الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Seaweeds (marine macroalgae) represent a diverse group of photoautotrophic organisms live in sea or brackish water. They are classified based on their pigment constituents into red algae (Rhodophyta), brown algae (Phaeophyta) and green algae (Chlorophyta). They can provide several different types of high-value derivatives which have several applications including nutritional supplements, antioxidants, cosmetics, natural dyes, and renewable biofuels. They have emerged as one of the most promising feedstocks for biogas, biobutanol, bioethanol and biodiesel production. They have several key traits that make them desirable energy source, such as they do not need arable land or freshwater for cultivation and their yields of oil and carbohydrates are higher than those from traditional oilseeds. In addition, seaweeds help in the capture of carbon dioxide from industrial emissions. The present work was intended to throw some light on using seaweeds as feedstock for biofuel production. The first step in the current work was the screening of various strains in four seasons to select the most suitable species with a high lipid and carbohydrates productivity in all seasons as a promising candidate for biodiesel and bioethanol production. The quality of extracted liquid biofuels was determined. The present work also aimed to investigate the performance of sequential bioprocesses for biodiesel and/or bioethanol prod6uction from seaweeds using methylation and fermentation. Moreover, the gross energy output and energy conversion rate using the three studied routes were evaluated.