Biomass research at CNRS Nancy shortlrgp-nancy.cnrs.fr/IMG/pdf/Biomass_research_at_CNRS_Nancy_shor… · Biomass research at CNRS Nancy Research on biomass thermo-chemical conversion

Biomass research at CNRS Nancy

Research on biomass thermo-chemical conversion done in the CNRS-LRGP

Short overview

1/2013

The lab has privileged links with INPL (National PolytechnicInstitute of Lorraine) which is a part of Lorraine University

The lab is hosted in two Engineering schools in INPL� National school for industrial chemistry (ENSIC)

� National school of agronomy and food industry (ENSAIA)

Laboratory of Reactions and Processes Engineering (LRGP) – UPR CNRS 3349

A national laboratory of the french CNRS (National Center for Scientific Research), within the Institute of Engineering Sciences and Systems

The lab is composed of ~ 300 persons� 30 research scientists (CNRS)� 80 professors and lecturers� 50 technical or administrative staff members� 140 PhD students or post-doc scientists� Head of the lab : Gabriel Wild

Deputy director : Jean-Pierre Leclerc

- 2 -

BIOMASS feedstock(lignin, hemicelluloses and cellulose)

Main routes studied at LRGP for biomass conversion

Combustion

T>800°CO2

CO2 + H2O+ ashes

Heat and/or

electricity

Syngas

T=200-1000°CNo O2

Pyrolysis

Char

Liquefaction

T=200 - 400 °CPH2=20-200 Bars

Bio-oils

Electricity, liquid biofuels, Gaseous biofuels (CH4, H2,), etc.

T=700-1500°C

~1/3 O2

Gasification

Biofuels, chemicals

+ Up-grading Gasification Refineries

- 3 -

Multi-scale approach to optimize the processes

Scale

Topics

Molecule Particle Reactor Process

Tar conversion

Particle modelling

Reactor modelling

Energetic optimisation of

processes

Process modelling (Aspen)

Pyrolysis and

gasification reactors

Gas/solid reactions (char

oxidation, catalysis)

Chemical kinetic

Mechanisms of solid pyrolysis

- 4 -

Summary of the main reactions in thermochemical reactors

BIOMASS

CO, H2O, H2,

CO2, CH4, etc.

PRIMARY TAR

CHARPRIMARY PYROLYSIS

HEAT (W m-2 K -1)

+ O2, H2O, CO2

GAS-PHASE and/or CATALYTIC CONVERSION CO2, H2O,

CO, H2

TAR, etc.

CO2, H2O

CO, H2

CHAR OXIDATION

+ O2, H2O, CO2

CH3

CH3 CH3

CH3

- 5 -

Primary pyrolysis of biomass

Polymers carefully extracted from the biomass network (by Pr. Brosse)

Thermogravimetry (TG) - differential scanning calorimetry (DSC)

0

20

40

60

80

100

150 250 350 450

Temperature (°C)

Mass f

ractio

n (

%)

(m

ass /

in

itia

l m

ass)

Xylan

Miscanthus

Cellulose

Lignin

5 K min-1, ~ 1mg initial sample

- 6 -

Quantitative DSC in a 3D sensor

(Setaram, France)


In-situ analysis of biomass pyrolysis by 1H NMR (with

Pr. Snape group, Nottingham) and rheology (see ACS meeting, San Diego)

Mobility of protons are analysed by in-situ 1H NMRInteractions between polymers in the native network

- 7 -

Dufour et al., ChemSusChem, 2012

Visco-elastic, swelling and shrinking properties are analysed by rheometry (mechanical spectroscopy).

- 8 -

Transducer

Motor

Biomass pellet (~2mm)

2 parallel plates

Normal force (200g)

0

1

2

150 200 250 300 350 400

Temperature (°C)

tan

(δδ δδ)

Xylan

Miscanthus

Cellulose

LigninMainly

VISCOUS

Mainly

ELASTIC

Mechanisms of softening and resolidification (“char formation”) are evidenced.

Energy&Fuels, 2012


BIOMASS

CO, H2O, H2,

CO2, CH4, etc.

PRIMARY TAR


HEAT (W m-2 K -1)

+ O2, H2O, CO2


CO, H2

TAR, etc.

CO2, H2O

CO, H2

CHAR OXIDATION

+ O2, H2O, CO2

CH3

CH3 CH3

CH3

- 9 -

Char oxidation and reactivity

TG – DSC + IR or µGC analysis, fixed bed oxidation, etc.

Molecular structure of charsis analysed by High ResolutionTransmission Elec. Miscroscopy (with J.N. Rouzaud, Paris)

2nm

Mineral impurity

Carbon sheets

Analysis at nm scale

Carbon sheets of wood char like a “crumpled” paper.

- 10 -

Differential thermal annealing is an original method to characterize different “types” of carbons in char

- 11 -

Graphite fritted

Graphite support

Reactive & carrier gas

Thermocouple

Pyrometerspot

Particles

External carrier gas

A new set-up has been designed: heating of char up to 1800°C (in 30s) in a fixed bed

Heating of chars to 1800°C followed by XRD analysis allows to reveal different types of carbons and reactivity in chars.

- 12 -

5 15 25 35 45 55 65

Diffraction angle (2θθθθ, degree)

Inte

nsit

y (a

rbit

rary

uni

ts)

Char 2

*

Char 3

Char 4



BIOMASS

CO, H2O, H2,

CO2, CH4, etc.

PRIMARY TAR


HEAT (W m-2 K -1)

+ O2, H2O, CO2


CO, H2

TAR, etc.

CO2, H2O

CO, H2

CHAR OXIDATION

+ O2, H2O, CO2

CH3

CH3 CH3

CH3

- 13 -

Experiments on tar gas-phase conversion are conducted in a perfectly jet stirred reactor

Spherical geometry : no dead volume

Uniformity of composition and temperature

Reactor perfectly adapted to study kinetics of chemical reactions

GC instruments

Carbosphere columnTCD/FID detector

Capillary column Plot Q

FID detector

Molecular sieve 5Å

Gas Chromotography at the outlet of reactor

Quantitative GC*GC/MS-FID-FID (Dean switch, 2 columns)

Good prediction of tar conversion underCHEMKIN (> 1000 reactions)

O

CH3

CH3

OCH3 O

CH3

COCH

OH OH

CH

H

CH2

CH4

+ +

+

+ +

+CH3

+

+

+CH3

Anisole conversion = 80%

Real tar gas-phase conversion is studied in a JSR coupled to a tubular reactor (continuous pyrolysis reactor in progress)

Baumlin et al., Chem. Eng. Sci., 2005

Dufour et al., Int. Symp. Comb., 2010

Mass flowcontroller

H2O analysisKarl Fischer

Tar analysisGC/MS-FID

atm

Collapsible teflon bag

Gas analysisGC/TCD-FID

Mass flow controller

Jet stirred reactor

Secondaryreactions

Tubular reactor

Primary pyrolysis

N2 carrier gas Stirring

gas

Biomass particles

Primarytars

Vapours sampling4 cold-traps

- 17 -

Dufour et al., Int. Symp. Comb., 2010.

0%

20%

40%

60%

80%

100%

350 600 800 900

PSR temperature (°C)

Pro

du

cts m

ass y

ield

s (

%)

gas

H2O

tar

char

1

2 34 5

6 78 9 10

11

1213 14

15

16

1718

19

201

2 34 5

6 78 9 10

11

1213 14

15

16

1718

19

20

Mass yields of products as a function of tar conversion temperature in the JSR (residence time = 0.4s)

GC/MS analysis of tar

Real tar gas-phase conversion is studied in a JSR coupled to a tubular reactor

- 18 -


TAR catalytic conversion is studied in fixed bed reactor for tarcracking in gasification reactor or for tar hydro-deoxygenation

2 impingerswith propanol

(-60°C)

T

Vent

µGC - 4 modulesOn-line analysis

(CH4, H2, CO, etc.)To GC-FID-MSIntegral off-line analysis

Heated lines

Catalyst bed

Syringe pump

Oven

Fritted

Mass Flow Controllers

H2

N2

CO

CH4

4 ways valve

R. Olcese pH-D

- 19 -

Production of aromatic chemicals (benzene, etc.) from never-condensed lignin pyrolysis vapours

- 20 -

0

0.1

0.2

0.3

0.4

0.5

0.4 0.9 1.4 1.9 2.4

H/C

O/C

Lignins

Pyrolytic oil

Cyclo- hexanol

AlkanesBTX

O

OH

OH

O

O

OH

OH

LigninO

CH3

O

Lignin

O

O

CH3

O

OH

Lignin

CH3

CH3

O

OH

CH3

CH3 CH3

CH3

CH3CH3

Desired route

Undesired route

Pyrolysis

Guaiacol

Very good selectivity in BT (Benzene, Toluene) production from guaiacol with Fe/SiO2 catalyst: green and cheap catalyst

- 21 -Olcese et al., App. Catal. B., 2012 & 2013.

Mass residence time= 1/WHSV = g catalyst/(g guaiacol/h)


Scale

Topics


Tar conversion

Particle modelling

Reactor modelling


processes


Pyrolysis and




Chemical kinetic


- 22 -

Wood char particles, slow pyrolysis, from mm to µm (Scanning Electron Microscope): bubbles formation at µm length scale (Dufour et al., App. Catal., 2008)

Intra-particular mass transfer of pyrolysis products

High heat flux density (Boutin et al. 1998)

Cellulose before pyrolysis After pyrolysis

- 23 -

Modelling of biomass primary pyrolysis

A simplified model has been proposed including:

Modified Bradbury (1979) mechanism + intermediate liquidcompounds + evaporation of liquid tar + intra-particle conversion

γγγγ Gas + (1-γγγγ) CharBiomass1

Intermediate solid2

3

Liquid tar Evaporated tar

δ δ δ δ Gas + (1-δδδδ) Char

4

Intra-particle tar evaporation (thermodynamic equilibrium)

(Fletcher et al., 1991)

)T

M*Bexp(AP

59.0T

TG

−=

Internal mass transfer by convection (Darcy law)

L

PS

KQ

G

∆µ

=

bRT

E

ii

i

eAr ρ−

=

Dufour et al., Chem. Eng. Res. Des., 2011

Kinetic of 4 reactions

- 24 -


Modelling of primary pyrolysis

Comparison between model and experiments (from Milosavljevic and Suuberg,1995)

for different heating rates

Mass loss controlled by intra-particle liquid tar conversion, in agreement withSuuberg (1996)

Dufour et al., Chem. Eng. Res. Des., 2011

0.0

0.2

0.4

0.6

0.8

1.0

500 600 700 800

Temperature (K)

Mas

s lo

ss

a = 16.67 K/s

a = 1.67 K/s

a = 0.097 K/s

0.0

0.2

0.4

0.6

0.8

1.0

500 600 700 800

Temperature (K)

Mas

s fr

acti

on

Mass loss

Y B

Y I

Y TL

Y S1

Y S2

- 25 -

Heating of particle surface by xenon-arc lamp radiation = controlledheat flux density (~0.5MW/m2)

Primary vapours are immediately quenched at the outlet of the particle

Experiments on primary pyrolysis are conducted by the image furnace (Lédé, 1982, Authier et al., Ind. Eng. Chem Res., 2009)

- 26 -

Modelling of primary pyrolysis(Authier, I&ECR, 2009, Al Haddad, En&Fuels, 2009)

Simplified chemical mechanism

1D mass and energy balance

biomass

gas

tar

char

bRT

E

ii

i

eAr ρ−

=

∑∆−∂∂=

∂∂

+i

iizpccpbb rHz

T

t

TCC

2

2

)( λρρ

∑=∂

∂

iiij

j rt

νρMass balance

Energy balance

Without any internal mass transfer

- 27 -

Comparison between experiments from image furnace and model predictions with different kinetic rate constants (Authier, Mauviel, 2009)

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 5 10 15 20 25 30 35 40

Temps (s )

Pe

rte

s

/ M

as

se

in

itia

le d

u b

ois

) %

1,4 mm - 78 % oc c ultation



T hurner

C han

Di B las i

Wag enaar

F ont

Mass loss /

init

ial m

ass d

ry w

ood (

%)

Time (s)

Important effect of kinetic parameters

- 28 -


Scale

Topics


Tar conversion

Particle modelling

Reactor modelling


processes


Pyrolysis and




Chemical kinetic


- 29 -

Reactors for biomass pyrolysis and gasification

The cyclone is a multi-functional reactor for fast pyrolysis (Lédéat al., 1990, 2000)

Complete hydrodynamic & thermal modelling

Fluidised bed gasification reactors are developed up to 50kg/h(in a collaborative facility with EDF – French Power Company)

Biomass particles

Char

Gases

Condensers

& Filters

Bio-oils

Carrier gas

Heating of

the wallFast pyrolysis +

separation of char

Analysis

Analysis

- 30 -


Biomass3 t/h

Steam500 kg/h

Air

CO2, H2O, N2

H2 + CO + CO2 + CH4 + H2O + TAR

T= 850°C

Cokedolivine +

char

Olivine 140 t/h

Modelling of the dual fluidised bed of Güssing (Austria)(Authier O. , ph-D for EDF, J. Lédé & G. Mauviel)

Dense bed model:

Fluidised bed hydrodynamic

Steam and heat transfer to biomass particle

Particle model (internal heat transfer, drying, pyrolysis, char gasification)

Gas-phase reactions

Freeboard model:

Kinetics of:

Water Gas Shift,

Methane reforming

Gas-phase and catalytic tar conversion

+ enthalpy balance

T= 950°C

- 31 -


Scale

Topics


Tar conversion

Particle modelling

Reactor modelling


processes


Pyrolysis and




Chemical kinetic


- 32 -

Coupling between Aspen software and Fortran allowsa more detailed modelling of processes

More detailed reactor modelling under ASPEN thanks to Fortran files

More detailed products compositions, mass and enthalpybalances

Process flow sheet

Products data base

Mass and enthalpy

flow rates

Aspen

Detailed reactor

modelling

Mass balance

Kinetic model

FortranReactor

inlet

Reactor

outlet

- 33 -Abdelouahed, submitted to En& Fuels

55

60

65

70

Eff

icie

ncy

(%

)

A biomass gasification process was modelledunder Aspen Plus

The efficiency of the process is improvedby catalytic tar conversion over char

Char is a green catalystfor tar cracking Tar cracking

over char

Base

process

Optimised

process

App. Catal., 2008

Abdelouahed, En& Fuels, 2012

Francois, Biomass Bioenergy, in press

- 34 -

Aspen models are used to optimise gasification processes

Modelling of biomass conditionning and pretreatment

Modelling of a whole gasification processfrom forests to power with minerals and NOx, SOx, etc. emissions

Life cycle assessment of a combined heatand power plant based on the detailedAspen mass and energy balances

- 35 -

In CNRS-LRGP laboratory, research on biomass

thermo-chemical conversion are conducted on:

pyrolysis and gasification,

a multi-scale approach, from molecular to

process scale.

Nancy and its wonderful Stanislas square!

- 36 -

[email protected]


Thank you for your attention

- 37 -Thank you to all the contributors ( > 40 people)

KinCom and GREENER groups

- 38 -

Summary of LRGP set-ups and models for biomassthermochemical conversion

Reactors: from 20 to 2000°C

• TG-DSC

• Image furnace and laser heating (imposed heat flux density)

• Catalytic fixed bed

• High temperature fixed bed (up to 2000°C)

• JSRs for tar (model or real compounds) gas-phase conversion

• Cyclone reactor

• Fluidised beds (lab scale 3Kg/h and pilot scale 50kg/h, under development.)

Analysis

• Solid analysis: elemental analysis, ICP-MS & AES, MEB, N2 sorption, Hg porosim., Raman, IRTF, etc.

• Liquid analysis: LC-MS-UV-RI, GC*GC/MS-FID

• Gas analysis: 3 µGC, many GCs, on line IR, etc.

Models

• CHEMKIN

• ASPEN/FORTRAN

- 38 -

Documents

Biomass research at CNRS Nancy shortlrgp-nancy.cnrs.fr/IMG/pdf/Biomass_research_at_CNRS_Nancy_shor… · Biomass research at CNRS Nancy Research on biomass thermo-chemical conversion