(698d) Design and Development of Integrated Biorefinery Paths

Process integration has a pivotal and critical role in the development of biorefineries. The general view is increasingly supported by results and analysis that prove the significance of this technology in future developments. The design and the synthesis of biorefineries is a particularly challenging and complex problem. This is because it has to cope with large, unknown product portfolios arising from different chemical itineraries and processing paths, while dealing with alternative processes that have to be integrated. In all cases, the designs must match maximum efficiencies in the use of materials and energy, assessing uncertainties in processing and economic parameters that may affect the selected designs and the level of integration.

To cope with the challenges, the paper outlines an approach that mobilizes a complete and powerful list of systems methods in process synthesis and integration, optimization and modelling. At a conceptual level, process synthesis determines process and products to use, enabling a systematic screening with a simultaneous approach and the use of optimization. Process integration, integrates for maximum efficiency in raw materials and energy, as well as for a maximum performance against environmental targets. Process flowsheeting validates with process simulation and enables improvements with parametric optimization. The coordinated use of the methods constitutes a significant advancement in the state of the art, currently deploying case-by-case analysis (flowsheeting) using commercial simulators (NREL work on bioethanol production; 2012).   

The work is applied both to lignocellulosic and oleochemical biorefineries, also in emerging algo-biorefineries. Its application has scoped paths of 70-odd chemicals that include basic intermediates (sugars, lignin, ethylene, oils), bulk chemicals (ethanol, butanol, propanol, isopropanol), bio-based polymers (PVC, resins, polyamides, PEIF, polyacrylates, PUs), and a wide range of chemicals (xylitol, xylonic acid, itaconic acid, sorbitol, isosorbide, hydrogel etc). Other than developing and scoping integrated paths for the plant, the analysis reduces energy by 70% and water use by 50-60%. The work is further integrated with LCA calculations with results explaining that, unless fully integrated, the biorefinery is not sustainable, actually not even feasible. Instead, fully integrated biorefineries remain viable, operational and offer a strong promise to the development of sustainable industries based on renewables.