submitted to the Office of Graduate Studies of

    Universidad de Los Andes

    In partial fulfillment of the requirements for the degree of

    M.SC. CHEMICAL ENGINEERING

    August 2013

    Major Subject: Chemical Engineering

  • Retrofitting analysis to integrate the MixAlco process to the crude oil distillation

    process

    Copyright 2013 Laura Patricia Prada Villamizar

  • RETROFITTING ANALYSIS TO INTEGRATE THE MIXALCO PROCESS

    TO THE CRUDE OIL DISTILLATION PROCESS

    Thesis

    By

    LAURA PATRICIA PRADA VILLAMIZAR

    Submitted to the Office of Graduate Studies of

    Universidad de Los Andes

    In partial fulfillment of the requirements for the degree of

    M.SC. CHEMICAL ENGINEERING

    Approved by:

    Chair of committee, Roco Sierra Ramrez, PhD.

    Committee Members, Jorge Mario Gmez, Phd.

    Head of Department, Oscar Alvarez Solano, PhD.

    August 2013

    Major Subject: Chemical Engineering

  • i

    ABSTRACT

    Retrofitting analysis to integrate the MixAlco process to the crude oil distillation

    process (August 2013)

    Laura Patricia Prada Villamizar, Universidad de los Andes, Colombia

    Advisor: Roco Sierra Ramrez, Ph.D.

    The MixAlco technology comprises a processing facility to produce liquid

    transportation fuels and/or value-added chemicals from biomass resources; however,

    build and run a new MixAlco plant may be very costly. On the other hand, high quality

    and easily exploitable fossil-fuels resources inevitably dwindle worldwide. Both the

    preservation of high quality fossil-fuel resources and the feasibility of a MixAlco plant

    can be importantly enhanced by retrofitting the MixAlco process into an existing

    fossil-fuel processing facility. This retrofitting is attainable because both processes have

    similar products (bio-gasoline, gasoline, bio-jet, jet). This work assesses a retrofitting

    analysis to integrate the MixAlco process to a selected case of crude oil distillation

    process (CODP). The proposed methodology suggests a hierarchy cost using the

    following tools: process simulations, mass and energy integrations, and economic

    evaluations. The work starts by assessing improvements for a base case of each of the

    two involved plants separately. Then, comparisons between base cases and the

    retrofitting of both processes (the resulting plant is regarded here as integrated bio-

    refinery) is made. The most remarkable result was a Net Present Value (NPV)

  • ii

    increment from MM USD 7.30 to MM USD15.7, and Return On Investment (ROI)

    increment from 11.1% to 12.4% for MixAlco process.

  • iii

    RESUMEN

    Retrofitting analysis to integrate the MixAlco process to the crude oil distillation

    process (August 2013)

    Laura Patricia Prada Villamizar, Universidad de los Andes, Colombia

    Advisor: Roco Sierra Ramrez, Ph.D.

    MixAlco es una tecnologa donde se producen combustibles lquidos de

    transporte y / o productos qumicos de valor agregado a partir de fuentes de biomasa, sin

    embargo, construir y operar una planta nueva de MixAlco puede ser muy costoso. Por

    otro lado, los recursos combustibles fsiles de alta calidad y fcilmente explotables

    disminuyen en todo el mundo. La preservacin de los combustibles fsiles de alta

    calidad y la viabilidad de una planta MixAlco, pueden mejorarse mediante la

    integracin del proceso MixAlco en una instalacin existente de procesamiento de

    combustibles fsiles.

    Esta integracin es posible gracias a que ambos procesos tienen productos

    similares (bio-gasolina, gasolina, bio-jet, jet). Este trabajo evala un anlisis de

    integracin entre el proceso de MixAlco con el proceso de destilacin de crudo de

    petrleo (PDCP) como caso seleccionado. La metodologa propuesta sugiere una

    jerarqua de costos con las siguientes herramientas: simulacin de procesos,

    integraciones de masa y energa, y evaluaciones econmicas. Este trabajo inicia

    evaluando mejoras para un caso base en cada una de las plantas involucradas por

  • iv

    separado. Despus, se hacen comparaciones entre los casos base y la integracin de los

    dos procesos (la planta resultante se considera como "bio-refinera integrada"). El

    resultado ms importante para el proceso de MixAlco presenta un incremento en el

    Valor Presente Neto (VPN) de MM USD 7.30 a MM USD 15.7 y un incremento en la

    tasa interna de retorno de la inversin (TIR) de 11.1% a 12.4%

  • v

    ACKNOWLEDGEMENTS

    I would like to thank my family for the love, belief, and support they have

    provided me throughout my life, especially to my mother, Laura Villamizar. She gave

    me much love and support, and thanks to my two brothers Dany and Sergio. I would like

    to thank my two big loves Guillermo and Santiago, for their compression, support and

    company all the time, especially during this work.

    I would to express my deepest gratitude to Dr. Roco Sierra, for her guidance,

    and for her patience throughout this work. Thank you for all support during my graduate

    study. I would like also to thank to all her group members for all their support and help.

    I would like also to thank Cesar Mahecha for the support that he provide me

    during this work.

  • vi

    NOMENCLATURE

    AEA: Aspen Energy Analyzer

    AFC: Annualized Fixed Cost

    AGO: Atmospheric Gas Oil

    APEA: Aspen Process Economic Analyzer

    API: Standard API gravity

    BPD: Barrel Per Day

    C: Cooler

    CE: Chemical Engineering Plant Cost Index

    CM: Compressor

    CODP: Crude Oil Distillation Process

    CON: Conveyor

    CSTR: Continually Stirred Tank Reactors

    DHFORM: Formation Enthalpy

    DW&B: Direct Wage and Benefits

    E: Heat Exchanger

    EIA: US Energy Information Administration

    FCI: Fixed Capital Investment

    FOB: Free On Board

    FOC: Fixed Operating Cost

  • vii

    GAL: U.S liquid gallon, (231 in3)

    GCC: Grand Composite Curve

    H: Heater

    HEN: Heat Exchange Network

    HVGO: Heavy Vacuum Gas Oil

    IRR: Internal Rate of Return

    INHSPCD: In-house Pure Component Database

    LVGO: Light Vacuum Gas Oil

    M: Mixer

    MACRS: Modified Accelerated Cost Recovery System

    MOC: Minimum Operating Cost

    MM: Million

    MR: Cumulative Mass Lost

    MS: Marshall and Swift Cost Index

    MSA: Mass-Separating Agent

    MTAC: Minimizing Total Annualized Cost

    MW: Molecular weight

    MW&B: Maintenance Wages and Benefits

    Net_G: Net Generation

    NF: Nelson-Farrer Refinery Construction Index

  • viii

    NPV: Net Present Value

    NREL: National Renewable Energy Laboratory

    NRTL: Non-random-two-liquid

    P: Pump

    PBP: Payback Period

    PSA: Pressure Swing Adsorption

    R: Reactor

    ROI: Return On Investment

    RKS: Redlich-Kwong-Soave

    S: Splitter

    SCF: Standard Cubic Foot

    SG: Standard specific gravity at 60F

    SP: Separator

    T: Distillation tower

    TBP: True Normal boiling point

    TCI: Total Capital Investment

    TEHL: Table of Exchangeable Heat Loads

    TID: Temperature-Interval Diagram

    TK: Tank

    TR: Turbine

  • ix

    TON: Metric ton (1,000kg)

    USD: United States dollars

    VFAs: Volatile Fatty Acids

    VLSTD: Standard Liquid MolarVolume at 60F

    VOC: Variable Operating Cost

    VP: Venture Profit

    VS: Volatile Solids

    WCI: Working Capital Investment

    WWT: Waste Water Treatment

    ZC: Critical Compressibility Factor

  • x

    TABLE OF CONTENTS

    Page

    ABSTRACT .............................................................................................................. i

    RESUMEN ................................................................................................................ iii

    ACKNOWLEDGEMENTS ...................................................................................... v

    NOMENCLATURE .................................................................................................. vi

    TABLE OF CONTENTS .......................................................................................... x

    LIST OF FIGURES ................................................................................................... xiii

    LIST OF TABLES .................................................................................................... xv

    1. INTRODUCTION ............................................................................................... 1

    2. OBJECTIVES ..................................................................................................... 5

    2.1 General objective ..................................................................................... 5

    2.2 Specific objectives ................................................................................... 5

    3. METHODOLOGY .............................................................................................. 6

    3.1 Description of the proposed methodology .............................................. 6

    3.1.1 Define needs ................................................................................. 6

    3.1.2 Process arrangements .................................................................. 7

    3.1.3 Feasibility .................................................................................... 7

    3.2 Simulation Tools ........................................................................................... 9

    3.2.1 MixAlco process base case ........................................................ 9

    3.2.2 CODP base case ............................................................................ 11

    3.2.3 MixAlco process and CODP retrofitted plant ............................ 14

  • xi

    Page

    3.3 Process integration ........................................................................................ 14

    3.3.1 Material rerouting .......................................................................... 15

    3.3.2 Heat Exchanger Network (HEN) .................................................. 16

    3.3.3 Cost Analysis................................................................................. 16

    4. RESULTS AND DISCUSSION ................................................................... 19

    4.1 Simulation results .................................................................................... 19

    4.1.1 Simulation builds up and results for MixAlco base case ......... 19

    4.1.1.1 MixAlco block description .......................................... 21

    4.1.1.2 MixAlco overall mass balance results ......................... 54

    4.1.1.3 MixAlco overall heat balance results .......................... 56

    4.1.2 Simulation builds up and results for CODP base case ................ 57

    4.1.2.1 CODP Block description ................................................ 58

    4.1.2.2 CODP overall mass balance results ............................... 68

    4.1.2.3 CODP overall heat balance results ................................. 69

    4.2 Define needs ............................................................................................ 69

    4.3 Retrofitting procedure applied: Process arrangements ............................ 70

    4.3.1 Internal rearrangements ............................................................... 70

    4.3.1.1 MixAlco process ......................................................... 70

    4.3.1.2 CODP ............................................................................. 79

    4.3.2 Internal modifications ................................................................. 84

    4.3.2.1 MixAlco process ......................................................... 84

  • xii

    Page

    4.3.2.2 CODP ............................................................................................ 95

    4.3.3 External modifications ................................................................ 103

    4.3.3.1 Case 1 ............................................................................. 105

    4.3.3.2 Case 2 ............................................................................. 110

    4.3.3.3 Comparison between cases ............................................. 123

    4.4 Sensitivity analysis .................................................................................. 125

    4.4.1 Variation of gasoline prices ......................................................... 125

    4.4.2 Variation of Jet prices ................................................................. 126

    4.4.3 Variation of Biomass prices ........................................................ 127

    4.4.4 Variation of MixAlco plant capacity ........................................ 127

    CONCLUSIONS ....................................................................................................... 129

    RECOMMENDATIONS AND FUTURE WORK ................................................... 132

    REFERENCES .......................................................................................................... 134

    APPENDIX A ........................................................................................................... 137

    APPENDIX B ........................................................................................................... 153

    APPENDIX C ........................................................................................................... 157

    APPENDIX D ........................................................................................................... 159

    APPENDIX E ............................................................................................................ 166

    VITA ................................................................................................................ 177

  • xiii

    LIST OF FIGURES

    FIGURE Page

    1-1 Pathways for converting biomass to hydrocarbon fuels .......................... 2

    3-1 Flowchart of the proposed methodology ................................................. 8

    3-2 Crude oil distillation TPB ....................................................................... 13

    4-1 Blocks of MixAlco process simulation. ............................................... 20

    4-2 Feed handling simulation ........................................................................ 23

    4-3 Pretreatment simulation ............................................................................ 25

    4-4 Fermentation simulation .......................................................................... 29

    4-5 Dewatering simulation ............................................................................ 34

    4-6 Ketonization simulation .......................................................................... 39

    4-7 Lime kiln simulation ............................................................................... 43

    4-8 Final simulation ....................................................................................... 46

    4-9 Distillation curve for gasoline ................................................................. 49

    4-10 Distillation curve for Jet ............................................................................. 50

    4-11 Gasification simulation... ........................................................................... 51

    4-12 Blocks of CODP simulation ....................................................................... 57

    4-13 First pre-heating train ................................................................................. 58

    4-14 Second pre-heating train ............................................................................. 61

    4-15 Atmospheric distillation column ............................................................... 63

    4-16 Vacuum distillation column ....................................................................... 66

    4-17 Mass integration for MixAlco process .................................................... 73

  • xiv

    FIGURE Page

    4-18 Power integration for MixAlco process .................................................. 73

    4-19 Heat integration in Reactors for MixAlco process .................................. 74

    4-20 Cash flow for MixAlco process in the base case .................................... 79

    4-21 Hot and Cold composite for MixAlco HEN............................................ 87

    4-22 Grand composite curve for MixAlco HEN ............................................. 87

    4-23 Grid diagram for MixAlco HEN ............................................................. 89

    4-24 Cash flow for MixAlco process with HEN ............................................. 95

    4-25 Hot and Cold composite for CODP HEN .................................................. 97

    4-26 Grand composite curve for CODP HEN .................................................... 97

    4-27 Grid diagram for CODP HEN .................................................................... 99

    4-28 MixAlco and CODP simulation integrated ............................................. 104

    4-29 Cash flow of MixAlco process in case 1 ................................................. 109

    4-30 Hot and Cold composite for case 2 ............................................................ 112

    4-31 Grand composite curve for case 2 .............................................................. 113

    4-32 Grid diagram for case 2 .............................................................................. 115

    4-33 Cash flow of MixAlco process in case 2 ................................................. 123

    4-34 Variation of gasoline price for MixAlco process .................................... 125

    4-35 Variation of Jet price for MixAlco process ............................................. 126

    4-36 Variation of Biomass price ......................................................................... 127

    4-37 Variation of MixAlco plant capacity ....................................................... 128

  • xv

    LIST OF TABLES

    TABLE Page

    3-1 Biomass feed composition for MixAlco process .................................... 10

    3-2 MixAlco operating conditions ................................................................. 11

    3-3 Assay data for crude oil .............................................................................. 12

    3-4 Assay data for crude oil Light ends ............................................................ 12

    3-5 CODP operating conditions ....................................................................... 13

    3-6 Feedstock, utilities and product prices ....................................................... 17

    4-1 Feed handling mass and heat balance ........................................................ 24

    4-2 Heat balances for Feed Handling equipment ............................................. 24

    4-3 Pretreatment mass and heat balance ........................................................... 27

    4-4 Fermentation mass and heat balance .......................................................... 30

    4-5 Heat balances for Pretreatment and Fermentation equipments .................. 33

    4-6 Dewatering mass and heat balance ............................................................. 35

    4-7 Heat balances for Dewatering equipments ................................................. 38

    4-8 Ketonization mass and heat balance ........................................................... 40

    4-9 Heat balances for Ketonization equipments ............................................... 42

    4-10 Heat balances for Lime kiln equipments .................................................... 43

    4-11 Lime kiln mass and heat balance ................................................................ 44

    4-12 Final mass and heat balance ....................................................................... 46

    4-13 Heat balances for Final equipments ........................................................... 49

  • xvi

    TABLE Page

    4-14 Gasification mass and heat balance ............................................................ 52

    4-15 Heat balances for Gasification equipments ................................................ 53

    4-16 MixAlco yields ........................................................................................ 54

    4-17 Summary fo heat balances for MixAlco processs ................................... 56

    4-18 First train preheating mass and heat balance .............................................. 59

    4-19 Heat balances for equipments in 1st preheating train ................................ 60

    4-20 Second train preheating mass and heat balance ......................................... 62

    4-21 Heat balances for equipments in 2nd preheating train ............................... 62

    4-22 Atmospheric distillation mass and heat balance ........................................ 64

    4-23 Heat balances for equipments in atmospheric distillation unit .................. 65

    4-24 Vacuum distillation mass and heat balance ................................................ 67

    4-25 Heat balances for equipments in vacuum distillation unit ......................... 68

    4-26 CODP Yields .............................................................................................. 68

    4-27 Overall heat balances for CODP ................................................................ 69

    4-28 Fresh MixAlco streams ........................................................................... 71

    4-29 Waste MixAlco streams .......................................................................... 72

    4-30 VOC of MixAlco process in base case.................................................... 75

    4-31 FOC of MixAlco process in base case .................................................... 76

    4-32 FIC of MixAlco process in base case ...................................................... 77

    4-33 Summary MixAlco economic results in base case .................................. 77

    4-34 Fresh CODP streams .................................................................................. 80

  • xvii

    TABLE Page

    4-35 Waste CODP Streams ................................................................................ 81

    4-36 FCI for CODP in base case ........................................................................ 82

    4-37 VOC for CODP in base case ...................................................................... 82

    4-38 FOC for CODP in base case ....................................................................... 83

    4-39 MixAlco process streams for HEN ......................................................... 85

    4-40 Heat integration for MixAlco process ..................................................... 88

    4-41 Heat exchangers for MixAlco HEN ........................................................ 90

    4-42 Coolers for MixAlco HEN ...................................................................... 90

    4-43 Heaters for MixAlco HEN ...................................................................... 91

    4-44 VOC of MixAlco process with HEN ...................................................... 92

    4-45 FOC of MixAlco process with HEN ....................................................... 93

    4-46 Summary MixAlco economic results with HEN..................................... 94

    4-47 Process streams for CODP ......................................................................... 96

    4-48 Summary of HEN cases for CODP ............................................................ 98

    4-49 Heat exchangers in the best CODP case .................................................... 100

    4-50 Coolers in the best CODP case .................................................................. 101

    4-51 Heaters in the best CODP case ................................................................... 102

    4-52 VOC of CODP with HEN .......................................................................... 102

    4-53 Heat integration for MixAlco and CODP in case 1 ................................ 106

    4-54 VOC of MixAlco process in case 1 ......................................................... 106

    4-55 FOC of MixAlco process in case 1 ......................................................... 107

  • xviii

    TABLE Page

    4-56 Summary MixAlco economic results in case 1 ....................................... 108

    4-57 Process streams for case 2 .......................................................................... 110

    4-58 Heat integration for MixAlco and CODP case 2..................................... 114

    4-59 Heat exchangers for case 2 ......................................................................... 115

    4-60 Coolers for case 2 ....................................................................................... 118

    4-61 Heaters for case 2 ....................................................................................... 119

    4-62 VOC of MixAlco process in case 2 ......................................................... 120

    4-63 VOC of CODP in case 2 ............................................................................ 120

    4-64 FOC of MixAlco and CODP in case 2 .................................................... 121

    4-65 Summary MixAlco and CODP economic results in case 2 .................... 122

    4-66 Heat integration comparison of cases ......................................................... 124

    4-67 Economic comparison of cases .................................................................. 124

  • 1

    1. INTRODUCTION

    World liquid fuels consumption grew by 0.800 MM bpd in 2012. US Energy

    Information Administration (EIA) expects consumption growth will be higher over the

    next two years, at 0.900 million bpd in 2013 and 1.20 MM bpd in 2014 (EIA, 2013).

    However, the liquid fuel production is estimated to be decline. Furthermore, the price of

    crude oil is very sensitive to international politic issues. Clearly, new alternatives for

    renewable fuels are necessary.

    The MixAlco technology, invented by Professor M. Holtzapple at Texas A&M

    University (Holtzapple, 2009), comprises a processing facility to produce liquid

    transportation fuels and/or value-added chemicals from sustainable resources.

    MixAlco converts materials such as municipal solid waste (MSW), sewage sludge,

    forest product residues, and non-edible energy crops such as sweet sorghum into a wide

    array of chemicals and secondary alcohols that can be further refined through separate,

    well-established processes to produce renewable gasoline, jet fuel or diesel. The bio-

    gasoline produced through the MixAlco technology is not ethanol. In fact, it has a

    higher energy value than ethanol and can be blended directly with gasoline produced

    from hydrocarbons. (Terrabon, 2010).

    MixAlco process comprises a fermentation stage, which employs a mixed culture

    of acid-forming microorganisms that convert biomass components (carbohydrates,

    proteins, and fats) to carboxylate salts. Depending on the choice of buffer, the salts may

  • 2

    be ammonium carboxylates (buffered by NH4HCO3) or calcium carboxylates (buffered

    by CaCO3) among others. Via pathway C in Figure 1-1, calcium carboxylates are

    thermally converted into ketones, which are subsequently hydrogenated into a mixture of

    secondary alcohols. Finally, these alcohols are chemically converted into hydrocarbon

    fuels (gasoline, jet fuel, and diesel) (Pham, Holtzapple, & El-Halwagi, 2010). In

    Appendix A, details on the MixAlco process are briefly discussed.

    Figure 1-1. Pathways for converting biomass to hydrocarbon fuels (Pham et al., 2010)

    Build and run a new plant, such as the one required for the MixAlco process, is

    very costly; however, its economic performance may be greatly enhanced by retrofitting

    analysis. This strategy comprises adding a bio-fuels plant like MixAlco process to an

    existing fossil fuel plant like a crude oil distillation process (CODP).

    Juan Camilo

  • 3

    This mechanism is beneficial for both parties because an inexpensive increase of

    the production capacity of the refinery may be obtained, while economic matters for the

    biofuels-producing plant are resolved. The systems obtained by integrating a biomass

    fuel plant to the fossil fuel plant is regarded here as bio-refineries or integrated fossil

    bio-refineries.

    Basically, CODP comprises a preheating train where crude oil is fed from the

    holding tank; then vaporized in the furnace where the combustion of a fuel is taking

    place. Finally, it is fed to the bottom of the distillation column. The distillation column is

    considered the master unit since all different cuts like light and heavy naphtha, kerosene,

    light and heavy gas oils, and atmospheric residue are separated and purified. The

    vacuum distillation unit further distills residual bottoms from the atmospheric tower,

    where different cuts can be obtained like atmospheric, light vacuum, and heavy vacuum

    gas oil. A large amount of heat is transported out to the preheating train from the

    condenser, the end products, the strippers and the pumparounds.

    The substantial energy requirement of crude oil distillation columns is met partly

    by costly utilities, such as steam and fuel for fired heaters, and partly by heat recovered

    from the process, using process-to-process heat exchange. Energy savings, therefore,

    demand not only a distillation column that is energy-efficient, but also a heat exchanger

    network (HEN) which minimizes utility costs by maximizing heat recovery. (Benali &

    Tondeur, 2011). The CODP in this work corresponds to a modified version of a

    Juan Camilo

  • 4

    distillation unit of Ecopetrol. Modifications were necessary to protect intellectual

    property rights.

    This work assesses a retrofitting analysis to integrate the MixAlco process to

    the crude oil distillation process. Focus is given to the problem of process modification

    to the crude oil distillation system by considering increase the process profitability and

    material substitution with biomass feedstocks. The approach proposed for this analysis

    was developed by B. Cormier under the advisory of Dr. M. El-Halwagi at Texas A&M

    University (Cormier, 2005). The proposed hierarchy is based on costs analysis and

    involves internal process modification, operating-condition adjustment, and feedstock

    substitution. If is needed, new units are added followed by the incorporation of new

    production lines. Then, heat and mass integration techniques are used to link the units

    and streams. (Cormier, 2005)

    The competitiveness of markets nowadays and the focus on energy efficiency

    requires improved heat-integrated process designs. Aspen Energy Analyzer (AEA)

    working in concert with flowsheet simulators such as Aspen Plus provides an easy

    environment to perform optimal heat exchanger network design and pinch analysis.

    For the economic evaluation, an Aspen Process Economic Analyzer (APEA)

    provides benefits that will be explored in this study.

  • 5

    2. OBJECTIVES

    2.1 General Objective

    Apply a retrofitting analysis to integrate into a crude oil distillation system, the

    MixAlco process using the kenitonization route.

    2.2 Specific Objectives

    Conduct process integration studies to determine cost-effective strategies for

    enhancing production incorporating the MixAlco process into the crude oil

    distillation system.

    Develop several energy and mass integration approaches and use them to induce

    synergism and to reduce cost by exchanging heat, material utilities, and by

    sharing equipment.

    Develop cost-benefit analysis to guide the decision-making process and to

    compare various production routes.

  • 6

    3. METHODOLOGY

    Results from a previous work on MixAlco process economics were used as a base

    case (Pham et al., 2012). In that work, the economics of the calcium carboxylate

    platform (pathway C in Figure 3-1) using municipal solid waste or sugarcane bagasse as

    feedstock were estimated. On this basis, the following MixAlco process features were

    used: no requirement for sterility or any external enzymes, low capital cost, and cost-

    effective dewatering, which comprise the use of an effective evaporation system, briefly

    explained in Appendix A. In the previous work, the minimum selling prices of

    hydrocarbon fuels reported can be around 1.57 USD /gal if municipal solid waste is

    available at the US average tipping fee of 45 USD/dry ton (40 ton/h plant, with internal

    hydrogen production). (Pham et al., 2012)

    Retrofitting analysis was performed using the methodology developed by Cormier &

    El-Halwagi developed on the framework of mass and energy process integration. An

    overview of the methodology is shown in Figure 3-1 (Cormier, 2005). An explanation is

    found in Section 3.1.

    3.1 Description of the proposed methodology

    3.1.1 Define needs

    In the first step for the retrofitting analysis, it is possible to define the

    opportunities in the processes that would result in an increased profitability.

    Juan Camilo

    Juan Camilo

    Juan Camilo

  • 7

    3.1.2 Process arrangements

    Figure 3-1 shows three building blocks that are arranged in order of increasing cost.

    The definition of each block is explained below (Cormier, 2005):

    - Internal rearrangements: The goal is to reach the production target using low cost

    strategies. These include process reconfiguration (e.g., stream rerouting) and

    modification of operating conditions.

    - Internal modification by adding new units: it is aimed to pursue medium-cost

    modifications. These include required addition of new units, and/or replacement of

    the existing units with new ones.

    - External modification by adding new lines: Capital-intensive strategies are

    invoked. These include the addition of new production lines.

    3.1.3 Feasibility

    Once two candidates are integrated into the current plant by heat and mass

    integration, the ROI can be calculated. The decision to go deeper into the analysis

    depends on the obtained value. (Cormier, 2005)

  • 8

    Figure 3-1. Flowchart of the proposed methodology (Cormier, 2005).

    Define needs

    Internal

    rearrangements

    only

    Simulation

    improvement

    Cost analysis

    Feasible?

    Internal

    modification by

    adding new units

    Simulation

    improvement

    Cost analysis

    Feasible?

    External

    modification by

    adding separated

    lines

    Simulation

    improvement

    Cost analysis

    Proposal to the

    company

    Feasible?

    Medium Cost

    Low Cost

    High Cost

    Redefine needs

    Internal rearrangements:

    Process Reconfiguration

    Modification of Operating Conditions

    Internal Modifications:

    Add New units

    Modification of Operating Conditions

    External Modifications:

    Add new lines

    Modification of Operating Conditions

    Yes

    Yes

    Yes

  • 9

    3.2 Simulation Tools

    Regardless to existence of specialized software for petroleum industry (Aspen

    Hysys and PRO II), Aspen Plus software was used according a specific database

    that estimates most of the desired properties of biomass.

    Initially, each one of these two base cases was simulated separately. Then, both

    plants were put together in a single worksheet to make integrations possible.

    Specificities of each of these simulation cases are given below. For all simulations, the

    following three steps were necessary:

    - Flow sheet definition: All inlet and outlet streams to the different stages in both

    the MixAlco and the CODP systems, as well as all unit operations and their

    interconnecting streams were defined.

    - Chemical components: All chemical components in the system, from reagents

    to intermediates and products were specified during simulations. Appendix B

    shows the properties for each of the substances used in the simulations..

    - Operating conditions: The operating conditions, such as temperature, pressure,

    heat duties etc., for each unit operation were specified for each process in next

    sections.

    3.2.1 MixAlco process base case.

    The simulation was made using the National Renewable Energy Laboratory

    (NREL) database In-house Pure Component Database (INHSPCD). Within this tool,

  • 10

    estimation of most of the properties of biomass components such as glucose, xylose,

    cellulose, xylan, lignin were possible. Components other than the ones listed above, are

    identified within this database as solslds. (Wooley & Putsche, 1996).

    As Wooley and Putsche, (1996) suggested, the thermodynamic package used in

    this simulation was non-random-two-liquid (NTRL), where NRTL liquid include

    activity coefficient model, Henrys law for the dissolved gases, and Redlich-Kwong-

    Soave (RKS) equation of state for the vapor phase.

    The MixAlco process simulation was made for a capacity of 40.0 ton/h of

    biomass. The biomass feedstock in the simulation was a mixture 80.0% - 20.0% w/w of

    sugarcane bagasse (like carbohydrate source) and chicken manure (like secondary

    nutrient source) respectively. Table 3-1 shows the biomass feed composition. Other

    details on the feedstock stream (e.g., properties) are shown with simulation results in

    Section 4.1.1.1.

    Table 3-1. Biomass feed composition for MixAlco process

    Component Feedstock

    ton/h %w/w

    Cellulose 16.8 43.0

    Hemicellulose (xylan) 7.50 19.0

    Lignin 10.0 25.0

    Solslds 5.20 13.0

    Total 40.0 100

    Operating conditions used for simulation of all MixAlco unit operations are

    shown in Table 3-2.

    Juan Camilo

  • 11

    Table 3-2. MixAlco operating conditions

    Process Parameter Value

    Feed handling Temperature (C) 55.0

    Pressure (bar_a) 1.00

    Pretreatment Temperature (C) 55.0

    Pressure (bar_a) 1.00

    Fermentation Temperature (C) 55.0

    Pressure (bar_a) 1.00

    Ketonization Temperature (C) 430

    Pressure (bar_a) 0.0400

    Ketone hydrogenation Temperature (C) 130

    Pressure (bar_a) 55.0

    Lime kiln Temperature (C) 500

    Pressure (bar_a) 1.00

    Alcohol dehydration Temperature (C) 300

    Pressure (bar_a) 3.00

    Oligomerization Temperature (C) 300

    Pressure (bar_a) 3.00

    Olefin hydrogenation Temperature (C) 130

    Pressure (bar_a) 55.0

    Gasification Temperature (C) 760

    Pressure (bar_a) 1.00

    Steam-gas shift Temperature (C) 254

    Pressure (bar_a) 1.00

    3.2.2 CODP base case.

    The CODP simulation was made using Grayson Streed and Braun k-10 (BK10)

    as thermodynamic packages, for a crude oil load of 27,012 bpd (162 ton/h) and 22.8

    API. Because, Grayson property methods were developed for systems containing

    hydrocarbons and light gases and BK10 property method is suited for vacuum and low

    pressure applications. (Aspen plus, 2013). Table 3-3 and 3-4 shows the assay data.

    The crude oil distillation curve is presented in Figure 3-2.

  • 12

    Table 3-3. Assay data for crude oil****

    %Distilled* Molecular Weight Specific

    Gravity

    Sulfur

    curve**

    Viscosity***

    (80C)

    Viscosity***

    (100C)

    0.929 71.0 0.646

    2.54 97.0 0.725

    5.46 116 0.759 5x10-3

    8.71 144 0.788 0.0190

    11.5 153 0.810 0.0500

    13.7 171 0.823 0.0790

    16.6 186 0.838

    21.9 206 0.862 0.322

    28.8 250 0.872

    36.6 280 0.897 0.808

    41.3 323 0.920 9.13 5.80

    44.9 357 0.921 0.995 10.3 5.79

    53.8 378 0.932 18.0 10.3

    62.1 436 0.946 1.19 43.3 22.5

    67.3 514 0.956 1.42 77.8 34.5

    85.0 1,247 1.03 289,150 31,971

    Molecular weight:

    288

    Bulk value:

    0.0488

    *Mid-percent distilled (same basis as distillation data, i.e., volume or weight)

    **Given in %w/w

    ***Given in centistokes

    ****Data supply by Ecopetrol

    Table 3-4. Assay data for crude oil Light ends**

    Component* % Mass

    C2 0.212

    C3 3.60

    IC4 5.40

    NC4 14.5

    IC5 24.4

    NC5 23.5

    Hexane 28.4

    Total % light ends in the assay 0.940

    *The number after C refers to the number of carbons in the alkane molecule. I is for iso (non-linear)

    structures and N for straight chains

    **Data supply by Ecopetrol

  • 13

    Figure 3-2. Crude oil distillation TPB

    Operating conditions used for the atmospheric and vacuum columns are shown in

    Table 3-5.

    Table 3-5. CODP operating conditions

    Process Parameter Value

    Column T-204 - Atmospheric tower

    Heat duty condenser (kJ/s) 7,206

    Tray crude feed 17.0

    Tray steam feed 19.0

    Tray number 19.0

    Condenser Partial

    Temperature tray 1 (C) 98.0

    Temperature tray 19 (C) 366

    Pressure tray 1 (bar_a) 1.70

    Pressure tray 19 (bar_a) 2.20

    Heat duty pumparound MPA (kJ/s) 5,113

    Heat duty pumparound MPACAL (kJ/s) 563

    Column T-205- Vaccum tower

    Heat duty condenser (kJ/s) 308

    Tray crude feed 7.00

    Tray steam feed 8.00

    Tray number 8.00

  • 14

    Process Parameter Value

    Condenser Partial

    Temperature tray 1 (C) 60.0

    Temperature tray 8 (C) 389

    Pressure tray 1 (bar_a) 0.0400

    Pressure tray 8 (bar_a) 0.140

    Heat duty pumparound UPA (kJ/s) 2,117

    Heat duty pumparound MPA (kJ/s) 5,874

    Heat duty pumparound MPACAL (kJ/s) 219

    3.2.3 MixAlco process and CODP retrofitted plant

    The simulation of MixAlco process and CODP integrated was made from the base

    case of each plant, so the operating conditions and feedstock properties were the same

    shown in sections 3.2.1 and 3.2.2; regarding the thermodynamic package: NTRL and

    Grayson Streed.

    3.3 Process integration

    The design of any industrial process relies on process simulators and programs for

    unit operation design. The core of process design rests on two important dimensions:

    mass and energy. Mass involves the creation and routing of chemical species in reaction,

    separation, and byproduct/waste-processing systems. These constitute the heart of the

    process and define a companys technology base. Energy provides the necessary heating,

    cooling, and shaftwork for those systems.

    Because most industrial processes are complicated, performance and economics

    depend not only on proper selection and design of individual components but also on

  • 15

    proper assembling of building blocks. Fundamental principles can guide this assembly.

    Process integration comprises all means to achieve the goals of optimal assembly and

    performance. In process integration, the unity of the entire process is emphasized.

    Pinch analysis is the most successful way to achieve energy integration; which impacts

    mainly in process economics. Mass integration, on the other hand, has received great

    attention and development, because it directly impacts process performance. (El-

    Halwagi & Spriggs, 1998).

    For this, material rerouting and heat exchanger network (HEN) were considered

    (Cormier, 2005).

    3.3.1. Material rerouting

    Mass integration is a systematic methodology that provides a fundamental

    understanding of the global flow of mass within the process and employs this

    understanding. To apply this integration the following steps were used:

    Analysis: Detect the minimum fresh resource consumption and minimum waste

    discharge streams.

    Retrofit: Modify an existing water-using network to maximize water reuse and

    minimize wastewater generation through effective process changes (Cormier,

    2005).

    For additional details about this type of integration see Appendix C.

  • 16

    3.3.2 Heat Exchanger Network (HEN)

    In the plant, heating and cooling represent an important operating cost. In order to

    minimize the operating cost for the heat utilities, heat integration is needed. The

    following multiple design objectives are pursued:

    Minimize the investment cost of the units (i.e., surface area of exchanger, heater

    and/or cooler).

    Minimize the operating cost of utilities (steam, cooling water, etc).

    Minimize the number of units (i.e., heat exchanger). (Cormier, 2005)

    In this work, energy integration was performed using Aspen Energy Analyzer

    (AEA) in compliance to all license agreements. For additional details about this type of

    integration see Appendix D.

    3.3.3 Cost Analysis

    Many technical and environmental decisions during process design are strongly

    impacted by economic factors; therefore, an essential component of any sustainable

    design is an economic analysis, which is performed on the basis of total investment and

    operating costs. (El-Halwagi, 2012). Typically, a minimum of 15.0% for the ROI is

    pursued. If this is not achievable, ROIs of 5.00 to 10.0% may be acceptable under

  • 17

    current market conditions. (Cormier, 2005) Additional details about economic analysis

    concepts are presented in Appendix E.

    In this work, the prices for feedstocks, chemicals and material disposal for

    MixAlco process were taken from Pham et al., (2012). The prices of crude oil were

    taken from the EIA official website. The utilities costs were taken from the database of

    AEA except for the steam cost, which was taken from Seider, (2004). Finally, the prices

    for refinery products were found in the EIA official website. Appendix D shows the

    price profile for these products. For Atmospheric Gas Oil (AGO) and Light Vacuum Gas

    Oil (LVGO) prices, a factor of 10% from the price of Heavy Vacuum Gas Oil (HVGO)

    was used. All these prices are shown in Table 3-6.

    Table 3-6. Feedstock, utilities and product prices

    Item Costs and Prices

    (USD / unit)

    Fee

    dst

    ock

    cost

    s

    Sugarcane bagasse (USD/ton) 60.0

    Chicken manure (USD/ton) 10.0

    Crude oil (USD/ton) 643

    Crude oil (USD/barrel) 93.4

    Quick Lime (USD/ton) 70.0

    Flocculant (USD/ton) 991

    Iodoform (USD/kg) 25.0

    CaCO3 (USD/ton) 50.0

    Material disposal (USD/ton) 18.0

    Uti

    liti

    es c

    ost

    Fired Heat (USD/ton) 2.55

    MP Steam (USD/ton) 4.36

    Cooling Water (USD/m3) 4x10-3

    LP Steam (USD/ton) 4.17

    Refrigerant (USD/m3) 0.0130

    Electricity (USD/kWh) 0.0620

    Steam @ 353C (USD/ton) 10.0

    Steam @ 454C (USD/ton) 10.0

  • 18

    Item Costs and Prices

    (USD / unit) P

    rod

    uct

    s se

    llin

    g

    pri

    ces

    Gasoline (USD/gal) 3.28

    Jet (USD/gal) 2.88

    Diesel (USD/gal) 3.75

    AGO (USD/gal) 2.40

    LVGO (USD/gal) 2.30

    HVGO (USD/gal) 2.20

    Asphalt (USD/gal) 1.30

  • 19

    4 RESULTS AND DISCUSSION

    Simulation results are presented for each one of the two base cases (MixAlco and

    COPD). This simulations were necessary in order to be able to compare MixAlco

    alone vs MixAlco retrofitted within a COPD plant. Then, the methodology for

    retrofitting (shown in Figure 3-1) will be followed, which eventually (third loop)

    conduces to the results obtained for the combined MixAlco-COPD integrated plant.

    An economic analysis is presented for each one of the integration possibilities and for

    the combined MixAlco-COPD. Extensive comparisons are presented at the end. The

    Enthalpy reported by Aspen Plus is in their standard states at 1 atm and 298.15K.

    4.1 Simulation results

    In this section, simulation building procedures as well as relevant results of each one

    of the base cases are discussed next (MixAlco base case and COPD base case).

    4.1.1 Simulation builds up and results for MixAlco base case

    The MixAlco simulation was divided in seven blocks to build up a simulation,

    as shown in Figure 4-1.

    These blocks are listed and explained below:

    1. FEED-HAN: Feed handling process

    2. PRET -FER: Pretreatment and fermentation process

    3. DEWATER: Dewatering process.

    4. KETONIZA: Ketonization and ketone hydrogenation processes.

  • 20

    5. LIME-KIL: Lime kiln process.

    6. FINAL: Dehydratation, oligomerization and saturation processes.

    7. GASIFICA: Gasification reactor, steam gas shift reactor, and adsorption process

    Figure 4-1. Blocks of MixAlco process simulation

  • 21

    4.1.1.1 MixAlco Block description

    - Feed Handling (Unit 1)

    The Feed Handling block exists only for simulation purposes and it is meant: (i) to mix

    the reacting substances (biomass, water, and lime) to prepare them for pretreatment and (ii)

    to obtain lime (Ca(OH)2) from quick lime (CaO) as shown in Equation 4-1.

    (4-1)

    Quick lime Lime

    In the actual MixAlco process, feed handling would occur simultaneously (in the

    same unit) with pretreatment. This is because the reaction in Eq. 4-1 is exothermic

    (Enthalpy of reaction obtained was 1.960kJ/s shown in Table 4-2); thus, it is advantageous

    to use the reaction heat to obtain an increase of temperature necessary for pretreatment to

    occur at a measurable rate. Because in the simulation feed handling and pretreatment were

    not put in the same unit, this fact could not be considered. Instead, an external source of

    heat was implemented for the pretreatment stage.

    Two sources for quick lime were considered: The first is CaO produced in-site and

    the second is make-up fresh quick lime. The quick lime that is produced in site comes from

    the LIME-KIL block explained in a later section. The stream that carries this reactant has

    been labeled as CAO-RECY in Figure 4-2. As shown in Table 4-1, this stream contains

    4.06 ton/h of CO2 which corresponds to 44.0% w/w of the stream composition. This gas is

  • 22

    a reaction byproduct which in the actual process is expelled as it is produced, but in this

    simulation has to be carried all the way to the end gasification block in the SP-115. The

    unit operation CON-101 is a conveyor set up to transport this recycled stream. On the other

    hand, the fresh, make-up CaO (labeled as CAO-MAKE in Figure 4-2) is purchased with a

    cost of 70.0USD/ton. The mass ratio CAO:CAO-MAKE is 1:10 which clearly shows that a

    lime recovery process is represented in a saving operating cost. In addition a water fed at a

    flow rate of 2ton/h, stream labeled as H2O-LIME in Figure 4-2 was considered.

    For the reaction (Eq. 4-1, occurring in R-101), a conversion factor of 1 was

    employed, although the reactants (i.e., water and quick lime) were fed in exact

    stoichiometric amounts (i.e., no reactant was fed in excess). (Gosseaume, 2011).

    Two streams leave this block: (i) Stream 1(OUT) in Figure 4-2 required for the

    reactor convergence and after a mixing unit (TK-101) (ii) Stream (BIOM-LIM(OUT))

    which is the stream that contains biomass mixed with water and lime and goes to

    pretreatment.

    Results from mass and heat balance in the simulation for this block are shown per

    stream in Table 4-1. On the other hand, the heat balance for the equipment in this block is

    shown in Table 4-2, where the conveyor power consumption is very low.

  • 23

    Figure 4-2. Feed handling simulation

  • 24

    Table 4-1. Feed handling mass and heat balance

    BIOMASS CA-BIO CA-BIOM CAO CAO-MAKE CAO-RECY H20-LIME

    Temperature (C) 25.0 55.0 55.0 55.0 55.0 55.0 25.0

    Pressure (bar_a) 1.00 1.00 1.00 1.00 1.00 1.00 1.00

    Mass vapor fraction 0 0.0800 0.0800 0.440 0 0.440 0

    Mass solid fraction 0.870 0.820 0.820 0.560 1.00 0.560 0

    Mass flow (ton/h) 39.5 51.6 51.6 9.24 0.900 9.24 2.00

    Enthalpy (kJ/s) 80,720 120,205 120,205 26,310 2,824 26,310 8,809

    Component mass flow (ton/h)

    CELLU-01 16.8 16.8 16.8 0 0 0 0

    XYLAN 7.50 7.50 7.50 0 0 0 0

    LIGNI-01 10.0 10.0 10.0 0 0 0 0

    SOLSL-01 5.17 5.17 5.17 0 0 0 0

    SOLUN-01 0 0 0 0 0 0 0

    WATER 0 0.0500 0.0500 0 0 0 2.00

    CO2 0 4.06 4.06 4.06 0 4.06 0

    CA(OH)2 0 8.03 8.03 0 0 0 0

    CAO 0 0 0 5.18 0.900 5.18 0

    Table 4-2. Heat balances for Feed Handling equipment

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Reactor R-101 -1,541 -5.55x106

    Conveyor CON-101 0.750 2.7 x103

  • 25

    - Pretreatment and Fermentation (Unit 2)

    Lignocellulosic materials are resistant to the enzymatic degradation, because cellulose

    and hemicelluloses (carbohydrates) are encapsulated by lignin, which keeps the enzymes

    secreted by the microorganisms from reaching it. Pretreatment is necessary to remove

    lignin and enable the fermentation step. (Gosseaume, 2011). The pretreatment simulation

    is shown in Figure 4-3. For pretreatment conditions 400 ton/h of fresh water stream

    (labeled as H2O-PRET in Figure 4-3) was required. Also a blower (CM-101) was

    simulated for bring the air in the pretreatment slurry (6.70ton/h).

    Figure 4-3. Pretreatment simulation

  • 26

    Due to the complex reaction in pretreatment stage, the reactor R-102 was simulated

    in two ways: (i) the first way (for mass balance) was through Ryield, based on known yield

    of the exit current. And (ii) the second way (for heat balance) was through Rstoic in order

    to calculate the endothermic heat of reaction that was 14,044kJ/s shown in Table 4-5.

    For the Rstoic reactor was assumed a conversion factor of 15.0% (Eq. 4-2), 35.0%

    (Eq. 4-3) and 30.0% (Eq. 4-4) for cellulose, xylan and lignin in the undigested biomass

    (Mixed), respectively (Sierra, Garca, & Holtzapple, 2010). These conversions were based

    on a study of lime pretreatment of poplar wood at laboratory scale. Based on previous

    studies of MixAlco process at different capacities as Holtzapple, (2004), it is assumed

    that yields are not affected by the scaling capacity. The biomass undigested conversion is

    0.200 ton per ton of biomass VS, (in stream BIOM-LVS, 34.9 ton/h is biomass VS)

    resulting in 8.80 ton/h of undigested biomass, that is directed to gasification process

    (labeled as BIOM-LV in Figure 4-3). The remaining biomass is digested (Cisolid) (labeled

    as BIOM-S in Figure 4-3) and continued to fermentation process.

    In this stream the theorical conversion of 0.800 ton of digested biomass per ton of

    biomass VS is satisfied, resulting in 26.1 ton/h.

    CELLU-01(Cisolid) --> CELLU-01(Mixed) (4-2)

    XYLAN (Cisolid) --> XYLAN (Mixed) (4-3)

    LIGNI-01(Cisolid) --> LIGNI-01(Mixed) (4-4)

    In fermentation process the biomass digested (labeled as BIOM-LV in Figure 4-3

    and 4-4) is converted in carboxylates salts using as a buffer CaCO3. The fermentation

    simulation is shown in Figure 4-4.

  • 27

    Table 4-3. Pretreatment mass and heat balance

    AIR AIR2 AIRR BIOM-LIM BIOM-LV BIOM-LVS BIOM-S H20-PRET

    Temperature (C) 25.0 30.5 30.5 55.0 55.0 55.0 55.0 25.0

    Pressure (bar_a) 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00

    Mass vapor fraction 1.00 1.00 1.00 0.0770 0 0 0 0

    Mass solid fraction 0 0 0 0.820 0.0200 0.0760 1.00 0

    Mass flow (ton/h) 6.70 6.70 6.70 51.6 416 442 26.1 400

    Enthalpy (kJ/s) 3.46x10-13 10.4 10.4 120,205 1,854,269 1,910,655 56,386 1,761,927

    Component mass flow (ton/h)

    CELLU-01 0 0 0 16.8 2.80 17.0 14.2 0.0

    XYLAN 0 0 0 7.50 2.80 7.80 5.00 0.0

    LIGNI-01 0 0 0 10.0 3.20 10.1 6.90 0.0

    SOLSL-01 0 0 0 5.2 5.00 5.00 0 0

    WATER 0 0 0 0.0 402 402 0 400

    CO2 0 0 0 4.10 0 0 0 0

    CA(OH)2 0 0 0 8.00 0 0 0 0

    NITROGEN 5.30 5.30 5.30 0 0 0 0 0

    O2 1.40 1.40 1.40 0 0 0 0 0

    Two sources for calcium carbonate were considered: The first is CaCO3 recycled from KETONIZA block and the second is

    make-up fresh CaCO3. The flow rate of CaCO3 recycled is 6.30 ton/h as shown in Table 4-4; this stream is labeled as CACO3REC in

    Figure 4-4. The make-up flow rate is 9.30 ton/h (labeled as MK-CACO3 in Figure 4-4) and is purchased with a cost of 50.0 USD/ton.

    The CaCO3 recycled represent 40.0% of CaCO3 consumption resulting in a saving operating cost.

  • 28

    The conversion factors for the serial reactions performed in the fermentation train

    (R-103 to R-105) are shown in Table A-1 (Gosseaume, 2011). Besides, the reactions in

    fermentation process are shown in Equations A-1 to A-11. The salts in solution are

    obtained in the stream called SALTS shown in Figure 4-4, with a total flow rate of 25.1

    ton/h as shown in Table 4-4. A theorical conversion is getting for 0.600 ton of carboxylate

    salts per ton of biomass feed. The stream residue from fermentation (BIOMASS) with a

    flow of 16.1 ton/h goes to a gasification process. Table 4-4 shows the material balance for

    this stage. In addition a water fed at a flow rate of 200 ton/h, stream labeled as H2O-FERM

    in Figure 4-4 was considered. The global heats of reaction are exothermic for reactor R-

    103, R-104, R-105 (with enthalpies 1,051kJ/s; 768 kJ/s; 278kJ/s respectively); and

    endothermic for reactor R-106 (with enthalpy 6,480kJ/s). Table 4-5 shows the summary of

    heat equipment loads.

    Finally, a water cooling circuit is simulated in order to quantify the cost of those

    equipment for improve the cost analysis of this process.

    Results from mass and heat simulation for this block are shown per stream in Table

    4-4. On the other hand, heat balances for this block shows a power consumption of 40.4kW

    (Table 4-5). For a heat integration study the heat exchangers simulated in this block were

    assumed as coolers for count the cooling water utility in the operating cost, that why the

    total cooling required in this block is 7,957 kJ/s.

  • 29

    Figure 4-4. Fermentation simulation

  • 30

    Table 4-41. Fermentation mass and heat balance

    BIO-SAL BIO-SAL1 BIO-SAL2 BIO-SAL3 BIOM1 BIOM2 BIOM3 BIOMASS

    Temperature (C) 55.0 55.0 55.0 55.0 55.0 55.0 55.0 55.0

    Pressure (bar_a) 1.01 1.01 1.01 1.01 1.01 1.01 1.01 1.01

    Mass vapor fraction 0 0.0100 0.0170 0.0210 0.147 0.302 0.418 0.486

    Mass solid fraction 0.177 0.129 0.0890 0.0590 0.853 0.698 0.582 0.514

    Mass flow (ton/h) 247.6 236.4 227.5 220.9 22.0 18.8 17.0 16.1

    Entalphy (kJ/s) -991,492 970,009 951,047 934,782 52,274 49.090 47,282 46,334

    Component mass flow (ton/h)

    CELLU-01 8.80 4.60 2.20 1.00 8.80 4.60 2.20 1.00

    XYLAN 3.10 1.60 0.80 0.400 3.10 1.60 0.800 0.400

    LIGNI-01 6.90 6.90 6.90 6.90 6.90 6.90 6.90 6.90

    WATER 200.5 200.3 200.1 200.1 0 0 0 0

    CO2 3.20 5.70 7.10 7.80 3.20 5.70 7.10 7.80

    CA(OH)2 0 0 0 0 0 0 0 0

    CACO3 1.30 3.20 3.90 2.50 0 0 0 0

    CA(CH-01 19.2 11.4 5.40 1.90 0 0 0 0

    CA(CH-02 1.40 1.00 0.30 0.100 0 0 0 0

    CA(CH-03 3.30 1.80 0.90 0.200 0 0 0 0

    (Continued Table 4-4)

    CACO3 CACO3-1 CACO3-2 CACO3-4 CACO3-5 CACO3REC CW-1 CW2 CW3 CW4

    Temperature (C) 55.0 37.3 37.3 37.3 37.3 130 25.0 31.1 25.0 31.1

    Pressure (bar_a) 1.00 1.00 1.00 1.00 1.00 7.60 1.00 0.800 1.00 0.800

    Mass vapor fraction 0 0 0 0 0 0 0 0 0 0

    Mass solid fraction 1.00 1.00 1.00 1.00 1.00 1.00 0 0 0 0

    Mass flow (ton/h) 6.30 3.90 3.90 3.90 3.90 6.30 301.8 301.8 301.8 301.8

  • 31

    CACO3 CACO3-1 CACO3-2 CACO3-4 CACO3-5 CACO3REC CW-1 CW2 CW3 CW4

    Entalphy (kJ/s) 21,066 13,018 13,018 13,018 13,018 20,949 1.33x106

    Component mass flow (ton/h)

    CELLU-01 0 0 0 0 0 0 0 0 0 0

    XYLAN 0 0 0 0 0 0 0 0 0 0

    LIGNI-01 0 0 0 0 0 0 0 0 0 0

    WATER 0 0 0 0 0 0 301.8 301.8 301.8 301.8

    CO2 0 0 0 0 0 0 0 0 0 0

    CA(OH)2 0 0 0 0 0 0 0 0 0 0

    CACO3 6.30 3.90 3.90 3.90 3.90 6.30 0 0 0 0

    CA(CH-01 0 0 0 0 0 0 0 0 0 0

    CA(CH-02 0 0 0 0 0 0 0 0 0 0

    CA(CH-03 0 0 0 0 0 0 0 0 0 0

    (Continued Table 4-4)

    CW5 CW6 CW6 CW7 CW8 H2O H20-FERM H20-PRET MK-CACO3 SAL-H2O SALT3

    Temperature (C) 25.0 31.1 31.1 25 31.1 41.1 50.0 25.0 25.0 55.0 55.0

    Pressure (bar_a) 1.00 0.800 0.800 1.00 0.800 0.800 1.00 1.00 1.00 2.06 1.01

    Mass vapor fraction 0 0 0 0 0 0 0 0 0 0 0

    Mass solid fraction 0 0 0 0 0 0 0 0 1.00 0.112 0.0800

    Mass flow (ton/h) 302 302 302 302 302 200 200 400.0 9.30 225.6 217.6

    Entalphy (kJ/s) 1.33x106 877,480 875,520 1,761,927 31,006 939,210 921,027

    Component mass flow (ton/h)

    CELLU-01 0 0 0 0 0 0 0 0 0 0 0

    XYLAN 0 0 0 0 0 0 0 0 0 0 0

    LIGNI-01 0 0 0 0 0 0 0 0 0 0 0

    SOLSL-01 0 0 0 0 0 0 0 0 0 0 0

    WATER 302 302 302 302 302 200 200 400 0 200 200

  • 32

    CW5 CW6 CW6 CW7 CW8 H2O H20-FERM H20-PRET MK-CACO3 SAL-H2O SALT3

    CO2 0 0 0 0 0 0 0 0 0 0 0

    CA(OH)2 0 0 0 0 0 0 0 0 0 0 0

    CACO3 0 0 0 0 0 0 0 0 9.30 1.30 3.20

    CA(CH-01 0 0 0 0 0 0 0 0 0 19.2 11.4

    CA(CH-02 0 0 0 0 0 0 0 0 0 1.40 1.00

    CA(CH-03 0 0 0 0 0 0 0 0 0 3.30 1.80

    (Continued Table 4-4)

    SALT4 SALT5 SALTS SALW1 SALW2 SALW3 SALW4 SALW5 SALW6

    Temperature (C) 55.0 55.0 55.0 46.3 55.0 46.3 55.0 46.3 55.0

    Pressure (bar_a) 1.01 1.01 1.01 1.86 2.06 1.86 2.06 1.86 2.06

    Mass vapor fraction 0 0 0 0 0 0 0 0 0

    Mass solid fraction 0.0490 0.0230 0.112 0.0800 0.0800 0.0490 0.0490 0.0230 0.0230

    Mass flow (ton/h) 210 205 226 218 218 210 210 205 205

    Entalphy (kJ/s) 903,943 888,661 939,217 922,979 921,020 905,896 903,936 890,613 888,653

    Component mass flow (ton/h)

    CELLU-01 0 0 0 0 0 0 0 0 0

    XYLAN 0 0 0 0 0 0 0 0 0

    LIGNI-01 0 0 0 0 0 0 0 0 0

    SOLSL-01 0 0 0 0 0 0 0 0 0

    WATER 200 200 200 200 200 200 200 200 200

    CO2 0 0 0 0 0 0 0 0 0

    CA(OH)2 0 0 0 0 0 0 0 0 0

    CACO3 3.90 2.50 1.30 3.20 3.20 3.90 3.90 2.50 2.50

    CA(CH-01 5.40 1.90 19.2 11.4 11.4 5.40 5.40 1.90 1.90

    CA(CH-02 0.300 0.100 1.40 1.00 1.00 0.300 0.300 0.100 0.100

    CA(CH-03 0.900 0.200 3.30 1.80 1.80 0.900 0.900 0.200 0.200

  • 33

    Table 4-5. Heat balances for Pretreatment and Fermentation equipments

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Cooler C-101 117 4.21x105

    Heat Exchanger E-101 1,960 7.06x106

    Heat Exchanger E-102 1,960 7.06x106

    Heat Exchanger E-103 1,960 7.06x106

    Heat Exchanger E-104 1,960 7.06x106

    Pumps P-101 7.50 2.70x104

    Pumps P-102 7.50 2.70x104

    Pumps P-103 7.50 2.70x104

    Pumps P-104 7.60 2.70x104

    Compresor CM-101 10.4 3.74x104

    Reactor R-102 14,044 5.06x107

    Reactor R-103 -1,051 -3.78x106

    Reactor R-104 -768 -2.76x106

    Reactor R-105 -278 -1.00x106

    Reactor R-106 6,480 2.33x107

    - Dewatering (Unit 3)

    Dewatering block exits only for simulated the water separation from the produced

    fermentation broth, using a vapor compression. Figure 4-5 shows the block simulation.

    The fermentation broth labeled as SALT-H20 comes 25.1 ton/h of salt plus 200 ton/h of

    water. A six train of heat exchangers and separators are used to simulate the vapor

    compression system, where the steam separated in the first train is compressed for recycling

    in the process. The separated water (labeled as WATDISTI in Figure 4-5) is a waste water

    stream. The separated salts labeled as SALTDES continued to ketonization process.

    Others packing units are simulated in order to quantify the cost of that equipment for

    improve the cost analysis of this block.

  • 34

    Results from mass and heat simulation for this block are shown per stream in Table 4-6. On the other hand, heat balances for this block

    shows power consumption for compressor CM-102 of 1,214 kW. A heating load required in this block is 113,763 kJ/s (Table 4-7)

    Figure 4-5. Dewatering simulation

  • 35

    Table 4-62. Dewatering mass and heat balance

    SAL-DESC SAL-H20 SAL1 SAL2 SAL3 SAL4 SAL5 SAL6 SALT SALT-H20

    SALT-

    WAT

    Temperature (C) 55.0 55.0 162 162 163 165 165 162 163 150 55.0

    Pressure (bar_a) 2.06 2.06 6.00 6.50 6.60 6.90 7.00 6.50 6.00 1.90 2.10

    Mass vapor fraction 0 0 0 0 0 0 0 0 0 0.900 0

    Mass solid fraction 0.112 0.112 1.00 1.00 1.00 1.00 1.00 1.00 1.00 0.100 0.100

    Mass flow (ton/h) 225.6 225.6 4.20 4.20 4.20 4.20 4.20 4.20 25.2 225.6 225.6

    Enthalpy (kJ/s) 939,210 939,210 10,431 10,431 10,431 10,431 10,431 10,431 62,572 796,918 939,210

    Component mass flow (ton/h)

    WATER 200 200 0 0 0 0 0 0 0 200 200

    CACO3 1.30 1.30 0.200 0.200 0.200 0.200 0.200 0.200 1.30 1.30 1.30

    CA(CH-01 19.2 19.2 3.20 3.20 3.20 3.20 3.20 3.20 19.2 19.2 19.2

    CA(CH-02 1.40 1.40 0.200 0.200 0.200 0.200 0.200 0.200 1.40 1.40 1.40

    CA(CH-03 3.30 3.30 0.500 0.500 0.500 0.500 0.500 0.500 3.30 3.30 3.30

    (Continued Table 4-6)

    SALTDE

    S

    SALWR

    1

    SALWR

    2

    SALWR

    3

    SALWR

    4

    SALWR

    5

    SALWR

    6

    SALWR

    7

    SALWR

    8

    SALWR

    9

    SALWR1

    0

    SALWR1

    1

    Temperature (C) 163 150 150 150 150 150 150 165 165 165 165 165

    Pressure (bar_a) 6.00 1.90 1.90 1.90 1.90 1.90 1.90 7.00 7.00 7.10 7.40 7.50

    Mass vapor

    fraction 0 0.900 0.900 0.900 0.900 0.900 0.900 0 0 0 0 0

    Mass solid

    fraction 1.00 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0.100

    Mass flow

    (ton/h) 25.2 37.6 37.6 37.6 37.6 37.6 37.6 37.6 37.6 37.6 37.6 37.6

    Enthalpy (kJ/s) 62,572 132,846 132,846 132,846 132,846 132,846 132,846 132,846 132,846 132,846 132,846 132,846

  • 36

    SALTDE

    S

    SALWR

    1

    SALWR

    2

    SALWR

    3

    SALWR

    4

    SALWR

    5

    SALWR

    6

    SALWR

    7

    SALWR

    8

    SALWR

    9

    SALWR1

    0

    SALWR1

    1

    Component mass flow (ton/h)

    WATER 0 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4

    CACO3 1.30 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200

    CA(CH-01 19.2 3.20 3.20 3.20 3.20 3.20 3.20 3.20 3.20 3.20 3.20 3.20

    CA(CH-02 1.40 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0.200

    CA(CH-03 3.30 0.500 0.500 0.500 0.500 0.500 0.500 0.500 0.500 0.500 0.500 0.500

    (Continued Table 4-6)

    SALWR12 SALWR13 SALWR14 SALWR15 SALWR16 SALWR17 SALWR18 ST2 ST3 ST4 ST5

    Temperature (C) 164 162 162 163 165 165 162 177 175 172 170

    Pressure (bar_a) 7.00 6.50 6.50 6.60 6.90 7.00 6.50 9.30 8.80 8.30 7.80

    Mass vapor fraction 0 0.1 0 0 0 0 0 1 1 1.00 1.00

    Mass solid fraction 0.100 0.100 0.100 0.100 0.100 0.100 0.100 0 0 0 0

    Mass flow (ton/h) 37.6 37.6 37.6 37.6 37.6 37.6 37.6 33.4 33.4 33.4 33.4

    Enthalpy (kJ/s) 151,669 150,843 151,649 151,649 151,649 151,649 151,649 121,929 121,971 122,015 122,061

    Component mass flow (ton/h)

    WATER 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4

    CACO3 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0 0 0 0

    CA(CH-01 3.20 3.20 3.20 3.20 3.20 3.20 3.20 0 0 0 0

    CA(CH-02 0.200 0.200 0.200 0.200 0.200 0.200 0.200 0 0 0 0

    CA(CH-03 0.500 0.500 0.500 0.500 0.500 0.500 0.500 0 0 0 0

  • 37

    (Continued Table 4-6)

    ST6 ST7 STEAMM WAT1 WAT2 WAT3 WAT4 WAT5 WAT6 WATDISTI WATER

    Temperature (C) 167 166 230 163 162 163 164 165 162 60.0 162

    Pressure (bar_a) 7.30 7.10 9.80 6.00 6.50 6.60 6.90 7.00 6.50 5.50 6.50

    Mass vapor fraction 1.00 1.00 1.00 1.00 1.00 1.00 0.0 1.00 1.00 0 1.00

    Mass solid fraction 0 0 0 0 0 0 0 0 0 0 0

    Mass flow (ton/h) 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 200 200

    Enthalpy (kJ/s) 122,110 122,130 120,971 122,185 122,193 122,185 122,185 122,185 122,185 875,450 733,155

    Component mass flow (ton/h)

    WATER 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 33.4 200 200

    CACO3 0 0 0 0 0 0 0 0 0 0 0

    CA(CH-01 0 0 0 0 0 0 0 0 0 0 0

    CA(CH-02 0 0 0 0 0 0 0 0 0 0 0

    CA(CH-03 0 0 0 0 0 0 0 0 0 0 0

    - Ketonization (Unit 4)

    Ketonization simulation is shown in Figure 4-6; and Table 4-8 shows the material balance. In ketonization block the carboxylate

    salts (labeled as SALDEH in Figure 4-6) are converted into ketones (labeled as KET-CACO in Figure 4-6) by a thermal conversion at

    high temperatures (430C), and vacuum pressure (30 mmHg); producing 9.60 ton/h of ketones. The conversion factor for the serial

    reactions performed in the reactor R-107 was 0.99 (Gosseaume, 2011). The reactions in ketonization are shown in Equations A-12 to

    A-16 (Appendix A).

  • 38

    Table 4-7. Heat balances for Dewatering equipments

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Heater H-101 18,956 6.82x107

    Heater H-102 18,956 6.82x107

    Heater H-103 18,956 6.82x107

    Heater H-104 18,956 6.82x107

    Heater H-105 18,956 6.82x107

    Heater H-106 18,983 6.83x107

    Heat Exchanger E-105 142,292 5.12x108

    Heat Exchanger E-106 958 3.45x106

    Heat Exchanger E-107 42.0 1.51x105

    Heat Exchanger E-108 44.0 1.58x105

    Heat Exchanger E-109 46.0 1.66x105

    Heat Exchanger E-110 48.0 1.73x105

    Heat Exchanger E-111 20.0 7.20x104

    Compressor CM-102 1,214 4.37x106

    By the thermal conversion 14.2 ton/h of calcium carbonate was produced. The

    carbonate produced (labeled as CACO3 in Figure 4-6) leaves this block to a LIME-KIL

    block explained in the next section.

    Followed by ketonization, a ketone hydrogenation process continued to produce

    alcohols. In reactor R-108 the conversion factor for serial reactions was 1 (Gosseaume,

    2011). The equations for hydrogenation are shown in (Appendix A) Eq. A-17 to A-22. The

    hydrogenation conditions are high pressure (55 bar) and isothermal (130C). The net

    demand of hydrogen is 0.0290 ton H2/ton mixed alcohol, and it is produced in gasification

    block explained in last section.

  • 39

    The reaction for R-107 is endothermic with enthalpy 4,580kJ/s, but the reaction for R-108 is exothermic with enthalpy -2,615

    kJ/s, then heat integration is possible to study. Table 4-9 shows the summary of heat equipment loads. On the other hand, heat balances

    for this block shows a power consumption of 1,309 kW for pumps and compressor (Table 4-9). The cooling demand in this block is

    4,792kJ/s and the heating demand is 4,003 kJ/s.

    Figure 4-6. Ketonization simulation

    Table 4-8. Ketonization mass and heat balance

    ALCOHOL CACO3 H2 H2-1 H21 KET KET-CACO KETO KETONES

  • 40

    ALCOHOL CACO3 H2 H2-1 H21 KET KET-CACO KETO KETONES

    Temperature (C) 130 130 43 130 961 130 430 133 130

    Pressure (bar_a) 55.0 7.60 0.900 54.8 55.0 7.60 0.0400 55.0 7.60

    Mass vapor fraction 0.0190 0 1.00 1.00 1.00 0 0.38 0 0

    Mass solid fraction 3x10-3 1.00 0 0 0 0.619 0.619 3x10-3 3x10-3

    Mass flow (ton/h) 10 15.5 0.340 0.340 0.340 25.2 25.2 9.6 9.6

    Enthalpy (kJ/s) 12,226 51,675 24 142 1,640 61,455 57,409 9,754 9,779

    Component mass flow (ton/h)

    CACO3 0 15.5 0 0 0 15.5 15.5 0 0

    CA(CH-03) 0.0300 0 0 0 0 0.0300 0.0300 0.0300 0.0300

    HYDROGEN 0.0500 0 0.340 0.340 0.340 0 0 0 0

    ACETONE 0 0 0 0 0 7.00 7.00 7.00 7.00

    BUTANONE 0 0 0 0 0 0.200 0.200 0.200 0.200

    HEXANONE 0 0 0 0 0 0 0 0 0

    PENTANON 0 0 0 0 0 0.500 0.500 0.500 0.500

    HEPTANON 0 0 0 0 0 0 0 0 0

    NONANONE 0 0 0 0 0 1.90 1.90 1.90 1.90

    ISOPROPANOL 7.20 0 0 0 0 0 0 0 0

    BUTANOL 0.180 0 0 0 0 0 0 0 0

    HEXANOL 2x10-3 0 0 0 0 0 0 0 0

    PENTANOL 0.560 0 0 0 0 0 0 0 0

    HEPTANOL 0.0100 0 0 0 0 0 0 0 0

    NONANOL 1.90 0 0 0 0 0 0 0 0

    (Continued Table 4-8)

  • 41

    KETS KT-CACO3 OH SAL-DEH SALT SALTS

    Temperature (C) -14.6 -15 300 163.1 430 430

    Pressure (bar_a) 7.80 0.0400 3.00 6.00 5.50 5.50

    Mass vapor fraction 0 0 0.997 0 0 0

    Mass solid fraction 0.619 0.619 3x10-3 1.00 1.00 1.00

    Mass flow (ton/h) 25.2 25.2 10.0 25.2 25.2 25.2

    Enthalpy (kJ/s) 62,893 62,896 9,711 62,572 61,989 61,989

    Component mass flow (ton/h)

    CACO3 15.5 15.5 0 1.30 1.30 1.30

    CA(CH-01 0 0 0 19.2 19.2 19.2

    CA(CH-02 0 0 0 1.40 1.40 1.40

    CA(CH-03 0.0300 0.0300 0.0300 3.30 3.30 3.30

    HYDROGEN 0 0 0.0500 0 0 0

    ACETONE 7.00 7.00 0 0 0 0

    BUTANONE 0.200 0.200 0 0 0 0

    PENTANON 0.500 0.500 0 0 0 0

    NONANONE 1.90 1.90 0 0 0 0

    ISOPROPANOL 0 0 7.22 0 0 0

    BUTANOL 0 0 0.180 0 0 0

    PENTANOL 0 0 0.560 0 0 0

    HEPTANOL 0 0 0.0200 0 0 0

    NONANOL 0 0 1.91 0 0 0

  • 42

    Table 4-9. Heat balances for Ketonization equipments

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Heater H-107 583 2.10x106

    Heater H-108 905 3.26x106

    Heater H-109 2,515 9.05x106

    Cooler C-102 3,629 1.31x107

    Cooler C-103 1,163 4.19x106

    Pumps P-105 3.10 1.12x104

    Pumps P-106 25.2 9.07x104

    Compressor CM-103 1,281 4.61x106

    Reactor R-107 4,580 1.65x107

    Reactor R-108 -2,615 -9.41x106

    - Lime kiln (Unit 5)

    In LIME KIL block the calcium carbonate labeled as CACO3 that come from

    KETONIZA block is divided in two streams: (i) the stream labeled as CACO3-2 with a

    flow of 9.20 ton/h is converted into quick lime (CaO). And (ii) the second stream labeled as

    CACO3-1 with a flow of 6.30 ton/h is recycled to a PRET-FER block for Fermentation

    process as was explained in that block before. The lime kiln simulation is shown in Figure

    4-7. The conversion factor for Equation 4-5 in the reactor R-109 is 1, with an

    endohothermic enthalpy of 4,529 kJ/ (Gosseaume, 2011). Table 4-11 shows the mass and

    heat balance of this process.

    (Eq. 4-5)

  • 43

    Figure 4-7. Lime kiln simulation

    Table 4-10. Heat balances for Lime kiln equipments

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Cooler C-104 521 1.88x106

    Heater H-110 987 3.55x106

    Reactor R-109 4,529 1.63x107

  • 44

    Table 4-11. Lime kiln mass and heat balance

    CACO3 CACO3-1 CACO3-2 CACO3-3 CAO CAO-CO2

    Temperature (C) 130 130 130 500 500 55.0

    Pressure (bar_a) 7.60 7.60 7.60 1.00 1.00 1.00

    Mass vapor fraction 0 0 0 0 0.440 0.440

    Mass solid fraction 1.00 1.00 1.00 1.00 0.560 0.560

    Mass flow (ton/h) 15.54 6.3 9.24 9.24 9.24 9.24

    Enthalpy (kJ/s) 51,675 20,949 30,725 29,738 25,209 26,310

    Component mass flow (ton/h)

    CO2 0 0 0 0 4.06 4.06

    CACO3 15.54 6.30 9.24 9.24 0 0

    CAO 0 0 0 0 5.18 5.18

    - Final (Unit 6)

    The final block includes the mixed alcohols (stream labeled as OH in Figure 4-8)

    conversion produce hydrocarbon fuels by alcohols dehydration olefins oligomerization

    (product stream labeled as OLF-C9-12 in Figure 4-8) and olefin hydrogenation (product

    stream labeled as PARAFIN in Figure 4-8). The final block simulation is shown in Figure

    4-8.

    The alcohols dehydration from stream labeled OH to produced 7.30 ton/h of olefins C3

    to C9 stream labeled as OLF-C3-9 in Figure 4-8, occurred in reactor R-110, where the

    conversion factor is 1 for the reactions shown in Appendix A (Eq. A-23 to A-28)

    (Gosseaume, 2011). The heat duty for an endothermic reaction is 1,892kJ/s (Table 4-13).

    The olefins produced in R-110 goes to a Oligomerization process to produced 7.30

    ton/h of olefins C3 to C12 stream labeled as OLF-C3-12 in Figure 4-8, these reactions were

    present in reactor R-111. In Table A-2 (Appendix A) are shown the conversion factors for

  • 45

    reactions by the Equations A-29 to A-36.The heat duty for an exothermic reaction is -

    1,645kJ/s (Table 4-13).

    To improve fuel quality, the olefins labeled as OLEFIN in Figure 4-8 were

    hydrogenated to make 7.30 ton/h of corresponding paraffins (stream labeled as PARAFIN

    in Figure 4-8) in reactor R-112, where the conversion factor is 1 (Gosseaume, 2011).

    Olefin hydrogenation reactions are presented in Equations A-37 to A-45 (Appendix A).

    And the heat duty for an exothermic reaction is -2,421kJ/s (Table 4-13). In this block, the

    net demand of hydrogen is 0.0190 ton H2/ton hydrocarbon fuels; this hydrogen is produced

    in gasification block explained in the next section.

    Finally, the hydrocarbon fuel labeled as HC in Figure 4-8 is distilled into C8- and C9+

    fractions. The light fraction and the heavy fraction can be used as blending components for

    gasoline and jet fuel, respectively, as Pham et al., (2012) mentioned. A ratio of 53 gallons

    of light fraction per ton of biomass is obtained for a total of 2,127 gallon/h of gasoline. And

    for heavy fraction the ratio is 19 gallons per ton of biomass for a total of 762 gallon/h of jet.

    Table 4-12 shows the material balance of the entire block. On the other hand, heat

    balances for this block shows a power consumption of 997 kW for compressor CM-104 and

    CM-105 (Table 4-13). The cooling demand in this block is 4,470kJ/s and the heating

    demand is 1,536kJ/s.

    Figure 4-9 shows a comparison between the gasoline obtained by MixAlco and a

    mixture of light naphtha (LVN) and gases fossil fuel consulted in an article of Cartagena

    refinery (Fernndez, 2007). The gasoline curve obtained by MixAlco had a similar

    behavior of LVN except for gas fraction.

  • 46

    Figure 4-8. Final simulation

    Table 4-12. Final mass and heat balance

    C3 H2 H2- H2-1 H20 HC HC-C4--8 HC-C9-12 HEAVY LIGHT

    Temperature (C) 130 43 961 130 300 130 266 408 25 25

    Pressure (bar_a) 55.0 0.900 55.0 55.0 3.00 55.0 50.0 53.0 1.00 1.00

    Mass vapor fraction 0.770 1.00 1.00 1.00 1.00 0 0 0 0 0

    Mass solid fraction 0.230 0 0 0 0 0 0 0 0 0

    Mass flow (ton/h) 0.130 0.100 0.100 0.100 2.60 7.40 5.30 2.10 2.10 5.30

    Enthalpy (kJ/s) 32.0 7.97 537 537 9.17 4.04 2,081 481 1,228 3,382

    Component mass flow (ton/h)

  • 47

    C3 H2 H2- H2-1 H20 HC HC-C4--8 HC-C9-12 HEAVY LIGHT

    WATER 0 0 0 0 2.60 0 0 0 0 0

    CA(CH-03 0.0300 0 0 0 0 0 0 0 0 0

    HYDROGEN 0 0.100 0.100 0.100 0 0 0 0 0 0

    C3H6 0.100 0 0 0 0 0 0 0 0 0

    C4H10 0 0 0 0 0 0.0900 0.0900 0 0 0.0900

    C5H12 0 0 0 0 0 0.200 0.20 0 0 0.200

    C6H14 0 0 0 0 0 4.73 4.73 0 0 4.73

    C7H16 0 0 0 0 0 0.0300 0.0300 0 0 0.0300

    C8H18 0 0 0 0 0 0.230 0.230 0 0 0.230

    C9H20 0 0 0 0 0 1.41 0 1.41 1.41 0

    C10H22 0 0 0 0 0 0.0400 0 0.0400 0.0400 0

    C11H24 0 0 0 0 0 0.190 0 0.190 0.190 0

    C12H26 0 0 0 0 0 0.450 0 0.450 0.450 0

    (Continued Table 4-12)

    OH OLEFIN OLF OLF-C3-9 OLF-DEH OLFC3-12 PARAFIN

    Temperature (C) 300 130 399.9 300 300 300 130

    Pressure (bar_a) 3.00 54.5 55.0 3.00 3.00 3.00 55.0

    Mass vapor fraction 0.997 0.0390 0.996 0.997 0.996 0.997 7x10-3

    Mass solid fraction 3x10-3 4x10-3 4x10-3 3x10-3 4x10-3 3x10-3 4x10-3

    Mass flow (ton/h) 10.0 7.40 7.40 10.0 7.40 10.0 7.50

    Enthalpy (kJ/s) 9,711 1,699 287 7,819 289 9,464 4,073

    Component mass flow (ton/h)

    WATER 0 0 0 2.56 0 2.56 0

    CA(CH-03 0.030 0.030 0.030 0.030 0.030 0.030 0.030

  • 48

    OH OLEFIN OLF OLF-C3-9 OLF-DEH OLFC3-12 PARAFIN

    HYDROGEN 0.050 0.050 0.050 0.050 0.050 0.050 0.010

    ISOPROPANOL 7.22 0 0 0 0 0 0

    BUTANOL 0.180 0 0 0 0 0 0

    HEXANOL 0 0 0 0 0 0 0

    PENTANOL 0.560 0 0 0 0 0 0

    HEPTANOL 0.0200 0 0 0 0 0 0

    NONANOL 1.91 0 0 0 0 0 0

    C3H6 0 0.100 0.100 5.05 0.100 0.100 0.101

    C4H8 0 0.0900 0.0900 0.140 0.0900 0.0900 0

    C5H10 0 0.190 0.190 0.450 0.190 0.190 0

    C6H12 0 4.62 4.62 0.00 4.62 4.62 0

    C7H14 0 0.0300 0.0300 0.0100 0.0300 0.0300 0

    C9H18 0 1.38 1.38 1.67 1.38 1.38 0

    C8H16 0 0.230 0.230 0 0.230 0.230 0

    C10H20 0 0.0400 0.0400 0 0.0400 0.0400 0

    C11H22 0 0.180 0.180 0 0.180 0.180 0

    C12H24 0 0.450 0.450 0 0.450 0.450 0

    C4H10 0 0 0 0 0 0 0.0900

    C5H12 0 0 0 0 0 0 0.200

    C6H14 0 0 0 0 0 0 4.73

    C7H16 0 0 0 0 0 0 0.0300

    C8H18 0 0 0 0 0 0 0.230

    C9H20 0 0 0 0 0 0 1.41

    C10H22 0 0 0 0 0 0 0.0400

    C11H24 0 0 0 0 0 0 0.190

    C12H26 0 0 0 0 0 0 0.450

  • 49

    Table 4-13. Heat balances for Final equipments

    Type Unit Heat duty [kJ/sec] Heat duty [kJ/h]

    Heater Reboiler T-101 1,536 5.53x106

    Cooler C-105 381 1.37x106