The OpToKNuS project, running from January 2020 to June 2023, was funded by the German Federal Ministry of Education and Research under the sixth Energy Research Programme for the energetic use of biomass. The consortium comprised Hochschule Hof (HSH) as project coordinator, the German Biomass Research Centre (DBFZ) and the renewable‑energy specialist Spanner Re² GmbH. Prof. Dr.-Ing. Tobias Plessing led the effort, with key contributors from DBFZ and Spanner Re² providing experimental facilities and data.
The scientific aim was to develop a comprehensive optimisation toolbox that couples kinetic numerical simulation with practical measurements for the design and optimisation of thermochemical conversion plants using alternative fuels. The core technical work was organised into eight work packages. First, the existing simulation model was expanded (AP 1.1) to incorporate detailed kinetic data from the DBFZ reactor. Subsequent optimisation (AP 1.2) focused on improving accuracy, computational speed and numerical stability, achieving a reduction in simulation time by roughly 30 % while maintaining error margins below 5 % compared with benchmark experiments. The kinetic database was enriched with new measurements (AP 1.3) and validated against a market‑ready test plant (SRe²) through a dedicated measurement campaign (AP 1.4). Thermogravimetric analysis (TGA) experiments (AP 1.7) quantified the reactivity of reference and test fuels, yielding activation energies in the range 180–210 kJ mol⁻¹ and pre‑exponential factors between 10⁸ and 10¹⁰ s⁻¹, values that were incorporated into the simulation.
Parallel to model development, a user‑friendly toolbox interface was programmed (AP 2.2) and continuously refined (AP 2.3). The toolbox was linked to a relational database (AP 2.1, AP 2.6) that stores all kinetic parameters, experimental results and simulation outputs, enabling rapid scenario analysis. An industrial advisory circle (AP 2.4) was established to ensure that the toolbox met the needs of potential users in the bio‑energy sector.
Validation experiments (AP 3.2, AP 3.3) were carried out at the DBFZ laboratory fixed‑bed gasifier. Reference and test fuels were pyrolysed and CO₂‑gasified under controlled conditions. The measured syngas yields and tar concentrations matched the model predictions within ±10 % for syngas and ±15 % for tar, confirming the reliability of the kinetic descriptions. Parallel small‑scale tests at the Hochschule Zittau/Görlitz facility (AP 3.5) further corroborated the scalability of the approach. Throughout the project, regulatory compliance and economic feasibility were monitored (AP 3.4), and a detailed cost‑benefit analysis was produced (AP 4.9).
In summary, the OpToKNuS project delivered a validated, high‑performance optimisation toolbox that integrates kinetic data, numerical simulation and experimental validation. The toolbox’s accuracy, speed and user‑friendly design position it as a valuable tool for the design and optimisation of biomass‑based thermochemical plants, while the collaborative framework ensured that the developed technology aligns with industry requirements and regulatory standards.