Project No.: 2021/43/B/ST8/01924
Project duration: 11.07.2022 – 10.07.2026
Principal Investigator: Prof. Andrzej Białowiec
One of the most recent directions in the development of anaerobic digestion (AD) is the application of additives in the form of various carbon materials (CMs), such as biochar, hydrochar, and activated carbon, to a wide range of substrates used in this process, including food waste. The amount of food waste (FW) generated worldwide is increasing exponentially on an annual basis, making it one of the key global environmental challenges. Anaerobic digestion is one of the most effective methods for managing this waste stream, as it enables the production of renewable energy in the form of biomethane. However, a significant research gap still exists regarding the actual nature of the mechanisms by which carbon materials influence biomethane production and the role of their individual properties in microbiological processes.
The main scientific objective of the project is to identify the true nature of the mechanisms through which carbon materials affect the efficiency of biomethane production, as well as to determine the potential for intentional modification of CM properties in order to maximize biomethane yields.
The following research hypotheses have been formulated within the project:
carbon materials with high buffering capacity (BC) promote the stabilization of environmental conditions favorable for methanogenic microorganisms,
carbon materials characterized by high sorption capacity (SC) mitigate the negative effects of toxic by-products of anaerobic digestion and increase the availability of biodegradable organic compounds to microorganisms,
carbon materials with high electrical conductivity (EC) enhance direct interspecies electron transfer,
carbon materials with low zeta potential (ZP) promote the aggregation of methanogens in suspension and limit the growth of competing microbial groups,
it is possible—for the first time—to develop a quantitative and qualitative model describing the microbiological mechanism of the influence of carbon materials on anaerobic digestion, enabling the deliberate modification of their properties to optimize the process.
The research plan consists of four main work packages:
Work Package 1 – production and characterization of carbon materials, in which biochar, hydrochar, and activated carbon will be produced from wheat straw using thermochemical treatment. The resulting materials will be subjected to comprehensive analyses of their physical and chemical properties.
Work Package 2 – biomethane production from glucose (a pure substrate serving as an acetate precursor) using various carbon materials in batch and continuous-flow reactors, with the addition of CMs produced in Work Package 1. Biomethane potential and production kinetics will be determined, and a comprehensive characterization of substrates and digestate will be performed with respect to physical, chemical, microbiological, and genetic parameters.
Work Package 3 – analysis of the mechanisms responsible for increased biomethane production in the presence of carbon materials. Advanced statistical methods, including neural networks and fuzzy logic systems, will be applied to identify the key CM properties and to develop a mathematical model describing these relationships. In addition, advanced multi-omics analyses will be conducted to identify the microbiological basis of the influence of carbon materials on anaerobic digestion.
Work Package 4 – optimization of anaerobic digestion using carbon materials, in which the potential to intensify biomethane production through the application of deliberately modified CMs will be evaluated in batch and continuous-flow laboratory-scale reactors using food waste. The scope of analyses will correspond to those performed in Work Packages 1 and 2, and the tests applied will be analogous to those used in Work Package 3.
The innovativeness of the proposed research lies in its comprehensive and systematic approach to identifying the mechanisms by which carbon materials influence anaerobic digestion, determining the key CM properties responsible for enhancing process efficiency, and deliberately modifying these properties to intensify the anaerobic digestion of food waste. According to the current state of knowledge, such studies have not yet been conducted, and therefore the project is expected to generate new and unique scientific knowledge. Moreover, the results are anticipated to contribute to the development of solutions that increase biomethane yield and production rates, which may be of significant importance for optimizing biogas plant operation and supporting the implementation of circular economy principles.
