an overview of trends and approaches

Transcription

1 Open Workshop Global Issues pertaining to BioWaste March 15th Turin, Italy Composting and Anaerobic Digestion, an overview of trends and approaches D. Mainero Working Group "Biological Treatment", ISWA Technical Committee, CIC Plant Manager, Acea Pinerolese Industriale SpA

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

3 Drivers 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 28/98/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 21[ ] from Council Conclusions Green Paper on the management of biowaste in the European Union 2953rd ENVIRONMENT Council meeting Luxembourg, 25 June 29 The upcoming End of Waste criteria will partially answer the expected Biowaste Directive 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 22 A strategy for smart, sustainable and inclusive growth next step Bio - methane?

4 MSW in Europe Landfill directive gets its target in Europe, from 1995 to 29 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 29 from CIC rapporto annuale 211)

5 Biogas: renewable energy Primary production of biogas in the European union in 29 and 21 (ktoe). [ ] In 21, primary energy production from biogas enjoyed particularly strong growth (+31.3%), it produced more than 1.9 Mtoe in 21, which is an additional 2.6 Mtoe in 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. (Source EUROBSERV ER THE STATE OF RENEWABLES IN EUROPE 211 edition)

6 National Renewable Energy Plans EU27 National Renewable Energy Action Plan (NREAP), complete fulfillment 22 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 211 edition)

8 Aerobe and anaerobe processes The two processes occur in nature in combination or separately Composting turns organic matter into stabile humus, develops excess heat and releases CO 2 Anaerobic digestion develops CH 4 by mean of several intermediates, no heat is produced, but CO 2 is a by-product Anaerobic digestion processes has to be kept completely isolated Composting processes can take place in open windrows Strictly anaerobic conditions is most easily achieved in fluids Proper aeration is best obtained in dry materials with structure Why combining AD and composting?

9 Because 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 processes No organics can be totally turned into either biogas or compost, but both products are environmental friendly substitutes for either fossil fuels or fertilizers

11 AD European overview EU nations where AD plants are in operation (21) Operating plants MSW treatment capacity (t/y) MSW + other biomasses treatment capacity (t/y) OFMSW treatment capacity(t/y) OFMSW + other biomasses treatment capacity (t/y) MSW + OFMSW + others Biom. treatment capacity (t/y) Total capacity (t/y) % 4% 26% 25% 12% (Source Biogas e Compost dai rifiuti organici selezionati Technical committee CIC report)

12 Treatment capacity distribution in EU Spain 29,9% Italy 7,8% Denmark 4,8% France 11,2% Germany 29,3% Estonia,4% Finland,5% UK,8% Norway 1,% Poland Swedish Portugal,7% 1,7% 1,3% The Netherlands 4,4% Austria Belgium 1,8% 2,2% Switzerland 2,2% (Source Biogas e Compost dai rifiuti organici selezionati Technical committee CIC report)

13 Meso or Thermo, Wet or Dry? Wet Semi-Dry Dry n.d. TOT A B A B A B A B A B % Mesophilic % Termophilic % Meso+Thermo % Not classified % TOT % distribution 55% 1% 41% 2% A = OFMSW (+other biomasses) B = MSW (+ other biomasses as well as OFMSW) Wet (<1%TS), Semi-Dry (1 2%TS); Dry (>2%TS) Mesophillic (35 C-4 C) Thermophillic (5 C-55 C) (Source Biogas e Compost dai rifiuti organici selezionati Technical committee CIC report)

14 European AD thermal distribution plants fed by OFMSW + other biomasses plants fed by MSW + other biomasses (OFMSW included) 1% % 6% 4% % % Mesophilic Termophilic Meso+Thermo n.d. (Source Biogas e Compost dai rifiuti organici selezionati Technical committee CIC report)

16 MSW management in Italy: Production After a constant growth, MSW production in Italy has stabilized to 32.5 Mtpa since 26, from then a stable or slightly decreasing (Source: ISPRA year 29)

17 MSW management in Italy: OFMSW Separate collection under constant increase (+2 percentage points every year since 24); the organic fraction is the main contributor Separate collection target of 65% by the end of 212, 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 211 preview based on 5% diversion target)

18 Composting: a continuous growth 281 plants t OFMSW 28(t) OFMSW 29 (t) Composting AD + Composting ,4% 23,6% ,4% 26,6% +29% Total (Source Biogas e Compost dai rifiuti organici selezionati Technical committee CIC 21)

19 Composting facilities in Italy: treatment capacity Shareout of composting facilities with respect to treatment capacity 7% 6% % of total facilities 5% 4% 3% 2% 1% Green composting % n.a. 5. tpa >5. tpa; 1. tpa >1 tpa; 2 tpa >2. tpa OFMSW (and other putrescible waste) composting (Source: Scuola Agraria del Parco di Monza 211)

20 Composting facilities in Italy: process technology Shareout of facilities with respect to process technology 1% 9% 8% % of overall throughput 7% 6% 5% 4% 3% 2% 1% Green composting % Closed bioreactors Open bioreactors Bioreactors (not qualified) turned piles static piles OFMSW (and other putrescible waste) composting (Source: Scuola Agraria del Parco di Monza 211)

21 AD in Italy: a recent history First few AD plants in late 9s - early 2s 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 25: 18 waste treatment plants 6. ton of biowaste in AD plants in 29 All plants treat source segregated Waste Few cases of co-digestion Almost all plants integrate AD and digestate composting: compost is a product! (Source: Scuola Agraria del Parco di Monza 211)

22 AD in Italy: technological diversity Wet 13 Solid content Semi-dry 3 Dry 2 Mesophillic 11 One-stage 9 Temperature Thermophillic 4 Number of stages Two-stage 6 Not classified 3 n.a. 3 Continuous 17 Batch/continuous Batch 1 (Source: Scuola Agraria del Parco di Monza 211)

23 Potential drivers and limiting factors for integrated plants implementation (+) Renewable electric energy subsidy (up to 28 cent/kwh till 212) High Biogas potential production from italian Biowaste (mainly due to separate collection schemes) Lower odour emissions than composting only (-) Capital costs higher than composting plants (even double): diseconomy of scale Liquid waste treatment require a good integration with other plants, and/or proper layout able to exploit composting evaporation potential Waste purity can significantly affect plant robustness and rejects production Lower need of green waste for the aerobic step (i.e. urban areas) High technological diversity available Lower Ecological footprint than composting only Digestate composting allows to turn a waste into a product (compost) (Source: Scuola Agraria del Parco di Monza 211)

24 AD integration in existing composting plants: a survey (1) 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 (211) Besides: lack of space in 54% of plants problems with green waste availability in 18% of plants

25 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 (211) Besides: 54% of plants interested in throughput plant capacity increasing

27 Conclusions and perspectives In Europe the integration of Composting and anaerobic solutions is becoming a general approach to the biowaste management, 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 over the last 5 years, mainly for the treatment of source segregated biowaste (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.

28 Conclusions 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 29/28/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?)

29 Thank you for your attention D. Mainero.