Matching gasification, conditioning and synthesis for the

Matching gasification, conditioning and synthesis for the design of thermochemical

biorefineries

Pedro HaroFulbright-Schuman Scholar at Princeton UniversityAsst. Professor at Universidad de Sevilla, [email protected]

mailto:[email protected]

Matching gasification, conditioning and synthesis for TB

4

University of Seville

• Founded in 1505

• One of the oldest Universities in Spain

* with University of Málaga


5

Renewable electricity in Spain

• >40% renewable generation

• Rather stable increase of renewables

• Biomass and Waste are less than 3% of total generation (included in cogeneration)

• Transportation (biofuels): 4.3 % of total consumption


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Bioenergy Group – University of Seville

• Led by Prof. Pedro Ollero (2007-)• Background in

• Coal conversion (power plants)• Desulphuration (power plants)

• Several European Projects (Energy)• Strong cooperation with the industry

• Energy: Total Gas & Power, CEPSA, Endesa• Biofuels: Abengoa• Waste management (waste-to-energy)• Concentrated Solar Power (CSP) Plants

• Experimental, modeling and simulation• Gasification pilot plant, modeling in CFD• Temperature measurements using high-speed cameras for coal

fluidized bed combustor/gasifiers• Biofuel labs (catalysts tests), process design and simulation (Aspen)• LCA: Dynamic modeling of climate impact (waste-to-energy and

GHG removal technologies)

50% carbon captured in Bio-CCS

-1.E-15

-8.E-16

-6.E-16

-4.E-16

-2.E-16

0.E+00

2.E-16

0 10 20 30 40 50 60 70 80 90 100

K·k

g-1

Spain2120

BAU

21002020

net cooling

Base case

Sensitivity to renewable-derived plastic production

Sensitivity to Bio-CCS incorporation


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Personal experience in Thermochemical Biorefineries

• KIT: bioliq (Karlsruhe, Germany), 3 MWth• Chalmers: GoBiGas (Gothenburg, Sweden), 20 MWth• Bioenergy Group: Abengoa (Seville, Spain), conceptual design

• Common feedback for all cases:• Complex designs• High uncertainty• Main objective: maximum production (despite complexity)

• Performance == Energy efficiency


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Structure

1. Introduction to the problem

2. Proposal


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Thermochemical Biorefineries

• Thermal conversion:• Gasification (entrained-flow,

direct, or indirect gasification) • Pyrolysis (fast)• others (HTL, HTC, …)

• Syngas (gasification): • mixture of H2, CO, CO2 and CH4

• conversion into multiple products

• Biofuels:• methanol, ethanol, FT-liquids,

dimethyl-ether (DME), hydrogen and substitute natural gas (SNG)

• the term BtL/G: biomass-to-liquids/gases is also common

Like conventional refineries, target is:

large market and low-value products


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Not very efficient removal

Energy integration

Example of Thermochemical Biorefinery

• Modular top-to-bottom design but for:• Recycling of unconverted syngas• Recycling of by-products

• Highly non-linear and non-convex behavior• Kinetics: temperature, compositions (upgrading)• Mixers/Splitters• Distillation columns: zero flow, unrealistic temperatures, etc. issues

Haro P, Villanueva Perales AL, Arjona R, Ollero P. Thermochemical biorefineries with multiproduction using a platform chemical. Biofuels, Bioproducts and Biorefining. 2014 Mar 1;8(2):155-70.


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Measuring the performance (efficiency)


System expansion?

Energy/Carbon basis?

Different alternatives to measure performance:


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Strategies for an enhanced performance

• Optimization of gasification conditions (although not very realistic)

• Advanced syngas cleaning (high uncertainty)

• Complex synthesis loops (complex chemical routes, in-series reactors)

• Economics: Multiproduction (high-value/low-volume & low-value/high-volume)Thermochemical Biorefinery

using a platform chemical

Route 1 Product 1

PlatformchemicalSyngas Route 2 Product 2

Route 3 Product 3

Thermochemical Biorefinery combiningdirect routes

Route 1(BTL/G)

Product 1

SyngasRoute 2(BTL/G)

Product 2

Route 3(BTL/G)

Product 3



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Example of a complex design

• Looking for a better performance results into:• Higher energy efficiency (e.g. there are no by-products)• Higher risk (higher capital investment and tighter operation)

Product separation Powergeneration

DME conversion

DME synthesisSyngas clean-up

and conditioning

GasificationFeedstockpretreatment

Methyl acetate

Methanolsynthesis

Productseparation

DME synthesis

Steam methanereformer

DME

Water

Methanol

Ethanol

DME Hydrocarbonylation Product

separation

Fuel gas

CO2removal

CO2

Power Island

Electricpower

Dryer & Milling iCFBGBiomass



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CO, H2 (syngas)

AcOH

2.1.

2

2.1

FT, H2, SNG

2.1.

4

Methyl Acetate

Gasoline Olefins2.1.10

2.1.8 2.1.9

Ac2O

2.1.

6 2.1.7

Diesel Jet Fuel

Ethyl Acetate

2.1.

7 2.2.4 ButOHEtOH

2.1

EtOHDMEMeOH

Chemicals

CH3COOH(acetic acid)

CH3COOCH3(methyl acetate)

CH3OHCO, H2(syngas)

CO

Eq. (1)

Eq. (10)

(CH3CO)2O(acetic anhydride)

Eq. (17)

COEq. (8)

CH3OCH3 (DME)

Eq. (4)

CO

Eq. (15)

H2O

H2O



CH3OH

C2H5OH

H2

CO, H2(syngas)

CO

Eq. (1) Eq. (10)

Eq. (18)

H2O

C2H5OH

(CH3CO)2O(acetic anhydride)

Eq. (17)

CH3COOCH2CH3(ethyl acetate)

Eq. (13)

Complex Chemical Routes (Synthesis)

Haro P, Ollero P, Villanueva Perales ÁL, Vidal‐Barrero F. Potential routes for thermochemical biorefineries. Biofuels, Bioproducts and Biorefining. 2013 Sep 1;7(5):551-72.


CH3COOCH2CH3(ethyl acetate)

CH3OH

C2H5OH

H2

CO, H2(syngas)

CO

Eq. (1) Eq. (8) Eq. (11)

Eq. (13)

H2O

C2H5OH

• Complex reaction systems

• In-series and parallel reactors

• Homogeneous catalysts


CH3OH C2H5OH

H2

CO, H2(syngas)

CO

Eq. (1) Eq. (8) Eq. (9)

H2O



CH3OH

C2H5OH

H2

CO, H2(syngas)

CO

Eq. (1) Eq. (8) Eq. (10)

Eq. (12)

H2O

CH3OH

CH3OCH3 (DME)

CH3COOCH3 (methyl acetate)

CO

CH3OH

C2H5OH

H2

CO, H2(syngas)

H2O

Eq. (1)

Eq. (4)

Eq. (15)

Eq. (12)


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Motivation for a deeper analysis

• Thermochemical biorefineries are not commercial• The closest to be commercial experiences proved that

complex designs are to be avoided• Despite very complex designs, more complicate than for

conventional processes, are not giving very promising results…Current research efforts moving to:

• Power-to-gas• Multiproduction/Polygeneration• Multi-feedstock• Solar gasification, microwave, ultrasound, etc.

• Therefore, there is a gap between research and industrial needs


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General overview of the problem

• For a “conventional” gasification-based thermochemical biorefinery:

• Surprisingly, there is a lot of uncertainty on the impact of gasification technologies on the synthesis

Haro P, Gomez-Barea A. Unpublished results.

No impact

Important impact

Uncertain impact

Biomass Dryer & Milling

d-FB

i-FB

EFCleaning

(H2S)

Tar cracker &

Reforming

Cleaning(tar, H2S)

Cleaning(H2S)

Reforming

CO2removal(optional)

WGS(optional)

Synthesissection

H2/CO,CH4, CO2,Pressure

Pyrolysis

Torrefaction

[oil scrubber]


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Synthesis

• Closer look at “conventional” biofuels

• Candidates for optimization

• Requirements for syngas composition

• (very) Hard to include in optimization (?)

BtL/G process

H2/CO ratioa

Observations % Hydrocarbons

(molar)

% CO2 (molar)

Pressure for synthesis

(bar)

Methanol

synthesis

& MTG

2 S = 2b <10 4-8 80

DME

synthesis

2 S = 2b <10 4-8 40-60

1 H2/CO = 0.5-2.0 <10 <25c 20-50

FT

synthesis

2 Catalysts active

for WGS, S = 2b

<10 <10-20 20-35

SNG 3 S = 3.00b (10)15-25%

(desired

maximum CH4)

(minimum) 40-60

Hydrogen

synthesis

(maximum) - <4 <5 >50

Ethanol

synthesis

2 S2Mo catalyst,

H2/CO = 2.0-2.2

50 ppm H2S

<15 c <10 50

1 Rh catalyst,

H2/CO = 1.0-1.2

<10 <20c 100-140

Fermentation,

1.3 (1.0-1.7)

1 - atmospheric

a Only as an indication often given in the literature, not as a design parameter (see observations). b The stoichiometric ratio (S) is defined as the 𝐻𝐻2−𝐶𝐶𝐶𝐶

𝐶𝐶𝐶𝐶+𝐶𝐶𝐶𝐶2 molar ratio at the inlet.

c Higher values might be possible [].



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Hydroc. = 3%CO2 = 3%

Reactor(50 bar)

10% v/v

-30°CH2/CO = 1.25 H2/CO = 1.70 UpgradingReforming(SR, ATR, POx)

CO2 removal(amines)

Hydroc. = 5.6%CO2 = 21.5%

Reactor(50 bar)

Electricity


CO2 removal(amines)

Hydroc. = 5.6%CO2 = 21.5%

Reactor(50 bar)

25% v/v


CO2 removal(amines)

Electricity

Electricity

Conventional process

Once-through

Hybrid case

Synthesis: understanding some nuances

• Let’s check a selection of “conventional” biofuels• Only biofuels where recycling is possible• CH4 is an inert compound (build-up)

• 3 alternatives:

Example (Dimethyl Ether)


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Synthesis Loop: biofuel candidates

• Solution for the conventional case (maximum biofuel production)

Stream 1 (% v/v)

H2 42.00

CO 35.75

CO2 19.00

CH4 3.25

Stream 3 (% v/v)†

H2 29.70

CO 37.30

CO2 22.20

CH4 10.00

(*) 3H2 + 3CO CH3OCH3 X = 50%

(**) 3H2 + CO2 CH3OH + H2O X = 8%

CH4 ≤ 3.25%CO2 ≤ 20%

Reactor(50 bar)

(1)(2)

(3)

10% v/v

-30°CH2/CO = 1.2 H2/CO = 0.8 Upgrading

(Moderate)

DME synthesis

Q(2)Q(1)

= 2

† the difference are DME and other hydrocarbons

Stream 1 (% v/v)

H2 65.00

CO 28.25

CO2 3.00

CH4 3.75

Stream 3 (% v/v)

H2 62.00

CO 24.00

CO2 4.00

CH4 10.00

(*) 2H2 + CO CH3OH X = 25%

(**) 3H2 + CO2 CH3OH + H2O X = 8%

CH4 ≤ 3,.5%CO2 = 3%

Reactor(50 bar)

(1)(2)

(3)

10% v/v

35°CH2/CO = 2.3 H2/CO = 2.6

S = 2Upgrading

(Easy)

Methanol synthesis

S = H2−CO2CO+CO2

Q(2)Q(1)

= 3

Stream 1 (% v/v)

H2 62.00

CO 31.00

CO2 5.00

CH4 2.00

Stream 3 (% v/v)

H2 44.80

CO 22.40

CO2 23.10

CH4 9.30

(*) 4H2 + 2CO CH2 + 2H2O X = 85-40%

Only if Fe-based catalysts:

(**) 2H2 + CO CO2 + H2O Equilibrium

CH4 ≤ 2%CO2 ≤ 5%

LT Reactor(35 bar)

(1)(2)

(3)

% v/v

35°CH2/CO = 2 H2/CO ≈ 2

S = 2Upgrading

(Hard)

FT synthesis

S = H2−CO2CO+CO2

Q(2)Q(1)

= 1

H2 toupgrading

area

Stream 1 (% v/v)

H2 62.00

CO 30.00

CO2 5.00

CH4 3.00

Stream 3 (% v/v)†

H2 52.60

CO 25.7

CO2 10.50

CH4 10.80

(*) 4H2 + 2CO C2H5OH + H2O X = 20%

(**) H2 + 2CO CH3OH X = 10%

(***) 3H2 + CO CH4 + H2O X = 2,5%

CH4 ≤ 3%CO2 ≤ 5%

50 ppm H2S

Reactor(50 bar)

(1)(2)

(3)

15% v/v

35°CH2/CO = 2.1 H2/CO = 2 Upgrading

(Hard)

EtOH synthesis (S2Mo)

Q(2)Q(1)

= 2

† the difference are other hydrocarbons


Stream 1 (% v/v)

H2 49.00

CO 43.00

CO2 4.00

CH4 4.00

Stream 3 (% v/v)†

H2 35.90

CO 34.40

CO2 19.90

CH4 9.50

CH4 ≤ 4%CO2 ≤ 4%

Reactor(100 bar)

(1)(2)

(3)

15% v/v

35°CH2/CO = 1.1 H2/CO = 1 Upgrading

(Hard)

EtOH synthesis (Rh)

Q(2)Q(1)

= 2


(*) 4H2 + 2CO C2H5OH + H2O X = 22%

(**) H2 + 2CO CH3OH X = 5%

(***) H2 + CO2 CO +H2O Equilibrium


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Analysis of the Performance


• We need to understand the impact of recycling, not only a result from simulations

0

10

20

30

40

50

60

70

80

90

100

0 1 2 3 4 5 6 7 8 9 10

Glo

bal C

onve

rsio

n (%

)

Hydrocarbons in % molar (inlet synthesis loop)

FT

Conventional BtL/G studies

Once-through(synthesis section)

Ethanol ”H2/CO=2 ratio”

FT

DME

Ethanol

Methanol

DME”H2/CO=1 ratio”

Methanol

Methanol

Ethanol ”H2/CO=2 ratio”

DME”H2/CO=1 ratio”

DME / FT

FT

Methanol

Hybrid

Not feasibleregion


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Matching: Conditioning

• Decision tree (biofuels)

CLEANED SYNGAS

Hydrocarbons <10%?

H2/COHydrocarbons

CO2

Reforming(SR, ATR, POx)

considering H2/CO ratio

H2/CO or Sadmissible?

WGS

CO2 removal(Amines, Selexol,

Rectisol)

NO

YES

NO

YES

YESCO2

admissible?

NO

SYNTHESIS SECTION

Once-through?

NOHydroc. < 3% /Limited prod.?

NO

YES YES

Multi-stagecompression

YESpressure

OK?

NO


CLEANED SYNGAS

H2/COHydrocarbons

CO2

Hydrocarbons <10%?


considering H2/CO ratio

NO

YES

Once-through?

NOHydroc. < 3% /Limited prod.?

NO

YES YES

H2/CO or Sadmissible?

WGS

NO

YES

CO2 removal(Amines, Selexol,

Rectisol)

YESCO2

admissible?

NO

SYNTHESIS SECTION

Multi-stagecompression

YESpressure

OK?

NO


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Gasifier and cleaning become more important

FB (oil scrubber)


SNGEthanol

MethanolFT-liquids

DMECO2 removal

WGS reactor

SNGLimited production

Ethanol (S2Mo)Methanol

DMEHydrogen

CO2 removal

Limited productionEthanol (Rh)

FT-liquidsDME*

CO2 removal

Limited productionDME*

CLEANED SYNGAS

H2/CO = 0.4-1.6Hydroc. = 5-12%

CO2 = 5-25%

Scenario 1

Scenario 2

Scenario 3

Scenario 4


FB (tar cracker)

WGS reactor

SNGEthanol (S2Mo)

MethanolFT-liquids

DMEHydrogenCO2 removal

Ethanol (S2Mo)FT-liquids

DMECO2 removal

CLEANED SYNGAS

H2/CO = 1.5-3.5Hydroc. = 1-2%CO2 = 20-30%

Scenario 1

Scenario 2

Scenario 3

Scenario 4 (no biofuel can be produced)

EF

WGS reactor

SNGEthanol

MethanolFT-liquids

DMEHydrogen

CO2 removal

DME*CO2 removal

Limited productionDME*

CLEANED SYNGAS

H2/CO = 0.4-0.7Hydroc. = <1%CO2 = 10-20%

Scenario 1

Scenario 2

Scenario 3

Scenario 4



Matching: gasification-cleaning, conditioning & synthesis


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Testing the matching

• Only feasible cases• Brute force


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Results: Example (DME)

• For a d-FB gasfierParameters

Conventional synthesis

(max. production)Once-through

Hybrid

(Limited production)

H2/CO (molar) 1.65 1.25 1.15

CH4 (% v/v) 10 5.6 10

CO2 (% v/v) 8.4 21.5 21.0

DME (production) 9.18 MJ/kgdafb 3.84 MJ/kgdafb 6.57 MJ/kgdafb

Methanol

(production)0.69 MJ/kgdafb 0.75 MJ/kgdafb 1.18 MJ/kgdafb

Electricity

(production)-0.12 MJ/kgdafb 2.95 MJ/kgdafb 1.28 MJ/kgdafb

Efficiency (LHV%) 43.0% 36.1% 43.3%

Advantages1. Higher global conversion to DME

2. Conversion of hydrocarbons into DME

1. No syngas conditioning

a. Lower capital investment

b. Reduction on operating cost

(steam)

2. Larger combined cycle (larger efficiency)

1. No syngas conditioning

2. Larger syngas conversion than once-

through

3. No CO2 build-up (CO2 is removed from the

unconverted syngas due to cryogenic

separation)

Disadvantages

1. Reformer and CO2 removal are necessary

(capital- and energy-intensive section)

2. The reforming increases the H2/CO ratio

above requirements

3. Low efficiency for electricity production

1. Low global conversion (only per-pass

conversion)

2. Electricity has a lower price than DME

3. Higher methanol production due to the

presence of CO2

1. Electricity has a lower price than DME

2. Higher methanol production due to the

presence of CO2

3. Low efficiency for electricity production


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Final remarks

• Lessons to be learn

• Natural limits to the process (seek the feasible combinations)

• Check alternatives for product maximization

• Further efforts should be made for the design of “simple” but profitable

biorefineries designs

• Industry participation/leadership?

• Next: Evaluation/Optimization of first-ok-a-kind (FOAK) thermochemical

biorefineries

• Uncertainty analysis (specific for FOAKs)

AcknowledgementsFulbright-Schumann ProgramUniversidad de Sevilla, VI Plan Propio de Investigación

T h a n k y o u fo r y o u r a t te n t i o n !

Documents

Matching gasification, conditioning and synthesis for the