Project

Production of Methanol from Coal Page 1

Production of Methanol from Coal

Session: 2009-2013

Project Advisor

Engr.Usman Farooq

Group Members

Bilal Shafiq 09033123-058

Noman Arshad 09033123-056

Ahmad Zeeshan 09033123-005

Ch. Naveed Anwar 09033123-019

DEPARTMENT OF CHEMICAL ENGINEERING

UNIVERSITY OF GUJRAT GUJRAT-PAKISTAN


Production of Methanol from Coal

This report is submitted to department of Chemical Engineering,

University of Gujrat

Gujrat- Pakistan for the partial fulfillment of the requirements for the Degree

Of Bachelor of Science

In

CHEMICAL ENGINEERING

Internal Examiner Signature:

(Supervisor) Name

External Examiner Signature:

(Supervisor) Name

DEPARTMENT OF CHEMICAL ENGINEERING

UNIVERSITY OF GUJRAT GUJRAT-PAKISTAN


DEDICATED TO

Our beloved parents

teachers and sincere

friends whose love

affection and continuous

prayers for our success

is the most precious

asset of our lives.


Contents

Acknowledgement ......................................................................................................................... 11

Chapter 1 ........................................................................................................................................ 12

Introduction .................................................................................................................................... 12

1.1 Historical Development of Methanol ................................................................................. 14

1.2 Physical Properties ............................................................................................................. 14

1.3 Physical properties ............................................................................................................. 15

1.4 Reaction of methanol ......................................................................................................... 17

1.5 Chemical Properties of Methanol ...................................................................................... 17

1.5.1 Combustion of Methanol: .......................................................................................... 17

1.5.2 Oxidation of Methanol: .............................................................................................. 17

1.5.3 Catalytic Oxidation of Methanol: .............................................................................. 18

1.5.5 Dehydration of Methanol: .......................................................................................... 18

1.5.6 Esterification of Methanol: ........................................................................................ 18

1.5.7 Substitution of Methanol with Sodium: ..................................................................... 19

1.5.8 Substitution of Methanol with Phosphorus Pent chloride: ......................................... 19

1.5.9 Substitution of Methanol with Hydrogen Chloride:................................................... 19

1.6 Applications of Methanol .................................................................................................. 20

1.6.1 Transportation Fuel: ................................................................................................... 20

1.6.2 Wastewater Denitrification: ....................................................................................... 20

1.6.3 Fuel Cell Hydrogen Carrier: ...................................................................................... 21

1.6.4 Methanol as a cleansing agent: .................................................................................. 21

1.6.5 Biodiesel Transesterification: .................................................................................... 21

1.6.6 Electricity Generation: ............................................................................................... 21

1.6.7 Methanol as a solvent:................................................................................................ 22

1.6.8 Chemical Feed Stock ........................................................................................................ 22

Chapter 2 ........................................................................................................................................ 23

Process Selection ........................................................................................................................... 23

2.1 Choice of Feedstock: ...................................................................................................... 24

2.1.1 Biomass: ................................................................................................................. 24

2.2.3 Natural Gas: ........................................................................................................... 25

2.2.4 Natural Gas Reserves in Pakistan: ......................................................................... 25

2.2.5 Coal: A Fossil Fuel: ............................................................................................... 25
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2.2 Choice of Syngas Technology: ...................................................................................... 26

2.2.1 Steam Methane Reforming: ................................................................................... 26

2.2.2 Partial Oxidation Reforming: ................................................................................. 27

2.2.3 Auto thermal Reforming: ....................................................................................... 28

2.2.4 Gas Heated Reforming: .......................................................................................... 30

Chapter 3 ........................................................................................................................................ 31

Process Description ........................................................................................................................ 31

3.1 Process Flow Sheet .............................................................................................................. 32

3.2 Feed Preparations ........................................................................................................... 33

3.3 Production of Syn Gas ................................................................................................... 33

3.4 Cooling of Syn Gas ........................................................................................................ 33

3.5 Purification of Syn Gas .................................................................................................. 33

3.6 Rearrangement of H2 and CO ........................................................................................ 33

3.7 Production of Methanol ................................................................................................. 33

3.8 Refining of Methanol. .................................................................................................... 33

Chapter 4 ........................................................................................................................................ 38

Capacity Selection ......................................................................................................................... 38

4.1 Global Demand of Methanol: ........................................................................................ 39

4.2 South Asia Methanol Demand ....................................................................................... 40

4.3 China Methanol Industry ............................................................................................... 41

Chapter # 5 ..................................................................................................................................... 43

Material and Energy Balance ......................................................................................................... 43

5.1 Material Balance on Distillation Column: ..................................................................... 44

5.2 Material Balance on Flash Drum: .................................................................................. 45

5.3 Material Balance on Reactor: ......................................................................................... 48

5.4 Material Balance on Water Gas Shift Reactor: .............................................................. 49

5.5 Material Balance on Acid Gas Absorber: ...................................................................... 51

5.6 Material Balance on Gasifier: ........................................................................................ 53

Energy Balance: ............................................................................................................................. 55

5.7 Energy Balance on Gasifier .......................................................................................... 55

5.8 Energy Balance on Heat Exchanger: ............................................................................. 57

5.9 Energy Balance on Water Gas Shift Reactor: ................................................................ 59

5.10 Energy Balance on Distillation Column: ....................................................................... 61
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5.11 Energy Balance on Gasifier: .......................................................................................... 62

Chapter 6 ........................................................................................................................................ 64

Designing of Gasifier ..................................................................................................................... 64

6.1 Types of Gasifier: ......................................................................................................... 65

6.1.1 Entrainment bed Gasifier ....................................................................................... 65

6.1.2 Fluidized Bed Gasifier: .......................................................................................... 66

6.1.3 Moving Bed Gasifier: ............................................................................................ 66

6.2 Design : .......................................................................... Error! Bookmark not defined.

6.3 Specification Sheet ......................................................................................................... 75

Chapter 7 ........................................................................................................................................ 76

Designing of Methanol Reactor ..................................................................................................... 76

7.1 Purpose: ......................................................................................................................... 77

7.2 Reactor selection criteria: .............................................................................................. 77

7.3 Reactor types:................................................................................................................. 77

7.4 Designing ....................................................................................................................... 78

7.5 Specification Sheet ......................................................................................................... 84

Chapter # 08 ................................................................................................................................... 85

Designing of Heat Exchanger ........................................................................................................ 85

Purpose ........................................................................................................................................... 86

8.1 Types of Heat Exchanger ................................................................................................... 86

8.2 Selection Criteria ............................................................................................................... 86

8.4 Types of Shell and Tube Heat Exchangers: ....................................................................... 87

8.5 Designing ........................................................................................................................... 87

8.6 Specification Sheet ............................................................................................................. 94

Chapter # 09 ................................................................................................................................... 95

Designing of Distillation Column .................................................................................................. 95

9.1 Purpose: ......................................................................................................................... 96

9.2 Choice between Plate and Packed Column .................................................................... 96

9.3 Plate Type Choice .......................................................................................................... 97

9.4 Construction ................................................................................................................... 97

9.4.1 Effect of temperature on the mechanical properties .............................................. 97

9.4.2 Pitting ..................................................................................................................... 98

9.4.3 Effect of stress ........................................................................................................ 98
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9.4.4 High-temperature oxidation ................................................................................... 98

9.5 Designing ..................................................................................................................... 100

9.6 Specification Sheet ....................................................................................................... 109

Chapter 10 .................................................................................................................................... 110

Coast Estimation .......................................................................................................................... 110

10.1 Introduction of Cost Estimation ................................................................................... 111

10.2 Accuracy and Purpose of Capital Cost Estimates ........................................................ 111

10.3 Preliminary Estimates .................................................................................................. 111

10.4 Authorization Estimates ............................................................................................... 111

10.5 Detailed Estimates ....................................................................................................... 112

10.6 Fixed Capital ................................................................................................................ 112

10.6.1 Direct Cost ........................................................................................................... 113

10.6.2 Indirect Cost ......................................................................................................... 113

Start-up expenses ......................................................................................................................... 113

10.7 Working Capital ........................................................................................................... 113

10.8 Operating Costs ............................................................................................................ 114

10.8.1 Fixed Cost ............................................................................................................ 114

10.8.2 Variable Costs ...................................................................................................... 114

10.9 Cost Indices .................................................................................................................. 114

10.9.1 Types of Cost Indices ........................................................................................... 115

Chapter 11 .................................................................................................................................... 116

Instrumentation and Process Control ........................................................................................... 116

11.1 Objective ...................................................................................................................... 116

11.1.1 Safe plant operation: ............................................................................................ 116

11.1.2 Production rate: .................................................................................................... 116

11.1.3 Product quality: .................................................................................................... 116

11.1.4 Cost: ..................................................................................................................... 116

11.2 Temperature Measurement and Control: ..................................................................... 117

11.3 Pressure measurement and control: .............................................................................. 118

11.4 Flow measurement and control: ................................................................................... 118

11.5 Control loops:............................................................................................................... 118

11.5.1 Feedback control loop: ......................................................................................... 118

11.5.2 Feed Forward Control Loop: ................................................................................ 119


11.5.3 Ratio control: ....................................................................................................... 119

11.5.4 Auctioneering control loop: ................................................................................. 119

11.5.5 Split range loop: ................................................................................................... 119

11.5.6 Cascade control loop: ........................................................................................... 120

11.6 Control loop around Gasifier ......................................... Error! Bookmark not defined.

11.7 Control loop around Absorber ..................................................................................... 120

11.8 Control loop around Waste Heat boiler ......................... Error! Bookmark not defined.

11.9 Control loop around Distillation Column .................................................................... 121

11.9.1 Objectives ............................................................................................................ 121

11.9.2 Manipulated Variables ......................................................................................... 121

11.9.3 Loads or Disturbances .......................................................................................... 121

11.9.4 Control Scheme .................................................................................................... 122

11.9.5 Advantage ............................................................................................................ 122

11.9.6 Disadvantage ........................................................................................................ 122

11.10 Control Loop around Flash Drum .............................. Error! Bookmark not defined.

Chapter 12 .................................................................................................................................... 123

HAZOP Study .............................................................................................................................. 123

12.1 Introduction .................................................................................................................. 124

12.2 Hazard and Operability Study Methodology ............................................................... 124

12.3 Sequence of Examination: ........................................................................................... 125

12.4 Details of Study Procedure: ......................................................................................... 126

12.5 HAZOP Effectiveness: ................................................................................................. 127

12.6 The HAZOP Team ....................................................................................................... 128

12.7 HAZOP Study on a Distillation Column ..................................................................... 129

Chapter # 13 ................................................................................................................................. 131

Environmental Impact Assessment .............................................................................................. 131

13.1 HAZOP Effectiveness: ................................................................................................. 132

An environmental impact assessment (EIA) is an assessment of the possible positive or

negative impacts that a proposed project may have on the environment, consisting of

the environmental, social and economic aspects. .................................................................... 132

13.2 Step-Wise Structure of EIA ......................................................................................... 132

13.2.1 Preliminary Activities & TOR ............................................................................. 133

13.2.2 Scoping ................................................................................................................ 133

13.2.3 Baseline Study ..................................................................................................... 134


13.2.4 Environment Impact Evaluation .......................................................................... 134

13.2.5 Mitigation Measures ............................................................................................ 135

13.2.6 Assessment of Alternative Measures ................................................................... 135

13.2.7 Preparation of the final document ........................................................................ 136

13.2.8 Decision-making .................................................................................................. 136

13.2.9 Monitoring of project implementation & its environmental impacts ................... 137

13.3 Environment Impact Assessment of a Proposed Methanol Plant: ............................... 137

13.3.1 Air Emissions ....................................................................................................... 137

13.3.2 Noise .................................................................................................................... 139

13.3.3 Water ........................................................................................................................ 139


Acknowledgement

All praises be to the "Allah Almighty "the most merciful, the most beneficent who guides

us in the darkness and helps us when despair surrounds us. Without His help one can't

reach ones destination. Undoubtedly these are His unlimited blessings that made us

complete this work. All respects and love for Prophet" Muhammad (PBUH) "who

enlightened our minds to recognize our creator.

We thank our dear parents, who brought us up, fed us and above all; made us educated.

Then we thank all our teachers who taught and guided us; and our dear friends who

encouraged us and moved us for the last four years. To our brothers and sisters who

stood by us and continue to stand by us because of their staunch belief in what we are

capable of.

We feel pleasure and deep sense of indebtedness for our teachers who have enriched the

text by their generous contribution. We express profound and cordial gratitude to our

learned, kind and experienced advisors Engr. Usman Farooq for his kind behavior,

constructive suggestions and all the way helpful supervision.

In the end, we thank all those who by any means helped us completing this project.


Chapter 1

Introduction


Methanol is a chemical building block used in making hundreds of products that touch

our daily lives. Methanol is also an emerging energy fuel for running our cars, trucks,

buses, and even electric power turbines. Methanol, also known as methyl alcohol or wood

alcohol is the simplest of all alcohols with the chemical formula CH3OH1.

Methanol is a light, colorless, flammable liquid at room temperature, and contains less

carbon and more hydrogen than any other liquid fuel. It is a stable biodegradable

chemical that is produced and shipped around the globe every day for a number of

industrial and commercial applications. Methanol occurs naturally in the environment,

and quickly breaks down in both aerobic and anaerobic conditions2.

The methanol industry spans the entire globe, with production in Asia, North and South

America, Europe, Africa and the Middle East. Worldwide, over 90 methanol plants have

a combined production capacity of about 75 million metric tons (almost 24 billion gallons

or 90 billion liters), and each day more than 100,000 tons of methanol is used as a

chemical feedstock or as a transportation fuel (33 million gallons or 125 million liters).

The global methanol industry generates $36 billion in economic activity each year, while

creating over 100,000 jobs around the globe.

This simple alcohol can be made from virtually anything that is, or ever was, a plant. This

includes common fossil fuels like natural gas and coal and renewable resources like

biomass, landfill gas, and even power plant emissions and CO2 from the

atmosphere. With its diversity of production feedstocks and array of applications, its

no wonder that methanol has been one of the worlds most widely used industrial

chemicals since the 1800s.

1 www.methanol.org

2 See Appendix A for properties of methanol


1.1 Historical Development of Methanol3

Year Events 1830 First commercial methanol process by destructive distillation of wood

1905 Synthetic methanol route suggested by French chemist Paul Sabatier

1923 First synthetic methanol plant commercialized by BASF

1927 Synthetic methanol process introduced in United States

Late 1940s Conversion from water gas to natural gas as source of synthetic gas for

feed to methanol reactors

1966 Low-pressure methanol process announced by ICI

1970 Acetic acid process by methanol carboxylation introduced by Monsanto

1973 Arab oil embargo reassessment of alternative fuels

1970s Methanol-to-gasoline process introduced by Mobil

1989 Clan air regulations proposed by Bush administration

1990 Passage of the amended Clean Air Act in United States

Early 1990s Discovery of enhanced crop yields with methanol treatment

1.2 Physical Properties

It is also called METHYL ALCOHOL, it is the simplest of a long series of organic

compounds called alcohols; its molecular formula is CH3OH. The modern method of

preparing methanol is based on the direct combination of carbon monoxide gas and

hydrogen in the presence of a catalyst at elevated temperatures and pressures. Methanol is

produced from the methane component of natural gas.

Pure methanol is an important material in chemical synthesis. Its derivatives are used in

great quantities for building up a vast number of compounds, among them many

important synthetic dyestuffs, resins, drugs, and perfumes. Large quantities are converted

to dimethyl aniline for dyestuffs and to formaldehyde for synthetic resins. It is also used

in automotive antifreezes, in rocket fuels, and as a general solvent.

3 Author: Kung, Harold H. Methanol Production And Use Chemical Industries


Methanol is a colorless liquid, completely miscible with water and organic solvents and is

very hygroscopic. It forms explosive mixtures with air and burns with a nonluminous

flame. It is a violent poison; drinking mixtures containing methanol has caused many

cases of blindness or death. Methanol has a settled odor.

1.3 Physical properties

Molecular Weight 32.04

Vapour Pressure 97 Torr at 20 0C

Refractive index 1.3284 at 20 0C

Density 0.7913g/ml (6.602 lb./gal) at 20 0C

0.7866 g.ml (6.564 lb./gal) at 25 0C

Dielectric Constant 32.70 at 25 0C

Dipole moment 2.87 D at 20 0C

Solvent Group 2

Polarity Index (P) 5.1

Viscosity 0.59 cp at 20 0C

Surface Tension 22.55 dyne/cm at 200C

Solubility in water Miscible in all properties

Flash point 11 0C

Auto ignition temperature 455 0C

Explosive limit 7-36%

Heat of formation -210.3 MJ/kmol


Critical pressure 81 bar

Critical volume 0.811 m3/kmol

Heat of Vaporization 35278 kJ/kmol

Melting Point -97.7 0C

Boiling Point 65 0C

Relative Density 0.79

Formula CH3OH

Molecular weight 32.042 kg/kmol

Heat of Formation -201.3 MJ/kmol

Gibbs Free Energy -162.62 MJ/kmol

Freezing point -97.7 C

Boiling point 64.6 C (at atm pressure)

Critical temperature 512.6 K

Regulatory and Safety Data

Acute Data Poisonous by ingestion or inhalation, may cause

respiratory failure, kidney failure, blindness

Chronic Effect As Acute, skin contact can cause dermatitis.


1.4 Reaction of methanol

Methanol is the 1st in a series of aliphatic, monohydric alcohol and it give many reaction

of this class. Methanol is a typical member of this class which has 1 carbon atom.

Methanol cannot give elimination of hydroxyl group as higher alcohol.

The reaction of methanol is generally breaking of C-0 or O-H bond and substitution of

the displacement of the H or Oh group. The O-H and C-O bond in alcohol are relatively

strong . Because of this bonding strength in alcohol is necessary to achieve acceptable

reaction rate.

1.5 Chemical Properties of Methanol

1.5.1 Combustion of Methanol:

Methanol burns with a pale-blue flame to form carbon dioxide and steam.

2CH3OH + 302 ===> 2CO2 + 4H2O

1.5.2 Oxidation of Methanol:

Methanol is oxidized with acidified Potassium Dichromate, K2Cr2O7, or with acidified

Sodium Dichromate, Na2Cr2O7, or with acidified Potassium Permanganate, KMnO4, to

form formaldehyde.

[O]

CH3OH ===> HCHO + H2

Methanol Formaldehyde

2H2 + O2 ===> 2H2O

If the oxidizing agent is in excess, the formaldehyde is further oxidized to formic acid

and then to carbon dioxide and water.

[O] [O]

HCHO ===> HCOOH ===> CO2 + H2O

Formaldehyde Formic Acid


1.5.3 Catalytic Oxidation of Methanol:

The catalytic oxidation of methanol using platinum wire is of interest as it is used in

model aircraft engines to replace the sparking plug arrangement of the conventional

petrol engine. The heat of reaction is sufficient to spark the engine.

1.5.4 Dehydrogenation of Methanol:

Methanol can also be oxidized to formaldehyde by passing its vapor over copper heated

to 300 C. Two atoms of hydrogen are eliminated from each molecule to form hydrogen

gas and hence this process is termed dehydrogenation.

Cu, 300C

CH3OH ===> HCHO + H2

Methanol Formaldehyde

1.5.5 Dehydration of Methanol:

Methanol does not undergo dehydration reactions. Instead, in reaction with sulphuric acid

the ester, dimethyl sulphate is formed.

Conc. H2SO4

2 CH3OH ===> (CH3)2SO4 + H2O

Methanol Dimethyl Water

Sulphate

1.5.6 Esterification of Methanol:

Methanol reacts with organic acids to form esters.

H(+)

CH3OH + HCOOH ===> HCOOCH3 + H2O

Methanol Formic Methyl Water

Acid Formate


1.5.7 Substitution of Methanol with Sodium:

Methanol reacts with sodium at room temperature to liberate hydrogen. This reaction is

similar to the reaction of sodium with ethanol.

2 CH3OH + 2 Na ===> 2CH3ONa + H2

Methanol Sodium Sodium Hydrogen

Meth oxide

1.5.8 Substitution of Methanol with Phosphorus Pent chloride:

Methanol reacts with phosphorus pent chloride at room temperature to form hydrogen

chloride, methyl chloride, (i.e. chloromethane) and phosphoryl chloride.

CH3OH + PCl5 ===> HCl + CH3Cl + POCl3

Methanol Phosphorus Methyl Phosphoryl

Pent chloride Chloride Chloride

1.5.9 Substitution of Methanol with Hydrogen Chloride:

Methanol reacts with hydrogen chloride to form methyl chloride (i.e. chloromethane) and

water. A dehydrating agent (e.g. zinc chloride) is used.

ZnCl2

CH3OH + HCl ===> CH3Cl + H2O

Methanol Methyl

Chloride


1.6 Applications of Methanol

Methanol is one of the most versatile compounds developed and is the basis for hundreds

of chemicals, thousands of products that touch our daily lives, and is second in the world

in amount shipped and transported around the globe every year. A truly global

commodity, methanol is a key component of modern life and new applications are paving

the way forward to innovation. While numerous applications transform methanol into

vital products and commodities that drive modern life, methanol is also used on its own

in a number of applications.

1.6.1 Transportation Fuel:

Methanol is the most basic alcohol. It is easy to transport, readily available, and has a

high octane rating that allows for superior vehicle performance compared to

gasoline. Many countries have adopted or are seeking to expand methanol fueling

programs, and it is the fastest growing segment of the methanol marketplace today. This

is driven in large part by methanol's low price compared to gasoline or ethanol, and the

very small incremental cost to modify current vehicles to run on blends of methanol

fuel. Methanol also produces much less toxic emissions than reformulated gasoline, with

less particulate matter and smog forming emissions.

1.6.2 Wastewater Denitrification:

Methanol is also used by municipal and private wastewater treatment facilities to aid in

the removal of nitrogen from effluent streams. As wastewater is collected in a treatment

facility, it contains high levels of ammonia. Through a bacterial degradation process this

ammonia is converted into nitrate. If discharged into the environment, the nutrient rich

nitrate in sewage effluent can have a devastating effect on water ecosystems - creating

miles long algae blooms that sap oxygen and sunlight from aquatic life. Methanol, which

is quickly biodegrades, is a cost-effective way to help revitalize waterways tainted by the

effects of nitrates.


1.6.3 Fuel Cell Hydrogen Carrier:

Methanol is used as a key component in the development of different types of fuel cells -

which are quickly expanding to play a larger role in our energy economy. From large-

scale fuel cells to power vehicles or provide back-up power to remote equipment, to

portable fuel cells for electronics and personal use, methanol is an ideal hydrogen

carrier. With a chemical formula of CH3OH, have more hydrogen atoms in each gallon

than any other liquid that is stable in normal conditions.

1.6.4 Methanol as a cleansing agent:

Methanol is used in many cleansing operation such as in washing steel surface before

coating are applied rinsing the interiors of electronic tubes before they are evacuated

cleaning resign sheets before further processing. It is employed as a reducing agent in the

vapor phase cleaning of copper. It is also used in special preparation for dry cleaning

leather goods, in glass and in flushing fluids for hydraulic brake system.

1.6.5 Biodiesel Transesterification:

In the process of making biodiesel fuel, methanol is used as a key component in a

process called transesterification - to put it simply, methanol is used to convert the

triglycerides in different types of oils into usable biodiesel fuel. The transesterification

process reacts methanol with the triglyceride oils contained in vegetable oils, animal fats,

or recycled greases, forming fatty acid alkyl esters (biodiesel) and the byproduct glycerin.

Biodiesel production continues to grow around the globe, with everything from large

commercial scale operations to smaller, backyard blenders mixing this environmentally-

friendly fuel for everyday use in diesel engines.

1.6.6 Electricity Generation:

Different companies are also exploring the use of methanol to drive turbines to create

electricity. There are a number of projects currently underway that are using methanol as

the fuel source to create steam to drive turbines - which is an excellent option for areas

rich in resources other than traditional electricity sources.


1.6.7 Methanol as a solvent:

Methanol is miscible with most organic liquids and it is a solvent of substance like dyes,

nitrocellulose, polyvinyl and modified resin.it is use in the manufacturing of wood and

metal polishes. Water proofing formulation is coated fabrics and other inks. Its solution

has lower velocities than similar solution made from other alcohols. Methanol is use with

5 to 10 % combination of poly hydroxyl alcohol as a solvent for water aniline dyes in

manufacturing of none grain raising wood stain. Methanol does not dissolve cellulose

acetate and acetate butyrate, polyethene, polyvinyl chloride and co-polymers.

1.6.8 Chemical Feed Stock

Methanol is a key component of hundreds of chemicals that are integral parts of our daily

lives. Methanol is most often converted into formaldehyde, acetic acid and olefins - all

basic chemical building blocks for a number of common products. There are a number of

products that are developed from these materials, too many to list all on this page, but

needless to say methanol is all around us and is a critical component of modern life.

Here are just some types of materials that are made from methanol:

i. Plastics

ii. Synthetic fibers

iii. Paints

iv. Magnetic film

v. Safety glass laminate

vi. Adhesives

vii. Solvents

viii. Carpeting

ix. Insulation

x. Refrigerants

xi. Windshield washer fluid

xii. Particle

There are thousands more products that also touch our daily lives in which methanol

is a key component.


Chapter 2

Process Selection


Methanol is often called wood alcohol because it was once produced chiefly as a

byproduct of the destructive distillation of wood. Most methanols today is produced

from the methane found in natural gas, but methanol is also produced from all types of

biomass, coal, waste, and even CO2 pollution from power plants.

Methanol, unlike oil or gas, does not occur naturally, but, like hydrogen, it is an energy

vector. There are a very large number of routes to make methanol. These range from very

large scale processes based on gas, coal or other fossil resources, to a range of processes

based on renewable biomass feedstocks.

Methanol is manufactured in two major steps; the first step converts the feedstock into

syngas and the next step converts the syngas into methanol. The widest choices in the

route to methanol come in the choice of feedstock and the choice of syngas technology.

2.1 Choice of Feedstock4:

2.1.1 Biomass: Using biomass as a feedstock for making methanol has the overarching benefit of being a

sustainable source. Its main raw material is woody biomass which is short in Pakistan.

This has led to an extensive research into technologies of making methanol from

biomass. The bottleneck arrives at the fact that yields from all biomass to methanol plants

are substantially low; lesser than about 32%. For this reason, biomass was overlooked as

a potential source for making methanol. The feedstock costs is much higher due to its

uneasy availability.5

4 Kirk Othmer Encyclopedia of Chemical Technology, Volume 10

5 http://www.nrel.gov/docs/legosti/old/17098.pdf
http://www.nrel.gov/docs/legosti/old/17098.pdf


2.2.3 Natural Gas:

The majority of worldwide methanol plants use natural gas as their feedstock. Natural gas

is preferred firstly, because of its wide availability and secondly, because the syngas it

generates has a favorable composition for methanol formation.

2.2.4 Natural Gas Reserves in Pakistan6:

Exploration of natural gas reservoirs in the recent past has shown that Pakistan can be

self-sufficient in its natural gas demand. The fields of natural gas that exist in the country

are7:

i. Zarghun Gas Field

ii. Mari Gas Field

iii. Zindan Gas Field

iv. Hanna

2.2.5 Coal: A Fossil Fuel:

Fossil fuels are derived from plant and animal matter. They formed naturally over

millions of years. These energy-producing fuels are the remains of ancient life that have

undergone changes due to heat and pressure. The primary fossil fuels are coal, petroleum

and natural gas. Together they account for 85% of the world's energy consumption.

Coal is a dark, combustible material formed, through a process known as coalification,

from plants growing primarily in swamp regions. Layers of fallen plant material

accumulated and partially decayed in these wet environments to form a spongy, coarse

substance called peat. Over time, this material was compressed under sand and mud, and

heated by the earth to be transformed into coal. Some scientists refer to coal as

sedimentary rock. Coal is primarily composed of carbon, hydrogen, oxygen and nitrogen

along with variable quantities of other elements, chiefly sulfur, hydrogen, oxygen and

nitrogen. It is easily combustible, and burns at low temperatures; it is also making coal-

fired boilers cheaper. It is use widely and easily distributed all over the world; it is

comparatively inexpensive to buy on the open market due to large reserves and easy

6www.indexmundi.com

7 See Appendix B, Figure 1.1
http://www.indexmundi.com/


accessibility. The five largest coal users - China, USA, India, Japan and South Africa -

account for 82% of total global coal use.

2.2 Choice of Syngas Technology8:

A number of technologies are available for syngas formation9:

2.2.1 Steam Methane Reforming10:

The predominant commercial technology for syngas generation has been, and continues

to be, steam methane reforming SMR, in which methane and steam are catalytically and

endothermic ally converted to hydrogen and carbon monoxide. In this kind of reactors a

pre-heated mixture of natural gas and steam is passed through catalyst-filled tubes,

allocated inside a direct heated furnace. A part of the fuel is combusted inside the furnace

to generate the heat necessary for the endothermic reforming reactions inside the tubes.

Depending on the position of the burners these reformers are categorized within top-fired,

bottom-fired, side-fired, etc. In natural gas steam reforming, 35-50% of total energy input

is absorbed by the reforming process, of which half is required for temperature rise and

the other half for the reaction itself. The produced syngas leaves the reformer at a

temperature of 800900C. The heat of the flue gases is usually utilized in the convective

part of the reformer by generating steam and preheating the feedstock, thus bringing the

overall thermal efficiency to over 85%. In the SMR configuration the needed energy for

the endothermic reforming reaction must pass throughout to different barriers e.g. from

the combusted fuel to the tube walls and from the tube walls to the catalyst inside the

tubes. Typical operating parameters of the SMR process are: pressure 20-26 bar,

temperature 850950C H2/CO ratio 2,96,5. Complete conversion cannot be obtained in

the SMR process: typically 65% of methane is converted, at best it is about 98%, and so

secondary reforming must be used if a higher conversion rate is desired. The SMR

process is the most proven technology with a great deal of industrial experience; it

requires no oxygen and produces syngas with a high H2/CO ratio. It also has relatively

low operating temperatures and pressures in comparison to other technologies.

8 CHRISGAS October 2005_WP11_D89 Literature and State-of-the-Art review (Re: Methane Steam

Reforming 9 See Appendix B, Table 1.2

10 See Appendix B, Figure 1.2


Nevertheless, expensive catalyst tubing and a large heat recovery section make an SMR

plant a costly investment that can only be justified for very large-scale production.

2.2.1.1 Advantages:

i. Most extensive industrial experience

ii. Oxygen not required

iii. Lowest process temperature requirement

2.2.1.2 Disadvantages:

i. H2/CO ratio is often higher than required (3-6)

ii. Highest air emissions

2.2.2 Partial Oxidation Reforming11:

An alternative approach is partial oxidation, the exothermic, non-catalytic reaction of

methane and oxygen to produce a syngas mixture. SMR and partial oxidation inherently

produce syngas mixtures having appreciably different compositions.

In partial oxidation reformers, a part of the fuel is combusted inside the reformer to

supply the heat necessary for the endothermic reforming reactions. A refractory-lined

pressure vessel is fed with natural gas and oxygen at a typical pressure of 40 bars. Both

natural gas and oxygen are preheated before entering the vessel and mixed in a burner.

Partial oxidation reaction occurs immediately in a combustion zone below the burner.

To avoid carbon deposition the reactants should be thoroughly mixed and the reaction

temperature should not be lower than 1200C. Sometimes steam is added to the mixture

to suppress carbon formation. In the case of catalytic partial oxidation steam is not

required and the temperature can be below 1000C. The syngas produced leaves the

reactor at temperatures of 13001500C. The syngas from the POX process has a H2/CO

ratio between 1.6 and 1.8, so a shift converter or steam injection is necessary to increase

this ratio for methanol synthesis.

11

See Appendix B, Figure 1.3


The non-catalytic process allows the use of a broad range of hydrocarbon fuels from

natural gas to coal and oil residue and remains the only viable technology for heavy

hydrocarbons. The catalytic process has a reduced size and consumes less oxygen, but

runs the risk of catalyst destruction by local thermal stress.

2.2.2.1 Advantages:

i. Feedstock desulfurization is not required

ii. Absence of catalyst permits carbon formation and therefore, operation

without steam, significantly lowering syngas CO2 content.

iii. Low methane slip

iv. Low natural H2/CO ratio is an advantage for applications requiring ratio

less than 2


i. Low natural H2/CO ratio is an advantage for applications requiring ratio

greater than 2

ii. Very high process operating temperatures

iii. Usually requires Oxygen

iv. High temperature heat recovery and soot formation/ handling adds process

complexity

v. Syngas Methane content is inherently low and not easily low and not

easily modified to meet downstream processing requirements.

2.2.3 Auto thermal Reforming12:

This process combines partial oxidation and steam reforming in one vessel, where the

hydrocarbon conversion is driven by heat released in the POX reaction. Both light and

heavy hydrocarbon feed stocks can be converted. In the latter case, an adiabatic pre-

reformer is required. In this process a preheated mixture of natural gas, steam and oxygen

is fed through the top of the reactor. In the upper zone, partial oxidation proceeds at a

temperature of around 1200C. After that, the mixture is passed through a catalyst bed,

where final reforming reaction takes place. The catalyst destroys any carbon formed at

12

See Appendix, Figure 1.4


the top of the reactor. The outlet temperature of the catalyst bed is between 850 and

1050C.

The main advantages of ATR are a favorable H2/CO ratio (1.6 to 2.6), reduction of

emissions due to internal heat supply, a high methane conversion, and the possibility to

adjust the syngas composition by changing the temperature of the reaction. However, it

requires an oxygen source. The capital costs for auto thermal reforming are lower than

those of the SMR plant by 25%. Operational costs, however, are the same or even higher

due to the need to produce oxygen. The heat transfer to the catalyst bed is more favorable

in an auto thermal reformer than in the externally heated tubular reformers, since in the

former case the heat in the gas is supplied directly to the catalyst bed. This means that a

high temperature in the catalyst bed can be achieved by burning only a small portion of

the product gas. The quantity of the gas to be burned will be dependent to the inlet

concentration of the methane and other reform able compounds (such as tars) in the

gas. It is more likely that the initial temperature increase in the combustion zone will

reduce the concentration of the tars and other hydrocarbons sharply. However it must be

taken to account that the combustion reaction will consume a part of the hydrogen that is

present in product gas.

2.2.3.1 Advantages:

i. Natural H2/CO ratio is often favorable

ii. Lower process temperature requirement than partial oxidation

iii. Low methane slip

iv. Syngas Methane content can be tailored by adjusting reformer outlet

temperature


i. Limited commercial experience

ii. Usually requires Oxygen


2.2.4 Gas Heated Reforming13:

In the gas heated reformer (GHR) concept the heat for the endothermic reaction is

supplied by cooling down the reformed gas from the secondary reformer. The feed in the

gas-heated reformer is passed first to the primary reformer where about 25% of reforming

takes place. The partially reformed gas is then passed to a secondary oxygen-fired

reformer. The effluent of the latter is used to heat up the feed in the primary reformer. For

start-up, an auxiliary burner is employed. The volume of a GHR is typically 15 times

smaller than the volume of a fired reformer (SMR or CO2) for the same output.

Overheating of hot metal parts and a poor temperature control can lead to problems

concerning the reliable operation of heat exchange reformers. To overcome these

problems, reformers usually use counter-current flows in the low-temperature part with

effective heat transfer and co-current flows in the hot section for a better temperature control.

2.2.4.1 Advantages:

i. Compact overall size

ii. Application flexibility offers additional options for providing incremental

capacity


i. Limited commercial experience

ii. In some configurations, must be used in tandem with another syngas

generation technology.

iii. Increased compression costs in methanol plant

The choice of technology for manufacturing of synthesis gas depends on the scale of

operation. For capacities below 1000-1500 tons/day steam reforming would be cheapest,

whereas auto thermal reforming (ATR) would be cheapest at capacities around

5000 tons/day. For the intermediate range, a combination would be the optimal

solution14

.

13

See Appendix B, Figure 1.5 14

TKP 4170 Process Design Project, Norwegian University of Science and Technology


Chapter 3

Process Description


3.1 Process Flow Sheet


Production of methanol from coal by gasification process is consisting of following steps.

3.2 Feed Preparations

3.3 Production of Syn Gas

3.4 Cooling of Syn Gas

3.5 Purification of Syn Gas

3.6 Rearrangement of H2 and CO

3.7 Production of Methanol

3.8 Refining of Methanol.

3.2 Feed Preparation

Coal is the main feedstock that should be prepared before entering the Syn gas production area. Firstly coal is crushed in a crusher and eventually it

is made fine powder by using ball mill. The coal particle size should be less than 0.1 mm.

Although we can use coal slurry but our feed site contains only solid coal. The coal we

extract from THAR Coal is sub-bituminous Coal. This coal enters at room temperature

into the gasifier where it is reacted. The oxygen stream from Air separator system is

compressed to the desired temperature of 3200 kPa so that it may react with coal. The

steam used should be super saturated at a temperature of 230C.

3.3 Production of Syn Gas

SYN gas (synthetic gas) is the mixture of varying ratios of CO, CO2, and H2 mainly and

small quantities of CH4, NH3, and sulfur contents. Syn gas is produced from coal by

gasification process using Entrained flow gasifier.

We select Entrained flow gasifier because of following reasons.

i. The fine coal particles react with flowing steam and oxygen.

ii. Since the gasifier operates at a high temperature.

iii. A good conversion of about 99% is obtained

iv. The destruction of tar and oil yields a very pure syngas.

v. It has a high oxygen demand.

vi. The high ash content in the sub-bituminous would drive the oxygen consumption

to higher levels.


Gasification is a process for converting carbonaceous materials to a combustible or

synthetic gas (e.g., H2, CO, CO2, CH4).In general, gasification involves the reaction of

carbon with air, oxygen, steam, carbon dioxide, or a mixture of these gases at 1,500C

and under pressure of 3200 KPa.

The Syn gas product ratio of H2: CO has a target of 2:1 for direct synthesis to methanol.

However, there are several different gasification operators that produce a variety of

products from Syn gas. The aim for methanol synthesis is to use the operation that will

minimize an extra processing step, namely the downstream water gas shift reactor to

adjust the levels of CO to meet the 2:1 ratio with methanol.

Reaction Reaction heat

kj/kg.mol Process

Gas ReactionSolid

C+O2 CO2 +393770 Combustion

C+ 2H2 CH4 +74900 Hydrogasification

C+ H2O CO+H2 -175440 Steam-carbon

C+ Co2 2CO -172580 Boudouard

Gas-Phase Reaction

H2o + CO H2+ C02 +2853 Water gas shift

Co + 3H2 CH4+ H2

O +250340 Methanation

A great deal depends on the gasifier system, coal reactivity and particle size, and method

of contacting coal with gaseous reactants (steam and air or oxygen). It is generally

believed that oxygen reacts completely in a very short distance from the point at which it

is mixed or comes in contact with coal or char. The heat evolved acts to pyrolysis the

coal, and the char formed then reacts with carbon dioxide, steam, or other gases formed

by combustion and pyrolysis.


3.4 Cooling of Syn Gas

The hot Syn gas mixture from the gasifier outlet is at the temperature of about 1500C.

This is very much high temperature as for as Syn gas is concerned for further processing.

So it is cooled in multistage heat exchanger decreasing its temperature up to 300C.

3.5 Purification of Syn Gas

The Syn gas produced contains various types of impurity gasses the most prominent of

them are CO2 and sulfur containing gasses. They should be removed otherwise they can

damage the catalyst in methanol reactor.

A non-reactive absorption unit is installed for this purpose. The solvent employed here

may be

i. MEA (mono ethanol amine)

ii. DEA (di ethanol amine)

The solvent rich in sulfur gasses is then further processed by Clause Process to

produce elemental sulfur.

3.6 Rearrangement of H2 and CO

As we can see from the kinetics and equilibrium data that at this stage the exact ratio of

CO and H2 is not 1:2.It is very much important to achieve that ratio or their approximate

value. So in either adiabatic or isothermal reactor this ratio is achieved. Adiabatic

reactors have no heat transfer, but the temperature within the reactor increases due to the

reaction being exothermic.

Another consideration is the catalyst. According to the literature, the catalysts are

manufactured by iron oxide with 5-15% Cr2O3. The particle size, time in contact with the

stream and the pressure - all affect the reaction rate. The operating temperature of the

reactor is 400C.


The reaction involved is

CO + H2O CO

2 + H

2

As the reaction is exothermic so a cold water jacket is supplied around the

reactor to keep the temperature constant at 400C.

3.7 Production of Methanol

The next step is the reaction of CO and H2 to produce methanol. This may accompanied

by another reaction that also produce one mole of methanol and water. The reactor used

for this is plug flow reactor because as the feed moves forward it is converted into

methanol product.

The first reaction is the primary methanol synthesis reaction, a small amount of CO2 from

the water gas shift reaction in the feed (210%) acts as a promoter of this primary

reaction and helps maintain catalyst activity. The stoichiometry of both reactions is

satisfied when the ratio is

2. Hydrogen builds up in the recycle loop; this leads to an actual R value of the Combined

synthesis feed (make up plus recycle feed) of 3 to 4. The reactions are exothermic and

give a net decrease in molar volume. Therefore, the equilibrium is favored by high

pressure and low temperature.

During production, heat is released and has to be removed to keep optimum catalyst life

and reaction rate. The produced methanol reacts further to form side products such as

dimethyl ether, formaldehyde, or higher alcohols (van Dijk et al. 1995) these by products

will be negligible in the preliminary design reported, but noted for awareness.

Conventionally, methanol is produced in two phase systems, the reactants and products

forming the gas phase and the catalyst forming the solid phase. Before refining of this

methanol solution, it is passed through a flash drum where pressure is reduced up to 500

KPa. Due to this pressure reduction, the syn gasses are separated from methanol-water

solution. These gasses are vented or recycled while methanol solution is sent for refining.

CO + 2H2 CH

3OH

CO2 + 3H

2 CH

3OH + H

2O


3.8 Refining of Methanol

The stream entering the distillation column had a weight composition of 56.78%water,

42.225% methanol, 1.40% ethanol. The distillate from the distillation column had a

weight composition of 0.005% water, 99.95% methanol, 0.56% ethanol.

The AA methanol grade purity specifications require that the weight composition of the

methanol be greater than 99.85% methanol on a dry basis, less than 0.1% water, and less

than 50 ppmw ethanol will .be greater than 99.85% methanol on a dry basis, less than

0.1% water, and less than 50 ppmw ethanol. The distillate does not match these

specifications.


Chapter 4

Capacity Selection


The methanol industry is one of the worlds most dynamic and vibrant producing a

basic chemical molecule that touches our daily lives in a myriad of ways. From the basic

chemical building block of paints, solvents and plastics, to innovative applications in

energy, transportation fuel and fuel cells, methanol is a key commodity and an integral

part of our global economy.

4.1 Global Demand of Methanol:

The methanol industry spans the entire globe, with production in Asia, North and South

America, Europe, Africa and the Middle East. Worldwide, over 90 methanol plants have

a combined production capacity of about 75 million metric tons (almost 24 billion gallons

or 90 billion liters), and each day more than 100,000 tons of methanol is used as a

chemical feedstock or as a transportation fuel (33 million gallons or 125 million liters).

Methanol is also a truly global commodity, and each day there is more than 80,000 metric

tons of methanol shipped from one continent to another

.

In 2010, global methanol demand totaled about 45.6 million metric tons and is expected

to exceed 50 million metric tons in 2011, driven in large part by the resurgence of the

global housing market and increased demnd for cleaner energy.


But the methanol industry is not just those companies large and small throughout the

globe that produce methanol every day from a wide array of feedstocks including

natural gas, coal, biomass, waste and even CO2 pollution the industry is also made up

of thousands of distributors, technology innovators, downstream manufacturers and

service providers.

4.2 South Asia Methanol Demand

Domestic Production

The production of Methanol totaled at 29291 tons in the June 2012, declined 14% y-o-y

but improved robustly261% sequentially. Indian companies have produced 23191 tonne

of Methanol in May and 27594 tons in April.

i. Deepak Fertilizers & Petrochemicals Corporation is the second largest methanol

producer with installed capacity of 1, 00,000 TPA.

ii. Rashtriya Chemicals & Fertilizers (RCF) is the third largest methanol producer

with installed capacity of 72,600 TPA.

iii. Assam Petrochemicals has an installed capacity of 33,000 TPA of methanol.

iv. Total domestic production of methanol in India is 4743000 TPA.

v. More than 60% of Methanol domestic demand is being meeting by imports and

the international market has a direct bearing on domestic prices.


vi. If we add this methanol import in total methanol domestic production then we can

say from calculations that total methanol demand of India in last year is 1182500

TPA.

4.3 China Methanol Industry

China has been the largest methanol consuming country, and will increase its share of

world consumption from almost 41% in 2010 to about 54% in 2015. With total installed

methanol capacity in China does around 38 million tons comprise 60% of the global

capacity with a production of 15.88 million tons indicating capacity utilization of 65%. In

spite of such a low capacity China is further adding around 15 million capacity of

methanol in the coming years on prospect of less reliable on crude oil. Increased demand

in the Chinese market has been fueled by methanol gasoline blending and dimethyl ether

(DME), which combined account for 33% of the Chinese methanol demand and are

expected to grow by 30% this year alone.


Total Demand of methanol in China is around 21 million tons comprising 5 million tonne

of imports mainly from import from Middle East Countries. Middle East countries

produces methanol at a much cheaper cost due to lower natural gas prices while in China,

methanol is mainly produced from coal, which accounts for about 60% to 70% of the

total production cost of methanol.

Coal is the major raw material for the production of methanol in China constituting

around 57% followed by natural gas of around 28% and coke oven gas of around 15%.

Middle East Countries too are adding around 11 million tons of methanol capacity.

China to overcome excess methanol capacity is developing and exploiting new

application potentials for methanol. Millions of metric tons of methanol will be mainly

used for direct blending into gasoline and for conversion into DME - again for use as a

fuel. China is promoting methanol to olefin technology.

Methanol is used to produce acetic acid, formaldehyde, and a number of other chemical

intermediaries that are utilized to make countless products throughout the global

economy and by volume, methanol is one of the top 5 chemical commodities shipped

around the world each year. The global methanol industry generates $36 billion in

economic activity each year, while creating over 100,000 jobs around the globe.

Keeping in view the trends of the methanol industry and the global demand, the capacity

selected for our process is 250 Metric tons per day (MTPD).


For the material and energy balance of the entire plant, the following conditions used:

Chapter # 5

Material and Energy

Balance


Basis=1 hour

Reference Temperature= 25 oC

Reference Pressure= 1 bar

Methanol grade AA=99.95 wt %

5.1 Material Balance on Distillation Column:

In Stream

m 11= 578.08 MT/Day

No Component % Age Flow rate

1 CH3OH 43.225 249.87508

2 H2O 56.78 328.23382

Out Stream

m1 279.05 Mt/day

m2 48.71 Mt/day

m3 580.08 Mt/day

m4 872.94 Mt/day

m5 818.34 Mt/day

m6 818.34 Mt/day

m7 872.94 Mt/day

m8 28.28 Mt/day

m9 846.62 Mt/day

m10 846.62 Mt/day

m11 578.08 Mt/day

m12 268.54 Mt/day

m13 328.08 Mt/day

m14 250 Mt/day

m 11

m 14

m 13


m14 = 250 MT/Day

No Component % Age Flow Rate

1 CH3OH 99.95 249.875

2 H2O 0.05 0.125

m13=328.08 MT/Day


1 H2O 100 328.28

Capacity = m14 = 250 Metric Ton /Day (1)

Overall Balance

m11 = m13 + m14 (2)

m11 (0.43225) = m14 (0.995) + m13 (0)

From (1)

m11 = 578.08 MT/Day

Similarly from Eq. (2)

m13 = 328.08 MT/Day

5.2 Material Balance on Flash Drum:

m 12

m 10


In Stream

m10 = 846.62 MT/Day


1 CH3OH 29.5 249.7529

2 H2O 38.77 328.2345

3 CO 1.86 15.7471

4 CH4 0.59 4.995

5 N2 0.54 4.5717

6 H2 1.7 14.392

7 CO2 27.03 228.841

8 Ethanol 0.00573 0.04851

9 Solvent 0.0047 0.03979

Out Stream

m12=268.54 MT/Day


1 CO 5.86 15.7364

2 H2 5.36 14.39

3 CH4 1.86 4.99

4 N2 1.7 4.565

5 CO2 85.19 228.76

6 Solvent 0.0148 0.03974

7 Ethanol 0.018 0.04833

m11=578.08 MT/Day

m 11



1 CH3OH 43.225 249.875

2 H2O 56.78 328.233

m11 = 578.08 MT/Day (3)

Overall Balance

m10 = m11 + m12 (4)

m10 (0.3877) = m11 (0.5678) + m12 (0)

From Eq (3)

m10 = 846.62 MT/Day

Put this in Eq (4)

m12 = 268.54 MT/Day


5.3 Material Balance on Reactor:

CO + 2H2 CH3OH

CO2 + 3H2 CH3OH + H2O

In Stream

m9= 846.62 MT/Day


1 CO 24.54 207.760

2 H2 49.07 415.436

3 CH4 0.47 3.979

4 N2 0.43 3.640

5 CO2 22.15 187.526

6 H2O 3.34 28.277

7 Solvent 0.0037 0.03132

m10 = 846.62 MT/Day

Overall Balance

m9 = m10 (5)

From Eq. (5), we get

m9 = 846.62 MT/Day

m 10 m 9


5.4 Material Balance on Water Gas Shift Reactor:

CO + H2O CO2 + H2

In Stream

m8=28.28 MT/Day


1 Stream 100 28.28

m6= 843.28MT/Day


1 CO 55.82 456.797

2 H2 38.83 317.761

3 CH4 0.61 4.991

4 N2 0.54 4.419

5 CO2 4.2 34.370

6 Absorber 0.3928 0.3928

m 8

m 6

m 9


Out Stream

m9=846..62MT/day


1 CO 24.54 207.760

2 H2O 3.34 28.277

3 N2 0.43 3.640

4 H2 49.07 415.436

5 CO2 22.15 187.526

6 CH4 0.47 3.979

7 Solvent 0.0037 0.0313

m9 = 846.62 MT/Day (6)

Overall Balance

m9 = m6 + m8 (7)

Water Balance

m9 (0.0334) = m6 (0) + m8 (1.0)

From Eq (6)

m8 = 28.28 MT/Day

Put this in Eq (7)

m6 = 818.34 MT/Day


5.5 Material Balance on Acid Gas Absorber:

In Stream

m5= 818.34MT/day

no Component % age Flow rate

1 Absorber Solvent 100 818.34

m4=872.94 MT/day


1 CO 52.17 455.412

2 H2O 5.58 48.710

3 N2 0.54 4.713

4 H2 36.27 316.615

5 CO2 3.92 34.21

6 CH4 1.12 9.776

7 NH3 0.049 0.4277

m 7

m 6

m 5

m 4


Out Stream

m7=872.94 MT/day


1 N2 0.027 0.235

2 H2O 5.36 46.789

3 CH4 0.53 4.626

4 H2 S 0.39 3.40

5 Solvent 93.7 817.944

m6= 818.73MT/day


1 CO 55.82 456.797

2 H2 38.83 317.76

3 CH4 0.61 4.99

4 N2 0.54 4.419

5 CO2 4.2 34.37

9 Absorber 0.048 0.392

m6 = 818..28 MT/day (8)

Overall Balance

m4 + m5 = m6 + m7 (9)

Solvent Balance

m4 (0) + m5 (1.0) = m6 (0) + m7 (1.0)

m4 = 817.947 + m7 (0.063) (10)

H2S Balance

m4 (0.0039) + m5 (0) = m6 (0) + m7 (0.0039)

m4 = m7

Put in (10), we get

m4 = 872.94 MT/Day

From Eq. (9)

m5 = 818.34 MT/Day


5.6 Material Balance on Gasifier:

In Stream

m1=279.05MT/day


1 C 66.84 186.517

2 H 4.89 13.645

3 N 1.49 4.15

4 S 1.22 3.40

5 O 13.04 36.38

6 Ash 12.51 34.90

m2=48.71MT/Day


1 Steam 48.71 48.71

m3= 580.08 MT/day


1 O2 100 580.08

m 4

m 1

m 2

m 3


Out Stream

m4=872.94 MT/Day


1 CO 52.17 455.412

2 H2 36.27 316.615

3 CO2 3.92 34.219

4 H2O 5.58 48.71

5 N2 0.54 4.713

6 H2S 0.39 3.404

7 CH4 1.12 9.776

8 NH3 0.049 0.427

m4 = 872.94 MT/Day (11)

Overall Balance

m1 + m2 + m3 = m4 + A (12)

Steam Balance

m1 (0) + m2 (1) + m3 (0) = m4 (0.0558) + A (0)

From (11)

m2 = 48.71 MT/Day

Ash Balance

m1 (0.1251) + m2 (0) + m3 (0) = m4 (0) + A (1)

A = (0.1251) m1 (13)

Atomic Sulfur Balance

m1 (0.0122) + m2 (0) + m3 (0) = m4 (0.0039

m1 = 279.05 MT/Day

From (13)

A = (0.1251)(279.05)

A = 34.9 MT/Day put in (12)

279.05 + 48.71 + m3 = 872.94 + 34.9

m3 = 580.08 MT/day


Energy Balance:

5.7 Energy Balance on Gasifier

Overall Energy Balance

Q W = K.E + P.E + H

W, K.E and P.E is neglect

So it becomes,

Q = H

H = H(product) - H(reactant) + H(formation)

Component

s

hf

KJ/Mol Flow Rate Components

hf

KJ/Mol

Flow

Rate

O2 0 36.38 H2 0 13.64

H2O -241.8 48.71 N2 0 4.15

C 0 186.517 H2S -20.7 3.40

CO2 -293.59 34.21 CH4 -74.6 9.77

CO -110.25 455.412

Coal 25 C

3200KPa

Steam 230 C

3200KPa

O2 25 C

3200KPa

Syn Gas 1500 C

3200KPa


Enthalpy of Formation:

H = ( Hf) (products) - ( Hf) (reactants)

Reaction Hf K J/mol

C+O2 CO2 -393.59

C+0.5 O2 CO -110.525

C+ H2O CO+ H2 131.275

C+ Co2 2CO 283.065

H2o + CO H2+ C02 -41.256

Co + 3H2 CH4+ H2 O 205.875

C+ 2H2 CH4 -74.6

H2 + S H2S -20.6

N2 +3H2 2NH3 -45.90

Hf=Hf1 + Hf2 + Hf3+Hf4 + Hf5 + Hf6 + Hf7 + Hf8 + Hf9

Hf = -478.011 KJ/mol of feed reacted

Hf = -0.022 KJ/s

Heat Output

Hproduct = mCp T

After putting values Cp, we get

Cp = 26330* 1017

J/Kmol. C

Hproduct = 519.67 * 26330 * 1017

* (1500-25)

Hproduct = 5606192.27 * 1017

KJ/s

Heat Input

From Steam Table

Hin = 420.345 KJ/s

Heat Required = Hin - Hout + Hf

420.345 5.6.6 * 1023

+ 227.84

Heat Required = -5.61E23 KJ/s


5.8 Energy Balance on Heat Exchanger:


Q W = K.E + P.E + H


So it becomes,

Q = H

H = H(product) - H(reactant)

Q = H = m Cp T

Heat in by Syn Gas

As from previous

Heat in = 5.6.6 * 1023

KJ/s

Heat in by Water

As water is in at reference temperature, so heat in by water is 0

Heat out by Cooled Syn Gas

Q = m Cp T

Cp of Syn gas is = 2.633 * 1023

J/Kmol. C

Q = 520 * 2.633 * 1021

* (300 C - 25 C)

Q = 0.1045886 * 1 0

23 KJ/s

Water Out 616 C

Hot Syn 1500 C

Gas 3200KPa

Water in 25 C

Cooled Syn 300 C

Gas 3127 KPa


Heat out by Water

From steam table

H = 67327.38 KJ/gmol

From ASPEN

Flow rate of outlet water n = 300.269 Kmol/hr

Q = H = 67327.38 * 300.269

Q = 5615.64 KJ/s

So total

Qout = 1.0458886 * 1022

+ 5615.645

Qout = 5.61669 * 1023

KJ/s

So proved,

Qin = Qout


5.9 Energy Balance on Water Gas Shift Reactor:

Reaction:

CO + H2 O CO2+ H2


Q W = K.E + P.E + H


So it becomes,

Q = H

H = H(product) - H(reactant) + H(formation)

Component Hf KJ/mol.K Flow Rate

H2 O -241.8 28.27

CO -110.525 207.76

H2 0 415.43

CO2 -393.509 187.52

Enthalpy of Formation

Hf = { (-393.509) + (0) } - { (-110.525) + (-241.8) }

Hf = - 41.184 KJ/mol

Hot purified Gas 400 C

3100KPa

Steam 400 C

3100KPa

Syn Gas 400 C

2400 KPa


Heat input

H reactant = m Cp T

There are two reactants

H steam = 3231 KJ/Kg

Mass flow rate = m = 2.28 MT/day

m = 0.3273 Kg/s

m H steam = 3231 * 0.327

m H steam = 1075.55 KJ/s

H Syn Gas = m Cp T

Cp of Syn Gas = -8.53992E16 J/gmol. C

Q = m Cp T

= 487.17 * (-8.53992E16)(400 25)(100

Q = -433.374E16 KJ/s

Heat Output

H out = m Cp T

Cp = 2.4737E16 J/kmol. C

m = 504.019 Kmol/hr.

Q = 504.019 * 2.4737E16 * (400 25) (1

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