The project activities were divided into the following categories: (1) technical development and validation of the key enabling technologies, (2) feedstock supply chain optimization, (3) evaluation of utilization options for biomethane and biochar, (4) techno-economic and environmental assessments and case studies, and (5) exploitation, dissemination and communication.
The technical development activities focused on the four key enabling technologies - low-cost oxygen supply with oxygen transport membranes, flexible gasification, filtration and catalytic reforming - that form the backbone of the FlexSNG concept. During the first half of the project, preliminary pilot runs were carried out to optimize the process conditions in the gasifier, the filter and the catalytic reformer for both operation modes: (1) co-production of biomethane, biochar and heat, and (2) maximised production of biomethane and heat. In parallel, lab-scale testing and screening of reformer catalysts and sulphur removal sorbents were performed to support the pilot activities. Development of oxygen transport membranes suitable for gasification started with lab-scale tests in simulated gasification conditions. Based on the experiences gained in the lab tests, a proof-of-concept oxygen production module was designed and constructed.
The experimental work culminated to three pilot test campaigns where the operation of the gasifier, the filter and the catalytic reformer were successfully validated to TRL5. The process was operated under gasification conditions for over 190 hours using different types of woody residues, waste wood and waste-derived feedstock mixed with wood and/or biochar. The proof-of-concept oxygen production module was also coupled with the gasification pilot. The oxygen production unit was operated successfully for over 150 hours in real gasification conditions, demonstrating more than 50% reduction in energy consumption compared to state-of-the-art oxygen production technologies.
Feedstock supply chain optimization activities started with mapping of the feedstock potential and gathering of relevant feedstock quality and cost data. The most eligible feedstocks were selected for FlexSNG based on the collected data and the assessment of their suitability for the gasification process. The pre-processing requirements, storage and collection methods were then determined for the selected feedstocks and the potential benefits of co-handling forest/agro/waste feedstocks were evaluated. This data was ultimately implemented into optimization models that could demonstrate up to 30% reduction in feedstock supply costs through optimized operational planning and better coordination of logistics operations.
The different end-use options for biomethane and biochar were assessed by experimental characterization of biochar samples produced in the pilot tests and studying the current and future markets for both products. The most potential applications for FlexSNG biochar were considered to be energetic use and carbon sequestration. The most promising markets for biomethane, on the other hand, were the hard-to-electrify sectors for long-distance transport (heavy trucks and maritime) as well as industries with demand for high temperature heat, e.g. cement production, when considering the longer-term perspective.
Techno-economic assessments, including designing and cost estimation of a commercial-scale FlexSNG process and benchmarking it against the state-of-the-art reference, were carried out towards the end of the project. The FlexSNG process was estimated to achieve up to 29% lower biomethane production costs compared to the state-of-the-art biomass-to-biomethane reference case. Case studies were also carried out to evaluate the implementation potential of the FlexSNG process in selected regions in Canada and Europe. The case study assessments showcased the significance of economies of scale and the need for public funding especially for demonstration and first-of-a-kind plants. A pathway for the follow-on demonstration stages was also prepared.
The project has been very active in disseminating the project results throughout the project. Several project events, including workshops and a webinar series, were organized to engage with key stakeholders. Already now six academic papers have been published, two manuscripts submitted for review in scientific journals and several papers are in the pipeline.
