El ciclo del agua II: Proyecto innovador de Biometano usando

Tecnología de Microalgas

Raúl Muñoz (mutora @iq.uva.es)Instituto de Procesos Sostenibles

Valladolid University

The biogas upgrading market

(IEA Bioenergy 2018)

Today….

Physical/Chemical CO2 removal Technologies

(Bauer et al. 2013)

Physical/Chemical CO2 removal Technologies

0.4-0.51 kWh Nm-3

0.55 kWh Nm-3

(Bauer et al. 2013)

Energy demand: 3-12 % energy content of Biogas

Technology Niche

Photosynthetic Biogas Upgrading

Microalgae recycling

Upgraded biogas

Raw biogas

Nutrient solution HRAP Sedimentation

tank

Ab

sorp

tio

n

colu

mn

▪ Photosynthetic fixation of CO2 as algalbiomass→ Valorization

CO2 + H2O + Light→ O2 + microalgae

▪ Free nutrient source: Digestate

▪ Simultaneous removal of H2S

▪ [CH4] > 95 %

Photosynthetic Biogas Upgrading

CH4 > 95 %, CO2 < 1 %, N2 < 3%, O2< 0.5 %

Photosynthetic Biogas Upgrading

Microalgae recycling

Upgraded biogas

Raw biogas

Nutrient solution HRAP Sedimentation

tank

Ab

sorp

tio

n

colu

mn

LG

Key operational parameter: Recycling Liquid/Biogas ratio

Photosynthetic Biogas Upgrading

Photosynthetic Biogas Upgrading

Photosynthetic Biogas Upgrading

LG

Photosynthetic Biogas Upgrading

CO2 content (%) in the upgraded biogas with the control system(green) and without control system (blue) under biogas flow rateperturbation (red)

Photosynthetic Biogas Upgrading

Microalgae recycling

Upgraded biogas

Raw biogas

Nutrient solution HRAP Sedimentation

tank

Ab

sorp

tio

n

colu

mn

▪ The high pH value→ High H2S masstransfer

▪ RE-H2S > 99 %

N = 600-4000 mg/LP = 100-500 mg/L

[Microalgae]=7-50 g/L

Digestate

Low PhotosyntheticEfficiency↓↓

Photosynthetic Biogas Upgrading & Nutrient Recovery

Photosynthetic Biogas Upgrading & Nutrient Recovery

Removal Recovery as Algal Biomass

Biomass productivity (g m-2 d-1)Biomass productivity (g m-2 d-1)

Tota

l Nit

roge

nR

emo

val(

%)

Tota

l Ph

osp

ho

rou

sR

emo

val(

%)

Photosynthetic Biogas Upgrading & Nutrient Recovery

Technology Scale-up

120 L

180 L

32 m2

Wastewater Treatment Plants

Preliminary Sustainability Analysis

REFERENCE FLOW RATE: 300 Nm3/h

Preliminary Sustainability Analysis

Activated Carbon + Water Scrubber Photosynthetic Biogas UpgradingVersus

Table S1. Investment costs of a ACF-WS for the upgrading of 300 Nm3 h-1 of biogas

Cost Units Total cost (€) References

Land 100 € m-2 10 000 INE, 2015

Activated

carbon filter 129 € (Nm3/h)-1

treated biogas 38 766 Xiao et al. (2008)

Water scrubber 3500 € (Nm3/h)-1treated biogas 1 050 000

SGC Rapport

2013:270

Table S2. Investment costs of the HRAP-AC for the upgrading of 300 Nm3 h-1 of biogas Cost Units Total costs (€) References

Land 10 127 € ha-1 188 712 MAGRAMA, 2014

HRAP

construction 26 616 € ha-1 356 382

Craggs et al., 2012;

Lundiquist et al., 2010

Paddlewheel

stations 35 400 € ha-1 474 006 Craggs et al., 2012;

Screw press 86 000 € unit-1 86 000 HUBER Technology,

Germany

Solar dryer 325 000 € unit-1 650 000 HUBER Technology,

Germany

AC 3 980 € unit-1 51 745 Delf Grupo España S.L.

Gas diffusers 250 € (10 units)-1 3 250 Xylem Inc.

Preliminary Sustainability Analysis

HRAP-AC ACF-WS0.0

0.2

0.4

100

200

300

400

500

600

700

b)

HRAP-AC ACF-WS0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

En

ergy

(KW

-h (

Nm

3)-1

treate

d b

iogas)

La

nd

(m2 (

Nm

3/h

)-1

treate

d b

iogas)

a)

HRAP-AC ACF-WS0.0

0.2

0.4

100

200

300

400

500

600

700

b)

HRAP-AC ACF-WS0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.35

En

ergy

(KW

-h (

Nm

3)-1

treate

d b

iogas)

La

nd

(m2 (

Nm

3/h

)-1

treate

d b

iogas)

a)

Land Requirements Energy Consumption

Preliminary Sustainability AnalysisHRAP-AC ACF-WS

0

1000

2000

3000

4000

5000

6000

7000

a)

b)

I

nv

estm

ent

cost

(€ (

Nm

3/h

)-1

trea

ted

bio

ga

s)

HRAP-AC ACF-WS0.00

0.05

0.10

0.15

0.20

0.25

O

per

ati

ng

co

sts

(€ (

Nm

3)-1

trea

ted

bio

ga

s)

Investment costs associated to theproduction of dry algal fertilizer

Take home Message

Biogas Upgrading market dominated by physical/chemicalTechnologies→ High Operating Cost & Environmental Impact

✓ Algal-Bacterial Processes have shown a similar CO2 and H2Sremovals & high robustness but at:

▪ Lower operating costs and environmental impacts▪ No need for previous removal of particles/H2O/siloxanes▪ Tested at pilot scale▪ Use of residual nutrients from digestate

✓ Photosynthetic upgrading allows for a simultaneous H2S & CO2

removal and Nutrient Recovery from Digestates as algal-biofertilizer

University of Valladolid

Institute of Sustainable Processes

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Contact e-mail: mutora@iq.uva.es

http://www.ips.uva.es/

Muñoz R*, Meier L., Diaz I, Jeison D (2015) A critical review on the state-of-the-art ofphysical/chemical and biological technologies for an integral biogas upgrading. Reviews inEnvironmental Science and Bio/Technology