Periodic Reporting for period 2 - BELENUS (Lowering Costs by Improving Efficiencies in Biomass Fueled Boilers: New Materials and Coatings to Reduce Corrosion)
Berichtszeitraum: 2020-09-01 bis 2021-08-31
Energy from biomass corresponds to more than 60% of all renewable energy sources in Europe and is currently the most widely used worldwide. Recently, the Paris Agreement in the 21st Conference of the Parties for global climate change (COP21) set the objective of global electricity production in 2050 will be almost entirely based on zero-carbon emitting technologies, so biomass energy will contribute to that objective and significantly reduce dependence of fossil fuels. However, currently biomass plants has not reached the efficiency that can be obtained with fossil fuels, mainly due to severe corrosion caused by alkali metals, chlorine and other corrosive elements, resulting in a shorter boiler components lifetime, so maximum temperatures and steam pressures are limited, which translates into lower overall efficiency and profitability. Moreover, biomass feedstock is increasingly diverse and there is a need for generic understanding of the associated corrosion risks. Today’s dominant bioenergy source is clean wood, it is expected that the share of lower cost, but more corrosive waste will increase in the future.
BELENUS will reduce bioenergy CAPEX and OPEX through a holistic approach to prevent mainly corrosion in the boiler, in particular in superheater tubes: a) new surface engineering: biomass corrosion highly resistant coatings on creep resistance materials; b) new strategies of welding and bending for coated tubes improving the quality and efficiency of boiler components; and c) new online corrosion monitoring system specifically designed for biomass CHP plants. These contributions will allow raising the plant efficiency by increasing the operating temperature resulting in reducing the fuel expenditure and providing flexibility by allowing the use of different types of biomass, as well as the lifetime of critical components of biomass fired boilers. Finally, modelling and lifetime prediction tools and cost and life cycle analysis undertaken so the optimum materials and coatings are chosen from the durability, economic and environmental perspectives, maximising the sustainability in economic and environmental terms.
BELENUS will reduce bioenergy CAPEX and OPEX through a holistic approach to prevent mainly corrosion in the boiler, in particular in superheater tubes: a) new surface engineering: biomass corrosion highly resistant coatings on creep resistance materials; b) new strategies of welding and bending for coated tubes improving the quality and efficiency of boiler components; and c) new online corrosion monitoring system specifically designed for biomass CHP plants. These contributions will allow raising the plant efficiency by increasing the operating temperature resulting in reducing the fuel expenditure and providing flexibility by allowing the use of different types of biomass, as well as the lifetime of critical components of biomass fired boilers. Finally, modelling and lifetime prediction tools and cost and life cycle analysis undertaken so the optimum materials and coatings are chosen from the durability, economic and environmental perspectives, maximising the sustainability in economic and environmental terms.
The work carried out from the beginning of the project to the end of this period 2 (M30) has covered the following aspects for each work package (WP):
WP1 was focused in selecting biomass fuels, alloys and coatings systems, as well as defining the test parameters regarding lab, pilot and plant scale and the test matrices for corrosion, erosion and mechanical testing.
In the WP2 a total of 30 coatings on SVM12 steel were developed by different deposition technologies. They were screening tested (500 h) under simulated fire- and steam-side in WP3. From that test, the best performing systems have been reengineered to optimize their quality and have been produced for long-term test, mechanical (tensile and erosion), bending and pilot plant testing (tests on-going). On the other hand, electrochemical sensors for on-line corrosion monitoring were also developed and pre-tested in steam at lab scale. Currently, its behaviour has been validated under biomass atmosphere at pilot plant scale.
Most of the work at that scale (WP4) was focused on biomass fuel and ash characterisation, as well as modelling of the combustion process for all the selected biomass fuels and analysing leaching procedures (not considered in the GA). In addition, studies about the biomass preparation (pelletized) and continuous feeding methodology were carried out for commissioning the pilot plant of 10 kWth was achieved. In the WP5, thermo-physical simulation of uncoated and coated samples integrity after welding processes by means of heat affected zone (HAZ) experiments was performed. Transversally, in the WP6, a modelling method for analysis of fouling risks by coupling computational fluid dynamic modelling (CFD) and thermodynamic equilibrium calculations, a first set of calculation to predict the stable phases formed on the best performing materials, as well as starting the lifetime assessment and methodology development with a SVM12 tube case and LCAs of some coatings were performed. At full scale in the WP7, trial tube with 18 trial coatings was installed within the final superheater of the Steven’s Croft boiler, as well as corrosion probes and online corrosion monitoring system, which will be installed in Blackburn Meadows boiler, have been manufactured. Additionally, another corrosion probe and erosion probes (not considered in the GA) are being developed. Regarding dissemination activities have been the most affected by the Covid-19 pandemic, due to the cancellation of face-to face events and the delays in other WPs. Therefore, WP8 was focused on maximise it through the project website (https://belenus-project.eu) and social networks (LinkedIn and Twitter). Finally, in the frame of WP9, coordination and management administrative activities have been performed (GA, SC meetings organization, amendment process, evaluation of the pandemic impact on the activities of the project, etc.). The project progress from technical and financial points of view have been monitored monthly by means of work package leaders and coordinator meetings. In addition, the project coordinator has centralizes the coordination activities among the project consortium and the European Commission (EC).
WP1 was focused in selecting biomass fuels, alloys and coatings systems, as well as defining the test parameters regarding lab, pilot and plant scale and the test matrices for corrosion, erosion and mechanical testing.
In the WP2 a total of 30 coatings on SVM12 steel were developed by different deposition technologies. They were screening tested (500 h) under simulated fire- and steam-side in WP3. From that test, the best performing systems have been reengineered to optimize their quality and have been produced for long-term test, mechanical (tensile and erosion), bending and pilot plant testing (tests on-going). On the other hand, electrochemical sensors for on-line corrosion monitoring were also developed and pre-tested in steam at lab scale. Currently, its behaviour has been validated under biomass atmosphere at pilot plant scale.
Most of the work at that scale (WP4) was focused on biomass fuel and ash characterisation, as well as modelling of the combustion process for all the selected biomass fuels and analysing leaching procedures (not considered in the GA). In addition, studies about the biomass preparation (pelletized) and continuous feeding methodology were carried out for commissioning the pilot plant of 10 kWth was achieved. In the WP5, thermo-physical simulation of uncoated and coated samples integrity after welding processes by means of heat affected zone (HAZ) experiments was performed. Transversally, in the WP6, a modelling method for analysis of fouling risks by coupling computational fluid dynamic modelling (CFD) and thermodynamic equilibrium calculations, a first set of calculation to predict the stable phases formed on the best performing materials, as well as starting the lifetime assessment and methodology development with a SVM12 tube case and LCAs of some coatings were performed. At full scale in the WP7, trial tube with 18 trial coatings was installed within the final superheater of the Steven’s Croft boiler, as well as corrosion probes and online corrosion monitoring system, which will be installed in Blackburn Meadows boiler, have been manufactured. Additionally, another corrosion probe and erosion probes (not considered in the GA) are being developed. Regarding dissemination activities have been the most affected by the Covid-19 pandemic, due to the cancellation of face-to face events and the delays in other WPs. Therefore, WP8 was focused on maximise it through the project website (https://belenus-project.eu) and social networks (LinkedIn and Twitter). Finally, in the frame of WP9, coordination and management administrative activities have been performed (GA, SC meetings organization, amendment process, evaluation of the pandemic impact on the activities of the project, etc.). The project progress from technical and financial points of view have been monitored monthly by means of work package leaders and coordinator meetings. In addition, the project coordinator has centralizes the coordination activities among the project consortium and the European Commission (EC).
Biomass waste fuels, materials systems, and test parameters regarding lab, pilot and plant scale and the test matrices for corrosion, erosion and mechanical testing was established. Results obtained in the screening tests carried out on the total of coatings developed indicate that most of them have promising results. In order to confirm their good behaviour, they are being evaluated at longer times and mechanically (tensile, erosion and bending tests, and experimental study of the heat affection zone caused by welding) at lab scale and under pilot and real plants conditions in order to confirm their reliability to achieve a technological readiness level enough to be deployed at commercial stage. The experience gained during these tests performed and the validation of the on-line corrosion monitoring system, jointly with the modelling method for analysis of fouling risks in biomass boilers and the predictions about their anticipated grainsize/oxide microstructure, as well as the lifetime assessment and methodology and LCAs performed on coatings, will be a proof for investors and developers to reduce the technical uncertainty that this technology entail. Finally, the results obtained will allow the members of the consortium to offer a new solution in future CHP tenders by providing a cost competitive technology with a high level of flexibility in the energy supply and with no environmental drawbacks.