ionic liquids could replace expensive gas cleaning process

Research Institutes of Sweden

Ionic liquids could replace expensive gas cleaning process

Bio4Energy meeting

Medlefors, Skellefteå

2019-05-15

RISE ETC

Gasification based biofuels production

2

Biomass Pretreatment (Drying/milling/pelletization) Gasification Syngas cleaning

and conditioning Fuel synthesis

Syngas cleaning and Acid Gas Removal(AGR) can amount to a substantial part ofthe biofuel production cost (<30-40 %) usingexisting technologies (Rectisol / Selexol)

CO2 (& H2S)

Challenge - to find a cost effective system for CO2 capture:Polyamines are relatively cheap and benefit from several sites for CO2 absorptione.g. pentaethylenehexamine (PEHA)+ High thermal stability+ Low vapor pressure (regeneration)+ Low toxicity

CO, H2, CO2, H2O, CH4

CO, H2, (CH4)H2O

CO2 absorption

3

Monoethanolamine, MEA

Polyethylenehexamine, PEHA

-”But how do they behave using real syngas containing impurities from biomass gasification?”

4

High temperature gasification in a fixed-bed oxygen blown gasifierSpruce barkSpruce needles/fine twigsBirch stem woodPretreated birch

Different operating conditions, λ = 0.35 - 0.50

Development of acidgas absorption systemSampling & evaluationof CO2 capture

CO2 absorption from real bio-syngas

5

T

GC

Water bath Thermometer

Reactor

Gas flowmeter

Magnetic rotorMagnetic stirrer

Syngas from gasifier

Glass wool filter

Polyethylenehexamine, PEHA (aq)

Gasification experiments and resulting syngas composition

6

0

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45

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CO H2 N2 CO2 CnHm

Gas

con

cent

ratio

n (%

)

BW, λ=0.45BW, λ=0.38BW, λ=0.33BW*, λ=0.36SB, λ=0.48SB, λ=0.41SB, λ=0.34SN, λ=0.47SN, λ=0.42SN, λ=0.34

0

5

10

15

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25

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08:00 09:00 10:00 11:00 12:00 13:00 14:00 15:00

Syng

as co

ncen

trat

ion

(mol

-%)

COH2CO2CH4

λ = 0.47 λ = 0.42 λ = 0.34

Example from Spruce needles (SN)

CO2 capture efficiency

7

T

GC

Water bath Thermometer

Reactor

Gas flowmeter

Magnetic rotorMagnetic stirrer

Syngas from gasifier

Glass wool filter

Addition of PEHA (aq) solution

Conclusions

8

• B4E funding successful for bringing the research partners in northern Sweden closer together, developing ideas for more sustainable energy solutions

• Large potential for this type of CO2 capture. Now proven with real syngas in lab scale. Next step to develop pilot scale system for testing, i.e. increase TRL.

• PEHA showed >70 % CO2 capture efficiency during the initial ~30 min of the experiment, with a maximum absorption capacity of ~0.12 g CO2/g solvent at atmospheric pressure and 25 °C

• This is valuable information for evaluating the process techno-economically in comparison with existing technologies

9

The project is a combined effort of Umeå

University (UmU) and Luleå University of

Technology (LTU), Swedish University of

Agricultural Sciences (SLU), Umeå, and

RISE Energy Technology Center which

represent multiple B4E research platforms

(P3, P4, P6 and external expertise)

Thank you for listening!