6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
1
Optimization of Steel and Methanol
Production in an Integrated
H. Ghanbari, H. Helle, M. Helle,
F. Pettersson and H. Saxen
Åbo Akademi University
Heat Engineering Laboratory
Åbo / Turku, Finland
tel. +358 2 215 4440
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
2
Energy saving is an important issue in the steel industry. Improvement of the
energy efficiency, to reduce the energy consumption, will increase the
economic profitability as well as reducing the environmental impacts.
Introduction1
Steel plants have a significant contribute to the global CO2
emission:
4-6% of man-made CO2,
largest point source of CO2 in the world,
Blast Furnace Ironmaking is responsible for 80-90 % of this emission,
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
3
Introduction2
Potential Direction:
New Technologies
New Reductant and fuels; focus on biomass
Process Integration; by-products and CO2 Capture and Storage
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
Most of the high value Off-gases from different units such as Coke Oven Gas
(COG), Blast Furnace (BF) and Based Oxygen Furnace (BOF) are used in
Combined Heat and Power plant which is not the most efficient way to use
them.
According to ULCOS:
CO2 issue is a business risk for the Steel Industry in Europe
Cost Acceptance by society
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
4
Introduction3
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
MeOH as a FUEL
MeOH production from natural gas or biomass resources
Several commercial technology to produced MeOH from COG in china e.x. Shanxi
Tiianhao chemical company Ltd (first plant, 2005); production of 300000 tons per year.
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
5
CP: coke-making plant, SP: sintermaking plant, ST: hot stoves, CS: CO2
stripping unit, BF: blast furnace, BOF: basic oxygen furnace and PP: power
plant.
Models of the Unit Process and Emissions1
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
6
Models of the Unit Process and Emissions2
Input and output variables and their
constraints, as well as sinter and coke mass
production rate constraint.
Blast Furnace Model:
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
Treatment of the Gas Preheating
State Hot Stoves Comp.
State NO. 1 TGR+BL* TGR+BL
State NO. 2a BL TGR+BL
State NO. 2b BL(No TGR) BL(No TGR)
State NO. 3 TGR TGR+BL
State NO. 4** TGR TGR
*Bl: Oxygen Enriched air
**State No. 4: pressuerized Cold Oxygen
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
7
Models of the Unit Process and Emissions3
Coke Plant: Linear relations between the mass flow rate of feed coal and the mass flow rate of
coke and volume flow rate of (purified) coke oven gas (COG) are assumed
t
nm319.7;0.695
3
cokeCOGcoalcoke mVmm
t
MJ12.85;0714.0;046.0 ,042.1 sintsintsintsintlime,sintsintcoke,oresint mQmmmmmm
sintcoke,cokeint coke, mmm
Sinter Plant: Only the raw materials iron ore, coke and limestone are considered, and in
addition to them, the recovered heat is also taken into account, i.e.,
which gives the (internal) flow rate of coke available for the blast furnace:
Hot Stoves: The strongly oxygen-enriched blast and the recycled and CO2-stripped top gas are
compressed and then heated in the hot stoves, which are assumed to operate as a single
continuous counter-current heat exchanger in steady state with the heat transferred from burning
oil.
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
8
Models of the Unit Process and Emissions4
Basic Oxygen Furnace: The mass flow of liquid steel and the volume flow rates of oxygen to and
off-gases from the BOF are given as function of the mass flow of hot metal (hm);
t
nm5.41;
t
nm6.45;895.0
3
hmBOF
3
hmBOF,Oscraphmls 2mVmVmmm
CHP plant: overall energy balance between residual of gases from BF and part of the BOF are
used to produce electricity and district heat.
.
; 1PP PPP QE E
Epp=(1-β-М)VBFHBF+kVBOFHBOF
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
9
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
Treatment of the Gas Preheating
Coke Plant: Linear relations between the mass flow rate of feed coal and the mass flow rate of
coke and volume flow rate of (purified) coke oven gas (COG) are assumed
t
nm319.7;0.695
3
cokeCOGcoalcoke mVmm
t
MJ12.85;0714.0;046.0 ,042.1 sintsintsintsintlime,sintsintcoke,oresint mQmmmmmm
sintcoke,cokeint coke, mmm
Sinter Plant: Only the raw materials iron ore, coke and limestone are considered, and in
addition to them, the recovered heat is also taken into account, i.e.,
which gives the (internal) flow rate of coke available for the blast furnace:
Hot Stoves: The strongly oxygen-enriched blast and the recycled and CO2-stripped top gas are
compressed and then heated in the hot stoves, which are assumed to operate as a single
continuous counter-current heat exchanger in steady state with the heat transferred from burning
oil.
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
10
Models of the Unit Process and Emissions5
Gas Reforming unit:
Endothermic Reaction favored by high temperature and low pressure.
The reaction produces 1:3 CO/H2 instead of the 1:2 needed for MeOH
synthesis, so CO2 is imported to the unit and in water-gas shift reaction, CO2
is shifted back to CO by consuming some H2. The CO2 to CH4 molar feeds
ratio needs to be 1:3 to get 1:2 CO to H2 for MeOH synthesis, though any
incomplete conversion of CO2 would call for a slightly higher feeds ratio.
Unconverted CO2 will be purged from the synthesis loop.
Methanol unit: The converter in Lurgi LP plant is a cooled multi-tubular
reactor. The heat of reaction is directly used to generate high pressure steam
4 2 2, ,
0
MeOH MeOH purge purge j j
j CH H O CO
out MeOH MET
F H F H F H
Q F Q
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
11
SMR Reactor Condition: CH4+H2O=CO+3H2
• Endothermic Reaction; therefore, during its operation it will be heated via
the combustion of natural gas.
• T=700-1000 ‘C
• Methane Conversion more than 95%[13]
MeOH Reactor Condition:
T=250-300 ‘C
P=5 MPa
Selectivity more than 99%
Different Catalysts
CO+2H2=CH3OH
CO2+3CH4+2H2O=4CH3OH
Models of the Unit Process and Emissions6
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
12
COP BF
Methanol Reactor
BOF
CHP
MeOH Plant
Gas Reformersteam
Coal
Coke
Oil
Air/O2
Ore
Limestone
Pellet
scrap
Heat
Power
Steel
Slag
Co2
methanol
Schematic description of PI model
k
β
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
1313
Core 80 €/t
Cpellet 100 €/t
Ccoal 145 €/t
Ccoke,ext 300 €/t
Coil 150 €/t
Clime 30 €/t
CO2 50 €/km3n
Cscrap 100 €/t
Cel 50 €/MWh
Cheat 10 €/MWh
Cmethanol 250 €/t
Objective Function
Costs in the objective function
2,2
. .
,
440.95
12CO strip rg CO stripm V Y
2 , lime C,lime ,
, , , , ,
. 44(
12
)
COCoal C coal Oil C Oil
Coke ext C coke C bio ls C ls MeOH C MeOHbio
m m X m X m X
m X m X m X m X
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
2 2 2 2
lim lim
3 3
2,
(pel pelore ore coal coal
coke coke oil oil e e
o o co coscrap scrap
co strip
m Cm C m CF
Euro t steel t h Euro t t h Euro t t h Euro t
m C m C m C
t h Euro t t h Euro t t h Euro t
V C m Cm C
t h Euro t km n h Euro km n t h Euro t
m
) /strip MeOH MeOH el dh heat steel
steel
C m C C Q C mP
t h Euro t t h Euro t MW Euro MWh MW Euro MWh t h
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
14
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
15
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
16
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
17
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
18
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
19
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
20
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
21
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
22
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
23
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
24
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
25
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
26
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
27
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
28
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
29
Conclusion1
Effect of increasing cost of emission is more significant in comparison of
cost of biomass.
The effect of first and second stage of integration shows that the price of
steel will decrease 10-20 euro/t and 30-45 euro/t, respectively which the
effect of integration increasing by rising the cost of emission.
The optimum operational condition of integrated system does not a
significant change according the cost of emission and biomass in case
study.
Both integrated stages produce less CO2 than steelmaking without
integration.
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
30
In order to considering the emissions from fossil fuels in the systems,
using biomass decreases around 0.2 tCO2 per tsteel emission in steel plant
without integration .
The first and second stage integration will decrease 0.4-0.45 tCO2 per tsteel
emission in comparison with steelmaking without integration.
Production of methanol has increased by increasing of steel production
rate and is estimated to be between 17-24 tone per hour and 24-30 tone
per hour for the first and second stage integration respectively.
Conclusion2
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
31
Conclusion and Future works1
The study has demonstrated that the optimal recycling degree of top gas varies
with the cost structure of emissions, CO2 stripping and will effect in methanol
production.
- Lower values of top gas recycling at high stripping cost
- Max recycling at high cost of emission
- Costs of liquid steel are estimated to be 10 Euro/t steel lower
than common case.
- Min CO2 emission is found in Max CO2 cost
For state which the cost of emission and stripping are equal (Cco2=Cstrip=20
€/t), in lower production rate the optimal condition is in high values of top gas
recycling that shows the balance between decreasing CO2 emission and
methanol production in minimization of steel production cost and in higher
production rate the condition change to lower β and increasing in CO2 emission
and methanol production.
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
32
By increasing production rate, estimation of the steel cost –in case study- will
be decreasing in an integrated plant between 3.4-4.35% which the lower values
will decline by increasing the CO2 emission cost.
The costs of liquid steel are estimated to be 17-25 €/t ls lower than for the case
without top gas recycling and methanol plant.
The price of liquid steel has increased by of 10 and 13 €/t when the cost of CO2
stripping and emission rise by 20 €/t respectively.
Conclusion and Future works2
The results show that with the assumed amount of available top gases could
be produced nearly 12-18 tone per hour methanol in an integrated steelmaking
plant with top gas recycling in blast furnace.
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
33
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
Future Works
6-Oct-10 Åbo Akademi University - Thermal and Flow Engineering
Biskopsgatan 8, FI-20500, Åbo, Finland
34
Thank you for your attention !
Questions, Comments, Remarks, Advice?
Process Integration Forum for the steel industry 3rd annual meeting, 6-7 September, 2010, Luleå, Sweden
Top Related