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.
