BMP testingFruit, vegetables and their residues

Durian shells — BMP: 2 studies, weighted mean 93 m³ CH₄/t VS

Durian husks are a hard, fibrous waste from a tropical fruit with a large spread of results; they contain a lot of lignin and cellulose, and the yield depends on comminution.

CH₄ ≈ 52 % (estimate)

Published 3 October 2022Updated 29 October 20263 min readFeedstockData Editorial Team

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

Weighted mean: 93m³ CH₄/t VS
Range: 35–152m³ CH₄/t VS
Records: 2studies
Publications: 2sources
Temperatures: —of the test

Methane in biogas

≈51–53% CH₄

Low 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 (protein from total nitrogen (N 0.7 % DM × 6.25)) 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 (93); 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
Zhao et al. (2016) DOI	152	—	Durian (Durio zibethinus) – Shell	end point (model curve)
Muenmee i Prasertboonyai (2021) DOI	35	—	Durian shell	end point (model curve)
Weighted mean	93	arithmetic mean 93, SD 83

Typical composition

Volatile solids (VS): 94.6 % DM (range 94.6–94.6)
Nitrogen: 0.7 % DM
C/N ratio: 59.9

Median and range of the determinations reported in the publications behind this substrate's BMP records (read from: BCBPD); dry matter: 0 determinations, volatile solids: 1 determination. C/N was calculated as the ratio of C and N content (% DM) from the same source. No DM in the sources – the calculator has to ask for a value.

Sources: Zhao 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
dilutes the feed (low DM)
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 yield in the compendium: median 93 (range 35-152) m³ CH₄/t VS, 2 records from 2 studies (weighted mean 93).
Durian husks were studied in mono- and co-digestion with food waste (Muenmee et al. (2021))

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

No source limits on the dose for this substrate.

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

Durian (Durio zibethinus) is a tropical fruit grown in South-East Asia, known for its strong smell. The edible part is a small fraction of the mass of the fruit, and most of it is husk (shell) and seeds. The husks end up as waste in markets and in processing. In Poland durian is an imported product that is rarely encountered, so the material is of comparative interest only.

Properties relevant to digestion

The durian husk is woody and fibrous. It consists mainly of cellulose, hemicellulose and lignin, and its content of simple sugars is low. This structure makes hydrolysis slow, and without size reduction and pretreatment part of the material remains undigested. On the other hand, the risk of acidification is small. The low protein content means a high C/N ratio, so it combines well with nitrogenous materials such as manure or sludge. The spiny surface makes mechanical handling and feeding difficult.

How to read the spread of results

The dataset contains several records from several studies, and the spread is very large. One of the studies gives the result in the unit ml/g VS without explicit normalisation, and the samples differ in preparation, variety and the degree of ripeness of the fruit. Comminution (from coarse pieces to grinding), test length and inoculum also matter. For woody material, the test duration is particularly important, because slow decomposition may not be complete.

In biogas plant practice

Durian husks require grinding and, in industrial installations, also pretreatment (steam, chemical or biological) if the full energy value is to be exploited. Dosing in a mixture with rapidly degradable wastes stabilises the process. Storage is easier than for soft fruits, because the material is more durable, but in tropical conditions it also decomposes. Because of the discrepancies in results, a dedicated BMP test of the batch is recommended.

In practice it is considered that for such woody materials, the cost-effectiveness of pretreatment matters more than the result of a short test, because the cost of grinding or steam treatment may exceed the value of the additional biogas if the husks come from a distant source.

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.