MODELLING MICROALGAE GROWTH WITH THE BREAKAGE EQUATION

摘要

Biofuels such as biodiesel and bioethanol, from microalgae are considered as one of the alternative fuelrnsources, which can replace petroleum. Therefore, a number of kinetic studies have been previously carried out to modelrnthe overall mass growth rate of microalgae. However, these studies failed to address more fundamental aspects such asrnmicroalgae population growth. The cell growth of a single-cell microalga is divided into four stages – “growing”,rn“ripening”, “maturing” and “division”. It has been found out that microalgae growth rate varies at different stages. Inrnorder to address such problems, a novel growth model based on the breakage equation has been initially developedrnuntil the stationary phase of the microalgae growth cycle. The breakage equation is widely used to model crystallizationrnprocesses for representing size and population growth. In this paper, the model has been further developed to representrnthe entire lifecycle of microalgae that is, including the death phase of the growth cycle. The parameters obtained byrnusing this model are specific to Chlorella vulgaris. The newly developed model is able to determine the population sizerndistribution and the number of cells at a specific time. The model has been verified by experimental data by taking thernmeasurements of mass concentration, number of cells, and size distribution at specified operating conditions.