Recent advances in algal cultivations as feedstock for renewable energy production toward a circular economy

In recent years, algae have emerged as promising feedstocks for renewable bioenergy production. In addition, algae inherently contribute to lowering the earth's carbon footprint among other environmental benefits. Microalgae have been extensively studied for decades for biodiesel production by scientists around the globe. Macroalgae are generally aligned toward biogas production due to its high carbohydrate content. The combination of wastewater grown microalgae (both of various types) provides a sustainable and cost-effective cultivation operation for biofuel production with the simultaneous tertiary treatment of effluent (phycoremediation). Researchers are currently still exploring this trend, as to this day it remains the most favorable approach with the greatest potential of materializing. Nonetheless, there are very many factors (biotic, abiotic, and process parameters) that influence system operations, and optimization of these processes (which encompasses a myriad of components) is crucial to a successful endeavor. Commercialization attempts of bioenergy from algae are still underway, with the end goal of creating, quite simply, an optimized, eco-friendly, and feasible biofuels operation.