Coal to Desired Fuels and Chemicals Maohong Fan SER Professor in - - PowerPoint PPT Presentation

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Coal to Desired Fuels and Chemicals Maohong Fan SER Professor in - - PowerPoint PPT Presentation

Oct 25, 2023 263 likes •554 views

Coal to Desired Fuels and Chemicals Maohong Fan SER Professor in the Department of Chem. & Petroleum Eng. UNIVERSITY OF WYOMING 2-4-2013 mfan@uwyo.edu Phone: (307) 766 5633 1 Im smelly Im dirty Im sticky Oil Oil Coal Coal

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SLIDE 1

1

2-4-2013

Coal to Desired Fuels and Chemicals

Maohong Fan

SER Professor in the Department of Chem. & Petroleum Eng. UNIVERSITY OF WYOMING mfan@uwyo.edu Phone: (307) 766 5633

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SLIDE 2

Coal Coal Oil Oil Trona Trona Iron ore Iron ore

Rare earth Rare earth

I’m dirty I’m sticky I’m smelly I’m picky I’m sneaky I’m rusty

Without me, life isn’t easy!

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SLIDE 3

Maohong Fan’s Research Group

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SLIDE 4

UW’s Clean Coal Technology Development Map

High‐value carbon based materials

Catalytic pyrolysis mode in the same reactor Catalytic gasification mode in the same reactor Cleaning & separating CO + CO2

  • btained with 1st

choice of feed gases Catalytic CO coupling (converting the CO

  • btained with 1st choice
  • f feed gases)

Dried coal impregnated with catalysts 1st choice of feed gases: CO2 + limited O2 Separation (note: One of the

  • bjectives is to minimize

CH4 production in pyrolyis and gasification modes) Light tar separation (into naphthalene, 1‐ naphthaleneacetic acid, anthracene, phenol, diesel H2O Char/coke CO+CO2 CO2 CO2 + small amout of CH4 Synthesis conversion (converting the CO & H2

  • btained with 2nd choice
  • f feed gases)

2nd choice of feed gases: CO2 + CH4 (natural gas) limited O2 + H2O IGCC Electric Power Synthetic ammonia Synthesis of methanol F‐T synthesis Oxalic acid Ethanol Ethylene glycol higher alcohols Urea Olefins Gasoline DME Jet/Diesel Chemicals Polyester CO H2 Feed gases: CO2 + limited O2 H2:CO≈2 + near zero CH4 CO2 CO + zero H2 + zero CH4

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SLIDE 5

 Catalytic Coal Pyrolysis and Gasification

  • Na-Fe based

 Syngas to liquids

  • Ethylene glycol

 Environmental management

  • CO2

Three Sample Projects to Be Presented

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SLIDE 6

 Why catalyst?

  • Increase gasification or carbon conversion

rate/kinetics

  • Decrease gasification temperature

 Improve energy efficiency  Increase life span of gasifier

  • Change the composition of syngas

 Obtain desired CO:H2 ratio  Decrease CH4 concentration in syngas

Sample Project 1- Catalytic Coal Gasification

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SLIDE 7

7

Catalytic Coal Pyrolysis and Gasification Setup

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SLIDE 8

Effect of Na Catalyst on PRB Coal Pyrolysis

 Addition of Na2CO3 (as a catalyst) can

increase

  • H2/CH4 ratio by ~170%
  • H2/CO ratio by ~115%

Raw coal With 4% Na 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5

Mole ratio

CO2/CO H2/CO H2/CH4

 Mole ratios of

different gas products from catalytic coal pyrolysis at 600 oC [coal heating rate: 10

  • C /min; pyrolysis

time at 600 oC: 30min; flow rate of N2 :15 ml/min]

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SLIDE 9

Effect of Na Catalyst on PRB Coal Conversion (X) and Gasification Kinetics (k)

0.2 0.4 0.6 0.8 1 100 200 300 400 500 600 700

Fractional conversion, X Time, min

700 C 750 C 850 C 900 C 0.2 0.4 0.6 0.8 1 50 100 150 200

Fractional conversion, X Time, min

700 C 750 C 800 C 850 C 900 C y = -0.7044x + 1.123 R² = 0.9648 y = -1.0758x + 4.1535 R² = 0.9841

  • 7.5
  • 7
  • 6.5
  • 6
  • 5.5
  • 5
  • 4.5

8.5 9 9.5 10 10.5

ln k 1/T * 10-4 (K-1)

5 wt% Na 0 wt% Na

Raw coal

Coal + 5% Na catalyst

 Complete conversion at 750 oC

  • Only ~200 min needed with the use of Na

catalyst

  • ~700 min needed without use of Na catalyst

 Activation energy [determined by

lnk~(1/T) plot]

  • ~60 kJ/mol with catalyst
  • ~100 kJ/mol without catalyst
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SLIDE 10

Effect of Composite Catalyst on CO Concentration in Syngas

 Test conditions

  • Mass of DAF coal: 5 g
  • H2O flow rate: 180 ml/min
  • N2 flow rate: 4.1 ml/min
  • #1:1%-Fe+3%-Na
  • #2: 2%-Fe+2%-Na
  • #3: 3%-Fe+1%-Na

 Observations

  • Increase in temperature →

significant increase in CO

  • Increase in Fe in composite

catalyst → considerable decrease in CO

Molar yield of CO per mole of carbon in the char vs. different loadings of Fe and temperatures

10

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SLIDE 11

Effect of a Composite Catalyst’s Composition and Temperature on H2 Concentration in Syngas with Steam Gasification

 Composite catalyst can take the

advantage of two individual catalysts and overcome their challenges

 Molar yields of H2 per mole of

carbon

  • 3% Fe loading leads to the increase in

H2 production by 35% at 700 oC.

2015/8/19

1 2 3 4 700 750 800 850 900 % F e l

  • a

d i n g T(°C)

1.1 1.2 1.3 1.4 1.5 1.6

m

  • l

H 2 / m

  • l

C

Test conditions- Mass of coal: 5 g; #1: 1%-Fe+3%-Na; #2: 2%-Fe+2%-Na; #3: 3%-Fe+1%-Na: #4: 4%-Fe+0%-Na. Molar yield of H2 per mole of carbon in the char vs. different loadings of Fe and temperatures

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SLIDE 12

Effect of Na Catalyst on Carbon Conversion with CO2 Gasification

 Test conditions

  • Gasification Temperature: 700
  • C
  • Mass of DAF coal: 5 g
  • CO2 flow rate: 180 ml/min
  • N2 flow rate: 4.1 ml/min

 Observations

  • Addition of trona can

significantly accelerate carbon conversion X (mole fraction) or coal gasification rate

  • Gasifying the same amount of

coal with catalyst needs

 less time  a smaller gasifier

12

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SLIDE 13

Effect of Catalyst on CO2 Gasification (continued)

2015/8/19

Test conditions – Gasification temperature: 700 oC; mass of coal: 5 g; CO2 flow rate: 180 ml/min; N2 flow rate: 4.1 ml/min.

 Pure CO could be

  • btained

 1,200 min is needed

for gasifying the coal without presence of catalyst.

 Only 300 min is

needed for gasifying the coal with the presence of catalyst.

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SLIDE 14

The Mechanism of PRB Coal Gasification with Fe Catalyst: Mössbauer spectroscopy data

During pyrolysis iron oxides are reduced to metallic iron Fe0, Fe3C and higher coordination iron Fen+

After steam introduction Fe3C is oxidized to Fe0 and Fe(O)

The catalytic mechanism on oxidized iron layer: Fe + H2O → Fe(O) +H2 Fe(O) + C → C(O) + Fe C(O) → CO 3Fe(O)+H2O → Fe3O4 +H2 Fe3O4 +CO→ 3Fe(O)+CO2 CO2 + C ↔2 CO

97.5 98.0 98.5 99.0 99.5 100.0

  • 12
  • 8
  • 4

4 8 12 Absorption (%) Velocity (mm/s)

3% Fe in raw coal, 20oC

Fe2O3,multiple coordinations

90.0 92.0 94.0 96.0 98.0 100.0

  • 12
  • 8
  • 4

4 8 12 Absorption (%) Velocity (mm/s)

3% Fe coal after pyrolysis at 800oC

Fe0 Fe3C

cementite

Fen+

90.0 92.0 94.0 96.0 98.0 100.0

  • 12
  • 8
  • 4

4 8 12 Absorption (%) Velocity (mm/s)

3% Fe coal after pyrolysis at 800C + 10 min H2O

Fe0 Fe3O4 Fen+

np-Fe-ox

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SLIDE 15

Sample Project 2- Catalytically Coverting Syngas to Ethylene Glycol (EG)

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SLIDE 16

16

Syngas to ethylene glycol

Disadvantages of methyl nitrite:

  • Highly flammable
  • Highly explosive
  • Toxic
  • Being controlled in the US

Advantages of ethyl nitrite:

  • Less flammable
  • Non-explosive
  • Less toxic
  • Transportation allowed

2CO + 2CH3ONO (COOCH3)2 + 2NO

Methyl nitrite (MN)

2NO + 0.5O2 N2O3 N2O3 + 2CH3OH 2CH3ONO + 2H2O

Methyl nitrite (MN)

Dimethyl Oxalate (DMO)

(COOCH3)2 + 4H2 (CH2OH)2 + 2CH3OH

Dimethyl Oxalate (DMO) Ethylene glycol (EG)

Methyl nitrite to Ethylene glycol 2CO + 2CH3CH2ONO (COOCH3CH2)2 + 2NO

Ethyl nitrite (EN)

2NO + 0.5O2 N2O3 N2O3 + 2CH3CH2OH 2CH3CH2ONO + 2H2O

Ethyl nitrite (EN)

Diethyl Oxalate (DEO)

(COOCH3CH2)2 + 4H2 (CH2OH)2 + 2CH3CH2OH

Diethyl Oxalate (DEO) Ethylene glycol (EG)

Ethyl nitrite to Ethylene glycol

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SLIDE 17

 UW DEO synthesis catalyst

  • 0.1% DEO production catalyst prepared at UW can perform better

than 1% that prepared with conventional method.

  • Cost-effectiveness of UW catalyst is 9 times or 900% better than that
  • f conventional ones.

1st Step of Syngas to EG: (CO +EN) → DEO

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SLIDE 18

Integrated in-situ FTIR Based Set-up for Studying EG Reaction Mechanism

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SLIDE 19

19

Without promoter With a promoter (0.8 wt-%)

In-Situ FTIR Observation of DEO Synthesis with and without Uses

  • f a Promoter

140 oC;1 atm; CO: EN;1.4 :1.

CO EN DEO CO DEO EN

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SLIDE 20

2nd Step of Syngas to EG: DMO→EG

  • UW’s AC based

catalysts achieve higher DMO conversion and EG + MG (methyl glycolate) selectivity in lower temperature range ( < 200 oC)

  • UW’s 20Cu-AS30-AC

is the best catalyst

– 100% CO conversion – 90% EG + MG

2015/8/19

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SLIDE 21

Sample Project 3- New CO2 Capture Technologies

  • Sorption based CO2 capture technology

–Advantages

  • Easy in operation
  • Applicable to gases with a wide range of CO2

concentrations

– Absorption: for pre-combustion CO2 capture – Adsorption: for flue gas with low CO2 concentration

–Shortcoming

  • Slow CO2 desorption rates (especially for absorption based

technology) → high desorption energy consumption

– the largest obstacle for reducing overall CO2 capture cost since about 70% of overall CCS capital is spent on CO2 desorption step

  • What to do? Using catalysis
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SLIDE 22

Catalytic CO2 Capture set-up

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SLIDE 23
  • Carbonates for CO2 capture

– Mechanism (reversibility of the following reaction )

  • Na2CO3 + H2O + CO2 ⇄ 2NaHCO3

Or : CO3

2- + H2O + CO2 ↔ 2 HCO3

  • – Advantages
  • Stoichiometric CO2-H2O ratio: almost equal to that in

actual flue gas

  • Na2CO3: inexpensive, stable, easily available

– Disadvantage

  • More difficult than amines based CO2 capture technology

in CO2 desorption or sorbent regeneration step

23

Sample Project 3- Catalytic Based CO2 Capture

Background

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SLIDE 24

Catalytic Based CO2 Capture - Inorganic

CO2 Desorption Rate Constants (k) with and without Uses of a Catalyst

  • Test Conditions

– Mass of spent CO2 sorbent (NaHCO3):50-100 mg – NaHCO3/Catalyst (called NHF) – N2 flow rate: 100 mL/min

  • Observations

– Rate constants [k (min-1)] increased significantly at the same temperature due to use of the catalyst (e.g., kpure-

NaHCO3 = 0.005 min-1, while k 90% wt.%NHF = 0.19 min-1, k 50% wt.%NHF =

0.20 min-1, k 10% wt.%NHF = 0.06 min-1 at 100 oC )

  • CO2 desorbs much faster due to use of

catalyst

  • Reduce operating and capital costs

Samp Sample le Tempera Temperature ure (°C) C) m k m k (min (min-1

  • 1)

R2 Pure NaHC Pure NaHCO3 100 0.9 0.005 0.9992 120 1.0 0.02 1.0000 140 1.2 0.06 0.9991 150 1.2 0.13 0.9991 160 1.2 0.29 0.9999 90 wt.% 90 wt.% NHF NHF 100 0.7 0.19 0.9996 110 0.6 0.25 0.9994 120 0.4 0.49 0.9995 130 0.4 0.89 0.9990 140 0.3 1.32 0.9975 50 wt.% 50 wt.% NHF NHF 100 0.6 0.20 0.9989 110 0.4 0.32 0.9989 120 0.1 0.46 0.9994 130 0.1 0.59 0.9997 140 0.1 0.84 0.9995 20 wt.% 20 wt.% NHF NHF 100 0.5 0.06 0.9997 110 0.5 0.13 0.9998 120 0.5 0.23 0.9998 130 0.5 0.35 0.9998 140 0.5 0.50 0.9998 24

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SLIDE 25

Sample R2 A (min-1) EA (kJ/mol) Pure NaHCO3 0.9988 9.66×109 ± 3.16×108 86 ± 2.5 90 wt.% NHF 0.9529 2.65×108 ± 2.43×107 64 ± 5.8 50 wt.% NHF 0.9493 4.86×105 ± 4.06×104 44 ± 3.5 20 wt.% NHF 0.9899 4.02×108 ± 1.72×107 69 ± 2.8

Catalytic Based CO2 Capture - Inorganic

Arrhenius Parameters

a – catalyst b – 20 wt.% NHF c – 50 wt.% NHF d – 90 wt.% NHF

 Reduction in desorption

activation energy also implies better adsorption

  • ΔHR = EA,R – EA,-R

25

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SLIDE 26

Sample Project 4: Naphthalene synthesis

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SLIDE 27

Thanks to