introduction to composting and anaerobicastover/compost_course/20121030 - compost and... · 2012....

Introduction to composting and anaerobic digestion

07.11.2012, Tartu (Estonia)

jf, FiBL, CH-Frick 1

Research Institute of Organic AgricultureForschungsinstitut für biologischen Landbau


Jacques Fuchs ([email protected])

Institut de recherche de l’agriculture biologique

www.fibl.org Introduction to composting and anaerobic digestion, Tartu, Nov. 2012, jf


› Introduction (what is compost, what is digestate)

› Organic waste management in Europe

› (Bio-)waste concept in Switzerland

› What can we compost or digestate

› Systems of composting and anaerobic digestion

› Basis of biology of composting and anaerobic digestion

› Aspects of compost and digestate quality

› Aspects of utilization of compost and digestate quality

› Quality management

› What is the best composting system

› Conclusions


Introduction (what is compost, what is digestate)



› The natural cycle of life

Energie

CO2O2

Watermicroorganisms

Energy(heat)

Humus(compost)

Mineral nutrients

O2 CO2

livingorganisms

Organic residues



› Ways of degradation for organic material:

Anaerobic(anaerobicdigestion)

Aerobic(composting)



› What means composting ?

The term „composting“ describes a natural process,

in which microorganisms transform organic residues

in stabilized products.

Products resulted from composting:

- “heat”

- compost (more or less mature)






› What means anaerobic digestion?

The term „anaerobic digestion“ describes a natural

process, in which bacteria decomposed organic

residues in absence of oxygen.

Products resulted from anaerobic digestion:

- methan

- digestate



› Differences between

composting and anaerobic digestion?

› Oxygen

› Energy balance

› Degradation products

› Phases

› Utilization field

› Lignin (wood) can not be decomposed anaerobe!


Introduction

Dung Others organic

wastes

Field application

Anaerobicfermentation(mesophilic)

CompostingCo-fermentation (mesophilic)

Anaerobicfermentation

(thermophilic)

Digestated dung Solide digestatLiquid digestate Compost

› Pathways of the treatment of organic waste


Introduction

› Products of the treatment of organic waste

› Digestate› Entire digestate

› Liquide digestate

› Solid digestate

› Compost› Young compost (immediatly at the end of heat periode)

› Mature compost

› Vermicompost

› Nutrient rich compost

› Lignin rich compost

› …

› In this presentation, we speak only of composts or digestates produced with source separated organic waste


Organic waste management in Europe(Datas from Josef Barth, European Compost Network ECN)


Organic waste management in Europe

› About the European Compost Network ECN

Jose

f B

arth

, EC

N






› Organics Recycling by Composting in Europe (2009)

Jose

f B

arth

, EC

Nwww.fibl.org Introduction to composting and anaerobic digestion, Tartu, Nov. 2012, jf


› Green/Garden Waste Composting

Jose

f B

arth

, EC

Nwww.fibl.org Introduction to composting and anaerobic digestion, Tartu, Nov. 2012, jf


› Anaerobic Digestion (AD) of Organic Residues & Wastes in EU (2010)

Jose

f B

arth

, EC

N



› Use of Biogas

Jose

f B

arth

, EC

N



› Residual/mixed waste: Status of MBT and MSWComposting/AD (2009)

Jose

f B

arth

, EC

N

MBT:MechanicalBiologicalTreatment

MSW:MunicipalSolidWaste



› Pathes for Use of Recycled Organics on Soils in EU

Jose

f B

arth

, EC

N






Jose

f B

arth

, EC

N



› Main areas of compost utilisation and market prices (2005/6) in EU27

Jose

f B

arth

, EC

N



› Development of Nutrient Value of Compost2005 to 2007, Value in € per t fresh matter FM and ha

Jose

f B

arth

, EC

N


(Bio-)waste concept in Switzerland


(Bio-)waste concept in Switzerland

› Swiss expenses 2010 (federation + canton + local municipality):

179 billions CHF (CHF 22’900.- per inhabitant)

› Expenses for waste: CHF 150 - 200.- per inhabitant (separate collection + Composting / biogas production / incineration) = 1%

› Expenses for organic waste (source separated): CHF 10 - 20.- per inhabitant (+ collection expenses) = 0.1%


Waste concept in Switzerland






› Reduce

› Avoid

› Re-use

› Incinerate

› Recycling / separate collection maker only sense, if there is a market for the products



› Everybody is concerned!




clothesPET

glass green

glass white glassbrown

aluminiummetal

coffee grounds(Nespresso)

used oil

batteries

+ paper+ green waste+ electronics+ …






› Separate collection of waste in 2006 in CH!

Quantity in 1000 tons

used papers and cartons

green waste

used glass

electronic waste

textiles

PET bottles

tinplates

aluminium

batteries

about 50% from municipal solid waste (MSW) was 2006 recycled!



› Production of energy in waste plants in CH!

Pro

du

ctio

no

fen

erg

y[G

Wh]

anaerobicdigestion

landfillcement factory /heating plants incineration





Biowaste in Switzerland

3 www.fibl.org Introduction to composting and anaerobic digestion, Tartu, Nov. 2012, jf


› Biowaste compost production in Switzerland› Payment for taking over the green waste covers nearly the

production costs (for minimal quality compost)

› Costs for production of higher quality have to be covered with the sale of the compost

› Composting / biogas production / burning› Competition for input materials between composting and

biogas production increases continuously

› Motivations for composting› Disposal of green waste ?

› Soil fertility improvement ?

3



› Compost user

› Some users (among others horticultural producers) are convinced of the advantages of compost. They use compost to improve the fertility of their soils and to support the production of their plants.

› Other users still consider compost as a waste product and are not willing to pay for it.

› Compost producers have to work on the relationship with these users, to convince them of the positive effects of compost on soil and plants.


Compost production and use in Switzerland

3



› Each year, more than 100 kg of biowaste per inhabitant are collected (total: about 1’000’000 tons). These are composted or treated AD (anaerobic digestion).

› About 1/3 of this material is treated by AD, while 2/3 are composted. The proportion of AD has risen significantly in the past years.

› About 70% of the produced compost or digestate are used in agriculture.


Biowaste in CH: origins and end uses 2010

Waste treated in plants > 100 t/a1’080,000 t

Horticulturelandscape

24%

Waste collection services

55%

Industry21%

Weight lossas water and CO2, including methane

combustion

28%Agriculture + Recultivation

Compost

11% Horticulture

5% Hobby gardeners

12% Wood chips

Digestateto agri-culture

32%Liquid

11%Solid





ZH: quantities per type of supplier over time



› Composting systems in 2010

› Field edge composting (~6%)




› Windrow composting (~43%)




› Windrow composting (~43%)




› Box composting (~7%)




› Hall composting (~6%)







› Anaerobic digestion (~32%)




› Co-digestion (~6%)



› Evolution of the systems in Switzerland

0

10000

20000

30000

40000

50000

60000

70000

80000

90000

100000

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010

Gre

nn

was

teq

uan

tity

in t

on

s

Feldrandkompostierung Vergärung Platzkompostierung Co-VergärungField edge compost AD Windrow compost Co-digestion


What can we compost or digestate



› Horticultural waste: › Composting: OK

› Anaerobic digestion: depending of wood fraction



› Animal manure: › Composting: OK

› Anaerobic digestion: OK






› Vegetable waste: › Composting: OK (in little quantities)




› Cereals waste: › Composting: OK (in little quantities)




› Industrie waste: › Composting: +/- no












› Restaurant waste: › Composting: +/- no







› Source separated organic waste



› Theoretically all organic residues can be composted or digestated.

› However, not each one is easy to handle, biodegradable, and free from toxics and pathogenic germs.

› Depending of the system used, some residues are more or less easy to be treated

› Depending of the system, some input materials have to be treated before processing (e.g. pasteurization of kitchen waste before mesophilic anaerobic digestion)

› The start mixture is important for the success of the process



Humidity of the material

Structural (“woodness”)

Composting (anaerobic) Anaerobic digestionTrees branches

Rural horticultural wasteUrban horticultural waste

Kitchen and food waste

Kitchen wasteAbattoir waste



› Input material should be as good as possible free from not suitable materials (metal, plastic, …)



› Input material should be as good as possible free from not suitable materials (metal, plastic, …)


Systems of composting and anaerobic digestion






› Field edge composting

› For rural situation with horticultural waste



› Windrow composting (little pile)

› For horticultural waste, manure, some kitchen waste, …› Structure of input mixture relatively fine› Intensive process (mature compost in 2-3 months)



› Windrow composting (big pile)

› For horticultural waste, manure, some kitchen waste, …› Structure of input mixture relatively coarse› Middle intensive process (mature compost in 6-12 months)



› Box composting

› Process +/- managed automatically› Relatively little place demand› Can be closed + treatment of gas emissions



› Hall composting

› Closed system with treatment of gas emissions› Appropriate for urban region (less odor emissions)



› Anaerobic co-digestion

› Animal manure + other organic waste› Mostly mesophilic› For rural region (managed by farmers)






› Anaerobic digestion

› Industrial plants, mostly urban › Mostly thermophilic



› Anaerobic digestion in box

› Industrial plants, mostly urban› Input mixture with structure (not liquid) › Mostly mesophilic



› Good compost can be produced with a lot of systems, but with all systems bad compost can be produced !


Basis of biology of composting and anaerobic digestion



› Ways of degradation for organic material:

anaerobic aerobic



› Biology of anaerobic digestion:

› Hydrolyse

› Formation of acetic acid

› Production of methane

› Bacteria at work !

› No degradation of lignin






› The microorganisms of composting

Bacteria Mushrooms Actinomycetes




› Bacteria

› aerobic / anaerobic

› very active at the beginning

of the process

› responsible for the hot phase

› can not abolish wood efficiently




› Mushrooms

› aerobic

› abolish wood

› creation of stabilized crumbs

› important during maturity stage




› Actinomycetes (ray fungus)

› can abolish substances, which can

not be abolish with bacteria or

mashrooms, for example chitin

› responsible for decomposition of difficult decomposable materials



› Composting: rotting process

› Process of decomposition

› intensive microbiological activity

› increasing in temperature

› extreme loss in volume

› naturally hygienisation

› Maturity stage

› creation of stable humus

› development of positive characteristics of compost



› The process parameters

› Temperature

› Composition of gases

› Nmin forms

› Organic substance

› pH-value

› Intensity of extract coloration






› Final product: compost

› organic fertilization

› amelioration of soil structure

› biological plant protection product

› Compost is not waste material !



› Evolution of undesirable materials during the rotting process

› heavy metals

› other chemical compounds ???

› pathogenic germs and weed seeds


Aspects of compost and digestate quality



› Swiss compost and digestate guidelines 2010

› Five products classes

› Digestate liquid for agricultural use

› Digestate solid for agricultural use

› Compost for agricultural use

› Compost for field horticulture

› Compost for covered cultures



› Chemical characteristics of Swiss composts



› Influence on the mineralized nitrogen content of soils















› Reproduction potential of humus



› Influence on plant growth and health

Ds: digestate

Ca: compost foragricultural use

Ch: compost forhorticultural use

Cc: compost forcovered cultures




Ds: digestate










Ds: digestate







Ds: digestate







Ds: digestate







› Digestates are generally less compatible with plant growth than composts

› Plant growth compatibility is better in more mature composts

› There is considerable variations within a product class.

› Management of the composting process and product storage are at least as important for the biological quality as the maturity of the compost


Aspects of utilization of compost and digestate quality



› Compost and digestate: limits of application (CH)

› 25 tons DM/ ha and 3 years

› Balance of fertilisation

› Recultivation: 75 tons DM / ha und 8 years






› Application of compost and digestate

› Choose the right product for the desired application and searched effect !

› Digestates: short-term fertilization effect generally better than compost

› Composts: long-term effects on soil fertility (soil structure, humus, …) generally better than digestates

› Differences in the characteristics of the different digestates and composts have to be considered




› Environmental aspects have to be considered !

› Problematic of ammonium by digestates

› Protection of the ground water zones, river, lake, …




› Application superficially of the products (incorporation in the first 10 cm of soil)!

› Young woody compost: risk of nitrogen immobilization

› Digestate: application only when the plant can assimilate the nitrogen

› The quantity of product used has to be adapted to the need of the culture




› The application technique and concept have to be adapted to the product and to the product, and have to avoid any risk for the soil or for the environment

› Application of compost or digestate have to be done only if the meteorological conditions and soil conditions allowed it.


Quality management


Quality management

› Quality guidelines

› Formation, education› Basic course

› Quality course

› Odour course

› Experience exchange days

› ….

› Inspections of the compost plants and of the products





Quality management

› Process control

› If necessary: take actions

› From the concept of waste collection until the use of the produced products!


Compost quality management

› Concept of waste collection



› Composting system



› Composition of the start mixture



› Process management: humidity



› Process management: aeration






› Process management: compost turning



› Process management: storage of the products



› Process management: storage of the products



› Control of the quality of the products







› Parameters of process › O2

› humidity

› aeration

› Chemical and physical analysis› pH

› salt content

› NH4, NO2, NO3

› Biotests› phytotoxycity

› disease supressivity





What is the best system for composting or for anaerobic digestion


What is the best system for composting or for anaerobic digestion

› Is depending of:

› Input materials (quantity and quality)

› Planed utilization of the products

› Geographical situation

› Space at disposition

› Economical situation

› Personally preference

› Etc.

› The best composting system depend on the situation!


Conclusions


Conclusions

› Quality compost can improve soil fertility and plant growth and health

› Quality management is the key for a successful production and use of compost

› The choice of the right product and application strategy is decisive to obtain the desired impact

› The choice of the system depend on the situation


Thank you very much for your attention …

www.fibl.org www.biophyt.ch

introduction to composting and anaerobicastover/compost_course/20121030 - compost and... · 2012....

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