Modelling and optimization of microalgae growth and product formation in outdoor tubular photobioreactors

Introduction

The Algae2Future project wants to use the microalgae biomass in the production of bread, beer and fish feed. The composition of microalgae biomass is dependent on cultivation conditions, such as nutrient availability. Main groups of components in microalgae cells are the carbohydrates, lipids and proteins. Each of these components is of interest for use in food and feed products. The biomass must have a certain composition to be suitable for these food and feed applications. For instance, for application in fish feed, the biomass must have a large lipid content.

Aim

The aim of this PhD project is to develop a mathematical model which can predict the formation of different biomass components for several microalgae strains. This model will be used to optimize the cultivation process in an outdoor photobioreactor. The modelling of the formation of biomass components will be based on literature and already available experimental data. Subsequently, the component formation will be studied in lab scale photobioreactors.

Approach

The outdoor reactor of interest is a vertical tubular photobioreactor. To be able to model this outdoor system, the tubular reactor will be characterized based on its physical-chemical properties. Properties are for instance the gas transfer coefficient and light intensity along the tubes. These properties will be used to adapt the model. However, the model can only be used to optimize the outdoor process once it is validated. Independent experimental data sets are needed to perform this validation of the model. To obtain these data sets, a scale-down approach is used. This includes the development of a lab scale photobioreactor, that is able to simulate outdoor conditions and properties of the outdoor system. The conditions experienced by the cells in the outdoor reactor vary over time and position in the reactor. These conditions will be simulated in the down-scale reactor. In the end, the validated model will be used for process optimization.

Thesis project

If you would like to know more about my project or want to know more about BSc and MSc thesis possibilities, please feel free to contact Renske Rinzema.