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Starch-based bioplastics — BMP: 10 studies, weighted mean 266 m³ CH₄/t VS

Starch bioplastics (TPS, Mater-Bi, packaging foams) are materials with very different formulations, so BMP results depend on the share of starch and additives.

rating: goodCH₄ ≈ 52 % (estimate)

Published Updated 3 min readFeedstockData Editorial Team

Illustration: FeedstockData (AI, Google Gemini)

Weighted mean
266m³ CH₄/t VS
Range
69–554m³ CH₄/t VS
Records
10studies
Publications
5sources
Temperatures
35 °C, 37 °C, 55 °Cof the test

Methane in biogas

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: very high (246 m³ CH₄/t); process risk: acidification. Handling costs: physical contaminants (packaging, plastics), slow degradation.

Why? Rating factors

Potential per tonne +3

  • +3potential 246 m³ CH₄/t fresh matter (BMP 266 × DM 93.3 % × VS 98.9 %)

Process stability −0.5

  • −0.5acidification: rapid degradation / acidic pH, risk of VFA accumulation, needs buffering

Handling and costs −1.5

  • −1physical contaminants (packaging, plastics) — depackaging and separation
  • −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: medium · excluding market prices

Add to the co-digestion calculator CSV data

BMP curves from 10 studies

Weighted mean Individual records

BMP curves: Starch-based bioplasticsCumulative methane production over time for 10 records and the weighted mean of 266 m³ CH₄/t VS. 10 of the curves are model curves (first-order kinetics).02004006000510152025303540time [d]m³ CH₄/t VSCho et al. (2011): 554 m³ CH₄/t VS (model curve)Guo et al. (2011) · 1: 264 m³ CH₄/t VS (model curve)Guo et al. (2011) · 2: 281 m³ CH₄/t VS (model curve)Guo et al. (2011) · 3: 294 m³ CH₄/t VS (model curve)Mohee et al. (2008): 221 m³ CH₄/t VS (model curve)Zhang et al. (2018) · 1: 69 m³ CH₄/t VS (model curve)Zhang et al. (2018) · 2: 113 m³ CH₄/t VS (model curve)Cucina et al. (2022) · 1: 142 m³ CH₄/t VS (model curve)Cucina et al. (2022) · 2: 194 m³ CH₄/t VS (model curve)Cucina et al. (2022) · 3: 224 m³ CH₄/t VS (model curve)mean266

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 (266); 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
Cho et al. (2011) DOI55435 °C · mesophilicPCL-starch blendend point (model curve)
Guo et al. (2011) · 1 DOI264—potato starch based foamend point (model curve)
Guo et al. (2011) · 2 DOI281—maize starch based foamend point (model curve)
Guo et al. (2011) · 3 DOI294—wheat based foamend point (model curve)
Mohee et al. (2008) DOI221—Mater-bi (Novamont)end point (model curve)
Zhang et al. (2018) · 1 DOI6937 °C · mesophilicStarch-based film blend 2end point (model curve)
Zhang et al. (2018) · 2 DOI11337 °C · mesophilicStarch-based film blend 1end point (model curve)
Cucina et al. (2022) · 1 DOI14255 °C · thermophilicstarch based shoppersend point (model curve)
Cucina et al. (2022) · 2 DOI19455 °C · thermophilicstarch based shoppersend point (model curve)
Cucina et al. (2022) · 3 DOI22455 °C · thermophilicstarch based shoppersend point (model curve)
Weighted mean266arithmetic mean 236, SD 134

Typical composition

Dry matter (DM)
93.3% (range 92.7–97.6)
Volatile solids (VS)
98.9 % DM (range 94.1–99.5)

Median and range of the determinations reported in the publications behind this substrate's BMP records (read from: MY-D); dry matter: 5 determinations, volatile solids: 5 determinations. Samples were tested dried/air-dry – the DM refers to the material in the test, not to fresh material.

Sources: Guo et al. (2011); Zhang et al. (2018).

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

  • slowly degrading
  • physical contaminants
  • easily degradable
  • 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 set: weighted mean 266.4 m³ CH₄/t VS (SD 133.9; 10 records, 5 sources).
  • The starch fraction degrades more readily than polyesters (Narancic et al. 2018).

Drawbacks and risks

  • Blends with polyesters degrade slowly (Narancic et al. 2018).
  • Mineral fillers lower the VS share.

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

Dosing

No source threshold.

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

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

  1. Benn, Zitomer (2018). Pretreatment and anaerobic co-digestion of selected PHB and PLA bioplastics. Front. Environ. Sci.
  2. Narancic et al. (2018). Biodegradable plastic blends create new possibilities for end-of-life management of plastics but they are not a panacea for plastic pollution. Environ. Sci. Technol.
  3. 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

Starch bioplastics are products in which the main component is potato, maize or wheat starch, plasticised and often blended with other polymers. This group includes thermoplastic starch (TPS), commercial blends of the Mater-Bi type and packaging foams used as filling for parcels. The dataset also includes a blend of starch with PCL polyester and starch films. They reach biogas plants usually as an admixture in municipal biowaste or packaging waste, rarely as a separate stream.

Properties relevant to digestion

Starch is a carbohydrate rapidly hydrolysed by microbial amylases, so foams with a high starch share degrade relatively quickly. In multi-component materials the situation is different: aliphatic polyesters, plasticisers and mineral fillers degrade more slowly or not at all, and part of the dry matter is not volatile solids. Anaerobic biodegradation requires contact of the polymer with extracellular enzymes, so the thickness and structure of the product matter greatly. The risks are small: starch does not contribute ammonia, and at a large, sudden load only temporary acidification is possible.

How to read the spread of results

The results in the dataset are spread very widely, which follows from the very definition of the substrate. Under one name there are almost purely starch foams, blends with polyesters and films with additives. The degree of size reduction (thin film, granulate, foam), the length of the test (slowly degradable materials do not reach a plateau in the typical time), the temperature, the activity and adaptation of the inoculum and the method of conversion to VS in the presence of fillers also have an effect. Some records come from mesophilic tests, and some have no temperature stated. A single figure should therefore not be treated as a characteristic of "starch bioplastic" in general.

In biogas plant practice

Starch bioplastics are not a planned raw material but a component of the waste stream. What matters is size reduction before digestion and a retention time in the chamber sufficient for the more slowly degrading fractions. It should not be assumed that a compostability standard, prepared with industrial composting in mind, means complete degradation in the digester. Undegraded fragments may end up in the digestate as a contaminant, which is worth taking into account in quality control. Legal requirements depend on the waste code and the origin of the stream; packaging material is waste within the meaning of the Waste Act, and the installation must have a permit to accept it.

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. Cho, H.; Moon, H.; Kim, M.; Nam, K.; Kim, J. (2011). Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment. Waste Management 31(3), 475–480. DOI: 10.1016/j.wasman.2010.10.029 DOI
  2. Guo, M.; Trzcinski, A.; Stuckey, D.; Murphy, R. (2011). Anaerobic digestion of starch–polyvinyl alcohol biopolymer packaging: Biodegradability and environmental impact assessment. Bioresource Technology 102(24), 11137–11146. DOI: 10.1016/j.biortech.2011.09.061 DOI
  3. Mohee, R.; Unmar, G.; Mudhoo, A.; Khadoo, P. (2008). Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions. Waste Management 28(9), 1624–1629. DOI: 10.1016/j.wasman.2007.07.003 DOI
  4. Zhang, W.; Heaven, S.; Banks, C.J. (2018). Degradation of some EN13432 compliant plastics in simulated mesophilic anaerobic digestion of food waste. Polymer Degradation and Stability 147, 76–88. DOI: 10.1016/j.polymdegradstab.2017.11.005 DOI
  5. Cucina, M.; Soggia, G.; De Nisi, P.; Giordano, A.; Adani, F. (2022). Assessing the anaerobic degradability and the potential recovery of biomethane from different biodegradable bioplastics in a full-scale approach. Bioresource Technology 354, 127224. DOI: 10.1016/j.biortech.2022.127224 DOI

All sources of the site: bibliography.

Other substrates in the group “Bioplastics and compostable packaging”