Susan T. L. Harrison, Christine Richardson, and Melinda J. Griffiths

Centre for Bioprocess Engineering Research Department of Chemical Engineering University of Cape Town, South Africa

CONTENTS

9.1 Microalgae for Bioenergy…………………………………………………………………………. 114

9.2 Analytical Tools for Assessing Environmental Sustainability…………………… 115

9.3 Environmental Sustainability of Microalgal Processes…………………………….. 117

9.3.1 Overview of Environmental Assessment of Algal Biodiesel…………. 117

9.3.2 Algal Bioreactors………………………………………………………………………….. 123

9.3.3 Nutrient Provision for Microalgal Culture…………………………………….. 125

9.3.4 Biomass Recovery……………………………………………………………………….. 126

9.3.5 Biomass Drying and Conversion………………………………………………….. 126

9.3.6 Impact of Species Selection…………………………………………………………. 127

9.3.7 The Biorefinery…………………………………………………………………………….. 127

9.4 Economic Considerations of Microalgal Production………………………………… 128

9.4.1 Cost of Algal Biomass and Algal Oil…………………………………………….. 128

9.4.2 Key Process Components Contributing to Cost……………………………. 132

9.4.3 Potential Earnings from By-Products…………………………………………… 132

9.5 Key Focal Areas for Improving Environmental and Economic

Sustainability……………………………………………………………………………………………. 133

References…………………………………………………………………………………………………………. 134