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BMP testingBy-products of the agri-food industrysingle study (3 samples)

Palm oil decanter cake — BMP: 3 studies, weighted mean 226 m³ CH₄/t VS

Decanter cake from palm oil mills is a moist waste rich in residual oil and fibre; it was tested at three loadings at a temperature of 40 °C.

CH₄ ≈ 63 % (estimate)

Published Updated 3 min readFeedstockData Editorial Team

Photo CEphoto, Uwe Aranas / Wikimedia Commons, licence CC BY-SA 3.0, source file; changes: cropping

Weighted mean
226m³ CH₄/t VS
Range
218–240m³ CH₄/t VS
Records
3single study (3 samples)
Publications
1source
Temperatures
40 °Cof the test

Methane in biogas

High methane content · ≈ 6.3 kWh/m³ of biogas

estimate from the substrate type The collected studies contain no measurement. The interval follows from the approximate composition (carbohydrate-dominated (no protein or fat characteristics); fat-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: Palm oil decanter cakeCumulative methane production over time for 3 records and the weighted mean of 226 m³ CH₄/t VS. 3 of the curves are model curves (first-order kinetics).01002003000510152025303540time [d]m³ CH₄/t VSChanthong et al. (2024) · 1: 218 m³ CH₄/t VS (model curve)Chanthong et al. (2024) · 2: 221 m³ CH₄/t VS (model curve)Chanthong et al. (2024) · 3: 240 m³ CH₄/t VS (model curve)mean226

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 (226); 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
Chanthong et al. (2024) · 1 DOI21840 °C · mesophilicpalm decanter cake 15% (DC)end point (model curve)
Chanthong et al. (2024) · 2 DOI22140 °C · mesophilicpalm decanter cake 10% (DC)end point (model curve)
Chanthong et al. (2024) · 3 DOI24040 °C · mesophilicpalm decanter cake 5% (DC)end point (model curve)
Weighted mean226arithmetic mean 226, SD 12

Process properties

  • fat-rich
  • fibrous
  • tendency to foam
  • seasonal
  • 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 226.2 m³ CH₄/t VS (SD 12.0; 3 records, 1 source).
  • Residual oil raises the potential (Poh and Chong 2009).

Drawbacks and risks

  • Fat risks LCFA and foaming (Long et al. 2012).
  • Spoils quickly.

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

Dosing

No source-based threshold; shared lipid limit.

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

Sources of the process data

  1. Hagos et al. (2017). Anaerobic co-digestion process for biogas production: progress, challenges and perspectives. Renew. Sustain. Energy Rev.
  2. Weiland, P. (2010) Biogas production: current state and perspectives. Applied Microbiology and Biotechnology
  3. Long et al. (2012). Anaerobic co-digestion of fat, oil, and grease (FOG): A review of gas production and process limitations. Process Saf. Environ. Prot.
  4. Poh, Chong (2009). Development of anaerobic digestion methods for palm oil mill effluent (POME) treatment. Bioresour. Technol.

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

What it is and where it comes from

Palm oil production generates large quantities of waste, among them empty fruit bunches, fibres, shells and mill effluent (POME). A solid fraction, called decanter cake, is separated from this effluent in a decanter. It is moist and contains residues of fruit pulp and some of the oil that was not recovered. The material occurs in palm oil producing countries, such as Malaysia and Indonesia. There is no such production in Poland.

Properties relevant to digestion

The cake is fibrous and fatty in nature: it contains fibre (cellulose, hemicellulose, lignin), protein and residual oil. Fat raises the energy potential, but increases the risk of accumulation of long-chain fatty acids, which inhibit methanogenesis and cause foaming. The presence of fibre will slow the hydrolysis of part of the material. The cake is moist and spoils quickly. The C/N ratio is usually moderate and depends on the protein content. In tropical conditions the material is sometimes combined with POME, which provides dilution and microorganisms.

How to read the spread of results

The dataset contains several records from one study in which the cake was tested at loadings of 5, 10 and 15 per cent, at a temperature of 40 °C. Results for the individual levels are close to each other, which indicates a small effect of loading in this range, but one source does not allow variability between mills to be assessed. The result also depends on the mill technology, the amount of remaining oil, moisture, inoculum and substrate-to-inoculum ratio.

In biogas plant practice

Decanter cake is dosed in a mixture with other mill wastes, in gradual portions, to avoid excessive lipid loading. It requires monitoring of volatile acids and gas production. In producing countries it is also used as fertiliser or feed, which competes with use at a biogas plant. For Poland it is mainly a comparative material for fatty plant wastes.

Because the data come from one study and one temperature, the assessment of repeatability is limited. Before using the cake on a larger scale its composition should be checked, especially the oil and water content, which can differ considerably between mills.

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. Chanthong, S.; Kongjan, P.; Jariyaboon, R.; O-Thong, S. (2024). Synergistic integration of hydrothermal pretreatment and co-digestion for enhanced biogas production from empty fruit bunches in high solids anaerobic digestion. Heliyon 10(15), e34817. DOI: 10.1016/j.heliyon.2024.e34817 DOI

All sources of the site: bibliography.

Other substrates in the group “By-products of the agri-food industry”