Composting and Anaerobic Digestion, an overview of trends ... · In Europe the integration of...

Composting and Anaerobic Digestion, Composting and Anaerobic Digestion,

an overview of trends and an overview of trends and

approachesapproaches

D. MaineroWorking Group "Biological Treatment", ISWA

Technical Committee, CIC

Plant Manager, Acea Pinerolese Industriale SpA

Open Workshop “Global Issues pertaining to BioWaste”

March 15th 2012 - Turin, Italy

OutlineOutline

• Drivers• Why choosing anaerobic-aerobic integrated system?• Trends in Europe on AD• A focus on Italy• Conclusions

DriversDrivers……

The “Biowaste Directive”…“The Council of the European Union […] IS AWARE that the issue of biodegradable waste is partially addressed, among others, by Directive 1999/31/EC on the landfill of waste, which sets the reduction targets for landfilling of biodegradable municipal waste, and by Directive 2008/98/EC on waste, which invites the Member States, among others, to introduce measures supporting separate collection and appropriate treatment of bio-waste […] ENCOURAGES the Commission to continue the impact assessment with a view to preparing, if appropriate, a EU legislative proposal on biodegradable waste by 2010[…]” from Council Conclusions Green Paper on the management of bio-waste in the European Union 2953rd ENVIRONMENT Council meeting Luxembourg, 25 June 2009The upcoming End of Waste criteria will partially answer the expected “BiowasteDirective”

The “Soil Framework Directive”…In Europe the so called landfill directive (99/31/EC) has created the fundamental push to ban organic fraction from landfill.

EUROPE 2020 A strategy for smart, sustainable and inclusive growth…next step Bio - methane?

MSW in MSW in EuropeEurope

Landfill directive gets its target in Europe, from 1995 to 2009 reducing landfill input from 296 to 195 Kg/inhabitants*year

Organic fraction goes not all to composting but also to MBT

Good organic fraction % of recovery are reached

Eco - taxes drives…

(Source: EU MSW 2009 from CIC rapporto annuale 2011)

Biogas: renewable energyBiogas: renewable energy

(Source EUROBSERV’ER – THE STATE OF RENEWABLES IN EUROPE 2011 edition)

Primary production of biogas in the European union in 2009 and 2010 (ktoe).

“[…] In 2010, primary energy production from biogas enjoyed particularly strong growth (+31.3%), it produced more than 10.9 Mtoe in 2010, which is an additional 2.6 Mtoein just twelve months and was primarily channeled into electricity production.

[…] Another type of biogas recovery, bio-methane injection into the natural gas grid, is booming in a number of countries, such as Germany, Sweden and The Netherlands.”

National Renewable Energy Plans EU27National Renewable Energy Plans EU27

National Renewable Energy Action Plan (NREAP), complete fulfillment 2020’s ambitions for biogas source electricity production (64TWh).The application of European legislation on waste that forces the dumping of biodegradable waste in landfills and waste recovery should also help the biogas sector development.

(Source EUROBSERV’ER – THE STATE OF RENEWABLES IN EUROPE 2011 edition)

OutlineOutline


Aerobe and anaerobe processesAerobe and anaerobe processes

The two processes occur in nature in combination or separatelyComposting turns organic matter into stabile humus, develops excess heat and releases CO2

Anaerobic digestion develops CH4 by mean of several intermediates, no heat is produced, but CO2 is a by-productAnaerobic digestion processes has to be kept completely isolatedComposting processes can take place in open windrowsStrictly anaerobic conditions is most easily achieved in fluidsProper aeration is best obtained in dry materials with structure

Why combining AD and composting?

BecauseBecause……

Waste facilities have to be flexible and robust to be economically feasible – thus fluids and solid treatment needed

Organic wastes are not a uniform well defined material– Impurities are difficult to tackle in a digester– “Solid” organic waste grow acid (malolactic fermentation etc)

creating feedstock for AD– Lignins and other slow degrading organic compounds are not

degradable in AD processesNo organics can be totally turned into either biogas or compost, but

both products are environmental friendly substitutes for either fossil fuels or fertilizers

OutlineOutline


AD European overviewAD European overview

9.594.446

1.109.800

2.337.430

2.484.716

405.500

3.197.000

202

16

12%

25%

26%

4%

34%

Total capacity (t/y)

MSW + OFMSW + others Biom. treatment capacity (t/y)

OFMSW + other biomasses treatment capacity (t/y)

OFMSW treatment capacity(t/y)

MSW + other biomasses treatment capacity (t/y)

MSW treatment capacity (t/y)

Operating plants

EU nations where AD plants are in operation (2010)

(Source “Biogas e Compost dai rifiuti organici selezionati” Technical committee CIC report)

Germany

29,3%

Spain

29,9%

Italy

7,8%

Denmark

4,8%

France

11,2%

Norway

1,0%UK

0,8%

Belgium

2,2%

The Netherlands

4,4%

Portugal

1,3%Poland

0,7%

Finland

0,5%

Estonia

0,4%

Swedish

1,7%Switzerland

2,2%

Austria

1,8%

Treatment capacity distribution in EUTreatment capacity distribution in EU


MesoMeso or Thermo, Wet or Dry?or Thermo, Wet or Dry?

2%41%1%55%% distribution

46156142261032388TOT

19%732100600626Not classified

4%1700000017Meso+Thermo

36%135901124002116Termophilic

41%2558031015011539Mesophilic

%BABABABABA

TOTn.d.DrySemi-DryWet

A = OFMSW (+other biomasses)B = MSW (+ other biomasses as well as OFMSW)Wet (<10%TS), Semi-Dry (10 – 20%TS); Dry (>20%TS)Mesophillic (35°C-40°C) Thermophillic (50°C-55°C)


58

597

32

24

131

7

0%

20%

40%

60%

80%

100%

Mesophilic Termophilic Meso+Thermo n.d.

plants fed by OFMSW + other biomasses plants fed by MSW + other biomasses (OFMSW included)

European AD thermal distributionEuropean AD thermal distribution


OutlineOutline


After a constant growth, MSW production in Italy has stabilized to 32.5 Mtpasince 2006, from then a stable or slightly decreasing

(Source: ISPRA year 2009)

MSW management in Italy: ProductionMSW management in Italy: Production

• Separate collection under constant increase (+2 percentage points every year since 2004); the organic fraction is the main contributor

• Separate collection target of 65% by the end of 2012, confirmed by the recently revised Italian Waste Framework Regulation, and diversion targets further drive biowaste recovery

• Organic Waste separate collection and recovery explicitly recommended by the revised Italian Waste Framework Regulation

(Source: CIC rapporto 2011 – preview based on 50% diversion target)

MSW management in Italy: OFMSWMSW management in Italy: OFMSW

2.192.9491.919.057Total

26,6%584.65523,6%453.000AD + Composting

73,4%1.608.29476,4%1.466.057Composting

OFMSW 2009 (t)OFMSW 2008(t)

(Source “Biogas e Compost dai rifiuti organici selezionati” Technical committee CIC 2010)

281 plants

3.715.000 t

+29%

Composting: a continuous growthComposting: a continuous growth

Shareout of composting facilities with respect to t reatment capacity

0%

10%

20%

30%

40%

50%

60%

70%

n.a. ≤5.000 tpa >5.000 tpa;≤10.000 tpa

>10000 tpa;≤20000 tpa

>20.000 tpa

% o

f tot

al fa

cilit

ies

Green composting

OFMSW (and otherputrescible waste)composting

Composting facilities in Italy: treatment Composting facilities in Italy: treatment

capacitycapacity

(Source: Scuola Agraria del Parco di Monza 2011)

Shareout of facilities with respect to process tech nology

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

Closedbioreactors

Openbioreactors

Bioreactors(not

qualif ied)

turned piles static piles

% o

f ove

rall

thro

ughp

ut

Green composting

OFMSW (and otherputrescible waste)composting

Composting facilities in Italy: process Composting facilities in Italy: process

technologytechnology


First few AD plants in late ’90s - early 2000s treating un-segregated MSW (Ca’ del Bue, Villacidro, Bassano del Grappa, …)Serious operational problems and increase of organic waste availability led them to close and/or turn to source segregated waste treatment

A second start after 2005:

18 waste treatment plants

600.000 ton of biowaste in AD plants in 2009

All plants treat source segregated Waste

Few cases of co-digestion

Almost all plants integrate AD and digestate composting: compost is a product!


AD in Italy: a recent historyAD in Italy: a recent history

2313

DrySemi-dryWet

Solid content

3411

Not classifiedThermophillicMesophillic

Temperature

369

n.a.Two-stageOne-stage

Number of stages

117

BatchContinuous

Batch/continuous


AD in Italy: technological diversityAD in Italy: technological diversity

Digestate composting allows to turn a waste into a product (compost)

Waste purity can significantly affect plant robustness and rejects production

Lower odour emissions than composting only

Liquid waste treatment require a good integration with other plants, and/or

proper layout able to exploit composting evaporation potential

High Biogas potential production from italian Biowaste (mainly due to separate

collection schemes)

High technological diversity available

Lower Ecological footprint than composting only

Lower need of green waste for the aerobic step (i.e. urban areas)

Capital costs higher than composting plants (even double): diseconomy of

scale

Renewable electric energy subsidy (up to 28€cent/kWh till 2012)

(-)(+)


Potential drivers and limiting factors for integrated plants

implementation

Besides:

• lack of space in 54% of plants

• problems with green waste availability in 18% of plants

Data are based on a survey on 22 composting plant (12 North, 4 Center and 6 South), treating OFMSW, 17 in a rural context, 3 in an industrial one and 2 in an urban area.

Source: Scuola Agraria del Parco di Monza (2011)

AD integration in existing composting plants: a survey (1)

Besides:

• 54% of plants interested in throughput plant capacity increasing

AD integration in existing composting plants: a survey (2)

Data are based on a survey on 22 composting plant (12 North, 4 Center and 6 South), treating OFMSW, 17 in a rural context, 3 in an industrial one and 2 in an urban area.

Source: Scuola Agraria del Parco di Monza (2011)

OutlineOutline


Conclusions and perspectivesConclusions and perspectives

In Europe the integration of Composting and anaerob ic solutions is becoming a general approach to the biowaste managem ent, thanks to the flexibility of the system that can evolve from MBT or simple composting to

an integrated one. AD has quickly grown in Italy ov er the last 5 years, mainly for the treatment of source segregated biowa ste (OFMSW).

At operating level Integration:

(+) reaches an easier control in odour emission compared to the simple MBT or composting process

(+) needs less surface per treated ton compared to the only compost solution, the strong volume reductions through anaerobic digestion and the homogeneity of the sludge help the aerobic process.

(+) Is a net energy producing process, matching the new issues of the energy market (green energy and energy efficiency title) and economic and environmental drivers are speeding up the fast growing of AD at least in EU countries.

Conclusions and perspectivesConclusions and perspectives

(+) gives an higher guarantee on pathogen organisms control thanks to the double thermic passage.

(-) waste purity impact affects plant robustness and rejects production. The use of biodegradable bags will affect deeply this aspect, reducing plastic impurity.

(-) the ammonia rich wastewater has to be seen, in perspective, as an opportunity for an integrated system that produces compost and nutrient for agricultural use but, up to now, we have no economical drivers to face fossil product cost on the market.

(-) At present, most of the EU countries have only electric energy production incentive schemes. The enforcement of the 2009/28/EC Directive will probably introduce some changes (lower incomes? Granting for heat or biomethane?)

(-) Digestate management criteria: often unclear to local authorities what are the conditions, duration and goals of this step (Upcoming End of Waste criteria will clarify?)

Thank you for your attention

D. Mainero.D. Mainero.

[email protected]

Composting and Anaerobic Digestion, an overview of trends ... · In Europe the integration of...

Documents

Transcript of Composting and Anaerobic Digestion, an overview of trends ... · In Europe the integration of...