Periodic Reporting for period 1 - PYSOLO (PYrolysis of biomass by concentrated SOLar pOwer)
Reporting period: 2023-07-01 to 2024-10-31
PYSOLO (PYrolysis of biomass by concentrated SOLar pOwer) project brings together 9 partners from 4 EU countries with the aim of preparing the ground for a novel groundbreaking and fully renewable process combining concentrated solar power and biomass pyrolysis. Thanks to the use of solar heat in the pyrolysis process, the production of valuable products bio-oil, biochar and pyrogas can be maximized and the associated CO2 emission minimized, with economic and environmental benefits compared to conventional pyrolysis. The proposed system uses particles heat carrier, ensuring operational flexibility and avoiding the need of heat transfer surface in the pyrolysis reactor that facilitates the system scale-up. Specifically, PYSOLO process aims at developing at TRL4 the two key unit operations of this novel solar pyrolysis system, namely: (i) the solar particle receiver and (ii) the pyrolysis reactor with the associated particle-char separator. The very innovative feature of PYSOLO lies in its innovative and unique coupling of pyrolysis technology with high temperature concentrated solar power system. This ground-breaking feature can potentially offer the following main advantages: 1) delivering solar bio-oil, electricity or pyrogas and biochar for many energy and non-energy uses, when solar energy supplies the heat necessary for the pyrolysis process, either in sunny hours or by exploiting high temperature stored solids; 2) run in self-mode the pyrolysis process (i.e. with electric heating or burning pyrogas and biochar), when solar energy is not sufficient and the thermal energy storage unit is discharged; 3) providing balancing services to the electric grid from the conversion of the available pyrogas, when solar energy or thermal energy storage are sufficient to maintain the pyrolysis process running and the grid requires the generation of additional electric power, and by using low-cost excess electricity from non-programmable renewable energy sources (i.e. photovoltaics and wind) and converting it in high temperature thermal energy via the induction electric heating system.
The work performed in the first reporting period was mainly devoted to preparing the ground for the experimental activities envisaged in the next reporting periods. In particular, the following activities have been carried out on each single component of the PYSOLO process:
• Particles Heat Carrier: 6 particles heat carriers (sand, bauxite, biochar, magnesium oxide, silicon carbide and olivine) were selected on the basis of their thermal, mechanical and optical properties and of the related safety information. Several experiments were conducted on such particles heat carrier, identifying bauxite and olivine as the two best candidates for testing with the solar receiver. Moreover, additional analyses have been conducted to assess further properties of the particles heat carrier crucial for the PYSOLO process efficiency, such as density and fluidization velocity, and safety analyses also have started.
• Pyrolysis reactors: the two existing pyrolysis units participating in the project, namely a Fluidised Bed reactor and an Auger reactor, have been adapted to operate with the selected particles heat carrier. The commissioning phase was successfully completed for the first one, whilst it is still ongoing for the second one.
• Particles heat carrier-char separation unit: A batch particles heat carrier-char separation unit based on fludized technology was designed and empirical correlations were used to predict the separation efficiency.
• Induction heating system: A new induction heating system for solid particles capable of reaching high temperatures was designed and built. The testing phase is ongoing.
• Biomass: On the basis of the analysis performed in the three target countries (Italy, Spain, Greece) pine wood was identified as the most available and accessible biomass, and was thus selected for the experimental campaign of the PYSOLO process. Furthermore, for the exploitation of the PYSOLO technology 4 species were identified: pine and oaks as forest biomass and olive mill waste and grape pomace as agricultural biomass. Suitability index maps for each selected forest biomass and for the three target countries with the best biomass conditions were also produced through a multi-criteria analysis for different scenarios. Such information will contribute to identifying the most suitable areas for the bio-refinery plants.
In addition, some preliminary studies were also carried out on the whole PYSOLO process: more in detail, the main PYSOLO process flowsheets were defined, together with 2 benchmark reference cases (conventional pyrolysis and solar pyrolysis with molten salts solar tower). Mass and energy balances of the flowsheets were computed, identifying the likely operating conditions of the key plant components. Furthermore, the economic framework and the economic performance indicators were defined and a preliminary economic optimization of the installed solar field size and of the thermal storage capacity was completed. A regulatory review also started, to evaluate the system compliance with reference to existing regulations focusing on Occupational Safety and Health directives, economic regulations, and environmental frameworks, together with a review of incidents involving concentrated solar power technology to compare the safety profile of the PYSOLO technology, highlighting potential advantages of solid particles heat carrier. The accident risk scenarios related to biomass, biochar, and pyrolysis have also been identified. As a preliminary step for the Life Cycle Assessment, the PYSOLO system was disaggregated into several sub-systems (particles heat carrier, infrastructure, pyrolysis process), for which the environmental impacts is being separately assessed.
• Particles Heat Carrier: 6 particles heat carriers (sand, bauxite, biochar, magnesium oxide, silicon carbide and olivine) were selected on the basis of their thermal, mechanical and optical properties and of the related safety information. Several experiments were conducted on such particles heat carrier, identifying bauxite and olivine as the two best candidates for testing with the solar receiver. Moreover, additional analyses have been conducted to assess further properties of the particles heat carrier crucial for the PYSOLO process efficiency, such as density and fluidization velocity, and safety analyses also have started.
• Pyrolysis reactors: the two existing pyrolysis units participating in the project, namely a Fluidised Bed reactor and an Auger reactor, have been adapted to operate with the selected particles heat carrier. The commissioning phase was successfully completed for the first one, whilst it is still ongoing for the second one.
• Particles heat carrier-char separation unit: A batch particles heat carrier-char separation unit based on fludized technology was designed and empirical correlations were used to predict the separation efficiency.
• Induction heating system: A new induction heating system for solid particles capable of reaching high temperatures was designed and built. The testing phase is ongoing.
• Biomass: On the basis of the analysis performed in the three target countries (Italy, Spain, Greece) pine wood was identified as the most available and accessible biomass, and was thus selected for the experimental campaign of the PYSOLO process. Furthermore, for the exploitation of the PYSOLO technology 4 species were identified: pine and oaks as forest biomass and olive mill waste and grape pomace as agricultural biomass. Suitability index maps for each selected forest biomass and for the three target countries with the best biomass conditions were also produced through a multi-criteria analysis for different scenarios. Such information will contribute to identifying the most suitable areas for the bio-refinery plants.
In addition, some preliminary studies were also carried out on the whole PYSOLO process: more in detail, the main PYSOLO process flowsheets were defined, together with 2 benchmark reference cases (conventional pyrolysis and solar pyrolysis with molten salts solar tower). Mass and energy balances of the flowsheets were computed, identifying the likely operating conditions of the key plant components. Furthermore, the economic framework and the economic performance indicators were defined and a preliminary economic optimization of the installed solar field size and of the thermal storage capacity was completed. A regulatory review also started, to evaluate the system compliance with reference to existing regulations focusing on Occupational Safety and Health directives, economic regulations, and environmental frameworks, together with a review of incidents involving concentrated solar power technology to compare the safety profile of the PYSOLO technology, highlighting potential advantages of solid particles heat carrier. The accident risk scenarios related to biomass, biochar, and pyrolysis have also been identified. As a preliminary step for the Life Cycle Assessment, the PYSOLO system was disaggregated into several sub-systems (particles heat carrier, infrastructure, pyrolysis process), for which the environmental impacts is being separately assessed.
Useful preliminary results have been obtained from the activities performed during the initial phase of PYSOLO, as indicated above. At this stage, the results gathered are being employed for internal uses only to support future developing phases of the project, as planned. Consolidated results will be publicly disseminated in the form of open reports and communications as the project evolves. Similarly, impact has been achieved through dissemination and communication activities carried out so far. More specific impacts of the project will arise as more results are available. These will be reported periodically through the envisaged communication and dissemination channels.