SOFC CCHP with poly-fuel: operation and management
Key Objectives of the project
The proposal is an applied research project devoted to demonstrate the technical feasibility, the efficiency and environmental advantages of CCHP (a three product plant based on cogeneration of cooling, heat and power) based on SOFC (solid oxide fuel cell technology) fed by different typologies of biogenous primary fuels (biogas and bio-syngas, locally produced), also integrated by a process for the CO2 separation from the exhaust gases.
The activity will be devoted to the scientific improvement of SOFC fed by biofuels, but especially to the technical and economical management of two demonstration of complete energy systems based on SOFCs. Several issues will be addressed: the impact of the fuel pollutants on the SOFC and fuel processing units, and consequently the necessity of gas cleaning; the operation of the integrated plants in CCHP configuration; the design and optimization of the carbon sequestration-management modules; the analysis and implementation of maintenance and repair strategies of those plants. Finally, the lessons learned from the demonstration will be used for pre-normative issues and scale-up analysis of this typology of integrated plants.
The general aim is the technological improvement of a virtual combination of fuel and technology: biogenous fuels (biogas, bio-syngas) as renewable fuels in high efficiency electrochemical CCHP generators (solid oxide fuel cells), able also to effectively separate and reuse the CO2 contained in its exhaust streams. To achieve this, the project foresees the design, installation and optimization of two demonstration plants, with the aim of facing and solving all the technical problems correlated to the coupling of biogenous fuels and SOFC, with CO2 removal. In particular, the following target will be faced: (1) Fuel issues considering detailed poisoning mechanisms, advancing in cleaning and processing technologies; (2) Define and operate new proof-of-concept fuel cell systems fully integrated with biomass processing units and carbon sequestration and handling technologies; (3) Maintenance, safety, repair and de-commissioning of fuel cell systems on a demonstration scale
The research activity will be devoted to the scientific, technical and economical management of two demonstration of complete energy systems based on SOFCs.
A first proof-of-concept SOFC system (Torino, Italy) will be able to operate with biogas produced in an industrial waste water treatment unit (WWTU). The plant will be in operation as CCHP plant, with heat recovery from the exhaust for the production of hot services (e.g. hot water) and conditioning services (through an adsorption chiller). Also, the plant will be completed with a CO2 separation from the anode exhaust and with a section of CO2 management (and disposal) integrated with the primary fuel processing system.
A second proof-of-concept SOFC system (Helsinki, Finland) will be demonstrated considering a SOFC stack operating with a syngas from biomass gasification. This second demonstration plant will be concentrated on the operation of a SOFC stack with a lean gasification fuel; all the concerns related to a proper fuel gas cleaning for fuelling the fuel cell system.
Expected socio and economic impact
The main impact of the project will be the ‘proof-of-concept’ demonstration of two SOFC units integrated with biogas or bio-syngas, respectively.
Such fuels have a wide potential in terms of availability and diffusion over the territory. The fuels considered are not only of interest because of their carbon neutrality, but also for certain peculiarities. In the case of biogas coming from the sewage plant, it represents a by-product of a dedicated process of waste-water treatment. Such plants have already a large diffusion over the territory (especially in urban areas where the continuously collected sewage has to be treated - only in Italy, more than 120 large plants in urban areas exist), with a mature technology already developed behind. Therefore it already subsists a huge biogas potential ready to be exploited, and therefore a large market potential for such SOFC integrated systems.
The bio-syngas option is another interesting one, investigated within the project, which will face different BoP integration and cleaning issues. Again the market potential of such integrated systems is high, especially for those areas where the biomass feedstock is ready available.
Another relevant impact accomplished by the project will be represented by the CCS capability of the integrated systems studied and tested during the project. Plants with a negative carbon emission balance will be then the focus and objective of our project, with an interest of such architectures of plants also in terms of energy economy and energy policy.
Finally a major impact will be represented by the CCHP mode of the tested demonstration units. Such operational mode will permit to achieve not only high electrical efficiency (>45% with biogenous fuel), but also global efficiencies exceeding values around 80-85%.
Therefore, the project foresees the design, installation and optimization of demonstration plants, with the aim of facing and solving all the technical problems correlated to the coupling of biogenous fuels and SOFC (with CO2 removal), with an optimization of their technological structure to achieve a optimization of their economic revenues.