Design of a plant producing 500,000 tonnes/annum synthetic oil from natural gas, using Fischer-Tropsch technology

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CPD NR

3287

Conceptual Process Design

Process Systems Engineering

DelftChemTech - Faculty of Applied Sciences Delft University of Technology

Subject

Final Report

Design of a plant producing 500,000 tonnes/annum

synthetic oil from natural gas, using Fischer-Tropsch

technology

Authors Study

nr.

Telephone

Berg, Ronald van den 9055041

015-2624681

Horzen, Wessel van

9366536 06-41395145

Pijl, Leon

9675059

010-2900886

Taoukil, Rachid

9823844 071-5313335

Vons, Vincent

9903067

06-21604467

Keywords

Fischer-Tropsch, synthetic oil, natural gas, Delft Design

Matrix, Autothermal Reforming, Hydrocracking, Crude

Distillation

Assignment issued

:

19/02/2003

Report issued

:

16/05/2003

Appraisal

: 03/06/2003

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Group Conceptual Process Design Project, CPD3287

Table of Contents

Table of Contents iii

Design Space 0

DS0 - Report of Design Space 0 1

R001 - Practical Implementation of Creative Methods 4

R003 - PIQUAR 8

R004 – Group Roules 12

R005 - Summary group evaluation results 15

R006 - Explanation of Time Table 18

Design Space 1

R102 - Product Specifications 7

R103 - DOW Fire and Explosion Index DS1 17

R104 - Waste and By-Product Streams 20

R105 - Process Economics 21

R106 - European Environmental Legislation 25

R107 - Utilities and Auxiliaries 29

R108 – Preliminary Mass Balances 30

Design Space 2

R202 - Synthesis Gas Production 8

R201 - Fischer Tropsch Synthesis 14

R203 - Product Workup 20

R204 - Mass Balances 26

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Table of Contents iv

Design Space 3

R301 - Syngas Tasks and Means 6

R302 - FT Tasks and Means 10

R303 - Hydrocracking processes 15

R304 - Economics, Calculation of Financial Margin 18

R305 - Blockscheme Integration and Alternatives 20

R306 - Aspen Modeling 28

Design Space 4

R4 - U101 - Autothermal Reformer 5

R4 – U102 – Recovery of Syngas 19

R4 – U201 – Fischer Tropsch 25

R4 – U203 – Settler 37

R4 – U301 – Hydrocracker 41

R4 – U303 – Product Fractioning 54

R4 – U Flash - Flash Units 65

R4 – U Heater - Heating and Cooling Units 69

R4 – U Pumps – Compressors 75

R4 – Aspen Simulation and Flowsheet 80

Design Space 5

R501 - Flowsheet Adaptation and Aspen Recycle Connection 4

R502 – Control, Safety and Pollution 8

R504 – Pinch Technology 13

R503 - Economics 22

Design Space 6

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Group Conceptual Process Design Project, CPD3287 Table of Contents Table of Contents v R6 – S107 - Membrane 7 R6 – R201 – Fischer Tropsch 15 R6 – R303 - Hydrocracker 28 R6 – C402 - Fractioning 38 R6 – Flash Vessels 62

R6 – Heat Exchangers and Burners 69

R6 – Pumps, Compressors and Turbines 73

R6 - Design Economics and Economic Criteria 77

Design Space 7

R701 – Control 4

R702 – Safety 8

R703 – Startup and Shutdown 11

Design Space 8

Creativity, Work Process and Tools Evaluation (DS9)

R901 - Creativity, Work Process and Tools Evaluation 1

Conclusions

xi

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Table of Contents vi

Table of Content of Appendices

Table of Content of Appendices Ai

APP A1 – Project Description A1

Design Space 0

APP001 - Group Formation Figures A1

APP002 - Creative methods and their implementations A2

APP003 - All available PIQUAR Criteria A4

APP004 - List of PIQUAR criteria of designers and principal A8

APP005 – Group Profile A9

APP006 - Gantt Chart A10

Design Space 1

APP101 - DOW Fire and Explosion Index DS1 A1

APP102 - Economic Calculations A2

APP103 - Quality of Water A4

Design Space 2

APP201 - AFS Distribution A1

APP202 - Mass Balances DS2 A3

Design Space 3

APP301 - Final block scheme Design Space 3 A1

APP302 - Hydrogen Excess Calculations A2

APP303 - Economics A3

APP304 - Overall (Simplified) Block Scheme A4

APP305 - Guidelines for Choosing Property Method A5

APP306 - Thermodynamic Graphs Syngas Area A7

APP307 - Thermodynamic Graphs FT Area A8

APP308 - Thermodynamic Graphs HC Area A9

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Table of Contents vii

APP311 - Aspen AFS Distribution A16

Design Space 4

APP401 – Block Scheme A1

APP402 – U102 - Mathcad A2

APP403 – Cobalt Price A3

APP404 – U201 - Calculations A4

APP405 – U203 – Settler Calculations A5

APP406 - Schematic Representation of Settler A6

APP407 - U203 - k and Ea Adiabatic Calculations A7

APP408 – U303 - Fractioning A10

Design Space 5

APP501 – Flowsheet A1

APP502 – HC Calculations A2

APP503 - Aspen Fractioning Recycle A4

APP504 - Pinch A5

Design Space 6

APP601 – Preliminary Flowsheet A1

APP602 – Unit from Block Scheme To PFS A2

APP603 – Equipment Data Summary Sheets A3

APP604 – ATR Price A22

APP605 – S107 - Calculations A23

APP606 – Fischer Tropsch Simulation A26

APP607 – R201 Internal A30

APP608 – R201 Economics A31

APP609 – R303 Calculations A32

APP610 – C402 Final design A35

APP611 – Flash Dimensioning A48

APP612 – Heat exchangers and burner A51

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Table of Contents viii

APP614 – Design Economics and Economic Criteria A54

APP615 – Equipment Data Specification Sheets A58

Design Space 7

APP701 – Flowsheet DS7 A1

APP702 – Control Systems A2

Design Space 8

APP801 – Final Preliminary Flowsheet DS8 and Blockscheme A1

APP802 – Stream Tables DS8 A2

APP803 – Pure Component Properties A19

Creativity, Work Process and Tools Evaluation (DS9)

APP901 – Creative team meeting CM501 A1

APP903 – Overview Iterations A5

APP904 – Gantt Planning A7

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Table of Contents2 A-i

Table of Content of Appendices

Table of Content of Appendices Ai

APP A1 – Project Description A1

Design Space 0

APP001 - Group Formation Figures A1

APP002 - Creative methods and their implementations A2

APP003 - All available PIQUAR Criteria A4

APP004 - List of PIQUAR criteria of designers and principal A8

APP005 – Group Profile A9

APP006 - Gantt Chart A10

Design Space 1

APP102 - Economic Calculations A2

APP103 - Quality of Water A4

Design Space 2

APP201 - AFS Distribution A1

APP202 - Mass Balances DS2 A3

Design Space 3

APP301 - Final block scheme Design Space 3 A1

APP302 - Hydrogen Excess Calculations A2

APP304 - Overall (Simplified) Block Scheme A4

APP305 - Guidelines for Choosing Property Method A5

APP306 - Thermodynamic Graphs Syngas Area A7

APP307 - Thermodynamic Graphs FT Area A8

APP308 - Thermodynamic Graphs HC Area A9

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Table of Contents2 A-ii

APP311 - Aspen AFS Distribution A16

Design Space 4

APP401 – Block Scheme A1

APP402 – U102 - Mathcad A2

APP403 – Cobalt Price A3

APP404 – U201 - Calculations A4

APP405 – U203 – Settler Calculations A5

APP406 - Schematic Representation of Settler A6

APP407 - U203 - k and Ea Adiabatic Calculations A7

APP408 – U303 - Fractioning A10

Design Space 5

APP501 – Flowsheet A1

APP502 – HC Calculations A2

APP503 - Aspen Fractioning Recycle A4

APP504 - Pinch A5

Design Space 6

APP601 – Preliminary Flowsheet A1

APP602 – Unit from Block Scheme To PFS A2

APP603 – Equipment Data Summary Sheets A3

APP604 – ATR Price A22

APP605 – S107 - Calculations A23

APP606 – Fischer Tropsch Simulation A26

APP607 – R201 Internal A30

APP608 – R201 Economics A31

APP609 – R303 Calculations A32

APP610 – C402 Final design A35

APP611 – Flash Dimensioning A48

APP612 – Heat exchangers and burner A51

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Table of Contents2 A-iii

APP614 – Design Economics and Economic Criteria A54

APP615 – Equipment Data Specification Sheets A58

Design Space 7

APP701 – Flowsheet DS7 A1

APP702 – Control Systems A2

Design Space 8

APP801 – Final Preliminary Flowsheet DS8 and Blockscheme A1

APP802 – Stream Tables DS8 A2

APP803 – Pure Component Properties A19

Creativity, Work Process and Tools Evaluation (DS9)

APP903 – Overview Iterations A5

APP904 – Gantt Planning A7

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Preface

Preface i

Preface

Why try to find the right words to describe the 12 weeks of work needed to produce this Conceptual Process Design when someone else has put it in the right phrase already. It was the Victorian thinker John Ruskin (1819-1900) who stated that;

Quality is never an accident; it is always the result of high intention, sincere effort, intelligent direction and skillful execution; it represents the wise choice of many alternatives, the cumulative experience of many masters of craftsmanship. Quality also marks the search for an ideal after necessity has been satisfied and mere usefulness achieved.

All the aspects Ruskin mentions are more or less applicable on this design. The high intention was set when the task was given to redo the CPD of a TWAIO group. Sincere efforts have been invested to gain enough knowledge on the many areas covered by the GTL process. Intelligent directions were provided both by the new design method DDM and the valuable assistance of the principle, Ir. P.L.J. Swinkels and the DDM specialist Austine Ajah.

Many alternatives have been generated. Care has been taken to document the different alternatives and to clarify the choices made.

Whether the execution of the design has been skillful and intelligent is up to the reader to decide.

[CPD3287]

Ronald van den Berg Wessel van Horzen Leon Pijl

Rachid Taoukil Vincent Vons

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Summary

Summary ii

Summary

This preliminary plant design has been made for the course Conceptual Process Design, which is part of the curriculum of Chemical Engineering at the Delft, University of Technology. The plant was designed using the methodology of the Delft Design Matrix. This is a highly structured framework that aims to increase creativity input and the effectiveness of design.

The Conceptual Process Design is a Fischer-Tropsch synthesis process. The process is able to produce 500,000 tonnes/annum of diesel and kerosene. The process begins with an autothermal reformer that produces synthesis gas. The synthesis gas is fed to a Fischer-Tropsch reactor, where it is converted to linear hydrocarbons. These are led into a hydrocracker, where heavy hydrocarbons are cracked and all hydrocarbons are isomerized. Then, finally, the hydrocarbons are fractionated in a distillation section, where the products diesel and kerosene are split off. Naphtha is also split off as a by-product.

The process is completely composed of units that are considered proven in industry. This rectifies the annual on-stream hours of 8000 hours. The annual production is: 241 ton diesel, 220 ton kerosene and 53 ton naphtha. The overall yield of the process is 68% (defined as [tons of product]/[tons of natural gas]). The total investment costs are 56 MUSD. The gross income is 66 MUSD. The annual production cost is 128 MUSD. This leads to a negative cash flow of –61 MUSD. The financial margin is also negative: –23 MUSD.

The variables, for which the sensitivity of the cash flow is greatest, are the prices of natural gas (93 USD/ton), diesel (120 USD/ton) and kerosene (135 USD/ton). The NCF will become 0 at a natural gas price of 22 USD/ton. It will also become 0 at a price of kerosene and diesel of respectively 298 and 257 USD/ton.

It is important to notice that waste heat might be utilized for electricity

generation. Calculations performed in Design Space 8 indicate, that the annual revenues could be around 100 MUSD. This would mean that the process would be profitable.

There’s a hydrogen purge stream in the steam. This stream is contaminated with carbon dioxide. If the carbon dioxide is removed, the stream can be sold as hydrogen.

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Abbreviations xiii

List of Abbreviations

AAA Advanced Activity Assistant

AFS Anderson-Flory-Schulz (distribution)

ASTM American Society for Testing and Materials

ATR Auto Thermal Reformer

BLEVE Boiling Liquid Expanding Vapor Explosion

BOD Basis of Design

CFD Computational Fluid Dynamics

CPD Conceptual Process Design

CPO Catalytic Partial Oxidation

CR Combined Reforming

DCFROR Discounted Cash Flow Rate of Return

DDM Delft Design Matrix

Dfl Dutch florin DS Design Space DS 0 Design Space 0 DS 1 Design Space 1 DS 2 Design Space 2 DS 3 Design Space 3 DS 4 Design Space 4 DS 5 Design Space 5 DS 6 Design Space 6 DS 7 Design Space 7 DS 8 Design Space 8

EOS models Equation Of State models

EP European Patent

F&EI Fire and Explosion Index

FT(S) Fischer-Tropsch (Synthesis)

GTL Gas To Liquid

HC Hydrocracking HC Hydrocrack(er)(ing) HP steam High Pressure steam (40 bar) HT Hydrotreating HTFT High Temperature Fischer-Tropsch

I/O Input Output

LP steam Low Pressure steam (3 bar)

LPG Liquid Petrol Gas

LTFT Low Temperature Fischer-Tropsch

MAC Maximum Allowable Concentration

MD Middle Distillates

MF Material Factors

MP Medium Pressure

MP steam Medium Pressure steam (10 bar)

MPDO Maximum Probable Days Out

MPPD Maximum Probable Property Damage

MUSD Million U.S. Dollars

NCF Negative Cash Flow

NFPA National Fire Protection Association

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Abbreviations xiv NPSH Net Positive Suction Head

PENG-ROB Peng Robinson

PFR Plug Flow Reactor

PIQUAR Plant design Improvement by QUAlity Review

POX Partial Oxidation

PR Peng Robinson

PRMVH2 Peng Robinson of state with modified Huron-Vidal mixing

PSE Process Systems Engineering

PSRK Predictive Redlich-Kwong-Soave equation of state

RKS-BM Redlich-Kwong-Soave equation of state with Boston-Mathias modifications

SBCR Slurry Bubble Column Reactor

SMR Steam Methane Reformer

SR-POLAR Schwartentruber-Renon equation of statefor highly non-ideal systems

Syngas Synthesis gas

TBP True Boiling Point

TFBR Tubular Fixed Bed Reactor TU Delft Delft, University of Technology U&A Utilities and auxiliaries

UNIFAC Unified Activity Coefficients model UNIF-DMD UNIFAQ modified by Dortmund UNIF-LBY UNIFAQ modified by Lungby

UNIF-LL UNIFAC for liquid-liquid systems with Redlich-Kwong equation of state and Henry’s law

USD United States of America Dollar VLE Vapor Liquid Equilibrium

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Introduction

Introduction ix

`

Introduction

The conceptual process design (CPD) is one of the most important and

challenging aspects of the work of a chemical engineer. It involves the design of an integrated process for the manufacturing of certain substances. The

conceptual process design often turns out to be a difficult task for students. This is because there are so many designs possibilities that the engineering student tends to drown in the wealth of information.

The goal of this conceptual process design, performed as part of the course CPD1 by a group of five students, is a conceptual process design for a plant that

produces 500,000 tons/annum of synthetic oil (in particular diesel and kerosene) from natural gas using the Fischer-Tropsch synthesis.

This CPD project (CPD-3287) is rather special. As a way of tackling the design, a new concept is used. Based on the hierarchal decomposition method of Douglas the Delft Design Matrix (DDM) was developed. The aim of this new method is to increase the creative input and the effectiveness of design. The extended

structure of the DDM aims to avoid short-circuiting at an early stage of the design, when flowsheets are proposed to soon, for instance based on existing flowsheets and units. The structure of the DDM is illustrated in the following table.

Table 1. The Delft Design Matrix

Level/generic

Design cycle Scope of Design

Knowledge

of Objects Synthesis Analysis Evaluation Report of Design

Go/No-go

Phase _{I II} _{III IV V} _VI_VII

0. Group formation process 1. Supply chain related input/output/ structure 2. Sub-processes (type, connection, and input output structure) 3. States (physical & chemical) and tasks 4. Unit operations 5. Process wide integration (heat, solvent) 6. Equipment design 7 System integration (safety, control) 8 Flow sheet optimization Final PFD Final

BoD Models Flow sheet Y.F.A H.E.S.Econ S.W.O.T Go?

1_{Conceptual Process Design (st4931), a 4}th_{year’s course for students studying} Chemical Process Technology at the Delft University of Technology, the

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Introduction

Introduction x

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To measure the effectiveness of the new method and compare it with the method as described by Douglas, this group was assigned an older CPD project,

previously performed by TWAIO’s in 1998. As a part of his Master’s thesis Austine Ajah monitors the group and aids the group in the use of the DDM. Later he will compare the two designs. Ir. Pieter Swinkels will act as the project principal and the creativity/group process coach.

Appendix A contains the project description. In short the assignment is to make a design for a plant producing 500,000 tonnes/annum synthetic oil products from natural gas using Fischer-Tropsch (FT) technology. Recently the old FT synthesis has gained renewed interest. This is because of the possibility of producing liquid and thus better transportable fuels from natural gas. The large amounts of natural gas require that the products of the plant must have a large market. The target products of this plant are therefore kerosene (C10-C14) and diesel (C15-C20).

At this moment (1998) it is very difficult to compete with the production of middle distillates derived from crude oil. This is because natural gas is not an

inexpensive feedstock and the plant itself has both high investment and operational costs. It is believed that the Fischer-Tropsch process will become economically feasible in a relatively short time period (20 years or less). This is thought because in the anticipated future shrinking oil reserves and dwindling crude oil production will raise the price for diesel and kerosene while the prices for natural gas will remain relatively unchanged. Strict regulations and more pressure from environmental organizations and the public will also increase demand for the cleaner Fischer-Tropsch fuels. The produced synthetic oils are very clean, because of low sulphur and nitrogen content in the feedstock.

Although the plant is situated in Brunei, South-East Asia, European emission rules are used. This is part of the corporate policy to use EU safety and emission

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Conclusion

Conclusion _xi

Conclusion

Design

Appendix A contains the project description. In short the assignment is to make a design for a plant producing 500,000 tonnes/annum synthetic oil products

(naphtha, kerosene and diesel) from natural gas using Fischer-Tropsch (FT) technology. Recently the old FT synthesis has gained renewed interest. This is because of the possibility of producing liquid and thus better transportable fuels from natural gas. The large amounts of natural gas processed require the

products of the plant to have a large market. The target products of this plant are therefore kerosene (C10-C14) and diesel (C15-C20), for which a large market exists.

First synthesis gas is produced from natural gas and pure oxygen in an Auto Thermal Reformer. A relatively small amount of hydrogen is extracted from the synthesis gas stream by membranes, in order to supply hydrogen for

hydrocracking later on. This synthesis gas is then converted to hydrocarbons in Low Temperature Slurry Bubble Fischer Tropsch reactors. Unconverted synthesis gas, together with carbon dioxide is partially returned to the ATR. Water formed in the FTS-reactors is also partially recycled to the ATR feed.

Liquid hydrocarbons, mostly in the wax range (C20+), are hydrocracked and isomerised to C5-C20 length. These are subsequently distilled using atmospheric distillation producing several fractions, ready to be sold as products. Unconverted wax is sent back to the hydrocracker. Fuel gas and LPG formed during FT

synthesis and hydrocracking are used as fuel in preheating of the ATR and hydrocracker feed.

Production quantity was met, but not all of the product specifications were met. There is insufficient isomerisation of the hydrocracker feed, which results in poor cold weather performance for kerosene and diesel. Increasing the temperature of the hydrocracker or the use of additives could possibly raise the cold weather performance up to specifications. On all other requirements the products meet the specifications set by the principal. Hardly any sulphur and aromatics are present; the product consists primarily of paraffins. The diesel has a high cetane number and the kerosene has a high smoke point.

Due to the nature of the reactions employed, large amounts of carbon dioxide and water are produced. Purification of the water is required due to dissolved hydrocarbons, but the purification is assumed to be performed outside the boundary limits. The CO2 will be discharged into the atmosphere.

The financial margin turned out to be negative. This is because of the high natural gas price in relation to product prices. The variables, for which the sensitivity of the cash flow is greatest, are the prices of natural gas (93 USD/ton), diesel (120 USD/ton) and kerosene (135 USD/ton). The Net Cash Flow (NCF) will become 0 at a natural gas price of 22 USD/ton. It will also become 0 at a price of kerosene and diesel of respectively 298 and 257 USD/ton. It is expected that within several years the prices of high-quality diesel and kerosene will rise.

It is important to notice that waste heat might be utilized for electricity

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Conclusion

Conclusion _xii

revenues from electricity generation could mount up to approximately 100 MUSD. Utilization of this waste heat could render the process profitable.

Delft Design Matrix

As mentioned in the introduction our group was the first to use the DDM during the conceptual design of a process. The following strengths and weaknesses of the DDM method were noticed.

One of the strongest points of the DDM was that it helps the user create a structured and efficient thinking pattern. It initially prevents one from going into too much detail. The Delft Design Matrix has had a great influence upon the working and reporting structure. Due to this new design methodology design rationale is presented more clearly. It also helps in distributing the workload between team members.

This group could not find serious flaws in the DDM; although certain design spaces and their requirements still need to be specified more clearly. In the beginning some problems occurred with the terminology and the forced

structured thinking. Later on this turned out to be a benefit because it was very efficient. The Delft Design Matrix proved itself to be a good guide during

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Report of design space 1

Description of Report Reference

Report of design space 1 (DS 1) DS 1

Version Author Date Description

1.0 LP 06/03/2003 First draft

1.1 LP 17/03/2003 Revision

1.2 LP 31/03/2003 Deleted feed and prod specs. and added options for waste streams H2O and CO2

1.3 RvdB 01/04/2003 Revision

1.4 LP 01/04/2003 R108 conclusions inserted

1.5 LP 23/04/2003 PIQUAR inserted

Summary

This report is about the results of Design Space 1. In this level of the Delft Design Matrix (DDM, [1]) the supply chain related input/output structure is defined.

Scope of Design

In this phase the designer defines the design space, which comprises of a number of objects:

1. Type of objects: - Plant inside - Facilities outside - Storage

2. Boundaries of the system - Natural environment - Suppliers and customers C:\Documents and Settings\Ronald\My

Documents\CPD3287\Reports\DS 1\DS 1.doc Page 1 of 6

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- Local authorities - Personnel - Capital

3. Exchange streams with the environment: - Feed stock (Natural gas from Brunei) - Product (Diesel and Kerosene)

- By-products (Naphtha and LPG)

- Auxiliaries (steam, air) and utilities (steam, air, cooling water)

4. Constraints on, and targets for the structure, scale, and (physical) behavior of the system:

- Function of the process is to be production of syntroleum products out of natural gas.

- Product specifications are given by the principal of the project. - Is there a pattern in production (seasonal demands)?

- Specs

- Production of products using the Fischer-Tropsch process.

- If possible heavy by-products are preferred above light by-products. These heavy by-products are to be treated in a hydro cracker to produce diesel and kerosene.

- Location constraints including safety, environmental and infrastructure. - Annual production hours.

- Only technical and economic data from before 1999 is to be used. - Economic potential

- Availability and education level of personnel - Availability of capital

- Quality control using PIQUAR as agreed with principal

5. Identifying the variables that characterize the objects in the design space and their topology:

- Stream compositions (concentration, pressure and temperature). - Feedstock reliability and availability.

- Market price for products and by-products. - Mode of delivery for each stream.

- Mode of operation (batch or continuous). - Annual production time

- Product split

- Annual production capacity

6. Identifying restrictions on the design stage itself with respect to manpower time available, and money.

- DS 1 is done by a team of 5 students and is to be finished on Friday 07/03/2003. Total hours: 6x5x8=240, actually used 159 hours. - DS 1 is part of the Basis of Design report, that is to be submitted on

Wednesday 25/03/2003

C:\Documents and Settings\Ronald\My

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Knowledge of objects

1. Identifying suitable objects:

The object of this design space, the supply chain input and output related

structure, is very much restricted. The input and output for the total process are a restriction of this project. The synthesis for this design space shall be very limited. The feedstock and its mode of delivery, the process to be used and the output stream are already defined. The only variables left to be specified are the mode of delivery for the output, the mode of operation and the annual production time.

2. Knowledge that is available and knowledge that is not available on these objects: - The feed stream is completely defined by the principal and its properties

are listed in R102. The mode of delivery shall be through pipeline. The feedstock is natural gas from Brunei.

- Information about product quality that is needed. As listed in R102. - The utilities and auxiliaries are to be defined (R107).

- The mode of operation for this process should be defined.

- The market price for products and by-products should be investigated. - The EU (Dutch) emission rules should be used. As a corporate policy,

safety regulations from Europe (The Netherlands) should be used. These rules are to be defined and future developments are to be examined. - Composition and prices of products as listed in R102 and R105. - Pure component properties as in R307.

3. Tools:

- Synthesis, analysis and evaluation:

o Not many variables need to be manipulated, so there are no tools needed for synthesis.

o To analyze the design space a number of tools will be used. o The Dow fire and explosion index shall be used to analyze the risk

of this process.

o The PIQUAR tool will be used to keep an eye on the quality of the design.

o An economic evaluation will be made of the process for this design space.

Synthesis, Analysis and Evaluation

The synthesis for this design space is limited, because of the large amount of constraints on the process. The feedstock and product specifications are set and listed in R102. The input output structure of the plant concluded from reports R101

to R107 is schematically shown in figure 1.

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Figure 1. Input/output structure for design space 1

For each stream a report was written. Furthermore the legislation for emissions was examined. The brainstorm session was summarized in a report. For the analysis of this design space a Dow fire and explosion index was made and an economic evaluation was carried out. On basis of figure 1 preliminary mass balances were calculated. The following reports listed were made for design space 1.

- R101 - Summary brainstorm session DS1

- R102 – Feedstock, product, byproduct specifications - R103 - DOW fire and explosion index

- R104 - Waste and by-product streams - R105 – Economics

- R106 - European environmental legislation - R107 - Utilities and auxiliaries

- R108 – Preliminary mass balances

Also a start was made with the Pure Component Properties. The DOW F&EI was calculated in F&EI DS 1.

The main conclusions for these reports are:

• The process shall be operated continuously.

• To reach the product specifications isomerization of Fischer-Tropsch products is needed.

• It’s not that viable to sell your diesel just as a cetane booster for poorer diesel. Except if there is a large on location demand for our diesel by another part of the plant.

• As much as possible water from the FT process must be recycled. If the water is pure enough it can maybe be sold as drink- or irrigation water. • Selling naphtha, LPG, gas-oil and wax as byproducts will depend on the

economics for the process. C:\Documents and Settings\Ronald\My

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• CO2 will probably be discharged into the atmosphere, since there are no stringent environmental guidelines that prohibit the emission. Depending on its purity it may also be sold.

• For NOx emission limitations were found.

• The auxiliaries en utilities to be used are steam, oxygen, furnace fuel, cooling water/oil and electricity.

• The use of auxiliaries and utilities should be minimized.

• A Dow fire and explosion index of 203 was found. According to the Dow index guide this means there is a severe degree of hazard. This means that safety measurements must be implemented. Future analysis of the design will result in more accurate and hopefully lower indices.

• An added value of 122,5 USD/ton NG is possible, with the distribution 25:50:25 for diesel/kerosene/naphtha, based on the input output structure of design space 1.

• With the distribution 25:50:25 for diesel/kerosene/naphtha, the weight yield of CH4 is 89%.

PIQUAR evaluation for DS 1

For each design space a PIQUAR analysis was done. In this design space the first analysis was carried out at the end of the design space. The results can be found in an excel file and are available on disk [6]. A quality of 0.435 out of 1 was found. All the unknowns that were still in our process caused this low number. The points for which the most quality could be won where; product quality and quantity, safety, low production cost, sustainability, operability and return on investment. These points are listed in order of unquality. Especially for product quality and quantity a big improvement could be made. We felt the isomerization necessary to reach the client specifications (R102), would be hard to reach.

Conclusion

The design such as symbolized in figure 1 and described in the reports will propagate to the next design space. A number of points for consideration are the water waste stream and the sale of by-products.

Literature

1. J. Grievink, C.P. Luteijn, K.E. Jap A Joe, S. Birmingham, A framework for

conceptual design of process plants, Draft, (2001) PSE-group, faculty of applied sciences, Delft University of technology.

2. Lide D.R., Handbook of Chemistry and Physics, 72nd edition, 1991-1992, CRC Press, Boston, (1992)

3. BP company ltd. [1977]

4. Perry, R.H et al., Handbook of Chemical Engineers, 6th Edition, Mc-Graw-Hill Book co. (1984)

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5. William L., Liquefied Petroleum Gas, 2nd revised version, John Wiley& Sons, New York (1982)

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Summary brainstorm session about DS1

Summary brainstorm session DS1 R/101

1.0 Rachid 28/02/2003 First draft

1.1 Wessel 4/3/2003 Revision

A brainstorm session about DS1 was conducted. Vincent put information on the flipchart. It produced some new elements we had not thought about before. The brainstorm was needed to see if we could come up with all the elements required for this stage.

Time taken to finish the brainstorm session: one hour (10:30 -11:30).

1 Type of object (given an input output structure): We came up with the following elements: Battery limits

• Plant inside (specify) • Facilities outside (idem) • Storage (how much) 2 Defining boundaries

• Natural environment

• Suppliers and customers (clients) • Owning company (specify)

• Local authorities (tax)

3 Determining the exchange streams: chemistry • Feed stock (natural gas composition Brunei) • Product (diesel, kerosene)

• By product (LPG, Naphtha)

• Auxiliaries (steam, air) and utilities (steam, air)

4 identifying constraints on and targets for the structure, scale, and (physical) behavior of the system.

• Function (syntroleum products out of natural gas) • Product specifications

• Pattern (seasonal demands) • Specs

• Production method Fischer-Tropsch

• Byproducts high carbon numbers (heavy byproducts preferred) • Location (safety, environmental, infrastructure, location) • Annual production hours (this is also a variable or a target • Use only technical and economic data from before 1999 • Economic potential

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Summary brainstorm session about DS1

summary brainstorm session DS1.doc Page 2 of 2

6 Identifying the variables that characterize the objects in the design space and their topology.

• Market price

• Stream composition (c, T, P)

• Feedstock reliability and availability • Safety

• Mode of delivery of each stream • Mode of operation (batch, continuous) • Total production time

9 Identifying restrictions on the design stage itself with respect to manpower time available, and money.

• This design space will be made by a team of 5 students • On the 7th of March this stage must be ready

Knowledge of objects: Just look at the simple input and output structure. In our case (where the feedstock and product is pre-defined) this stage will not produce many alternatives.

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Feedstock, Product and Byproduct specifications

Product specifications R/102

1.0 VV 06/03/2003 First draft

1.1 VV 11/03/2003 Revision

1.2 LP 14/03/2003 Continuous story implemented

1.3 VV 18/03/2003 n-paraffin fractions

2.0 RvdB 31/03/2003 Comments from BOD Review implemented

Introduction

This report discusses the specifications of feedstock, products and by-products.

Specifications & Conditions

Natural Gas

The client has provided the feedstock composition. lists the specifications to be used. The high methane content makes this a very suitable feedstock for

synthesis gas production, the other hydrocarbons are not a big problem, as they will either be converted to synthesis gas too or will be concentrated in the LPG and naphtha byproducts. Obviously sulphur is not a problem, as there is none in the feed. Nitrogen might be problem for certain catalysts.

Table 1

Table 1. Specification of Natural Gas.

Stream Name: Natural Gas

Specification Component Units

Available Design Notes

Additional Information (also ref. note number)

Methane wt% 89.53 Ethane wt% 4.33 Propane wt% 1.29 Butane wt% 0.68 C5+ wt% 0.42 Carbon Dioxide wt% 2.84 HS wt% 0 (1) Nitrogen wt% 0.91 Total 100

Process Conditions and Price

Temperature K 298

Pressure bara 40

Phase V/L/S V

Price USD/ton 92.5 (2)

1. HS has been removed at the well in a desulphurizer.

2. Price as in R105.

3. Source: Lide [1992] 4. Delivery by pipeline 5. Brunei Natural Gas

Diesel & Kerosene

Commercial grades: The specifications as given by ASTM (American Society for

Testing and Materials) are most commonly used to specify different diesel grades. These can be found on disk (ASTM D975, refer to table 1). Product price levels are best chosen for grade 2-D low sulphur diesel as specified in this report (as this is the most common grade used for automobiles).

ASTM 1655 specifies different kerosene grades. Again our product is compared to these grades to determine price level. The most probable product is Jet A1, or standard civil aviation fuel.

For the design process, specifications were received from the client (Table 2,Table 3). Furthermore 500.000 ton/annum kerosene, diesel and naphtha should be made.

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Table 2. Specification of diesel.

Stream Name: Diesel

C15-C20 wt% 100

Sulphur wt% <0.06 0

Total 100

Temperature K 323 Pressure bara 1 Phase V/L/S L Price USD/ton 120 (1) Pour Point o_C _35.0 Boiling Range o_C _250-360 Diesel Index [-] >41.8 Cloud Point 5% ASTM D86 95% ASTM D86 o_C o_C o_C -10 240 350 1. Price as in R105. 2. Ref: BP Company Ltd. [1977] 3. Ref: Perry, R.H. et.al, Handbook of

Chemical Engineers, 6th_Ed.,

McGraw-Hill (1984)

Table 3. Specification of kerosene.

Stream Name: Kerosene

C10-C14 wt% 100

Sulphur wt% <0.02 0

Total 100

Temperature K 323 Pressure bara 1 Phase V/L/S L Price USD/ton 135 (1) Spec. Gravity 15/15 0.82 Boiling Range o_C _150-250 Smoke Point mm 13.0 5% ASTM D86 95% ASTM D86 o_C o_C 185 ₂₉₀ 1. Price as in R105. 2. Ref: BP Company Ltd. [1977]

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LPG & Naphtha

As these are only by-products the process is not to be adapted for products to comply with these specifications. This makes the consequences of these specifications on the process much smaller than the diesel and kerosene

specifications. The only influence of these products on the process is on the design of the separation systems.

Table 4. Specification of LPG.

Stream Name: LPG

Methane wt% <0.5

C2’s wt% <8

Pentanes wt% <2

C3-C4 wt% >89.5

Total 100

Temperature K 323 Pressure bara 2.5 Phase V/L/S V (3) Price USD/ton 154.8 (1) Heating Value MJ/kg >49 Boiling Point o_C _-7 Freezing Point o_C _-150 Density kg/m3 ₅₈₀

Cal. Value Gross J/kg 49·106

1. Price as taken in R105.

2. Ref: William L, Liquefied Petroleum

Gas, 2nd_{rev., Wiley, New York (1982)}

3. Compression and cooling outside battery limit.

Table 5. Specification of naphtha.

Stream Name: Naphtha

C5-C9 wt% 100

Total wt% 100

Temperature K 323

Pressure bara 1

Phase V/L/S L

Price USD/ton 130 (1)

API Gravity °API 71.5

Boiling Range o_C _70-150 ASTM endpoint 95% ASTM D86 o_C o_C 150 ₁₈₅ 1. Price as taken in R105. 2. Ref: BP Company Ltd. [1977]

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Utilities & Auxiliaries

Oxygen

Table 6. Specification of oxygen.

Stream Name: Oxygen

Oxygen wt% >99.4 100 Nitrogen ppm <90 0 CH4/CO2 ppm <20 0 H2O ppm <2 0 Argon ppm (3) 0 Total 100.0

Temperature K 283

Pressure bara 14

Phase V/L/S V

Price USD/ton 27.0 (2)

1. Delivery by pipeline 2. Source: Air Products 3. Remainder, trace amounts

Steam

Superheated steam is considered to be available at the temperatures and absolute pressures given below.

Steam Class

Conditions _{High Pressure} _{Medium Pressure} _{Low Pressure}

p [bara] 40 10 3 T (superheated) [o_C)] _{410 220 190} T (condensation) [o_{C)] 250}₁₈₀_133.5 Fouling coefficient: 10 kW/m2 o_C Fouling factor: 0.1 m2o_C/kW Electricity

Power Voltage [V] Current

Low 220 AC

Medium 380 three-phase AC

High 3000-10000 three-phase AC

Pressurized Air

Pressurized air is intended for instrumentation and other applications, with the exception of process air. Pressurized air is available at the following conditions:

Conditions Value

T [o_{C] 20}

p[bara] 7

Dewpoint [o_{C] -40}_(max.)

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Water

Water T

[o_C] _[bara]P _[kW/mH 2 o_C] Fouling factor _[m2o_C/kW]

Demineralized Process Water 15 7

Cooling 20 [1], 40 [2] 3 [3] 2.0 0.5

Remarks

1. Design value 2. Maximum allowed 3. At ground level

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Design Consequences

In this chapter, the design consequences of the product specifications are discussed.

500.000 ton/year: This large annual production makes a continuously operated plant

economically more efficient. The limit for batch processes is around ~5000 ton/year [1].

Operating time: A continuous process has an annual operating time of around 8000

hours [8].

Pour point/ Cloud point (diesel only), freezing point (kerosene only): The pour point

is the temperature when the fuel becomes too solid to be able to flow and can’t be poured [2]. The wax appearance point or cloud point is the temperature at which the first wax crystals can be seen in the liquid. The pour point of diesel is thus always lower than the cloud point. The importance of this specification is that it ensures that the diesel can be used under most conditions. The freezing point for kerosene is essentially the same property as the pour point for diesel, and just as important. The maximum freezing point temperature is –40 in the US (jet A) and –47 outside the US (jet A1).

If the cloud point is –10 o_{C, the pour point is generally 4-11 °C lower than this} temperature. This means that if the diesel product complies with cloud point specifications it automatically complies with given pour point specifications. That is why we will try to achieve a cloud point of –10 o_C.

Both pour/ cloud point can be established using a test on the actual product (ASTM D97/ ASTM D2500 respectively). During the design stage an estimation of the cloud point can be made. Several relations for the cloud and pour points exist. The

simplest of these is equation (1) [3]:

1 2

CP n ar

T

= ⋅ + ⋅

a x

+ k

(1)

With:

TCP: cloud point temperature xn: molar fraction n-alkanes xar: molar fraction aromatics

a1, a2, k: constants (for cloud point: 74.9, 28.3, -37.4, for freezing point:81.3, 62.8, -86.4)

These are very simple equations and can only be used for superficial calculations, when n-paraffin and aromatics fraction are given. When the cloud point is taken as – 10 o_{C, this formula gives an n-paraffin fraction of 0.37, with higher n-paraffin}

content resulting in higher cloud point. A second calculation method for mixtures of different fuel stocks is given in equation (2) [4]:

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0.03 1 0.03 1 J J n T j j j CP n T j j

e

v

T

e

v

⋅ = ⋅ =

⋅ ⋅

=

⋅

∑

T

(2) With:

Tj: cloud point temperature of stock j vj: volume fraction of component j n: total number of different feed stocks

This equation can be used if it is realized that the melting point of a pure substance is a good indication of that substance’s cloud point. If the composition and the melting temperatures of the components are known, the cloud point can now be estimated.

Table 7. Melting and boiling point temperatures over a range of n-paraffins [5, 6]. n-paraffin TM (°C) TB (°C) n-paraffin TM (°C) TB (°C) CH4 -182 -161 C13H28 -5.3 235 C2H6 -183 -88.7 C14H30 5.8 254 C3H8 -187 -42.1 C15H32 9.9 271 C4H10 -138 -0.45 C16H34 18.1 287 C5H12 -128 36.1 C17H36 22.0 302 C6H14 -95.3 68.7 C18H38 28.2 316 C7H16 -90.6 98.6 C19H40 32.1 330 C8H18 -56.8 126 C20H42 36.8 343 C9H20 -53.5 151 C21H44 40.5 357 C10H22 -29.7 174 C22H46 44.4 367 C11H24 -25.6 196 C23H48 47.6 380 C12H26 -9.6 216 C24H50 54.0 391

The Fischer-Tropsch process’ primary (up to 99 %) product consists of linear alkanes (n-paraffins). If we look at the pure component melting point temperatures of these paraffins (Table 7, [5, 6]) it is noticed that even C15H32 has a melting point that is 15 degrees above spec. Using equation (2), a mixture with equal amounts of C15-C20 n-paraffins will have a cloud point of ~27 °C, which is 37 (!) degrees above spec. Certain additives can lower melting points, but a cloud point of –10 cannot be

achieved with only C15-C20 n-paraffins and small additions of additives. The same will likely hold for the freezing point of kerosene

This means that a significant degree of isomerization is needed to decrease the cloud point (as isomers of n-paraffins have consistently lower melting points. The amount of isomerization required is hard to estimate at this level because the mixture will become increasingly complex with increasing isomerization. Isomerization also C:\Documents and Settings\Ronald\My Documents\CPD3287\Reports\DS 1\R102 -

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Feedstock product byproduct specifications.doc Page 9 of 11

entails consequences for the other properties of the product, notably boiling range and cetane number (=diesel index)

Specific gravity (kerosene only): the density of the product in relation to water at 15

°C. The density of the kerosene product can be calculated from composition later in the design stage to check compliance with product specs. It is related to the API gravity through the following formula:

°API Gravity=-131.5 + 141.5/Specific Gravity

Boiling range: The boiling range for diesel is given above as between 250-360 °C.

Boiling range for kerosene is 150-250 °C. This, together with cloud point

specifications, determines separation characteristics and performance, as well as the income generated. When isomerization is involved, boiling points will be lower than the ones specified for n-paraffins. This will affect the relative kerosene/ diesel production rate.

ASTM D86 outlines a test method for distillation of petroleum products at

atmospheric pressure. 5 % means that during a batch distillation as specified in D86 at 240 °C a maximum of 5 % of the product should be evaporated. At 350 °C 95 % of the product should be evaporated. Looking at the values given in the client

specifications it can be seen that diesel and kerosene partly overlap and that thus separation can be tailored towards the more valuable product, providing flexibility. Diesel index = cetane number (diesel only): Indicates the quality of the diesel for

application in automobiles, with higher numbers being better. Typical minimum standards are set between 40-45. n-paraffins typically have a cetane number of 100-110 [2]. This means that the diesel produced through Fischer Tropsch, optimized for paraffin production, will exceed the diesel index specifications by far. When choosing reactor types and conditions, it is best to strive for the highest possible n-paraffin production, to obtain the best possible diesel.

Cloud point specifications however specify isomerization of the product to decrease cloud point temperature. This results in a certain desired wt % of iso-paraffins. As these have very low cetane number the overall cetane number will become lower.

This means that the end product is going to be a compromise between a high cetane number and low cloud point.

An empirical method to calculate the cetane number from density and distillation temperatures is given in ASTM D4737, which could be used to estimate product cetane number during the design stage. Another empirical method given for cetane number calculation uses equation (1) with a1, a2, k respectively 51.0, 29.4, 45. The product of the Shell SDMS process has a cetane index of 70 [7], which points (using equation (1)) to an n-paraffin fraction of ~0.49.

Smoke point (kerosene only): The smoke point gives an indication of the smoke

producing properties of kerosene fuels. Less smoke production is better, both for aviation turbine operation and environmental considerations. The smoke production is measured in millimeters of smokeless flame when burning the fuel in a wick fed

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lamp, as described in ASTM D1322. Higher flame means less smoke production and thus better fuel, the minimum for our product being 13 mm.

Generally, (n-) paraffins (>99 % of product) outperform any other hydrocarbon in terms of burning efficiency and low smoking tendency. Again isomerization will decrease the smoke point, because iso-paraffins are somewhat harder to burn and will thus cause more coke=smoke formation. Equation (1) can be used to achieve an estimation of the smoke point, a1, a2, k respectively 29.5, -75.6, 25.8.

Sulphur: As the feedstock is nearly sulphur free and no sulphur is added, at most

ppm amounts of sulphur will be present in the product, thus producing very clean diesel. This means that there is no need for sulphur removal.

Phase, Temperature, pressure: After the separation the product will have to be

brought to the right conditions. The product is delivered to storage tanks outside the boundary limits.

Conclusion

Apart from the diesel/ kerosene/ byproduct quantities the most important variable regarding the product is the degree of isomerization away from the n-paraffins produced during Fischer Tropsch synthesis. The degree of isomerization strongly influences:

- Cetane number (more isomerization leads to lower diesel burning efficiency). - Cloud point/ freezing point (more isomerization leads to better low

temperature performance, both for diesel and kerosene).

- Smoke point (more isomerization leads to lower burning efficiency of kerosene fuel).

In this report several equations relating the composition of the final product to these parameters are mentioned, which can be used during the design process to set process parameters. Preliminary results point to a maximum n-paraffin fraction xn,max between 0.37 and 0.49.

Apart from isomerization, another possibility would be to blend the product with other petroleum products having lower cloud point and (thus) lower cetane number, thus upgrading both products, the F-T-product with respect to cold flow

characteristics and the traditional crude product with respect to burning properties (and sulphur content). This would be most attractive if there is a crude oil refinery present at the plant location.

Literature

All ASTM specifications: www.ASTM.org

1. J.M. Douglas, Conceptual design of chemical processes, (1988), McGraw-Hill, p. 108.

2. J.I. Kroschwitz and M. Howe-Grant, Kirk Othmer Encyclopedia of Chemical

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3. D.J. Cookson et al., Composition-property relations for jet and diesel fuels of

variable boiling range, Fuel 74 (1) (1995), p. 70-78

4. S. Saiban and T.C. Brown, Kinetic model for cloud-point blending of diesel

fuels, Fuel 76 (14-15) (1997), p. 1417-1423.

5. D.R. Lide, Handbook of chemistry and physics, 81 edition,(2000) CRC Press, Boca Raton, p. 6-48/6-60

6. Same as 5 7. Same as 1, p. 163 8. Same as 1, p. 73

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Use of DOW fire and explosion index DS1

Use of DOW fire and explosion index DS1 R/102

1.0 Wessel 5/3/2003 First draft

Dow fire and explosion index

Safety must be an inherent part of the design of a plant. That is why the Dow fire and explosion index (Dow index) is incorporated in design space 1 already. The Dow

index is a hazard ranking system that ranks on the basis of properties of material, quantities, process conditions and (certain) preventive and protective measures [1].

The requirements for this method are listed below. 1. An accurate plot plan of the plant

2. Flow sheet

3. Process description and understanding 4. Summary of process conditions

5. Quantities and conditions of key substance 6. Economic data of equipment

The plant must then be logically subdivided into “process units”. A process unit could be a pump, a compressor, a distillation column or any other process equipment. For those units that are considered pertinent to the system and would have the heaviest impact to a fire or explosion a fire and explosion index (F&EI) is created. The degree of harm of the F&EI is defined as follows:

1-60 Light

61-96 Moderate

97-127 Intermediate 128-158 Heavy

159 > Severe

Usually indices above one hundred are considered undesired and action must be taken to reduce the risks. This F&EI, together with information on equipment prices and plant layout can produce a MPPD (maximum probable property damage) and a MPDO maximum probable days out) index.

The exact procedures for making the F&EI and the MPPD and MPDO are described in Dow’s F&EI guide [2] and Lees [1].

For each space an index is created. The results can be found in the map Dow F&EI in the map report. For each space the actual index in an excel sheet and accompanying word file is created. The object of design space 1 is an I/O model of the whole plant. Since the Dow index looks at individual process units and their mutual interaction, the index in principle can’t be used for a preliminary estimate of the safety of the C:\Documents and Settings\Ronald\My Documents\CPD3287\Reports\DS 1\R103 - DOW

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Use of DOW fire and explosion index DS1

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whole plant. Though if the plant is seen as one unit it can be used. This is a very rough estimate and should be interpreted as such. MPPD and MPDO can’t be created.

Literature

1 Lees, Frank P..: Loss prevention in the process industries; hazard identification, assessment and control. Vol. 1. Guildford Butterworth-Heinemann 1996.

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Waste and by-product streams

Waste and by-product streams R/104

1.0 Rachid 5/3/2003 First draft

1.1 Wessel 31/3/2003 Added waste streams

Waste and by-product streams for the process

Wastes and by-products produced during the process are: • H2O (waste water from FT process)

• CO2 (from syngas, FT process and from burning fuel gas, heating) • C (soot, coke from syngas, FT process)

• Oxygenates (alcohols from FT process) • Fuel gas (C1-C2) from FT process)

• Nitrogen species (NOx, N2, NH3 from feed stock, released in different stages) • Naphtha (C5-C9)

• LPG (C3-C4)

• Waxes (Unconverted after hydrocracking, >C21)

The alternatives we could come up with for the waste streams were:

• The water with some dissolved hydrocarbons (alkenes, oxygenates and paraffin’s), produced during the FT process could partially be used as a small recycle for the syngas production. Otherwise it has to be discharged directly into the environment or sent to a wastewater purification unit, depending on the concentration of contaminants. The wastewater purification is outside the battery limits. A suggestion was made to sell the excess water as drinking or irrigation water. This option might be viable depending on the quality of the water.

• CO2 could be partially converted back into CO by the WGS reaction. Extra hydrogen is then needed and water will be a by-product. CO2 can also be discharged into the atmosphere. If the CO2 is produced very pure it might be possible to sell the CO2.

• Oxygenates will mostly dissolve in water, and can then be recycled. A small of amount oxygenates in the diesel and kerosene is not a problem.

• The fuel gas, LPG and naphtha coming from the system can be burned to produce heat that is required for the different sub processes, it can be flared or it can be sold separately.

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Waste and by-product streams

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• A part of the wax that is produced could be sold as a specialty product. Another option is to convert as much as possible of it into diesel to obtain a higher product yield.

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Process Economics

Process Economics R/105

1.0 RvdB 07/03/2003 First draft

1.1 RvdB 10/03/2003 Added outlook

1.2 RvdB 11/03/2003 Changed NG price assumption

2.0 RvdB 31/03/2003 Changed prices to match the assumptions of the other CPD Group

2.1 RvdB 01/04/2003 Changed calculation of financial margin due to change in mass balance

2.2 RvdB 01/05/2003 Added price of fuel gas

Introduction

In this report, prices or costs of products, feedstock, utilities, by-products and auxiliaries are discussed. After that, the financial margin is discussed, according to the input-output structure of design space 1. Then, the outlook for the markets of our products will be discussed shortly.

Prices

The prices, that we found are listed in Table 1. In Table 2 and Table 3, the prices, that were used by the 1998 group are listed. The calculation of the prices is given in the section Price Conversion. The prices from Table 2 will be used in this

design. This decision is explained in the section Price Discussion.

Table 1. Prices of feedstock, products and by-products.

Component Price Description

Natural Gas &

Fuel Gas 79.37 USD/10

7

kcal Taken equal to the price in 1998 in Indonesia (because it’s closest to Brunei of all countries in the list). From Natural Gas

prices for industry, Energy Information Administration.1 Diesel 0.439

USD/gallon refiner sales price in 1998 (excluding taxes) of No. 2 Distillate, From Annual Energy Review 2001, p.169, Energy Information

Administration. Kerosene 0.465

USD/gallon refiner sales price in 1998 (excluding taxes) of kerosene, From Annual Energy Review 2001, p.169, Energy Information

Administration. Naphtha 0.465

USD/gallon Due to lack of correct price info, it is assumed equal to the price of kerosene. Assumption according to:

Price Relationships in the Petroleum Market

An analysis of crude oil and refined product prices, Frank Asche et.al.

Table 2. Prices of feedstock, products and by-products from the 1998 CPD Group.2,3

S/no Feedstock/Products Price (USD/ton) Reference

1 Natural Gas 92.5 Lide [1992]

2 Oxygen 27.0 Air Products

3 Naphtha 130 BP Company Ltd.[1977]

4 Kerosene 135 BP Company Ltd.[1977]

5 Diesel 120 BP Company Ltd.[1977]

6 LPG 154.8 US Department of Energy

Table 3. Prices of utilities and auxiliaries from the 1998 CPD Group. 2,3

S/no Utility Unit Price ( Dfl unit-1₎

1 HP Steam ton 35 2 LP Steam ton 30 3 Cooling Water m3_0.08 4 Process Water m3_2.5 5 Electricity (average)1_kWh_0.18 6 Pressurized Air Nm3_0.05 7 Refrigeration GJ 15

All utility costs in Table 4 are taken from Appendix 3 in the CPD Manual. However, minimum and maximum values for utilities aren’t used, but the mean value is

1_{In some publications, a price of 0.50 USD/MMBtu is assumed. For example in:} M.J.Gradassi and N.W.Green, Economics of natural gas conversion processes, Fuel Process. Technology, Volume 42, Issues 2-3, April 1995, Pages 65-83 2_{Webci ,1995, Dace prijzenboekje,17th edition.}

3_{Lide [1992], Lide D.R, Handbook of Chemistry and Physics, 72nd edition,} 1991-1992,CRC Press Boston.

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