Periodic Reporting for period 2 - HYSOLCHEM (A Hybrid Reactor for Solar CO2 and N2 Conversion Coupled to WasteWater Treatment)
Berichtszeitraum: 2022-07-01 bis 2023-12-31
O2. To develop efficient, low-cost and long-duration anodes for the electro-oxidation of microplastics and other organic pollutants in wastewater. An electrode composed by Ni foam decorated with a Ni-based oxide was selected as candidate to address the oxidation of wastewater/microplastics. The mechanism of the phenol degradation through electrooxidation using NiMnO3 as the active material was elucidated. Furthermore, the stability of the electrodes was improved by a dual approach. First by examining alternative electrode supports (graphite felts provide better performance than nickel foam), and second, by introducing reduced graphene oxide to achieve better electrode stability.
O3. To design and fabricate ion-exchange membranes. Membranes based on sulfonated polyether ether ketone (SPEEK) and polyvinyl alcohol (PVA) showed the most potential as self-supporting membranes. They were optimized in sulfonation and cross-linking degree, obtaining performances better than Nafion 117. The membrane concept was optimized in safety by using a less reactive catalyst and a green, non-hazardous solvent. The PVA membranes show superior fuel retention, but a lack in conductivity. A facile protocol to fabricate commercial competitive hierarchical ion exchange membrane was worked out. These membranes were optimized in mechanical properties by identifying and solving the rolling issue. In the end, the membranes of both concepts have made significant progress towards a successful scale-up.
O4. To determine the reaction mechanisms. Some points have been reached: 1) a liquid flow cell and an electro(photo)chemical flow cell for operando for synchrotron based XPS and NEXFFS measurements has been successfully designed, developed and use as tester of WP materials. 2) A protocol to study thin films photocathodes by TAS in order to determine the charge transfer mechanism has been developed.
O5. To integrate in a solar-powered flow reactor the developed CO2/ photocathodes, waste/microplastic oxidation anodes and ion-exchange membranes for simultaneous water detoxification and CO2/N2 valorisation. The upscaled prototype at TRL5 has already finished, consisting of a versatile pilot with two different cells (Photocathode/PV+EC with dark anode dual configuration and electrochemical cell). The procurement of the different elements has been started and pilot will be finished in April-May 2024
O6. To validate the prototype in a wastewater treatment plant to remove microplastics, urea and organic matter in general from wastewater, converting them from a residue to a fuel. The RP1 work has been focused on two main aspect: 1) to develop and optimise a method to analyse and quantify microplastics (MPs) present on waste water treatment plan (WWTP) based on the use of an optical microscope coupled with an FTIR spectrophotometer; 2) to evaluate the performance of the anode developed so far in the oxidation of pollutants in the prototype designed and built in the Objective 5. The RP2 work has been focused on two main aspects: 1) re-evaluation of the wastewater matrix to check for potential microplastics misidentification; 2) assessment of commercially available anodes for the anodic oxidation of polyethylene nanoplastics ; 3) development and optimisation of a method to analyse and quantify nanoplastics (NPs) by a pyrolyser coupled to a gas chromatograph and mass spectrometer (py-GC/MS).
O7. To study the performance of the developed materials and devices from an environmental, economic and social point of view. Life Cycle Assessment (LCA), social life cycle assessment (S-LCA) and Life cycle costing (LCC) data collection forms have been prepared, distributed among the project partners and compiled. Characterization of the environmental life-cycle profile and economic life-cycle profile of the HYSOLCHEM system and identification of its environmental hotspots across its whole supply chain has been completed. Definition of a representative supply chain of the HYSOLCHEM system and analysis of its geographical location, and environmental and economic benchmarking o with respect to competing technologies/processes have been started.