Deliverable 2.8 - Report on process
The deliverable 2.8 “Report on process integration” is the result of activities undertaken in Task 2.5, mostly related to the last two years of the project (months 18-33). Its objectives consist of:
- Optimization of the whole biorefinery technology chain in order to maximize water and energy savings and minimize the production of residual waste to be disposed of. The optimization is mostly related to the reuse of the solid-rich stream, which is produced in the solid/liquid separation stages for the refining of the fermented stream, and the liquid supernatant, which is produced from the solid/liquid separation after the polyhydroxyalkanoates (PHAs) accumulation stage.
- Testing of “conventional ways” such as anaerobic co-digestion (ACoD) for the reuse of the solid-rich stream from the centrifuge (solid cake, SC) and the retained phase from the membrane (MRP), after mixing with waste activated sludge (WAS). The process was tested under both mesophilic (37°C) and thermophilic (55°C) conditions with hydraulic retention time (HRT) ranging from 15 to 20 days and organic loading rate (OLR) ranging from 2.0 to 3.5 kg VS/m3 d.
- Characterization of the liquid supernatant from the solid/liquid separation after PHA accumulation and suitability assessment for its reuse in the PHA selection reactor.
- Assessment of a complete mass and energy balance of the whole platform and data analysis to be delivered to WP1 and WP5 partners, which were in charge of environmental assessment and economic assessment respectively.