treatment of animal waste in codigestion biogas plants in...

Treatment of animal waste in co-digestion biogas plants in

Sweden

Åke NordbergJTI - Swedish Institute of Agricultural

and Environmental Engineering

Disposition

• Implementation of ABP co-digestion in Sweden

• Laboratory and pilot studies on AD of slaughterhouse waste/animal by-products

• Experiences from Linköping biogas plant

• Hygienisation control

Uppsala

Kalmar

Kristianstad

Linköping

Helsingborg

Laholm

�

�

� � �

�

� Vänersborg

Existing biogas plants approved

for ABP co-digestion

Swedish co-digestion plants treating animal by-products

Solid digestate

Slurry organic fertiliser






Digestate

Heat, vehicle fuelThermophilicVänersborg

Vehicle fuelThermophilicUppsala

Vehicle fuelMesophilicLinköping

Upgraded gas to gridMesophilicLaholm

Heat, vehicle fuelMesophilicKristianstad

Vehicle fuelThermophilicKalmar

Heat, electricity, vehicle fuelMesophilicHelsingborg

Gas utilisationTemperaturePlant

Summary of capacity and treated waste in Swedish biogas plants* 2002 (m3)

219 004 m3

5 609 m3

5 745 m3

26 676 m3

96 923 m3

2 873 m3

14 545 m3

67 476 m3

124 000 m3

219 004 m3

300 000 m3

100 %

3 %

3 %

12 %

44 %

1 %

6 %

31 %

+41 %

73 %

100 %

Total amount of substrate

Water

Other organic waste

Waste from other food industry

Slaughterhouse waste

Source-sorted from restaurants, shops etc

Source-sorted household waste

Manure

Planned increase of treatment capacity

Used capacity

Treatment capacity

*7 ABP-approved biogas plants

Slaughterhouse waste in Sweden-legislation background

• 1988 (SFS 1988:537)– Meat meal from carcasses not allowed in

animal fodder• 1991 (LSFS 1990:51)

– Use of low-risk animal by-products in ruminant fodder prohibited in 1991

Calculated average quantity and composition of waste and by-products from slaughter of cattle

0,805,368270TOTAL

0,020,215Animal high risk

0,010,5319Blood

0,181,11538SRM

0,523,339116Animal low risk excl. blood

0,070,21092Rumen, stomach and intestinal content

PhosphorusNitrogenTSWeightCattle slaughter (kg/cattle)

Calculated average quantity and composition of waste and by-products from slaughter of cattle

0,805,368270TOTAL

0,020,215Animal high risk

0,010,5319Blood

0,181,11538SRM

0,523,339116Animal low risk excl. blood

0,070,21092Rumen, stomach and intestinal content

PhosphorusNitrogenTSWeightCattle slaughter (kg/cattle)

Calculated average quantity and composition of waste and by-products from slaughter of pig

0,1000,606,928TOTAL

0,0050,030,31Animal high risk

0,0010,080,63Blood

0,0790,475,217Animal low risk excl. blood

0,0150,020,77Stomach and intestinal content

PhosphorusNitrogenTSWeightPig slaughter (kg/pig)

Methane yields (batch digestion)

Waste fraction Methane yield(m3 ton-1)

Animal by-products (pasteurised) 225

Animal by-products (not pasteurised) 56

Slaughterhouse waste mixture 160

Source-sorted household waste 130

Manure 13

Calculated methane potential from slaughter of cattle and pigs divided into different waste fractions (% of total methane potential)

and the total amount (MJ or kWh per animal).

Rumen, stomach and intestinal content

Animal low risk (meat and bone)

SRM* Blood Animal high risk (average)

Total

% of tot % of tot % of tot % of tot % of tot MJ/animal kWh/animal

Cattle 9 62 21 5 3 1300 361

Pig 6 82 - 8 4 140 39

* Specified risk material (SRM) shall go to an incineration plant or after a pre-processing to burial in an approved landfill site (Commission Decision 2000/418/EC).

Description of the average waste mixtures (WM) wet weight composition, dry matter and nitrogen content used in the laboratory and pilot study

Process Animal by-products1

Stomach content & sludge2

Food waste

Dilution Liquid manure

DM in WM Nitrogenin WM

% of WM % of WM % of WM % of WM % of WM % of weight % of DM

Lab 13 21 14 51 - 11 5.9

Pilot 15 28 - 15 42 12 6.0

1) Animal by-products and blood. Animal by-products used for the continuous digestion experiments came from a rendering plant. At the rendering plant the animal by-products were crushed, minced and heat-treated (at minimum 133 oC and 3 bar for a minimum period of 20 minutes).2) Includes rumen, stomach and intestinal content from slaughtered animal and sludge from slaughterhouse wastewater treatment.

Data from laboratory and pilot digestion experiments

Process Oper.timedays

HRT

days

OLR

g VS/l,d

pH NH4-N

g/l

NH4N/TKN

%

CO2% biogas

m3 biogas/kg VS

m3 methane/ ton waste

Lab 84 40 2.5 8.0 5.0 75 28 0.86 62

Pilot 182 35 3.2 8,0 4.5 65 30 0.70 55

Linköping Biogas Plant

Linköping biogas plant 1997 1998 1999 2000 2001 2002Slaughterhouse waste High-risk waste t/year 2 830 7 094 10 785 8 243 0 0Low-risk waste -Animal by-products -Blood -Sludge t/year 4 129 9 588 10 881 19 840 31 827 37 432Rumen, stomach and intestinal content

Manure from stables Process water Liquid manure t/year 7 404 23 953 9 033 8 647 2 318 4 677Other t/year 0 7 430 6 784 10 547 9 583 8 394TOTAL t/year 14 363 48 065 37 483 47 277 43 728 50 503 Biogas production m3/year 2 600 000 3 700 000 3 300 000 4 400 000 5 300 000Biogas production GWh/year 18 25 22 30 36

m3 biogas /m3 waste 54 99 70 101 105m3 methane /m3 waste 37 67 47 68 71

Linköping biogas plant

• Operational data for digesters (2x3700 m3)– HRT: ca 45 d– TS-concentration: 4.7%– pH: 8.0– Ammonia-nitrogen: 4.5 g/l– Total nitrogen: 6.7 g/l– VFA: ca 1-3 g/l– Methane concentration: 68%

Quality assurance and certification system

• Absence of existing legislation � voluntary system• Requirements

– Input material and waste supplier– Collection and reception of waste– Treatment process– End product– Labelling and specification

• Procedure– Application– Qualification year– Certificate – Self control– Official control and testing

http://www.sp.se/cert/cert_prod/spcr/spcr120.pdf

Hygienisation Control• Microbiological analysis of digestate

– Salmonella– Enterobacteriaceae– Faecal Streptococci (4 log10-units reduction)

• Technical inspection of the plant– Focused on critical control points. Questionnaire

with 25 questions for description and judgement• Technical design and function• Operation and maintenance• Transport

Technical design and functionIncludes following issues:

• appropriate flow sheets, documents available• Internal transport of material in closed system• “clean” and “dirty” zones• possibility to lead content in the hygienisation tank

back to pre-storage in case of malfunctioning sanitation

• risk of cross flow of “clean” and “dirty” slurries• size reduction of incoming material

Operation and maintenance Includes following issues:

• operation instructions available• personnel with relevant knowledge and education• Monitoring and alert-functions, control and

documentation during operation (temp, holding time; stirring; valves)

• routines for handling disturbances in sanitation• action plan if un-sanitised material ends up in digester• routines for avoidance of vector animals• established contact with local sanitation expert• plans for maintenance and renewing equipment• cleaning routines for incoming area• calibration of instruments

TransportIncludes following issues:• avoidance of contamination of hygienised

material by incoming material• cleaning/disinfection of vehicles inside and

outside• clear instructions regarding cleaning• handling of cleaning water from vehicles and

surfaces

Kristianstad –two tank vehicle

Criteria for approval• Approved system for self-control• Microbiological criteria fulfilled• Technical inspection:

– Major deviations – not approved• e.g. technical solutions leading to insufficient sanitation

– Minor deviation – plant can be approved ifdeviations are corrected within 3 months

• e.g. missing operation- and control routines

Birgitta Strandberg, Linköping Biogas AB, has kindly provided the information on Linköping biogas plant

Acknowledgement


• Digestate– ~50 000 t/y– ~3000 ha farmland– Certificate in March

2003

Linköping Certification system 1)

Total solids % wet weight

4.7

Volatile solids % of TS 79 Tot N kg/m3 6.7 Ammonia-N kg/m3 4.5 P kg/m3 0.7 K kg/m3 1.0 Pb mg/kg TS <3 100 Cd mg/kg TS ~0.13 1 Cu mg/kg TS 91 100 2) Cr mg/kg TS 7.8 100 Hg mg/kg TS ~0.05 1 Ni mg/kg TS 8.3 50 Zn mg/kg TS 330 300 2)

1) Eco-Label criteria for soil improvers.2) Transition period for Cu and Zn. Until 2003,

max Cu 600mg/kg TS and Zn max 800 mg/kg TS.

Incentives for implementation of biogas technology

Political ambitions• 75% of phosphorous in waste and wastewater should

be recycled to arable land in 2010• 50% decrease of landfilled waste in 2005 calculated

on 1994 level Environmental committee (SOU 2000:52)

• National CO2-goal: 2% decrease during 2008-2012 on 1990 level Climate committee (SOU 2000:32)

Legislation• Landfill tax (250 SEK [28 Euro] started in year 2000)• Proclaimed ban on landfilling organic waste in 2005


Biogas for vehicle fuel• Most environmental friendly fuel (hydrogen

and electricity not included)• Tax exemptions for 10 years • No subsidies for electricity from biogas


Local Investment Programme [1998-2003]• Investment grants for municipalities(30%)• 7.3 billion SEK (~810 million Euro) allocated for

”sustainable development”- 130 million SEK (~14 million Euro) granted for

“biogas for vehicles” - 340 million SEK (~38 million Euro) granted for

“reduced landfilling”

Climate Investment Programme [2002-2004]• 900 million SEK (~100 million Euro)

Biogas and upgrading plants in Sweden

� Existing biogas plants for co-digestion

Uppsala

Kalmar

Borlänge

Kristianstad

Linköping

Kil

Helsingborg

Borås

Laholm

�

�

� �

�

� � �

�

� Vänersborg

� Filling stations for biogas in Sweden

Uppsala

Kalmar

Stockholm

Kristianstad

Linköping

Eslöv Helsingborg

Göteborg Jönköping �

�

� �

�

� � �

� � Trollhättan

Swedish legislation for anaerobic digestion of slaughterhouse waste (SJVFS 2000:166)

• Low-risk material– must pass a pasteurisation unit at 70 °C for at least

60 min, max. particle size: 12 mm• High-risk material

– must pass a sterilisation unit at 133 °C, 3 bar for at least 20 min, max. particle size: 50 mm

Today, high-risk material is blended with SRM at the two existing rendering plants � all waste is considered as SRM and must go to incineration


• Joint venture:

– Tekniska verken in Linköping– Swedish Meats and Swedish Farmers Association

• Investment cost ca 130 million SEK (~8.7 million Euro), including waste treatment and gas upgrading

• Subsidy from government ca 15 million SEK (~1.7 million Euro)

Linköping biogas plant 1997 1998 1999 2000 2001Slaughterhouse waste High-risk waste t/year 2 830 7 094 10 785 8 243 0Low-risk waste -Animal by-products -Blood -Sludge t/year 4 129 9 588 10 881 19 840 31 827Rumen, stomach and intestinal content

Manure from stables Process water Liquid manure t/year 7 404 23 953 9 033 8 647 2 318Other t/year 0 7 430 6 784 10 547 9 583TOTAL t/year 14 363 48 065 37 483 47 277 43 728 Biogas production m3/year 2 600 000 3 700 000 3 300 000 4 400 000Biogas production GWh/year 18 25 22 30m3 methane /m3 waste 37 67 47 68

Plant Feedstock Temperature Hygienisation Digestate Gas utilisationHelsingborg Slaughterhouse waste,

manuremeso pasteurisation slurry Heat, electricity,

vehicle fuelKalmar Manure, slaughterhouse

wastethermo pasteurisation slurry Vehicle fuel

Kil MSW termo pasteurisation Heat

Kristianstad Manure, slaughterhousewaste, MSW

meso pasteurisation slurry Vehicle fuel, heat

Laholm Manure,slaughterhouse waste

meso pasteurisation slurry Upgraded to grid

Linköping Manure, slaughterhousewaste

meso pasteurisation slurry Vehicle fuel

Uppsala Manure,slaughterhouse waste,restaurant waste

thermo pasteurisation slurry Vehicle fuel

Borlänge MSW meso composting compost Heat

Borås MSW meso composting compost Vehicle fuel, heat

Vänersborg MSW, slaughterhousewaste

thermo pasteurisation soliddigestate

Vehicle fuel, heat

Existing solid waste AD- plants

• Biogas utilisation– 5 km pipeline to bus terminal– Upgrading to vehicle quality (98% methane, 250

bar)– All 64 city busses, 125 other vehicles– Gas price in relation to petrol and diesel price– One bus decrease emissions of nitrogen oxides

with 1.2 t/year and 20 t/year of CO2


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