Training Session on Energy
Equipment
Industry Sectors
Presentation to
Energy Efficiency Guide for Industry in Asia
Chapter 15
1
© UNEP GERIAP
Training Agenda: Industry Sectors
1) Iron & Steel
3) Cement
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
2) Chemical
4) Pulp & Paper
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
2
© UNEP 2005
Iron & Steel Industry
Sector Description
Two categories:
1. Primary steel production
•
Manufactured right from the basic iron and
steel ore to final product
2. Secondary steel production
•
Conversion metal scrap, ignots and metal
scraps manufactured through various routes
3
© UNEP 2005
Iron & Steel Industry
Process Flow
 Basic primary steel
process
• High grade iron ore is
crushed for sizing and to
produce both fine and
lump ore
• Pelletizing is a process
that mixes very fine
ground particles of ore
with limestone, dolomite
etc
Figure: Primary steel making4 process
Source: JFE
© UNEP 2005
Iron & Steel Industry
Process Flow
 Basic secondary steel process
• Raw material
• Re-heating furnace
• Melting
• Rolling mill
• Refining
• Cooling
• Casting
• Shearing
• Rolling
• Inspection dispatch
• Re-rolling
5
© UNEP 2005
Iron & Steel Industry
Process Flow
 Steel foundry
• Can be classified into a) melting, b) moulding, c)
fettling and d) heat treatment
 Arc furnace
• Melting of scrap by application of intense heat
generated by the arc
 Induction furnace
• Transfers energy through a magnetic field and its
6
intensity decides the amount of absorbed energy
© UNEP 2005
Iron & Steel Industry
Process Flow
 Energy flows
Raw material
• Rolling
Electricity
• Thermal energy
Fuel
Electricity
Cutting
Reheating
Furnace
• Electrical energy
Electricity
Rolling
• Steel foundry
Electricity
Cooling
• Arc melting
Electricity
Shearing
• Induction melting
Finished Product
Figure: Energy flow in rolling
7
© UNEP 2005
Iron & Steel Industry
Process Flow
 Material & energy balance
8
Figure: Energy balance in reheating furnace
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
CP-EE measures:
9
Figure: Reheating furnace
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
CP-EE measures in reheating:
Table: CP-EE measures in reheating and heat treatment furnaces
Improvement Area
Energy-Saving Measure
Energy Saving
Potential
Efficient Combustion
Maintain minimum required free oxygen in
combustion products.
2% to 10%
Efficient Combustion
(burners)
Eliminate formation of excessive amount of
CO or unburned hydrocarbons. Also
eliminate or minimize air leak-age.
2% to 10%
Flue Gas Heat Recovery
Preheat and/or dry combustion air and the
charge/load. After-burn the combustibles
and cascade the exhaust gas heat.
5% to 25%
Heat Loss Reduction
Use optimum insulation for equipment and
maintain it regularly. Employ furnace
pressure control.
1% to 5%
10
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
CP-EE measures in reheating:
Table: CP-EE measures in reheating and heat treatment furnaces
Improvement Area
Energy-Saving Measure
Energy Saving
Potential
Design of Furnaces and
Heating
Select proper burner and furnace
design to enhance heat transfer to the load.
5% to 10%
Furnace Operation
Clean heat transfer surfaces frequently.
5% to 10%
Furnace and
Heating System Heat Transfer
Replace indirect heat systems with direct heat
systems where possible.
5% to 10%
Improved Scheduling and
Load Management
Operate with full load; minimize idle time,
shutdowns, and start-up cycles.
2% to 5%
Use of Process Simulation
Use models to optimize temperature settings to
avoid long "soak" times or overheating.
5% to 10%
Equipment Design Materials
Use advanced and improved materials.
11
2% to 5%
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
CP-EE measures in arc furnace melting:
•
•
•
•
Scrap preparation
Scrap segregation
Use of oxygen lancing
Temperature control
CP-EE measures in induction melting:
•
•
•
•
Idling periods
Charge metals
Optimizing heel
Radiation losses
12
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
Energy efficient technologies:
• Melting
• Ceramic recuperator
• Ceramic fiber
• Ceramic coatings
• Regenerator
13
© UNEP 2005
Iron & Steel Industry
Energy Conservation Opportunities
Energy efficient technologies:
Figure: Regenerative burner system operating principle
14
© UNEP 2005
Training Agenda: Industry Sectors
1) Iron & Steel
3) Cement
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
2) Chemical
4) Pulp & Paper
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
15
© UNEP 2005
Chemical Industry
Sector Description
• Production of graphite for brake linings and
lubricants, chemical catalysts for plastics,
elastomers and pharmaceuticals and more
• Most chemical applications require spray
drying or milling why particle size is
important
• Most milling processes comprise a grinder,
a classifier, a cyclone and a blower
• The formed material size needs to be
measured
16
© UNEP 2005
Chemical Industry
Process Flows
 Fertilizer industry
• 85% of the world’s ammonia production is used
for making chemical fertilizer
• Fertilize production accounts for 2% of total global
energy consumption
• Fertilize production accounts for 1% of global
carbon dioxide emissions
• Ammonia manufacture is expensive and is about
70-80% of the production costs
• Natural gas is the most commonly used hydro17
carbon feedstock for new fertilizer plants © UNEP 2005
Chemical Industry
Process Flows
 Primary reforming
• The natural gas that leaves the desulphurization
tank is mixed with process steam
• It is preheated in the primary reformer
 Secondary reforming
• Only 30-40% of the hydrocarbon feed is reformed
in the primary reformer
• In a secondary, the temperature is increased to
increase conversion
18
© UNEP 2005
Chemical Industry
Process Flows
 Energy balance
• Compared to natural gas, ammonia manufacturing
with heavy oil is 30-40% more energy intensive
and with coal route 80% more
• Steam reforming ammonia plants have surplus
heat available for steam production and modern
plants can be energy self sufficient
• The theoretical minimum energy consumption for
ammonia manufacture through steam reforming is
~21.6 GJ/t of ammonia (HHV)
19
© UNEP 2005
Chemical Industry
Process Flows
Natural gas
ZnS
 Material
balance
Sulphur Removal
ZnS
H2O, Fuel
Reformer (Primary)
Air, Power
Reformer (Secondary)
Heat
Shift conversion
Heat
• Emissions from Heat, Power
ammonia plants
include SO2,
NOx, CO, CO2,
VOCs, particles,
hydrogen sulfide,
Power
methane,
Power
hydrogen cyanide
and ammonia
Carbon dioxide Removal
Condensate
CO2
Methanation
Compression
Ammonia synthesis
NH3
20
Figure: Material balance for an ammonia plant
© UNEP 2005
Chemical Industry
Energy Conservation Opportunities
Areas for CP-EE measures in ammonia plants:
•
Primary reformer
•
Shift conversion
•
Excess air reforming
•
•
Heat exchange auto
terminal reforming
Carbon dioxide removal
section
•
Leakage of CO2 from
compressors
•
Flue gas from the furnace
•
Cogeneration
•
Reformer catalyst
•
Reformer tubes
•
Furnace design
21
© UNEP 2005
Chemical Industry
Energy Conservation Opportunities
Areas for CP-EE measures in ammonia plants:
•
Ammonia converter
•
Pre-reformer
•
Carbon dioxide removal
section
•
Ammonia synthesis
converter
•
Leakage of CO2 from
compressors
•
Absorption
refrigeration system
•
Compressors
•
•
Better purification
techniques
Cooling of synthesis
gas
•
Desulphurization
22
© UNEP 2005
Chemical Industry
Energy Conservation Opportunities
Energy efficiency technologies:
• Gas heated reformers
• Selectoxo unit
• Lower syngas inert level
• Heat exchange auto terminal reforming
• Purge gas recovery unit
23
© UNEP 2005
Chemical Industry
Energy Conservation Opportunities
Energy efficiency technologies:
• Pre-reformer
• Improved catalyst
• Carbon dioxide removal processes
24
© UNEP 2005
Training Agenda: Industry Sectors
1) Iron & Steel
3) Cement
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
2) Chemical
4) Pulp & Paper
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
25
© UNEP 2005
Cement Industry
Sector Description
•
Cement is produced by grinding, blending and
burning limestone, sand, clay, bauxite or laterite
•
These contain a suitable mixture of calcium oxides,
silicon oxides, aluminum oxides and iron oxides
•
Two types of CO2 emissions occur:
1.
2.
From the energy consumption
As a by product from the calcination process
•
The global cement industry contributes to ~20% of
all man made CO2 emissions
•
The energy consumption in the cement industry is
about 2% of the global primary energy consumption
26
© UNEP 2005
Cement Industry
Process Flows
 Production processes
• Mining
- surface mining is more eco-friendly
• Crushing
- size is reduced to 25 mm
• Raw material preparation
- roller mills for grinding and separators or classifiers for separating
ground particles
• Coal milling
- provides dried pulverized coal to the kiln and precalciner
27
© UNEP 2005
Cement Industry
Process Flows
 Production processes
• Pyro processing
- transform the raw material mix into gray clinkers in the form of
spherically shaped nodules
• Pre heater and pre calciner
- from the preheater/precalciner process 60 % of flue go to the raw
mill and 40 % to the conditioning tower
• Clinker cooler
- heat recovery from the hot clinker and temperature reduction of
the clinker
• Finish milling
- grinding of clinker to produce a fine grey powder
28
© UNEP 2005
Cement Industry
Process
Flows
Diesel
Limestone Mining
for loaders, dozers
and compressors
Diesel for dumpers and
trucks/ Electrical energy for
ropeway
 Energy flows
•
•
Energy
consumption
nearly 40-40% of
production costs
Mill drives, fans
and conveying
systems are
major energy
consumers
Electrical Energy
for crushers
Electrical Energy for
Mill drive and fans
Heat Energy from
kiln off gases
Heat Energy from
fuel input
Transport
Figure:
Energy flows
in a cement
plant
Crushing
Bauxite, Ferrite
Raw Milling
Pre calcination
Electrical Energy
for mill drive and fans
Coal Milling
Electrical Energy for
Kiln drive, fans and ESP Pyro Processing
Heat Energy from
fuel input
Electrical Energy
for fans, drive and
clinker breaker
Electrical Energy for
Mill drive and fans
Heat Energy from
fuel input/waste heat
from clinker cooler
Clinker Cooling
Gypsum
Cement Grinding
29
Packing & Dispatch
© UNEP 2005
Cement Industry
Process Flows
 Electrical energy flows
• Clinker burning: ~30%
• Finish grinding: ~30%
• Raw mill circuit: ~24%
 Thermal energy flows
• 50% of the energy costs
• The kiln and precalciner are major users
30
© UNEP 2005
Cement Industry
Process Flows
 Material & energy balance
• Important for optimized operation of the cement
kiln, diagnosing operational problems,
increasing production and improving energy
consumption
• In a cement plant processes involve gas, liquid
and solid flows with heat and mass transfer, the
combustion of fuel, reactions of clinker
compounds and any undesired chemical
reactions
• Parameters to consider include velocity, static
31
pressure, dust concentration, surface
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
CO2 reductions involves a two pronged
strategy:
1. Improving energy efficiency
2. Promoting blended cements that can
decrease the clinker percentage in the
cement
32
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
Table: Classification of CP-EE measures in three steps
Raw material process
Clinker burning process
Finish process
First
step
1) Selection of raw material
2) Management of fineness
3) Management of optimum
grinding media
1) Prevention of stoppages
2) Selection of fuel
3) Prevention of leak
1) Management of fineness
2) Management of optimum
grinding media
Second
step
1) Use of industrial waste material
2) Replacement of fan rotor
3) Improvement of temperature
and pressure control system
4) Improvement of mixing &
homogenizing system
1) Use of industrial waste material
2) Recovery of preheater exhaust
gas
3) Recovery of cooler exhaust gas
4) Replacement of cooler dust
collector
1) Installation of closed
circuit dynamic separator
2) Installation of feed
control system
Third
step
1) From wet process to dry
process
2) From ball and tube mills to
roller mill
1) From wet process to dry
process
2) Conversion of fuel
3)From SP to NSP
4)Use of industrial waste
5)From planetary and under
coolers to grate cooler
33
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
CP-EE measures:
10 -20 % electrical energy reductions have
been achieved in a cement plant by:
a)
b)
c)
d)
e)
f)
g)
h)
Raw meal mix design change
Elimination of run-on equipment
Finish Mill Optimization
Avoidance of air supply leakage
Installation of more efficient fan motors
Employees’ awareness
Power monitoring and targeting
Process Replacement Measures
34
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
CP-EE measures:
• Capacity utilization
-Essential for energy efficiency
-Brings down the fixed energy loss component
-At least 90% required to achieve low specific energy
consumption
• Fine tuning equipment
-Only requires marginal investment
-Can yield 3-10% energy savings if efficiently
performed
• Technology upgrades
35
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
Energy efficient technologies:
•
Process control and management systems
•
Raw meal homogenizing systems
•
Conversion from wet to dry process
•
Conversion from dry to multi stage pre-heater
kiln
•
Conversion from dry to pre-calciner kiln
•
Conversion from cooler to grate cooler
•
36
Optimization of heat recovery in clinker cooler
© UNEP 2005
Cement Industry
Energy Efficiency Opportunities
Energy efficient technologies:
•
High efficiency motors and drives
•
Adjustable speed drives
•
Efficient grinding technologies
•
High-efficiency classifiers
•
Fluidized bed kiln
•
Advance comminution technologies
•
Mineral polymers
37
© UNEP 2005
Training Agenda: Industry Sectors
1) Iron & Steel
3) Cement
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
2) Chemical
4) Pulp & Paper
• Sector description
• Process flow
• Energy conservation
• Sector description
• Process flow
• Energy conservation
38
© UNEP 2005
Pulp & Paper Industry
Sector Description
• World production of paper and paperboard
is about 323 million tons (year 2000)
• World pulp and paper devours over 4 billion
trees annually
• The industry produces the net addition of
450 million tones of CO2 per year (IIIED)
• The fuels within the sector are coal, oil, gas
and bio fuels
• There are significant opportunities for 39
© UNEP 2005
reduction of CO2 gas emissions
Pulp & Paper Industry
Process Flows
 Manufacturing process
• Wood preparation
• Pulping
• Washing
• Bleaching
• Stock preparation
• Paper making
• Chemical recovery
40
© UNEP 2005
Pulp & Paper Industry
Trees
Bark ( fuel)
Process Flows
Barking
Used Paper
Electricity
Wood Preparation
Chipping
Steam
Pulping
Electricity
Bleaching
Chemical Pulping
Mechanical
Pulping
Waste Paper
Pulping
Bleach Plant
Kneading
Steam
Electricity
Bleach Plant
Chemical Recovery
Steam
Electricity
Liquor concentration
Refiner
Electricity
Steam
Electricity
Fuel
Electricity
Energy Recovery
Recausticization
Paper making
Figure: Process flow diagram of the pulp and paper industry
41
© UNEP 2005
Pulp & Paper Industry
Process Flows
Paper making
Steam
Stock Preparation
Electricity
Electricity
Steam
Forming
Pressing
Electricity
Steam
Drying
Electricity
Paper
Figure: Process flow diagram of the pulp and paper industry
42
© UNEP 2005
Pulp & Paper Industry
Process Flows
 Energy flows in the paper industry:
• Thermal energy
-mainly consumed in the drier
-some mills use steam for drying the after coating
• Electrical energy
-used to power the rotor or impeller
-also used as rotary power for the cylinder,
transportation, motive power and lighting loads
• Water flow
-water consumption is significant both in terms of
consumed quantities as well as environmental
43
aspects
© UNEP 2005
Steam Line 2.5 Kg/cm2
Condensate
Line 2 Kg/cm2
Showers
Fan Pump
Tank
Drying Cylinders
Calender, 52.5 Kw
Vacuum Boxes
Foil Boxes
Couch Roll, 96 Kw
Process Flows
Head Box
22 Kw
22 Kw
Pope, 11 Kw
Press Roll I, 52.5 KwI
Press Roll I, 52.5 Kw
Pulp & Paper Industry
22 Kw
Vacuum Pumps
KVM 200
KVM 600
KVM 600
18 m3/min
60 m3/min
60 m3/min
37 Kw
75 Kw
130 Kw
50 - 200 mm Hg 400 mm Hg 200-250 mm Hg
High Pressure Pump
Common for PM I & II
350 m
24 m3/hr
45 Kw
Condensate
collection
Tank
Over Head
Condensate
Collection Tank
10 m
120 m3/hr
1.5 Kw
To Cogeneration
10 m
Plant
120 m3/hr
5.5 Kw
44
Figure: Energy balance in a paper machine
© UNEP 2005
Pulp & Paper Industry
Energy Efficiency Opportunities
CP-EE measures:
• Raw material preparation
-Enzyme-assisted barker
-Chip conditioners
-Improved screening process
-Belt conveyers
• Mechanical pulping
-Refiner improvements
-Low consistency refining (LCR)
-Heat recovery in thermo mechanical pulping
45
© UNEP 2005
Pulp & Paper Industry
Energy Efficiency Opportunities
CP-EE measures:
• Chemical pulping
-Continuous digesters
-Continuous digester modification
-Batch digester modification
• Chemical recovery
-Falling film black liquor evaporation
• Paper making
-High consistency forming
-Extended nip press (shoe press)
46
© UNEP 2005
Pulp & Paper Industry
Energy Efficiency Opportunities
CP-EE measures:
• General measures
-Optimization of regular equipment
-Efficient motor systems
• Efficient steam production & distribution
-Boiler maintenance
-Improved process control
-Flue gas heat recovery
47
© UNEP 2005
Pulp & Paper Industry
Energy Efficiency Opportunities
EE technologies:
• Alcohol based solvent pumping
• Bio pulping
• Ozone bleaching
• Black liquor gasification
48
© UNEP 2005
Pulp & Paper Industry
Energy Efficiency Opportunities
EE-technologies:
• Impulse drying
• Infrared drying
• Press drying
49
© UNEP 2005
Training Session on Energy
Equipment
Industry Sectors
THANK YOU
FOR YOUR ATTENTION
50
© UNEP GERIAP