fAssessment of lignite to liquid oil system
Background & Target1 g g
2 Idea & Scheme
3 Methods3 Methods
Results & Discussions４
５ Concluding remarks
Presenter: WenYing Li, Qun YiPresenter: WenYing Li, Qun Yi
0909--JuneJune--2015, Hohhot, China2015, Hohhot, China0909 JuneJune 2015, Hohhot, China2015, Hohhot, China
2015/6/19 FIC, Hohhot 1
1. Why do we do research on lignite?
211.8 billion tonnes, (12.69% of the total reserves); North east Inner Mongolia and Yunnan
Lignite---an unfully used coal
Lignite---a low-rank coal
, ( ); g
Mainly used in pithead power plants; Cause environmental problems (SO2, NOX, CO2 etc.)
Disadvantages:Disadvantages:
g
Compared with other high rank coals:
Advantage:Advantage: relatively cheapDisadvantages:Disadvantages:
High moisture contentHigh volatile content Higher cost to utilize the lignite
Advantage:Advantage: relatively cheap
Low heat valueHigh ash content
Low ignition point
(inevitable, but could take some actions to make it deserving)
g p
Enhance the added value of products and reduce the production costp
2015/6/19 FIC, Hohhot 2
1. What can we do with lignite
lignite
Solid Gas Liquid Final product
Drying
g
Steam Water F l
Pyrolysis Steam & tar & combustible gas
Tar Other methods
Fuels
Chemicals
Gasification Oil & chemicalsSyngas Synthesis
Materials
Ash
Combustible gas & steam
to develop a reasonable deep processing technology to investigate the key elements in the process to investigate the key elements in the process to investigate the CO2 emission in the lignite deep processing
2015/6/19 FIC, Hohhot 3
1. Background & target---product selection
formaldehydeAcetic acid
chemicalsLignite
pyrolysis t
Methanololefinsaromatics
Motor fuel
char
pyrolysis
gasification e m
arke
t
tar gas
Motor fuelDME fuels
gasification
ds a
nd th
syngas
gena
tion
F-T oilGasoline cutDiesel cut
gas
ocia
l nee
d
Electricity hydr
og
Paraffin wax
So
oil
D d f li d di lA lot of choices
Complementation
Demand of gasoline and diesel simplifying downstream treating Energy safety strategy
2015/6/19 FIC, Hohhot 4
p Increase oil production Share the same equipments
Part 1
System integration and assessment
2015/6/19 FIC, Hohhot 5
Foundation of the lignite to oil process
Drying+pyrolysisLignite Tar hydrogenation + gasification+F-T synthesis Separation Products
crude phenol
Gasoline
pyrolysisgas
Products separation
high-temp solid heat carrier
H2
Low-pressure t il
Coaltarwater
Gasification WGS
steamCO2
fractionDiesel
fractionTar hydrogenation
tail gas
H2
Pyrolysis Drying
Dry coal
h
Gasification
O2 slag/ash acid gas removal C1~C4FTS
residue H2
ashflue gas
Solid heat carrierair
Combustion
Process diagram of the new coproduction system2015/6/19 FIC, Hohhot 6
Key variable analysis and evaluation
Pithead pre-treating C l i
Drying PyrolysisAmount of SHC
Fixed handling scale(5 million t/a)
Pithead pre-treating Coal mineEnergy demand
r de
man
d
Moisture of lignite
Drying
Net fixed
Pyrolysis of SHC
For burning Reborn and
(5 million t/a)Output 1
Pow
er
carbonburning
For gasification
recycle
Gasifier
ergy
ava
ilabl
e
2Power demand
g
Syngas
SHC=solid heat carriers
type
Output : tar, pyrolysis gas
Ene
F-T synthesis
Note :
WGS shift
SHC=solid heat carriers
Lignite to oil production systemPower demand：compressor，transportation
Evaluation: Energy, Economy, CO2 emission
2015/6/19 FIC, Hohhot 7
Methods
E l ti Energy evaluation
Energy efficiency of lignite to oil =Energy of oil products
Energy efficiency of lignite to oil =Energy of lignite
Based on LHVTh t t l t t
The total energy efficiency =The total energy outputThe total energy input
Economy evaluation
Investment in unit oil product = The total investmentp
Internal rate of return (IRR) (estimate economic reliability and feasibility)
Oil production
Two price margins (the most favorable one and the least favorable one)
are set to study the economic performance of the system .2015/6/19 FIC, Hohhot 8
Results ---- Energy efficiency
Effect of different gasifiers and moisture contents on energy utilizaiton
under different bases
50
F-T synthesis without power generation
under different bases
30
40
y (%
) √F-T synthesis with power generation
20
30BGL-gasifierTexaco-gasifier
ergy
eff
icie
ncy
Shell-gasifier
Energy efficiency of lignite to oil
F T th i ith t F T th i ith t10
Ene total, without electricity generation
total, with electricity generation lignite to oil
F-T synthesis without powergeneration shows higher totalenergy efficiency
F-T synthesis without powergeneration shows higher totalenergy efficiency
0202020 303030 4040
Moisture content (%)40
Shell gasifier: presenting higherenergy efficiency
Shell gasifier: presenting higherenergy efficiency
2015/6/19 FIC, Hohhot 9
Results ---- Economic performance
Eff t f diff t ifi d i t t t i f f
120
Effect of different gasifiers and moisture contents on economic performance of
the system
80
100
108 C
NY
)
1.0
1.2
1.4
NYto
nne-1
)
System with power island is better in economy
25BGL-gasifierTexaco-gasifierShell-gasifier
40
60
l inv
estm
ent (1
0.6
0.8
BGL-gasifierTexaco-gasifierShell-gasifier
stm
ent (1
04 CN
√ √
15
20
20
40
Tota
l cap
ital
total, without electricity generation total, with electricity generation
0.2
0.4
unit investment
Uni
t inv
es√ √
10IRR
(%)
profit line
0 0.0202020 303030 4040
Moisture content (%)40
Reducing moisture content can
0
5
with electricity generation
best case worst case best case worst case
without electricity generation
reduce unit investment and improve IRR System with Texaco gasifier shows
0
Moisture content (%)202020 303030 404040better economic performance
2015/6/19 FIC, Hohhot 10
Part 2
CO2 control of the lignite to oil system
2015/6/19 FIC, Hohhot 11
Idea & scheme: CO2 control
General idea ：
Control CO2 emission reduction inside the system based on the features of
the system
Converting produced CH4 and CO2 to H2 and CO using CH4 reforming
Main ways：
Features
Converting produced CH4 and CO2 to H2 and CO using CH4 reforming
CH4 reforming as one of supplementary means in CO2 emission control
li it t il t id ifi l tf f CH f i
CH4 comes from the system itself, no external source
lignite to oil system provides a specific platform for CH4 reforming
2015/6/19 FIC, Hohhot 12
Idea & scheme: CO2 control
CH4-CO2 reforming and CH4-H2O reforming
CH4-CO2 reforming : CO2 control after its generatingCH4 CO2 reforming : CO2 control after its generating
CO2 controlCH4+CO2=2CO+2H2
CO2 source control before its generatingCH4-H2O reforming :
CH +H O=CO+3H
Reduce CO2 emission from WGS: CO+H2O=CO2+H2
CH4+H2O CO+3H2
CO2 sources CH4 sources H2O(steam) sources
Sources of CH4-H2O -CO2
gasificationSolid heat carrier regeneration ( char or syngas combustion)
F-T synthesisLignite pyrolysis
2 ( )
Drying & pyrolysis
or syngas combustion)WGS
2015/6/19 FIC, Hohhot 13
Eff t f l i E d d f l i
Idea & scheme: CO2 controlEffects of pyrolysis — Energy demand of pyrolysis process
1. Cleaner than char
2. Without blending and separation (char solid heat
Advantages:
separation (char, solid heat carriers, ash)
1. Increases gasification load g
2. Some equipments should be improvedDisadvantages:
1. CH4 reforming type2. The source of CH4 No reformingThe four key variables
4. Gasifier types
3. The ways of solid heat carriers regeneration
No reforming scenarioVS
2015/6/19 FIC, Hohhot 14
yp
kResults Comparison of CO apparent conversion efficiency
CO apparent conversion efficiency =The amount of CO converted into oil
CO apparent conversion efficiency /% Reforming No reformingSi l CH D l CH
CO apparent conversion efficiency The amount of CO from gasified gases
pp y Single-CH4 Dual-CH4
Syngas not to combust Dry-powder 49.4a/50.2b 54.9a/56.1b 47.9Coal-water slurry 54.3a/54.8b 61.3a/62.0b 52.8
Dry powder /37 8b 35 9
Case 1
Case 2Syngas to combust Dry-powder /37.8b 35.9
Coal-water slurry /38.9b 36.9a：CH4-CO2 reforming; b：CH4-H2O reforming ；Single-CH ：CH from F-T products；Dual-CH ： CH from F-T products and pyrolysis productsSingle-CH4：CH4 from F-T products；Dual-CH4： CH4 from F-T products and pyrolysis products
Case 1 has more potential in CO2 emission reduction.
Using Dual-CH4 and CH4-H2O reforming has higher CO apparent conversion
efficiency
2015/6/19 FIC, Hohhot 15
Coal water slurry gasification is better for CO2 control
kResults Comparison of CO2/Chydrocarbon
From element point of view:o e e e po o v ew
lignite = “feedstock carbon”, CO2 = “waste carbon”, Chydrocarbon =”product carbon”
CO2
Chydrocarbon
Carbon in raw material
Processing Waste carbon
Product carbon
CO2/ChydrocarbonReforming No reforming
Single-CH4c Dual-CH4
d
Syngas not to Dry powder 1 4a/1 3b 1 3a/1 1b 1 4Case 1 Syngas not to combust
Dry-powder 1.4a/1.3b 1.3a/1.1b 1.4Coal-water slurry 1.65a/1.6b 1.5a/1.3b 1.7
Syngas to combust Dry-powder /2.3b 2.4Coal-water slurry /3.3b 3.3
Case 2y
a：CH4-CO2 reforming; b：CH4-H2O reforming ；Single-CH4：CH4 from F-T products；Dual-CH4： CH4 from F-T products and pyrolysis products
2015/6/19 FIC, Hohhot 16
5. Concluding remarks
provide multiple products ( motor fuels, phenols and gases or electricity)
Such an lignite based liquid-oil aimed coproduction system is able to:
p p p ( , p g y)
improve liquid oil yield and reduce a part of fixed investment
h l ti l hi h ffi i ( 40% LHV) d IRR( 20% f th b t reach a relatively high energy efficiency(~40% LHV), and IRR(~20% for the best case )
CO2 emission of unit oil product is 7.5-9.5 t/t2 p
• The system produces insufficient CH4 , so WGS reaction is still necessaryto provide H2
• The pyrolysis process provides most of the CH4, but it also generates a large
If external CH4 is added into the system, WGS can be avoided and more CO2 emission can be reduced
part of CO2
If pyrolysis can be done by non-carbon based energy, CO2 emission will be much less
2015/6/19 FIC, Hohhot 17
Acknowledgements
Financial supports:
National Natural Science Foundation of China (No 51276120; U1361202)National Natural Science Foundation of China (No.51276120; U1361202)
National High Technology Research and Development Program 863
(2011AA05A202; 2011AA05A204)(2011AA05A202; 2011AA05A204)
Higher Specialized Research Fund for the Doctoral Program (20121402110016).
Thank you !
Key Laboratory of Coal Science and Technology, Taiyuan University of Technology 23
