(492a) A Mathematical Programming Model for the Integration of Power Plants Involving Chemical Looping Combustion with Algal Systems Under Carbon Policies Analysis

Nowadays, great amounts of electricity are required. In order to satisfy these demands, power generation plants are commonly used despite of the produced CO₂ emissions. Such tendency has led to several problems, for instance the rise in the atmospheric CO₂ concentration that is considered to contribute to the global warming. Therefore, alternatives to generate electric energy or strategies to reduce the emissions must be proposed and developed. This is not a simple task due to the several issues involved such as economic and technical constraints. The chemical looping combustion can be a potential option since it is a novel technology that allows to capture the carbon dioxide with small penalties in thermal efficiency. Also, once the CO₂ is captured, it can be sent to an algal cultivation system for its utilization. A microalgae system consists of different stages to process the algal biomass and produce biofuels. Accounting for this, the present work proposes a mixed-integer linear programming model to find the optimal integration between power plants and algal cultivation systems for the simultaneous production of electric energy and biofuels. Environmental and economic objectives are taken into account including the inherent separation and mitigation of CO₂ by means of the chemical looping combustion and the algal-to-biodiesel process; as well as the sale of electricity, biodiesel, glycerol, ethanol and proteins and the costs associated with the global system. In addition to this, carbon externalities involving distinct economic penalizations or compensations are evaluated in order to identify their impact on the minimization of emissions and maximization of profit. The results of the proposed approach include the optimal configuration for the system at a macroscopic level which consists of the optimum selection of fuel, combustion system, power cycle, technology for each algal system stage, the amount of CO₂ delivered to the algae and other specific conditions (flow rates and variables involved in the process). Furthermore, the solutions obtained through the case study show different scenarios with carbon taxes and bonuses where tradeoffs between the objective functions are observed. We found that the use of carbon bonus based on avoided emissions provides better compromises for the profit and emissions.