In recent years, the algal biorefinery is seen as a promising alternative to fossil derived products that reduce the environmental pollution, product costs and support circular bioeconomy. However, the upstream algal cultivation and downstream processing are the energy intensive processes and are considered as bottlenecks in promoting algal biorefinery. Improving the biomass productivity and bioproduct developments are still underway, while a number of novel bioprocess and bio-reactor engineering technologies were developed recently. Therefore, this book provides extensive knowledge of microalgae refineries. This book is divided into two volumes (Vol. I & Vol. II), which presents complete coverage of microalgae refineries. Therefore, Vol. I offers complete coverage of the algal bioproducts process, including biotechnological applications and environmental effects of microalgae cultivation. While Vol. II, provides various industrial applications and future prospects of algal biorefinery for sustainable development of circular bioeconomy. With contributions from world experts, focuses on microalgae from an organism perspective to deliver a complete picture from evolution to bioproducts. The edited book provides a concise introduction to the science, biology, technology, and application of algae. It covers downstream and upstream steps of the algal refinery for the production of algal biomass, which has several social benefits.