Total Site Synthesis: Selection of Processes to Save Energy and Boost Cogeneration
K. Pyrgakis, A. Kokossis
Computer Aided Chemical Engineering, Volume 48, pp. 1345-1350, 2020
Total Site integration; Turbine Hardware Model; Cogeneration; Utility levels optimization; Biorefineries
The design of biorefineries is challenged by new chemistries that need to be evaluated and properly integrated across industrial sites. Process and energy integration are necessary to maximize performance and sustainability margins. In a previous work, the authors addressed the combinatorial nature of the biorefinery synthesis and integration problem (Pyrgakis and Kokossis, 2019) introducing systems and an optimization model (MILP) to systematically screen and integrate value chain paths highlighting energy promising and high profitable biorefinery solutions. This work presents an updated version of the previous model to simultaneously address cogeneration and utility levels optimization. The previous version is also combined with cogeneration models to select processes that benefit energy savings and electricity production, as necessary co-product to offset price volatilities of upcoming biochemicals. New strategies are proposed to improve accuracy of Turbine Hardware Model (THM), in light of variable processes and utility levels, and revise regression parameters of turbine modules and predictions of input specific heat load. The optimization model (MILP) was used to examine 20 candidate chemistries and revealed biorefinery solutions with high energy savings (10.5%), shaft work production (25.6 MW) and profitability margins (9.3 M€/yr).