Biogas from the pulp and paper industry effluents

EBA: The Netherlands

October 1st 2014

Jörgen Ejlertsson R&D Director, VP, Professor

Agenda

● Introduction ● Background ● Partners and the project ● Approaches, assumptions and methods

● Biogas from Mechanical pulp mills effluents ● Overview ● Conclusions

● Biogas from Kraft pulp mill effluents

● Overview ● New approaches ● Conclusion

● Summary

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Scandinavian Biogas in brief

● Founded in December 2005

● Former Prime Minister of Sweden Göran Persson is Chairman of the Board

● Ability to prove and optimize concepts in both laboratory, pilot and full scale.

● Head office in Stockholm

● Operations in Sweden and South Korea

● BOO and BOT business model

● 40 employees

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Background: The Swedish pulp & paper industry

● Sweden have about 8% of global pulp production: ● Europe have ~25% global production and Sweden have ~30% of European

pulp production ● Practically the COD/TOC in Swedish effluents could give rise to ~100 Mm3 of

methane – 1000 GWh ● Biogas production today: 85 GWh generated from one plant – sulphite Kraft

pulp ● Very large process volumes with current techniques

● Miss-trust for anaerobic treatment for PPI effluents from the PPI-branch – activated sludge always works…

● Need of know-how – technique providers as well as PPI personal

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Background: The Swedish pulp & paper industry

● Production: mechanical pulp – 12 mills ● Total: 3 600 kton year-1

● Average: 300 kton year-1

● Net sales ~140 MEuro per mill-1 year-1

● Production: Kraft pulp – 25 mills ● Total: 8 200 kton year-1

● Average: 330 kton year-1

● Net sales ~160 MEuro per mill-1 year-1

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Operations at 35 locations

Background: Biogas production in Sweden

● 1 600 GWh of biogas was produced 2012

● Practically the Swedish P&P industry could add ~1000 GWh

Sewage treatment Co-digestion Farm-scale Industrial Landfills

Energigas Sverige, 2012

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The project: Establishing biogas production in the Swedish pulp & paper industry

● Partners ● Linköping University ● Scandinavian Biogas Fuels ● Pöyry Sweden AB ● Pulp & Paper Producers ● Equipment Supplier (UASB using EGSB technique)

● Financing ● Swedish Energy Agency 65% ● Partners 35%

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The project: Establishing biogas production in the Swedish pulp & paper industry

● Research project led by Linköping University, Department of Thematic Studies ● Prof. Bo Svensson, Ph.D. Annika Björn and

Adj Prof Jörgen Ejlertsson

● Objectives ● Show that methane production is possible from various process

streams at pulp and paper mills ● Reduce the investment cost per produced Nm3 of methane ● Biogas information and awareness to the P&P industry ● Targets:

•  45% of COD in PPI effluents converted to CH4 •  100 Mm3 CH4 from PPI effluents

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Pre-sedimentation Waste activated sludge

Fiber sludge

Recipient Process water from factory

Sludge dewatering

Sludge tank

Bio sludge

Sludge cake to incineration or compost

Current treatment of process water streams at PPI

Rejected water

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Pre-sedimentation Waste activated sludge

Fiber sludge

Recipient Process water from factory

Sludge dewatering

Sludge tank

Bio sludge

Sludge cake to Incineration or compost

Possible treatment of process water streams at PPI

Rejected water

Biogas

UASB

CSTR

Biogas

Internal substrates: Methanol Fibers

CSTR

or

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Pre-sedimentation Waste activated sludge

Fiber sludge

Recipient Process water from factory

Sludge dewatering

Sludge tank

Bio sludge

Sludge cake to Incineration or compost

Possible treatment of process water streams at PPI

Rejected water

Biogas

UASB

CSTR

Biogas

Internal substrates: Methanol Fibers

CSTR

or

Concentrated process water streams from factory

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Completely Stirred Tank Reactor (CSTR) with

sludge re-circulation

IC or EGSB- Reactors

UASB techniques

Assumed techniques

Rötkammare substrate

Solids re-circulation

Biogas

Liquid phase

Solid phase

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Methods

● Sampling at 7mills and 10 PPI processes

● About 80 wastewater streams were sampled and characterized ●  Kraft, CTMP and TMP processes were included ●  TOC, COD, Flows, Temperature, pH ●  Methane potentials via anaerobic batch digestion assays

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COD kg/m3 (measured)flöde m3/min

CH4  Yield %  of  theor. (end/max)

Y:-­‐83/2 Y 3/4COD:  0,6 COD 6,2

Yield 21/21 Yield -­‐20/56COD 6,1 Yield 42/42 COD 0,2

Flöde 0,33 COD -­‐/3,7 Yield -­‐43/13 Flöde 12,77Flöde 7,50 COD 1,0

flöde 11,17

Yield 13/22 Yield 8/15 1)  After  PMCOD 1,3 COD 1,4 2)  D0

Flöde 23,82 Flöde 16,67 3)  EOPYield 28/28 4)  COD 3,4 5)  

Flöde 30,00 Yield 4/17 6)  BleachingYield 15/22 COD 1,3 7)  Before  presedCOD 1,5 8)  After  presed

Flöde 30 9)  Debarking10)  Tot  fluting11)  After  presed  +  bleaching

DebarkingBleachingD  (EOP)  D  P

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TM1

PM  9

PM8

PM7

Presed.

1

PM4

P

Pulping  2

Pulping1

10

4

7 8

5

NSSC

leachate

Sodahus

6

D0 D1EOP

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2 3

Methods

● Laboratory reactor tests to identify needs for nutrition additives and optimize the hydraulic retention time etc. ●  Upflow Anaerobic Sludge Bed (UASB) reactors in lab-scale ●  Continuous Stirred Tank Reactor (CSTR) sludge recirculation in lab-

scale

● Pilot scale UASB (EGSB) at pulp- and paper mills ●  Cover variations in the wastewater characteristics ● Minimize storage effects

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Agenda

● Introduction ● Background ● Partners and the project ● Approaches, assumptions and methods

● Biogas from mechanical pulp mills ● Overview ● Conclusions

● Biogas from Kraft pulp mill effluents

● Overview ● New approaches ● Conclusion

● Summary

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A typical Thermo mechanic pulp mill

TMP mill Bleaching Plant

Paper Machine

WWTP

9.9 ton COD day-1

5.2 GWh CH4 year-1 11 ton COD day-1

8.6 GWh CH4 year-1 38 ton COD day-1

23 GWh CH4 year-1

Production of pulp: 500 kton year-1

Total potential: 37 GWh CH4 year-1

Effluent water

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Product

15 000-30 000 m3/d

Pre-sedimentation Waste activated sludge

Fiber sludge

Recipient Process water from factory

Sludge dewatering

Sludge tank

Bio sludge

Sludge cake to Incineration or compost

Suggested treatment of (C)TMP process water streams

Rejected water

Biogas

UASB

CSTR

Biogas

Other substrates: External

Concentrated process water streams from factory

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Results so far: 2013-2014 - TMP + CTMP

●  Most efficient biogas production obtained by treating whole effluent using UASB technique

●  Total bio-available biogas potential in Sweden: 290 GWh Methane (29 milj Nm3 CH4/y )

●  Challenges – changed performance strategy and addition of extra chemicals/nutriments: ●  Bleaching chemicals (H2O2) ●  Inhibitory resins from cooking of wood

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Agenda

● Introduction ● Background ● Partners and the project ● Approaches, assumptions and methods

● Biogas from mechanical pulp mills ● Overview ● Results and conclusions

● Biogas from Kraft pulp mill effluents

● Overview ● New approaches ● Results and conclusion

● Summary

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An average Kraft pulp Mill – soft wood

Production: 330 kton/yr

Pulp mill Bleaching Plant

Paper Machine

WWTP

0.6 ton COD/day 0.0 MNm3 CH4/yr

0.7 ton COD/day 0.1 MNm3 CH4/yr

2.2 ton COD/day pH 10 0.3 MNm3 CH4/yr

0.2 ton COD/day pH 2 0.0 MNm3 CH4/yr

Effluent Total potential: 4 GWh CH4 year-1

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20 000-40 000 m3/d

Ongoing Research Kraft pulp Mill – new approach

Pulp mill Bleaching Plant

Paper Machine

Alternative WWTP CSTR Internal

Substrates •  Bio sludge •  Condense methanol •  Fibers

Total potential: 25 GWh CH4 year-1

Effluent

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20 000-40 000 m3/d

Pre-sedimentation Waste activated sludge

Fiber sludge

Recipient Process water from factory

Sludge dewatering

Sludge tank

Bio sludge

Sludge cake to Incineration or compost

Suggested treatment of Kraft pulp water streams

Rejected water

Biogas

UASB

CSTR

Biogas

Other substrates: Methanol Fibers External

Concentrated process water streams from factory

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Results so far: 2013-2014 - Kraft pulp

● Total process flow and some individual effluents to be treated in activated sludge ●  Low concentration (< 1000 mgCOD/L) ●  Generally low anaerobic COD/TOC reduction (<20%) ●  Strong acid/base effluents ●  Ongoing research: to treat mixed concentrated bleach streams prior UASB

● However: Positive results from ongoing research to treat mixed concentrated bleach streams prior UASB – profitability?

● Condensates, fibrous solids and bio-solids are suitable for biogas production (CSTR)

● Perform COD reduction in active sludge with aim for high bio-solid production. Then anaerobic digestion.

● Total bio-available biogas potential in Sweden: 650 GWh/y

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Agenda

● Introduction ● Background ● Partners and the project ● Approaches, assumptions and methods

● Biogas from mechanical pulp mills ● Overview ● Results and conclusions

● Biogas from Kraft pulp mill effluents

● Overview ● New approaches ● Results and conclusion

● Summary

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Biogas production at PPI – End users

Internal:

● Heat and power production ● Boilers with environmental

restrictions ● Replacement of fossil fuel ●  IR-drying of coating

● Vehicle fuel ● Used for own vehicles

External:

● Vehicle fuel ● Up-graded and sold on the

market ● Raw gas sales to gas

company for upgrading to vehicle fuel

● Green gas ● Up-graded and injected to

gas grid as green gas

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The change in usage of fiber products – a possibility for biogas at PPI mills? 26

● Decreasing demand of printing paper leads to upshift in quality

-  Finishing

-  Bleaching

-  Coating

-  Final products

● Resulting in higher load on current WWTP - Environmental Demands

Establishing biogas production in the Swedish pulp & paper industry - Concluding remarks

● Anaerobic treatment of effluents from pulp & paper mills is an alternative to expanding aerobic wastewater treatment plants.

● Different strategies for wastewater treatment and biogas production need to be followed depending on raw material and production process at the specific mill

● The methane potential from an average mill is in the range of 10-50 GWh year-1

● The total methane potential from the Swedish pulp and paper industry is in the range of 700-1 000 GWh year-1. Of this methane potential approx. 300 GWh year-1 is located at the mechanical pulp and paper mills.

● Pulp & paper mills are located outside traditionally “substrate-rich” areas

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Thank you for your attention

Contact information

Matti Vikkula CEO and President matti.vikkula@scandinavianbiogas.com +46 (0)70 597 99 38

Jörgen Ejlertsson Director R&D, VP jorgen.ejlertsson@scandinavianbiogas.com +46 (0)73 993 95 73

Michael Olausson CFO, VP

michael.olausson@scandinavianbiogas.com +46 (0)70 537 53 73

Scandinavian Biogas Fuels AB Holländaregatan 21A SE-111 60 Stockholm

Switchboard: +46 (0)8 50 38 72

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