Gasification as a key enabler of decarbonisation

CENER is actively collaborating with a range of industrial stakeholders to carry out demonstration-scale testing assays at its BIO2C gasification unit in order to validate the technology under real-world, commercially relevant conditions. Demonstrating the long-term operational stability, efficiency, and cost-effectiveness of the gasification process with each specific feedstock is essential to build confidence among industry partners, support future deployment at industrial scale, and facilitate investment in advanced bioenergy solutions. By leveraging its semi-industrial facility, CENER provides a valuable testing platform for bridging the gap between laboratory research and full-scale commercial implementation.

The European Union’s Renewable Energy Directive III (RED III), adopted in 2023, represents a significant step forward in Europe’s ambition to achieve climate neutrality by 2050. By raising the renewable energy target to 42.5% (with an aspirational 45%), RED III reinforces the role of advanced biofuels and other renewable fuels of non-biological origin (RFNBOs) in decarbonizing hard-to-abate sectors such as aviation, maritime or heavy industries.

Among the technologies to capitalize on these regulatory developments is gasification—a thermochemical process capable of converting a wide range of solid waste and biomass streams into synthesis gas (syngas), which can be further upgraded into advanced fuels and chemicals. Indeed, gasification presents unique opportunities aligned with RED III objectives and Annex IX provisions.

One of the most important opportunity gasification offers is its ability to produce advanced fuels that are essential for decarbonizing sectors where direct electrification is technically unfeasible, economically impractical, or too slow to implement. These sectors include aviation, maritime, heavy-duty transport, chemicals, and energy-intensive industries—all targeted under RED III for accelerated decarbonization through advanced biofuels and RFNBOs. This way, gasification facilitates the production of high-value fuels crucial for sectors where direct electrification is limited by means of:

Renewable Methanol: Produced from syngas, renewable methanol serves as a marine fuel, chemical feedstock, and hydrogen carrier. It enables decarbonization of shipping and chemicals, and a hydrogen carrier.
Fischer-Tropsch (FT) Liquids: Syngas upgraded via FT synthesis provides synthetic diesel, jet fuel (SAF), and naphtha. These drop-in fuels are direct fossil substitutes for aviation, heavy-duty transport, and petrochemicals.
Synthetic Natural Gas (SNG): SNG is produced by methanation of syngas and can substitute fossil gas in grids and industry. It supports heating, industrial energy, and flexible storage within existing infrastructure.
Renewable Hydrogen (H₂): Hydrogen extracted from syngas via water gas shift and separation serves industry, mobility, renewable fuels production and energy storage. It complements electrolytic hydrogen in Europe’s hydrogen economy and RFNBO strategies.
Ammonia (NH₃): Green ammonia is synthesized from renewable hydrogen and used for fertilizers, shipping, and hydrogen transport. It decarbonizes agriculture and supports emerging ammonia-fueled shipping markets.
Dimethyl Ether (DME): DME from syngas or methanol is a clean-burning LPG substitute and diesel alternative. It reduces emissions in transport and off-grid applications where electrification is limited.
Biochar / Solid Carbon Co-Products: Certain gasification systems produce biochar for soil health or carbon removal credits.
High Temperature Renewable Heat in industrial processes: Syngas can fuel high temperature industrial processes like cement and steel production, or calcite or magnesite calcination or sintering ones as few examples.
These applications meet specific RED III targets and leverage Annex IX-A feedstocks (agricultural residues, forestry residues, industrial waste wood, MSW biogenic fractions), contributing directly to EU decarbonization and circular economy goals.

BRIDGING THE GAP BETWEEN POTENTIAL AND COMMERCIAL REALITY: THE NEED FOR TECHNICAL VALIDATION

However, while gasification offers significant potential to transform biomass, biowaste and residue feedstocks into high-value renewable fuels and chemicals, its successful scale-up faces critical technical challenges. Beyond the policy and market drivers established by RED III, the technology must deliver reliable, consistent performance under real-world conditions to gain investor confidence and meet regulatory and off-taker requirements.

Two areas stand out as essential for de-risking and commercializing gasification pathways: the behaviour of each specific feedstocks in the conversion process, and the effectiveness of gas cleaning and conditioning systems. Without robust, demonstration-scale validation of both, the transition from pilot to bankable commercial projects remains highly constrained.

One of the fundamental technical challenges in scaling up gasification lies in the variability and complexity of the feedstocks themselves. Under Annex IX-A of the RED III Directive, eligible materials include a broad spectrum of agricultural residues, forestry waste, industrial by-products, and the biogenic fractions of municipal solid waste (MSW) and solid recovered fuels (SRF). These heterogeneous feedstocks differ widely in key physical and chemical properties such as moisture content, minor elements composition (N, Cl, S), ash composition and melting behaviour, volatile matter, heating value, bulk density and particle size. Such variability directly affects plant viability, since the behaviour of the material within the gasifier, influences carbon conversion efficiency, syngas quality, and overall plant performance. Moreover, inconsistent feedstock characteristics can lead to operational issues like sintering, corrosion, and feeding system malfunctions such as blockages or equipment wear. To mitigate these risks and ensure stable, predictable, and bankable performance, experimental validation of each specific feedstock behaviour is essential through characterization and demonstration-scale testing. This process involves mapping safe and efficient operating conditions for each specific feedstock type and blend, including design and control of pre-treatment systems (drying, sizing, homogenization), feeding mechanisms, gasifier operation conditions and reactor configurations.

Equally critical to the commercial success of gasification is the production of syngas that meets the purity requirements necessary for downstream synthesis routes. Whether the end products are methanol, Fischer-Tropsch liquids, synthetic natural gas, or renewable hydrogen, the syngas must be clean to protect sensitive catalysts and ensure reliable, long-term process performance. Contaminants such as tars, particulates, sulphur and nitrogen compounds, chlorine, alkalis, and heavy metals must be removed.

For this reason, CENER is working for several industrial stakeholders in demonstration-scale testing campaigns at the gasification unit of BIO2C, since validation is crucial to prove the long-term operational stability, efficiency, and cost-effectiveness of these systems under commercial conditions. Such validation must confirm that that feedstock fluctuations and gas cleaning solutions can maintain performance over thousands of operating hours, and operate within the economic parameters necessary for project viability.

CENER’s gasification plant is a semi-industrial-sized installation with a nominal thermal capacity of 2 MW, capable of generating a synthesis gas suitable for several final uses. The plant essentially consists of the feeding system, an atmospheric bubbling fluidized bed gasifier, a pilot gas cleaning system, and a synthesis gas combustion system, and various auxiliary systems required to carry out the process. Under operation since 2012, is designed to work with a wide range of biomass feedstocks, with bulk densities between 80–800 kg/m³ and moisture content below 20%. This gasification plant is based on atmospheric bubbling fluidized bed (ABFB) technology and can operate in two different modes: using air as the gasifying agent or using steam/oxygen as the gasifying agent.

The scale of the plant plays a crucial role in ensuring that the results obtained are both valid and transferable to industrial applications. Our gasification unit was specifically designed with a nominal capacity of 2 MW to replicate the process conditions of a full-scale industrial gasifier, making the outcomes directly applicable to real-world projects. In contrast, smaller-scale gasifiers experience proportionally higher heat losses, which distort key parameters such as the oxygen-to-fuel ratio and result in operating conditions, and therefore process performance, that are not representative of those found in commercial settings. Furthermore, in fluidized beds with smaller diameters, the fluidization behaviour and fuel distribution in the cross section of the fluidized bed differs significantly, often leading to inaccurate or non-scalable performance data. With an internal diameter of 1.1 meters, our fluidized bed closely mimics the hydrodynamics of industrial-scale systems, providing a reliable and realistic environment for process validation and optimization.

As part of gasification validation trials CENER is conducting comprehensive characterization work, including analysis of feedstock properties, such as moisture, ash content, and elemental composition, as well as the detailed characterization of clean and raw syngas to assess composition, contaminant levels, and consistency. In addition, char analysis is being performed to better understand conversion efficiency, and potential valorization pathways. Ash melting behaviour is tested in real world conditions by monitoring bed fluidization conditions during the test and by characterizing bed physical and chemical properties at the end of the test. These activities are crucial for optimizing gasifier operation, improving process reliability, and generating high-quality data to support technology scale-up and integration with downstream fuel synthesis routes.

In addition to its role in technology validation and demonstration, the plant also serves as a platform for hands-on, in-plant training with the support and guidance of CENER’s experienced team. This practical training environment enables engineers, technicians, and industry professionals to gain direct experience operating and managing gasification processes under realistic conditions. With the expertise of CENER’s staff and access to a semi-industrial facility that closely mirrors industrial-scale systems, trainees acquire valuable technical skills and operational insights that are directly applicable to commercial plants.

CENER’s research priorities in the field of gasification are strategically aligned with the broader objective of transforming low-value biomass and waste streams into high-impact renewable fuels and bio-based products. A central focus of this work is the production of biomethane via syngas methanation, which offers a dispatchable energy carrier, direct route to renewable natural gas suitable for injection into the existing gas grid or utilization in the transport and industrial sectors.

Additionally, a novel and emerging area of interest at CENER involves the biological valorization of syngas through microbial conversion processes. Specifically, the center is exploring the use of syngas as a carbon and energy source in a multiple steps fermentation process for the production of microbial oils. These microbial lipids can serve as sustainable feedstocks for biodiesel, aviation fuels, and bio-based chemicals, offering a biotechnological complement to thermochemical fuel production. This line of research opens up new opportunities for integrating gasification with advanced bioprocessing in hybrid biorefinery concepts.

Together, these technology upscaling, validation and research efforts reflect CENER’s commitment to building robust scientific and technical foundation for the deployment of flexible, modular, and feedstock versatile gasification systems. By enabling syngas to serve as a versatile platform for multiple end-products, CENER aims to contribute to the development of integrated and commercially viable solutions that advance the EU’s renewable energy, circular economy, and climate neutrality goals.