(125a) A Multi-Objective Approach for the Integrated Design of Flexible Algae Biorefineries

The merits of microalgae as an alternative source of biomass are well established over the years, especially because of their versatility in terms of products. This potential in addition to the utilization of carbon dioxide, which microalgae need for their growth, render the development of a large-scale application extremely promising either as a standalone venture or in integration with other plants. Specifically, the co-production of specialty chemicals from microalgae is gaining ground as the related markets expand and profit margins grow. A plethora of microalgae has been studied and researched, especially for applications in the pharmaceutical, nutraceutical and cosmetic sector.

The work addresses current issues in algo-biorefinery systems following a multi-layer methodology based on optimization, design and knowledge engineering. The synthesis of value chains is generic and demonstrated in the D-Factory project (FP7 collaborative project, which aims at developing a commercial scale biorefinery process) against a background of 15 products and 12 technologies. By employing mathematical modeling, superstructures of potential processing paths and product portfolios are constructed according to customized constraints. The approach offers high-capacity screening with featuring techno-economic, environmental, market and business-related criteria. The work hosts models of different scales, enables bounds on the number of options to screen and delivers the best set of solutions according to each different criterion.

Further integration of synthesis with process design is also important. Scaling up algal biorefineries is challenging especially due to volatile microalgae productivities (location, environmental conditions, seasonality etc.). One is interested in the design of flexible plants that adjust production without significant reconstruction of the plant. Feasible options are investigated in strong interactions with real-life applications that include studies of stand-alone as well as integrated processes. Conceptual and commercial tools are employed in order to fathom the overall biorefinery plant. Efficiency targets are established resulting in energy, water and subsequent cost savings. The economic potential of algae biorefineries is highlighted following the assessment of potential investments which vary in terms of processes and product portfolios.