CO2 valorization in a biomass to fuel process ... · 2 valorization in a biomass to fuel process: experimental gasification study and process ... reforming H 2 Aspen + ... Dry biomass

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CO2 valorization in a biomass to fuel process: experimental gasification study and process

evaluation

12th of May 2015

Symposium on Renewable Energy and Products from Biomass and Waste

Sylvie VALIN, Laurent BEDEL, Pierre-Alexandre SETIER (CEA, LITEN)Sébastien GROS (EDF)

ANR-10-BIOE-000212th May 2015 - Symposium on Renewable

Energy and Products from Biomass and Waste

12th May 2015 - Symposium on Renewable Energy and Products from Biomass and Waste | PAGE 2

Overview of the presentation

The RECO2 project

Experimental investigation: CO2 in the gasification process

Technical assessments of SNG and FT pathways

Conclusions

20 MAI 2015 | PAGE 2


The RECO2 projectR&D project:

Objective: to assess the interest of CO2 recycling in a biomass gasification process, to synthesize gaseous (bio-SNG) or liquid fuels (Fischer-Tropsch diesel)

Gasification is performed in a dual fluidised bedCO2 is recycled in the process, replacing N2 (biomass feeding) and/or steam

3 years-project (2010-2013) funded by the French ANR (Agence Nationale pour la Recherche)Partnership:

20 MAI 2015| PAGE 3



The RECO2 project



Conclusions

20 MAI 2015 | PAGE 4


The fluidised bed facility

Ar/CO2

N2 H2O

To µGC

To tar protocol

Cold traps for water

Feeding screw (heated)

Biomass bunker

Pressurized vessel

Metallic filter

Internal reactor

Electric resistance heaters

Lower partΦ = 0.124 m

Disengagement zone

Φ = 0.20 m

CO2

Tmax 1000°C

Pabs 1.5 to 12 barsBiomass feeding rate 0.3-5 kg/h

Product analysis/quantification

Dry gas: µGCWater: condensationTar protocol (isopropanol) + GC-FID quantification

Ar


CO2 as a substitute of steam in fluidising gas

Experimental conditions

20 MAI 2015 | PAGE 6

Temperature 850°C

Pressure 1.5 bara

Biomass Beech wood particles 1-2mm

Woody biomassfeeding rate

3 kg/h

Bed material SiC

Fluidising velocity 0.17 m/s

Fluidising gas 40 vol% N2

60vol% (H2O, CO2) withCO2/(CO2+H2O) ratio from 0 to 100%

Ref test (without CO2):H2O/C mass ratio=1.2



20 MAI 2015 | PAGE 7

Main gas species yields: mainly influenced by H2O/CO2 addition and by water-gas shift equilibrium: CO + H2O ↔ CO2 + H2

In agreement with a rather steady (CO+CO2) net yield



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No significant influence on minor hydrocarbons – nor on tar contentConversion of tar and BTX seems to be as efficient in atmosphere rich in H2O or CO2



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No significant influence on C conversion nor on CGEAs expected, H2/CO ratio decreases as more steam is substituted by CO2

Ratio always too low for SNG or FT synthesis – for direct DME synthesis: the target -1- can be reached

biomassinCInputCOinCInputgasinCXC

2


CO2 as a substitute of inert gas in feeding system

20 MAI 2015| PAGE 10

C conversion and CGE increase with total oxidant inputThis additional oxidant input –more or less important according to the reactor –should be taken into account

Substitution of inert gas by CO2 in the feeding system induces an increase of total oxidant input in the reactor

• Study of the influence of total oxidant input

Gasification study: to summarise

Substitution of steam by CO2 in the fluidising gas:• Only significant chemical influence = modification of WGS equilibrium• Carbon conversion and CGE not significantly modified

In the global process, no influence on the biofuel yield expected• H2/CO ratio decreases as more H2O is replaced by CO2: could be of interest for direct DME synthesis

Substitution of inert gas by CO2 in the feeding system: • increases the total oxidant input • can increase the gasification efficiency + WGS equilibrium and H2/CO ratio




The RECO2 project



Conclusions

20 MAI 2015 | PAGE 12


Description of the process (SNG & BtL)

orGasifier Syngas cleaning

SNG synthesis & upgrading

FT synthesis& upgrading

Compo adjustment

Off-gas C5+

SNGAspen +

Prosim+

Biomass

100 MW



3 alternatives for adjustment of syngas composition:Autothermal option: water-gas-shift reaction (WGS) → H2 ↑ CO↓Allothermal option: addition of electrolytic H2 → H2 ↑

with CO transformation into fuelwith CO+CO2 transformation into fuel (SNG: CO2 methanation - BtL: RWGS)

orGasifier Syngas cleaning



Compo adjustment

WGS or

Off-gas

H2

Aspen +

Prosim+

C5+

SNG

Biomass

100 MW

or





2 alternatives for off-gas use (BtL pathway):Electricity productionSteam reforming → recycling in the syngas

Gasifier Syngas cleaning



Compo adjustment

WGS or

Off-gas

Electricityor

Steam reforming

H2

Aspen +

Prosim+

C5+

SNG

Biomass

100 MW

or





2 alternatives for off-gas use (BtL pathway):Electricity productionSteam reforming → recycling in the syngas

Different CO2 recycling ratios




Compo adjustment

WGS or

Off-gas

Electricityor

Steam reforming

H2

Aspen +

Prosim+

C5+

SNG

Biomass

100 MW

CO2

CO2 CO2


Biomass conversion in dual fluidised bed: adaptation of experimental results

Choice of technologies for gas cleaning, synthesis and upgrading made on the basis of EDF and CEA experience with the support of TUW expertise

Energetic integration

Performance indicators

Mass yield (kg/kg) →

Gross energy yield (LHV) →

Net energy yield (LHV) →

Product rate (biofuel)

Dry biomass feeding rate

Energy (products)

Energy (biomass + electricity + RME)

Energy (products)

Energy (biomass)

Description and definitions

17th October 2013 - SGC Seminar | PAGE 18

Technical performances: SNG case

No influence of CO2 recycling in autothermal and “Allo / CO & CO2 → CH4” cases

Increase in mass yield with CO2 recycling in “Allo / CO → CH4” case

Production can be doubled with H2 addition

Auto Allo/ CO -> CH4 Allo/ CO+CO2 -> CH4

RWGS/WGS Always = max from biomass


Technical performances: BtL case

Much higher yields with off-gas reforming

Without off-gas reforming With off-gas reforming

Autothermal case: influence of off-gas reforming


Technical performances: BtL case

Similar observations as for SNG

No influence of CO2 recycling in autothermal and “Allo / CO & CO2 → CH4” cases

Increase in mass yield with CO2 recycling in “Allo / CO → CH4” case

Production can be almost doubled with H2 addition

Auto Allo/ CO -> CH4 Allo/ CO+CO2 -> CH4

With off-gas reforming


CO2 net emissions for the process (SNG case)

CO2 recycling: positive influence only for “allo CO -> CH4” case

H2 addition in the process deeply decreases the CO2 net emissions (from -20% to -90%)

CO2 net emissions calculated for the process: difference between

• CO2 out (SNG upgrading + flue gas of the combustor)

• CO2 in (in the gasifier)



Compo adjustment

WGS or H2

SNG

Biomass

100 MW

CO2 in CO2 out

CO2 out


To conclude on this study

For SNG and BtL process, substitution of steam by CO2 in the fluidising gas:• Positive influence only if external H2 is added in the process - with transformation of CO only into fuel

• Mass yield increases and CO2 net emissions decrease

Addition of external H2: • Increases mass yield and decreases CO2 net emissions compared to “autothermal” case• Higher influence if CO2 is transformed into fuel (methanation or RWGS)

Economic aspect: • The options with H2 addition should lead to higher costs (electrolyser, electricity) in base conditions• The facility could be used in a flexible way with H2 addition only when electricity is “cheaper” (surplus of available renewable energy)

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Thank you for your attention !

12th of May 2015

Symposium on Renewable Energy and Products from Biomass and Waste

12th May 2015 - Symposium on Renewable Energy and Products from Biomass and

Waste

Documents

CO2 valorization in a biomass to fuel process ... · 2 valorization in a biomass to fuel process: experimental gasification study and process ... reforming H 2 Aspen + ... Dry biomass