Modelling airlift photobioreactors for algal bioenergy, using Scenedesmus sp. as the model species

Includes bibliographical references === Rising global energy demands and global warming concerns from fossil derived fuels are two major problems affecting future generations. Bioenergy from algae offers a part solution that is both attractive and sustainable, by supplementing energy demands from a...

Full description

Bibliographic Details
Main Author: Fraser, Murray
Other Authors: Harrison, STL
Format: Dissertation
Language:English
Published: University of Cape Town 2015
Subjects:
Online Access:http://hdl.handle.net/11427/12620
Description
Summary:Includes bibliographical references === Rising global energy demands and global warming concerns from fossil derived fuels are two major problems affecting future generations. Bioenergy from algae offers a part solution that is both attractive and sustainable, by supplementing energy demands from a renewable energy source (the sun) and consuming carbon dioxide in the process. Bioenergy from algae is a proven concept (e.g algal biodiesel), yet the low productivities and high costs of existing processes limit their ability to make a significant contribution. Algae production occurs in specially designed photobioreactors, which are typically light limited. Hence, optimization of light supply to algae is key. A mathematical model of a photobioreactor is useful to aid in the design and optimization process. A model enables the prediction of productivities as a function of changing model inputs and hence allows optima to be predicted. While these are typically validated experimentally, this greatly reduces the number of experiments required, thereby saving cost and time. For this work, the production of algal biodiesel using airlift photobioreactors was used as the case study for the model development. Scenedesmus sp. was chosen as the model species owing to its comparatively high lipid productivity, a desirable trait for the production of biofuels. Although many parameters affect algal growth and lipid productivity, this project focused on one critical parameter, that of light provision.