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Open research questions in Anaerobic Digestion and Biogas Production

87 unresolved questions extracted from the limitations and future-work sections of 574 Anaerobic Digestion and Biogas Production papers in our library. Each links back to the study that raised it.

What the literature leaves open

  • The mechanisms of ammonia inhibition in chicken manure at different total solids contents are not well understood. There is a need to elucidate the multi-level mechanism of ammonia inhibition in high-TS chicken manure digestion at the functional gene level.

    Ammonia Inhibition in Anaerobic Digestion of Chicken Manure with Different Total Solids Contents · 2026 · DOI

  • The paper identifies challenges in optimizing substrate ratios for anaerobic co-digestion. The study highlights the complexity of modeling methane production kinetics. The challenges include the need for balancing nutrient ratios and providing a richer mix of organic matter to increase biogas yields.

    Methane Production Using Anaerobic Co-Digestion of Swine and Nejayote Wastewater: Synergic Effects and Kinetic Modeling Studies · 2026 · DOI

  • Further studies could investigate the microbial community and metabolic pathways, - The effects of different operational conditions on the co-digestion process could be explored, - The scalability of the co-digestion process could be evaluated

    Methane Production Using Anaerobic Co-Digestion of Swine and Nejayote Wastewater: Synergic Effects and Kinetic Modeling Studies · 2026 · DOI

  • Further studies are needed to investigate the effect of seasonal variability in biomass composition on AD performance, - Research on the optimization of harvest windows for Helianthus annuus is necessary, - Investigation of the relationship between biomass yield and CH4 production efficiency is required

    Impact of Seasonal Trade-Offs in Biomass Yield and Composition on Techno-Economic Performance of Anaerobic Digestion of Helianthus annuus · 2026 · DOI

  • integrated analyses linking biomass yield, chemical composition, and bioavailability with AD performance, process kinetics, and energy-economic efficiency remain limited. the effect of seasonal variability in the chemical composition of Helianthus annuus biomass on AD efficiency is not well understood.

    Impact of Seasonal Trade-Offs in Biomass Yield and Composition on Techno-Economic Performance of Anaerobic Digestion of Helianthus annuus · 2026 · DOI

  • the high fiber content of the digestate can make dewatering difficult - the choice of technology affects the capital, operating costs, efficiency, and complexity of the separation process - the need to determine the size of the particles in the digestate

    Sustainable Use of Digestate from Biogas Plants: Separation of Raw Digestate and Liquid Fraction Processing · 2024 · DOI

  • further development of research on methods of digestate separation - investigation of membrane separation processes - study of centrifuge operation for digestate separation

    Sustainable Use of Digestate from Biogas Plants: Separation of Raw Digestate and Liquid Fraction Processing · 2024 · DOI

  • As a result, research on the field has expanded in diverse directions, yet a clear pathway is not being followed, which can lead to unexpected or contradictory results.

    Current Trends and Future Prospects of Biochar Use to Improve Anaerobic Digestion: An Up-to-Date Critical Review · 2026 · DOI

  • Persistent challenges include sensor fouling, calibration drift, and the lack of standardized open datasets.

    Artificial Intelligence in Anaerobic Digestion: A Review of Sensors, Modeling Approaches, and Optimization Strategies · 2025 · DOI

  • The impact of artificial humic acid (HA) under varying water management conditions on the interactions between carbon metabolic pathways in rice soils remains unclear.

    Coupling Mechanism of Methane Production and Carbon Fixation Regulated by Artificial Humic Acid in Paddy Soils: Insights into Microbial Communities and Metabolic Pathways · 2025 · DOI

  • However, acetogenic strains from the genera Terrisporobacter and Acetoanaerobium remained poorly investigated for biotechnological applications.

    Isolation and characterization of novel acetogenic strains of the genera Terrisporobacter and Acetoanaerobium · 2024 · DOI

  • The heat of anaerobic digestion is an important thermal parameter, but it has rarely been measured and calculated. The study aims to fill the gap in current knowledge and practical measurement of standard heat of anaerobic digestion, standard heat of biohydrolysis, and standard heat of bioredox.

    Integration of Mathematical Framework and Thermochemical Equation for Counting Heat of Anaerobic Digestion, Heat of Bioredox, and Heat of Biohydrolysis · 2026 · DOI

  • The data presented in Table 3 includes only 21 organic compounds; the generalizability of the derived correlations to a broader range of complex organic matter compositions requires testing with additional diverse substrates.

    Integration of Mathematical Framework and Thermochemical Equation for Counting Heat of Anaerobic Digestion, Heat of Bioredox, and Heat of Biohydrolysis · 2026 · DOI

  • There is a need to evaluate the potential of poultry and livestock organic waste for biogas production and fertilizer quality. The effects of substrate type on biogas production and fertilizer quality are not well understood.

    Biogas Production Efficiency and Slurry Fertilizer Quality Using Poultry and Livestock Organic Waste Under Anaerobic Composting · 2026 · DOI

  • Water binding dynamics and thermal activity during the 20-day anaerobic digestion process were mentioned in relation to dry matter changes, but actual temperature profiles, moisture retention curves, and their correlation with biogas production kinetics were not provided for the poultry-livestock waste system.

    Biogas Production Efficiency and Slurry Fertilizer Quality Using Poultry and Livestock Organic Waste Under Anaerobic Composting · 2026 · DOI

  • The lack of a simple equation for determining heat of anaerobic digestion, - The need for a better understanding of the relationship between heat of bioredox and Buswell's electron

    From Counting Heat of Organic Combustion to Determining Heat of Anaerobic Digestion · 2026 · DOI

  • Examining multi-factor coupling mechanisms. Applying results from lab to actual engineering applications. Using experimental design with multiple factors and systems biology methods to study fermentation system responses.

    Research Progress on Methane Production from Anaerobic Fermentation of Food Waste · 2026 · DOI

  • There is a lack of research on multi-factor coupling mechanisms. The long-term stability and economic performance of intensification technologies are not well studied. The application of results from lab to actual engineering applications is limited.

    Research Progress on Methane Production from Anaerobic Fermentation of Food Waste · 2026 · DOI

  • Investigating the scalability of the process. Examining the use of other microorganisms for PHB production. Optimizing the pretreatment and fermentation conditions for improved PHB yields.

    Impact of pretreatment severity and nutrient parameters on microbial PHB production from shrub willow hydrolysate using recombinant Escherichia coli · 2026 · DOI

  • The lack of sustainable feedstocks for PHB production. The need to optimize pretreatment severity and nutrient parameters for PHB production.

    Impact of pretreatment severity and nutrient parameters on microbial PHB production from shrub willow hydrolysate using recombinant Escherichia coli · 2026 · DOI

  • There is a need for a review of kinetic modelling in anaerobic digestion for biogas production. The study identifies a gap in the literature regarding the application of kinetic modelling in anaerobic digestion.

    Kinetic Modelling of Anaerobic Digestion of Biogas Production from Different Wastes: A Review · 2026 · DOI

  • Different feedstocks exhibit unique characteristics, such as varying organic matter content, nutrient profiles, and inhibitory compounds, which can affect the accuracy and applicability of kinetic models. Based on model assumptions, it is noteworthy that kinetic models rely on simplifying assumptions, such as uniform microbial populations and ideal mixing conditions, which may not accurately represent real-world anaerobic digestion systems. Accurate estimation of kinetic parameters requires high-quality experimental data, which can be challenging to obtain, particularly for complex feedstocks or co-digestion systems. During the review, findings may not directly translate to industrial-scale anaerobic digestion systems, where factors such as temperature fluctuations, pH variations, and equipment design can impact process performance. Furthermore, the study did not account for all potential inhibitory factors, such as toxic compounds, heavy metals or excessive ammonia production, which can impact microbial activity and process stability. Having established this, the choice of kinetic model can significantly affect prediction accuracy, and different models may be more suitable for specific feedstocks or process conditions. Finally, the quality and reliability of the experimental data used for model calibration and validation can significantly impact the accuracy of kinetic model predictions, which is also a limitation of the study. Addressing these limitations and challenges, kinetic modelling becomes an even more effective tool for optimizing anaerobic digestion systems and promoting the widespread adoption of biogas production technologies.

    Kinetic Modelling of Anaerobic Digestion of Biogas Production from Different Wastes: A Review · 2026 · DOI

  • The need for characterization of organic wastes for biogas production suitability - The lack of information on the properties and behaviors of organic wastes

    Characterization of Organic Wastes for Biogas Production Suitability · 2026 · DOI

  • The study identifies a gap in the understanding of methane production using soil samples from cold environments. The study highlights the need for future research to understand the methane production using soil samples from cold environments.

    Biogas production using the microbial community present in the soil from Deception Island, maritime Antarctica · 2026 · DOI

  • However, further studies are needed, including low-temper- ature BMP assays, controlled anaerobic bioaugmentation experiments, the use of different culture media to better reproduce the Antarctic environment, sequencing of other soil samples, and functional metagenomics to address the limitations of this study.

    Biogas production using the microbial community present in the soil from Deception Island, maritime Antarctica · 2026 · DOI

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87 open questions have been extracted from the limitations and future-work passages of 574 Anaerobic Digestion and Biogas Production papers in our library. Each one below links back to the study that raised it, so you can read the original claim in context.

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