Marketable products from waste – Opportunities and challenges

Centro de Edafología y Biología Aplicada del Segura
Marketable products from waste
– Opportunities and challenges
Prof. Dr. Maria-Pilar Bernal
CEBAS-CSIC
Murcia, Spain
© Maria Pilar Bernal,
CEBAS-CSIC
Waste concept
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
“Waste” any substance or object which the holder discards or
intends or is required to discard;
"Bio-waste" is defined in the WFD as "biodegradable garden and
park waste, food and kitchen waste from households, restaurants,
caterers and retail premises, and comparable waste from food
processing plants". It does not include forestry or agricultural
residues, manure, sewage sludge, or other biodegradable waste
(natural textiles, paper or processed wood).
"Biodegradable waste" is a broader concept (Landfill Directive) - any
waste that is capable of undergoing anaerobic or aerobic
decomposition.
Manure is excluded from the waste concept in WFD as it is
considered a valuable material for agriculture.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Types of biodegradable waste
Centro de Edafología y Biología Aplicada del Segura
Biodegradable fractions of municipal solid waste (MSW)
Other biodegradable wastes
commercial food waste, not collected as part of the MSW: waste from markets; catering
waste;
forestry residues: bark; wood residues;
waste from agriculture, including:
animal husbandry excrements (solid and liquid manure)
straw residues
sugar beet and potato haulm
residues of growing of beans, peas, flax and vegetables
spent mushroom compost
wastes from the food and beverage industry, including:
breweries and malt houses
wineries
fruit and vegetable production industry
potato industry including starch
sugar beet residues and soils
slaughterhouse residues
meat production
whey;
© Maria Pilar Bernal,
© Maria Pilar Bernal,
sewage
CEBAS-CSIC
CEBAS-CSIC
sludge
Manure: Waste or Resource
PHYTOREC
Intensification of the
animal production
Increased size of the
animal production units
Intensive agriculture
New systems in crop
production
Great amount of animal
manures
(>1500 million tones in
EU-27 annually)
Separation of farms
from agriculture
Manure turned into a waste, low agricultural
value, accumulation with potential
environmental risk:
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
• Water pollution
• Gaseous emissions
• Soil pollution
Upgrading concept
PHYTOREC
Upgrading wastes
Centro de Edafología y Biología Aplicada del Segura
“Upgrading concept” focuses on the addition of value to by-products
and wastes.
The medium-term goal of the concept is the creation of innovative
products, e.g. in the food industry: dietary fibres as matrices for
flavours, dyes or antioxidants, or bioflavours; in the agricultural
sector: advanced fertiliser products.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Upgrading
Manures into agriculture
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Objective: to obtain advanced fertiliser
products to be used safely in agriculture
A fertiliser should increase plant yield by:
Macro and micronutrients
 Providing plant nutrients;
OM
 Improving soil fertility;
 Avoiding negative effects on the environment Absence of pollutants
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Treatment options
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Physical: separation, drying, pelleting, combustion;
Chemical: precipitation, stripping-absorption;
Biological: composting, anaerobic digestion.
Stabilisation of the material;
Maintain or enhance nutrients
Elimination of contaminants & pathogens
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Physical treatments
PHYTOREC
Separation
Centrifugation
Screw press
Screw
Inlet
Solid fraction
Liquid fraction
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Sieve
Centro de Edafología y Biología Aplicada del Segura
Physical treatments
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Drying
Evaporator
Liquids: Evaporation
Solids: Drying
Condensed
Air
Condenser
Dryed product
Condensed
Dryer
Concentrated
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Physical treatments
Pelleting
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
PHYTOREC
Physical treatments
Pelleting
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
PHYTOREC
Physical treatments
Centro de Edafología y Biología Aplicada del Segura
Combustion





Granulation
Neutralise alkalinity, high pH
Convert all the P and K to soluble forms
Control dustiness of ash
Co-granulate ash with standard fertiliser
inputs
 Produce granules with hardness, bulk density,
and size comparable to commercial fertilisers
 High energy costs
 Gaseous emissions
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Chemical treatments
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Precipitation
Struvite precipitation: To obtain ammoniaphosphorus-magnesium salt
 Addition of MgCl2
MgNH4PO4.6H2O
 Alkaline pH (9)
Struvite precipitation from pig manure
 Quality depends on
residual OM
 Low price and difficult
to market
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Source: Giro CT
Chemical treatments
PHYTOREC
Struvite
From fresh pig slurry
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
From digested pig slurry
Source: Giro CT
Centro de Edafología y Biología Aplicada del Segura
Chemical treatments
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Stripping-absorption
To obtain ammonia-rich effluent and/or
ammonia salts
NH3
Absortion
Acidic water
Air
Ammoniacal water
Treated liquid
manure
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
• Volatilisation of ammonia by an airflow
under high pH and temperature
• Ammonia is absorbed into an acid
solution
• Concentrated (NH4)2SO4 solution is
obtained
Based on the reactions:
NH4+ ↔NH3 (l) + H+
NH3 (l) ↔NH3 (g)
pH
Temperature
PHYTOREC
Biological treatment options
Composting, anaerobic digestion.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
PHYTOREC
Biological treatments
Centro de Edafología y Biología Aplicada del Segura
Composting: aerobic process
Composting is a process of controlled decomposition of
biodegradable materials under managed conditions,
which are predominantly aerobic and which allow the
development of temperatures suitable for thermophilic
bacteria as a result of biologically-produced heat.
Compost is the stabilised and sanitised product of
composting, which has undergone an initial, rapid stage
of decomposition. It is beneficial to plant growth and has
certain humic characteristics.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Composting
Centro de Edafología y Biología Aplicada del Segura
Overview of composting
H2O + CO2 + NH3
Weight reduction
Microbial metabolism
Heat + water + CO2
Oxygen
Stabilised compost
Fresh organic material
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Cattle manure: 20-40 %
Poultry manure: 32 %
Pig manure: 21 % d.m.
Composting
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
The process
Biooxidative
Mesophilic
Thermophilic
Cooling
Maturing
Phases
Temperature ºC
70
50
Bacteria +
actinomycetes
pH
30
9
7
10
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Whirl
Composting time
Humus formation
5
Composting treatment
PHYTOREC
The compost
Centro de Edafología y Biología Aplicada del Segura
CO2
Breakdown
products
H2O
Oxygen
Moisture
ORGANIC
MATTER
New microbes
Soluble OM
Proteins,
Hemicellulose
Energy
dead
Heat
Lignin
Cellulose
Ash
COMPOST
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Controlable factors
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Formulation of the mix
•
•
•
•
•
•
Nutrient balance
Particle size
Porosity
Moisture
Temperature
O2 concentration
C/N ratio: 25-35
Surface area for microbial growth
To ensure aerobic process. Air-filled pore space
35-50 %
Rate of decomposition. 50-60%
To develop microorganisms and kill pathogens.
40-65 ºC
To optimise efficiency. 15-20 %
Process management
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Manures:
DM 0.5-15 %
C/N 5.4-15
pH >8
PHYTOREC
Composting manures
Bulking agent
Manure
Mixing
Water
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
Additives
Biooxidative
phase
Recycled compost
Curing
phase
Compost
PHYTOREC
Why composting of manures?
Centro de Edafología y Biología Aplicada del Segura
Composting
Manure application
Useful in areas
without enough
agricultural land for
direct application
Compost of high quality
must be produced to
offset the production costs
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Marketable
high quality
compost
PHYTOREC





Strategies for quality compost
High nutrient content
High OM humification
High compost maturity
Suppression of phytopathogens
Others ...
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
 Reduce nutrient losses
 Allow maturation phase
 Control maturity indices
 Special & high-value uses
(substrates, organic agriculture)
PHYTOREC
Compost quality to define use
Centro de Edafología y Biología Aplicada del Segura
Formulation of
compost “a la
carte”
Substrate
for pots
Organic
fertiliser
Mulch
++
++
++
-
Nutrients
-
+
+
-
pH & salts
++
++
+
-
Colour/odour
++
++
+
+
Impurities
+
+
- (+)
+
Maturity
++
++
+
-
Particle size
++
+
+
+
Plant growth
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Substrate for
seedlings
PHYTOREC
Manure compost in the market
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
PHYTOREC
Biological treatments
Centro de Edafología y Biología Aplicada del Segura
Anaerobic digestion
Anaerobic digestion is a process of controlled
decomposition of biodegradable materials under
managed conditions, predominantly
anaerobic and at temperatures suitable for mesophilic or
thermophilic bacteria.
Digestate is the semi-solid or liquid product of anaerobic
digestion of biodegradable materials.
It can be presented as whole digestate or separated into
a liquor phase and a fibrous semi-solid phase.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Anaerobic digestion
Biodegradable
organic wastes
Centro de Edafología y Biología Aplicada del Segura
Biogas = energy
Digestate
Viability of the
anaerobic digestion
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Recycling
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Anaerobic digestion
Viable alternative method to treat and
recycle wastes from livestock and
agroindustry:
This biological process transforms
the initial organic substrate into two
products:
• Reduces GHG emissions, especially NH3
and CH4.
• A source of renewable energy
(biogas)
• Maintains and improves the fertilising
value of the treated materials.
• A potential fertiliser, the digested
material (digestate)
© Maria Pilar Bernal,
CEBAS-CSIC
Digestate
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Potential use as fertiliser and/or organic amendment due to its richness
in OM and plant nutrients.
• Material not completely stabilised
biologically (residual biodegradability),
• High N (mostly in ammonia form),
• Potential phytotoxicity,
• Viscosity and excess of humidity,
• Potential presence of pathogens,
Definition of quality
digestate
characteristics for an
agricultural use
• Variability in composition, etc.
Treatments for
production of fertilisers
© Maria Pilar Bernal,
CEBAS-CSIC
Digestate
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Today, more than 95% of the digestate produced in
Europe is used directly in the agricultural sector as a
liquid fertiliser.
New products are increasingly released into the
European market:
dried or pelletised digestates,
upgrading by ultrafiltration and reverse osmosis: highly concentrated fertiliser and a purified aqueous stream of
drinking water.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Conditions for agricultural use
The microbial stability of digestate should be guaranteed: long
retention times, post-treatment;
Hygienic conditions: Salmonella absent; E. coli <100 NMP g-1;
Heavy metals: check for certain input materials;
Avoid application on non-germinated seeds or on young
plants (unless diluted);
Apply before sowing or diluted with the irrigation water;
Application should be integrated in the fertilisation plans,
partially substituting mineral fertilisers.
© Maria Pilar Bernal,
CEBAS-CSIC
PHYTOREC
Waste Framework Directive
(2008/98/EC)
Centro de Edafología y Biología Aplicada del Segura
Defining end-of-waste (EoW) criteria (Biodegradable waste subject to
biological treatment, 3rd draft)
Certain specified waste shall cease to be waste when it has undergone
a recovery operation and complies with specific criteria to be
developed in accordance with the following conditions:
a) The substance or object is commonly used for a specific purpose;
b) A market or demand exists for such a substance or object;
c) The substance or object fulfills the technical requirements for the
specific purpose referred to in (a) and meets the existing
legislation and standards applicable to products; and
d) The use of the substance or object will not lead to overall adverse
environmental
or human health impacts.
© Maria Pilar
Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
Centro de Edafología y Biología Aplicada del Segura
PHYTOREC
End-of-waste criteria
Setting standards for compost and digestate that
enable their free circulation in the internal market
and to allow their use without further monitoring and
control of the soils on which they are used.
Different quality criteria for compost and
digestate exist across Europe.
© Maria Pilar Bernal,
CEBAS-CSIC
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Conditions for end-of-waste criteria
The substance has undergone a recovery operation:
Composting and anaerobic digestion
The substance or object is commonly used for specific
purposes: Agriculture
A market or demand exists for such a substance or
object (in theory)
The substance fulfills the technical requirements for the
specific purposes and meets the existing legislation and
standards
The use of the substance or object will not lead to
overall adverse environmental or human health
impacts
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
End-of-waste
when registered as fertiliser
Centro de Edafología y Biología Aplicada del Segura
In many countries, compost has to be registered
under fertiliser regulations (e.g. as an organic
fertiliser or as a soil improver) before it can be used
in agriculture.
It is then implicitly assumed that registered compost
is a product and has ceased to be waste.
This situation can be found in the Czech Republic,
Greece, Spain, Italy, Latvia, Hungary, the
Netherlands, Poland, Portugal, Slovenia and Finland.
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
End-of-waste
PHYTOREC
Centro de Edafología y Biología Aplicada del Segura
Compost and digestate no longer holding waste
status under end-of-waste, is to be regarded as a
substance and therefore falls under the scope of
the REACH Regulation
European Community Regulation on Registration,
Evaluation, Authorisation and Restriction of Chemicals
© Maria Pilar Bernal,
© Maria Pilar Bernal,
CEBAS-CSIC
CEBAS-CSIC
PHYTOREC
Further opportunities and
challenges…
Centro de Edafología y Biología Aplicada del Segura
ManureOmics
© Maria Pilar Bernal,
CEBAS-CSIC