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Poultry feathers — BMP: 3 studies, weighted mean 181 m³ CH₄/t VS

Poultry feathers are keratinous waste from poultry slaughterhouses and ABP; records from several studies concern raw feathers, without pretreatment.

CH₄ ≈ 58 % (estimate)

Published Updated 3 min readFeedstockData Editorial Team

Illustration: FeedstockData (AI, Google Gemini)

Weighted mean
181m³ CH₄/t VS
Range
105–210m³ CH₄/t VS
Records
3studies
Publications
2sources
Temperatures
—of the test

Methane in biogas

Medium methane content · ≈ 5.8 kWh/m³ of biogas

estimate from the substrate type The collected studies contain no measurement. The interval follows from the approximate composition (protein-rich (process classification)) and the yields of compound groups according to FNR.

How we calculate it and what the zones mean

Rating for biogas plants

not rated — editorial rating for biogas plants

Not rated: no dry matter or volatile solids in the data. We calculate the rating when the dry matter and volatile solids of the material are known.

Editorial rating per the methodology

Add to the co-digestion calculator CSV data

BMP curves from 3 studies

Weighted mean Individual records

BMP curves: Poultry feathersCumulative methane production over time for 3 records and the weighted mean of 181 m³ CH₄/t VS. 3 of the curves are model curves (first-order kinetics).0501001502002500510152025303540time [d]m³ CH₄/t VSPatinvoh et al. (2016) · 1: 105 m³ CH₄/t VS (model curve)Patinvoh et al. (2016) · 2: 199 m³ CH₄/t VS (model curve)Salminen et al. (2003): 210 m³ CH₄/t VS (model curve)mean181

Dashed lines are a model curve (first-order kinetics, B(t) = B₀·(1 − e−kt)); the end point comes from the publication. All curves are model curves.

Cumulative methane production over the test [m³ CH₄/t VS]. The thick line is the weighted mean of all records (181); dots mark the end values given in the publications. Point at the chart to read values; click a legend item to hide or show a record.

Records and sources

Download CSV
SourceBMP
m³ CH₄/t VS		TemperatureSampleCurve
Patinvoh et al. (2016) · 1 DOI105—Untreated chicken feathers, anaerobic sludge inoculumend point (model curve)
Patinvoh et al. (2016) · 2 DOI199—Untreated chicken feathers, granular sludge inoculumend point (model curve)
Salminen et al. (2003) DOI210—Poultry feather (untreated)end point (model curve)
Weighted mean181arithmetic mean 171, SD 58

Process properties

  • protein-rich
  • nitrogen-rich
  • sulphur-rich
  • slowly degrading
  • ABP cat. 3
  • fibrous
  • editorial classification

Low confidence: the description is based on general characteristics of the substrate group, not on studies of this material. Treat it as a hint to be verified.

Advantages

  • Methane potential in the Substraty.pl BMP dataset: weighted mean 181.0 m³ CH₄/t VS (SD 57.7; 3 records, 2 sources).
  • Feather keratin is a rich source of carbon and nitrogen; after pretreatment, co-digested with slurry it gave a positive effect (Schommer et al. 2020; Salminen and Rintala 2002).

Drawbacks and risks

  • The disulphide bridges in keratin make feathers resistant to hydrolysis - degradation is slow and incomplete without pretreatment (Salminen and Rintala 2002; Schommer et al. 2020).
  • Protein breakdown releases ammonia and sulphur compounds, which increases H2S (Chen et al. 2008).
  • Keratin waste is classed among the hard-to-degrade fractions of poultry slaughterhouses (Salminen and Rintala 1999).

Co-digestion — what to combine it with, what to watch out for

Dosing

No source-based threshold. Use a low share, shredded and after pretreatment (microbial/thermal), with slurry as the base.

Introduce gradually, starting with a small dose and monitoring the process (e.g. FOS/TAC, pH, gas composition).

Practical requirements

  • ABP cat. 3 (Art. 10 of Reg. 1069/2009; admitted to biogas plants by Art. 14): hygienisation before the digester in a mandatory unit: shredding to a maximum of 12 mm, temperature throughout the mass of at least 70 °C for at least 60 min without interruption (Reg. 142/2011, Annex V Ch. I Section 1 and Ch. III Section 1); the installation requires approval by the competent authority (Art. 24(1)(g) of Reg. 1069/2009).
  • Do not feed hygienised substrate into the digester hot (FNR 2010, Ch. 3: hygienisation).
  • Shred: shredding increases the surface available for degradation and speeds it up, but does not necessarily raise the final gas yield (FNR 2010, Ch. 3 “Triturado”).

Sources of the process data

  1. Schommer et al. (2020). Anaerobic co-digestion of swine manure and chicken feathers: effects of manure maturation and microbial pretreatment of feathers on methane production. Renew. Energy
  2. Rajagopal, Masse, Singh (2013). A critical review on inhibition of anaerobic digestion process by excess ammonia. Bioresour. Technol.
  3. Salminen, Rintala (2002). Anaerobic digestion of organic solid poultry slaughterhouse waste - a review. Bioresour. Technol.
  4. Salminen, Rintala (1999). Anaerobic digestion of poultry slaughtering wastes. Environ. Technol.
  5. Chen, Cheng, Creamer (2008). Inhibition of anaerobic digestion process: A review. Bioresour. Technol.
  6. Rozporządzenie (WE) nr 1069/2009 określające przepisy sanitarne dotyczące produktów ubocznych pochodzenia zwierzęcego (art. 9, 10, 12–14, 24)
  7. Rozporządzenie Komisji (UE) nr 142/2011 wykonujące rozporządzenie (WE) nr 1069/2009 (zał. IV rozdz. III, zał. V rozdz. I i III)
  8. FNR (2010). Guía sobre el Biogás – Desde la producción hasta el uso (hiszp. wydanie „Leitfaden Biogas”, GIZ 2013)

The co-digestion calculator will assess a specific mixture containing this substrate.

What it is and where it comes from

Poultry feathers arise in slaughterhouses as waste from plucking carcasses. They are large quantities of light material rich in protein. In the European Union feathers are an animal by-product (ABP) within the meaning of Regulation (EC) No 1069/2009, and their processing at a biogas plant requires approval of the plant and compliance with the veterinary requirements for the relevant category of material. The dataset covers several records from several studies: chicken feathers in a test with anaerobic sludge and with granular sludge, and poultry feathers from a separate study.

Properties relevant to digestion

Feathers contain mainly keratin, a fibrous protein with a large number of disulphide bridges, which makes it resistant to enzymatic degradation. Hydrolysis is therefore the limiting step, and raw feathers degrade slowly and incompletely. The breakdown of keratin releases ammonia and sulphur, so the risk of inhibition and of hydrogen sulphide formation rises. Pretreatment (thermal, chemical or enzymatic) improves availability, but in this compilation only untreated material was included.

How to read the spread of results

The records from one study differ in the type of inoculum (anaerobic or granular sludge), which illustrates the effect of microbiology on the degradation of a difficult protein. The third comes from another study. The temperature is not given in the data read from the abstracts. The size reduction of the feathers, the duration of the test (keratin degrades slowly), the substrate-to-inoculum ratio and the purity of the sample also have an effect.

In biogas plant practice

Raw feathers are a difficult substrate: light, they form a floating crust, are hard to mix and degrade slowly. In practice they are used as a small addition after size reduction or are subjected to hydrolysis before digestion. A plant approved for ABP processing, receipt documentation and hygienisation in accordance with the rules are required. Because of ammonia and sulphur, the biogas composition and the ammonium nitrogen concentration must be monitored. Planning is based on a BMP test.

Methodology in brief

BMP is the amount of methane obtained from volatile solids (VS) in a batch test, given in m³ CH₄ per tonne of VS (numerically the same as NmL CH₄/g VS in the publications) and converted to normal conditions (0 °C, 101.325 kPa). The weighted mean gives each publication a total weight of 1, split equally between its results for the substrate — a paper testing twenty varieties does not outweigh a paper with a single sample. In inter-laboratory programmes the unit is the laboratory (total weight 1), and within it the weight of a test grows with the number of bottles (replicates). Results after pretreatment (e.g. thermal, chemical, enzymatic) are shown separately and are not included in the mean.

Solid lines are curves measured in the tests. Where a publication gives only the final result, we draw a first-order kinetic model, B(t) = B₀·(1 − e−kt): only the end point comes from the publication, and the shape of the curve serves purely as visualisation — do not read the production on a particular day from it. For this substrate k = 0.091 d−1 was assumed (no kinetic data for the group – the median of all available rate constants k (93 values) was used).

The statistics describe the spread of published results — a descriptive compilation, not a meta-analysis or a guarantee of plant yield.

Full methodology and correction policy

Bibliography

  1. Patinvoh, R.J.; Feuk-Lagerstedt, E.; Lundin, M.; Sárvári Horváth, I.; Taherzadeh, M.J. (2016). Biological Pretreatment of Chicken Feather and Biogas Production from Total Broth. Applied Biochemistry and Biotechnology 180(7), 1401–1415. DOI: 10.1007/s12010-016-2175-8 DOI
  2. Salminen, E.; Einola, J.; Rintala, J. (2003). The methane production of poultry slaughtering residues and effects of pre‐treatments on the methane production of poultry feather. Environmental Technology 24(9), 1079–1086. DOI: 10.1080/09593330309385648 DOI

All sources of the site: bibliography.

Other substrates in the group “Fats, oils and animal by-products”