BMP testingStraws and crop residues

Banana stalks and leaves — BMP: 2 studies, weighted mean 262 m³ CH₄/t VS

Banana plants – pseudostems and leaves are the largest waste of banana plantations; records from different studies concern pseudostems and leaves from Cuba.

CH₄ ≈ 52 % (estimate)

Published 17 April 2023Updated 29 October 20263 min readFeedstockData Editorial Team

Photo BalukuBrian / Wikimedia Commons, licence CC BY-SA 4.0, source file; changes: cropping

Weighted mean: 262m³ CH₄/t VS
Range: 256–269m³ CH₄/t VS
Records: 2studies
Publications: 2sources
Temperatures: 37 °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

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 2 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 (262); 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

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Source	BMP m³ CH₄/t VS	Temperature	Sample	Curve
Khan M.T. (2016)	256	37 °C · mesophilic	Banana stalk	end point (model curve)
López-Dávila et al. (2022) DOI	269	—	Banana straw (leaves)	end point (model curve)
Weighted mean	262	arithmetic mean 262, SD 9

Process properties

fibrous
dilutes the feed (low DM)
seasonal
variable composition
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 database: weighted mean 262 m³ CH₄/t VS (median 262; range 256-269; 2 records from 2 sources).

Drawbacks and risks

Spread of results in the database: standard deviation 9 at a mean of 262 m³ CH₄/t VS (2 records from 2 sources).

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

combines well
substrates: high dry matter — e.g. Wheat straw, Horse manure, Cattle manure, Cereal straw (unspecified), Meadow hay
Wet banana plant biomass balances dry, fibrous substrates (straw) in mixtures.^[1][2]

Dosing

No source dose limits; the entry is mainly comparative.

Practical requirements

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

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

What it is and where it comes from

The banana is a herbaceous plant with an apparent trunk (the pseudostem) formed of overlapping leaf sheaths. After the fruit bunch is cut, the pseudostem is usually removed so that the plant can renew itself from suckers, and leaves are cut off during plantation maintenance. As a result, a great deal of residual biomass arises on plantations. The dataset contains several records from several studies: pseudostems and banana plant leaves from Cuba.

Properties relevant to digestion

The pseudostem consists mostly of water and cellulose fibres, with a small share of lignin; it also contains a lot of potassium. Leaves are more fibrous and contain more lignin and surface waxes. Both materials have a low protein concentration, so the high C/N ratio favours co-digestion with slurry or animal waste. Banana fibres can be long, which creates a risk of wrapping around agitators and pumps if the material is not chopped.

How to read the spread of results

The records describe different parts of the plant and come from separate studies, so they are not replicates. In one case the temperature is mesophilic, in the other it is not stated in the compilation. The variety, the age of the plant, the share of outer and inner sheaths (which differ in composition), moisture content, degree of size reduction and the inoculum all have an effect. For these reasons, figures from the literature indicate an order of magnitude and do not replace a BMP test on local material.

In biogas plant practice

In banana-producing countries, plantation residues are considered as a substrate for agricultural biogas plants, provided that the logistics of harvesting and transport (large mass and moisture content) are cost-effective. Typical solutions include size reduction on site, dewatering and co-digestion with animal excreta. In Poland the material does not occur, and the entry serves as a reference point for other plant wastes with high moisture content and a fibrous structure.

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 = 0.136 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.