BMP testingFruit, vegetables and their residues

Banana peels — BMP: 17 studies, weighted mean 330 m³ CH₄/t VS

Banana peels are a common fruit waste in tropical countries, rich in fibre and potassium; results from many trials are fairly consistent, but depend on ripeness and chopping.

rating: good CH₄ ≈ 52 % (estimate)

Published 2 May 2023Updated 29 October 20263 min readFeedstockData Editorial Team

Photo Priwo / Wikimedia Commons, public domain, source file; changes: cropping

Weighted mean: 330m³ CH₄/t VS
Range: 243–409m³ CH₄/t VS
Records: 17studies
Publications: 5sources
Temperatures: 35 °C, 37 °C, 38 °Cof the test

Methane in biogas

≈51–54% CH₄

Medium methane content · ≈ 5.2 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)) and the yields of compound groups according to FNR.

How we calculate it and what the zones mean

Rating for biogas plants

good — editorial rating for biogas plantsStable, usually accepted without a fee

Potential per tonne of fresh matter: high (55 m³ CH₄/t); no particular threats to stability. Handling costs: fibres, floating layer, slow degradation.

Why? Rating factors

Potential per tonne +2

+2potential 55 m³ CH₄/t fresh matter (BMP 330 × DM 18.3 % × VS 91.4 %)

Process stability 0

0no factors

Handling and costs −1

−0.5fibres, floating layer — shredding and intensive mixing
−0.5slow degradation — long retention time

Total points: 1 · thresholds: ≥ 2.5 very good, ≥ 1 good, below — neutral; negative with cumulative process risk.

Editorial rating per the methodology · confidence of the rating: high · excluding market prices

Add to the co-digestion calculator CSV data

BMP curves from 17 studies

Weighted mean Individual records

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 (330); 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.

Show the remaining records in the legend (5)

Records and sources

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Source	BMP m³ CH₄/t VS	Temperature	Sample	Curve
Sharma et al. (1988) · 1 DOI	271	37 °C · mesophilic	Banana · pretreatment: Material were first dried in the sun and then in an oven at 90oC	end point (model curve)
Sharma et al. (1988) · 2 DOI	374	37 °C · mesophilic	Banana · pretreatment: Material were first dried in the sun and then in an oven at 90oC	end point (model curve)
Sharma et al. (1988) · 3 DOI	396	37 °C · mesophilic	Banana · pretreatment: Material were first dried in the sun and then in an oven at 90oC	end point (model curve)
Sharma et al. (1988) · 4 DOI	408	37 °C · mesophilic	Banana · pretreatment: Material were first dried in the sun and then in an oven at 90oC	end point (model curve)
Sharma et al. (1988) · 5 DOI	409	37 °C · mesophilic	Banana · pretreatment: Material were first dried in the sun and then in an oven at 90oC	end point (model curve)
Dubrovskis i Plume (2022) DOI	325	38 °C · mesophilic	Banana peel	end point (model curve)
Khan M.T. (2016)	322	37 °C · mesophilic	Banana peel	end point (model curve)
Gunaseelan (2004) · 1 DOI	243	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 2 DOI	274	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 3 DOI	277	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 4 DOI	284	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 5 DOI	300	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 6 DOI	314	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 7 DOI	321	35 °C · mesophilic	Banana peels	end point (model curve)
Gunaseelan (2004) · 8 DOI	322	35 °C · mesophilic	Banana peels	end point (model curve)
Sanjaya et al. (2016) · 1 DOI	332	35 °C · mesophilic	Rooten banana peel	end point (model curve)
Sanjaya et al. (2016) · 2 DOI	342	35 °C · mesophilic	Fresh ripe banana peel	end point (model curve)
Weighted mean	330	arithmetic mean 324, SD 49

Typical composition

Dry matter (DM): 18.3% (range 10.6–22.4)
Volatile solids (VS): 91.4 % DM (range 83.8–94.3)
C/N ratio: 55.4

Median and range of the determinations reported in the publications behind this substrate's BMP records (read from: CROPGEN D4, MY-D); dry matter: 3 determinations, volatile solids: 9 determinations.

Sources: Sharma et al. (1988); Gunaseelan (2004); Sanjaya et al. (2016).

The composition of the raw material varies between batches — for plant calculations use an analysis of your own sample. The calculator inserts typical values automatically.

Process properties

fibrous
slowly degrading
seasonal
variable composition
editorial classification

Advantages

Methane yield in the compendium: median 322 (range 243–409) m³ CH₄/t VS, 17 records from 5 papers (weighted mean 330).
Grinding banana peel gave a higher yield than chopping (Odedina et al. (2017))
Two-stage digestion with thermophilic prehydrolysis (HRT 4 d) before a mesophilic reactor improved energy yield and stability at a higher solids content (Odedina et al. (2017))

Drawbacks and risks

In a single-stage reactor (mesophilic, HRT 20 d) banana peel failed when fed at 2% DM, and stabilised after reduction to 1.5% DM (Odedina et al. (2017))

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

combines well
substrates: easily degradable — e.g. Maize silage (whole crop), Food waste, Sorghum, whole crop, Whey, Beet leaves and tops
In BMP studies, easily degradable substrates increased the yield of the mixture with slurry (synergy in some mixtures).^[1]

Dosing

The sources do not give a share in the feed. Odedina et al. (2017): a single-stage mesophilic reactor (HRT 20 d) failed when fed banana peel at 2% DM, and recovered stability at 1.5% DM; a two-stage system with thermophilic prehydrolysis operated at 2% DM.

Practical requirements

Shred: the yield depends on particle size (ground banana peels gave more than chopped ones) (Odedina et al. (2017); Sharma et al. (1988))

Sources of the process data

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

What it is and where it comes from

Banana peels (Musa spp.) are one of the largest waste streams in banana-producing countries, where they form a considerable part of the mass of the fruit. In Poland bananas are imported, and peels arise in ripening rooms, wholesalers, catering and processing (dried chips, puree). The scale is much smaller than in the tropics, but may be significant locally.

Properties relevant to digestion

The peels contain a lot of water, and the dry matter contains soluble sugars, pectins, cellulose, hemicellulose and lignin in moderate quantity, and in the peels of unripe fruit also starch. With ripening, starch is converted into sugars, which changes the rate of hydrolysis. The peels are rich in potassium, and also in polyphenols and tannins, which at typical shares are not a significant inhibitor. For digestion, the relatively low protein and lipid content is favourable, but it also means a high C/N ratio, so adding nitrogen (slurry) improves the balance. Pesticides used in banana cultivation may be present in the peels as a contaminant.

How to read the spread of results

The dataset contains several records from several sources, so it is relatively extensive. A considerable proportion of the records comes from one study in which different chopping fractions of the peels were examined. Chopping affects the rate and the final result, because finer particles are degraded faster. In addition, the results depend on the banana variety (dessert bananas or plantains), ripeness, the way the sample was prepared and the inoculum. The remaining results are mesophilic, which limits the effect of temperature.

In biogas plant practice

Banana peels are suitable for co-digestion with slurry or manure after chopping. Dosing should be gradual and pH monitored. The peels quickly darken and spoil, giving off odours, so they should not be stored for long. In Poland the material is available sporadically and usually in small quantities. Waste from trade and catering is subject to waste regulations, and its acceptance requires permits and compliance with the rules concerning kitchen waste.

For plants in Poland, banana peels are significant mainly as an example of a fruit waste rich in fibre and potassium; potassium passes into the digestate, which increases its fertiliser value, but in large quantities may affect soil salinity.

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 = 0.245 d⁻¹ was assumed (median of rate constants k reported in the sources and/or fitted to the mean measured curves).

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

All sources of the site: bibliography.