Process Design and Evaluation Framework of the Algal Biomass Co-firing Plant to set Target RD Parameters

Abstract

A generalized process model of a microalgal biomass co-firing and an evaluation framework for feasibility assessment was developed. The process model allows for the representation of a diverse array of algal co-firing scenarios by the characterization the parameters at each step of algal cultivation and processing. As the flue gas composition changes with the introduction of algal biomass fuel, the closed loop iteratively solves the model until the change in flue gas composition falls under a set tolerance. Evaluation of a 1 GW PC power plant with 10% co-firing showed that despite a reduction in specific global warming emissions from 282.9 kg CO2-eq/GJe to 254.0 kg CO2-eq/GJe, LCOE rose from 36.6/GJe to 38.6/GJe resulting in a baseline avoidance cost of 69/ton CO2. Due to the reliance on preliminary experimental data for parametric inputs, uncertainty was propagated with Monte Carlo simulations. The Monte Carlo distribution ranges for sustainability metrics revealed wide ranges with varying degrees of feasibility. Key RD parameters were identified by performing sensitivity analysis. Monte Carlo results accounting for uncertainty can be used to set targets for RD parameters such as algal productivity and biomass LHV. Conversely, the feasibility for a given algal co-firing plant can be assessed under the same framework.