project
DESCRIPTION
This is project regarding oiL and GasTRANSCRIPT
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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
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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
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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.
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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
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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
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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
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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.
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Chapter 1
Introduction
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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
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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
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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
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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.
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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
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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
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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
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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.
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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.
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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.
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Chapter 2
Process Selection
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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 -
Production of Methanol from Coal Page 25
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/ -
Production of Methanol from Coal Page 26
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
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Production of Methanol from Coal Page 27
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
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Production of Methanol from Coal Page 28
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
2.2.2.2 Disadvantages:
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
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Production of Methanol from Coal Page 29
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
2.2.3.2 Disadvantages:
i. Limited commercial experience
ii. Usually requires Oxygen
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Production of Methanol from Coal Page 30
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
2.2.4.2 Disadvantages:
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
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Production of Methanol from Coal Page 31
Chapter 3
Process Description
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Production of Methanol from Coal Page 32
3.1 Process Flow Sheet
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Production of Methanol from Coal Page 33
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.
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Production of Methanol from Coal Page 34
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.
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Production of Methanol from Coal Page 35
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.
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Production of Methanol from Coal Page 36
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
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Production of Methanol from Coal Page 37
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.
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Production of Methanol from Coal Page 38
Chapter 4
Capacity Selection
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Production of Methanol from Coal Page 39
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.
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Production of Methanol from Coal Page 40
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.
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Production of Methanol from Coal Page 41
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.
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Production of Methanol from Coal Page 42
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).
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Production of Methanol from Coal Page 43
For the material and energy balance of the entire plant, the following conditions used:
Chapter # 5
Material and Energy
Balance
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Production of Methanol from Coal Page 44
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
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Production of Methanol from Coal Page 45
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
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 46
In Stream
m10 = 846.62 MT/Day
No Component % Age Flow Rate
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
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 47
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 48
5.3 Material Balance on Reactor:
CO + 2H2 CH3OH
CO2 + 3H2 CH3OH + H2O
In Stream
m9= 846.62 MT/Day
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 49
5.4 Material Balance on Water Gas Shift Reactor:
CO + H2O CO2 + H2
In Stream
m8=28.28 MT/Day
No Component % Age Flow Rate
1 Stream 100 28.28
m6= 843.28MT/Day
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 50
Out Stream
m9=846..62MT/day
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 51
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
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 52
Out Stream
m7=872.94 MT/day
No Component % Age Flow Rate
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
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 53
5.6 Material Balance on Gasifier:
In Stream
m1=279.05MT/day
No Component % Age Flow Rate
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
No Component % Age Flow Rate
1 Steam 48.71 48.71
m3= 580.08 MT/day
No Component % Age Flow Rate
1 O2 100 580.08
m 4
m 1
m 2
m 3
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Production of Methanol from Coal Page 54
Out Stream
m4=872.94 MT/Day
No Component % Age Flow Rate
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
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Production of Methanol from Coal Page 55
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
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Production of Methanol from Coal Page 56
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
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Production of Methanol from Coal Page 57
5.8 Energy Balance on Heat Exchanger:
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)
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
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Production of Methanol from Coal Page 58
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
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Production of Methanol from Coal Page 59
5.9 Energy Balance on Water Gas Shift Reactor:
Reaction:
CO + H2 O CO2+ H2
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 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
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Production of Methanol from Coal Page 60
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