Economic Multi-Objective Dynamic Optimization (EMODO) as a Decision-Making tool in Biomethanation Process

Abstract

In biological methanation, the methane produced by anaerobic digestion (AD) is upgraded with the addition of syngas. The successful implementation of biomethanation requires the optimization of the production to be competitive in economic terms against chemical processes. Optimization is an arduous task, especially when it is desired to optimize multiple objectives that can be conflicting, such as yields, productivities, process times, and profit gains, among others. This work aims to implement an Economic Multi-Objective Dynamic Optimization (EMODO) approach as a decision-making tool for adequately operating the biomethanation process. The proposed EMODO strategy was based on a previously developed dynamic model for biomethanation. This strategy effectively optimized the ???????? and the ???????????? ???????????? by manipulating the inlet flow rates of gas ( ?? ?????? ???? ) and liquid ( ?? ?????? ???? ). The strategy also highlights the conflicting behavior of economic objectives and the dependence on substrates. The dynamic optimization improves the response time of the model smoothing the transitions between stages and achieving well adaptation to disturbances regarding the cost of the substrates and the selling prices of the products.