Extraction techniques in sustainable biofuel production: A concise review

The concerns of fossil fuel depletion and environmental issues have increased general interest in studies on the development of sustainable biofuel. In the biofuel production process, the extraction technique is a key technology with respect to energy consumption and product value. In this review, recent advances related to the extraction process in biofuel production are discussed. The major extraction methods were classified as conventional solvent extraction (CSE), physical-supported solvent extraction (PSSE), supercritical fluid extraction (SFE), and novel extractions. We address each of these classified extraction methods in turn both in relation to the feedstock utilized in the different biofuel generation methods and to the targeted biofuels. Our objective is to provide a concise, timely, and comprehensive review on various extraction methods applied/studied regarding biofuel production, their principles and advantages/limitations, and recent case studies. In particular, the classified extraction methods in the production of third-generation algal biofuel were intensively evaluated. Consequently, the concept of free from drying and cell disruption (FDC) routes was advanced herein as it may possess the potential to reduce the requirement for input energy during the production of algae biofuels. •Enhance understanding of the extraction process and biofuel development potential•Existing multifarious extraction techniques were simplified, arranged, and assessed•Biofuel feedstock relationships to classified extraction techniques were confirmed•The concept of free from drying and cell disruption (FDC) routes was advanced