Prospects of Multiproduct Algal Biorefineries Involving Cascading Processing of the Biomass Employing a Zero-Waste Approach

Purpose of Review Increasing environmental problems demand mitigation solutions to fulfill sustainability development goals. Microalgae offer possibility of valorizing the CO2 and wastewater-derived nutrients to produce numerous industrial bioproducts. However, developing self-sustained systems for the complete valorization of algal biomass into valuable biobased products is challenging. Currently, sustainable algal processing faces several challenges including costly cultivation, difficult harvesting, and incomplete biomass valorization. This review assessed the prospects of emerging technologies focusing on the integrated approaches for sustainable algal biorefinery development ensuring the sustainability of environment-water-energy nexus. Recent Findings Evaluation of various upstream, midstream, and downstream processing technologies provided insights into the processing issues. In upstream processing, high-rate algal ponds and integrated carbon capture and transformation technologies offer waste valorization into eco-friendly algal production. A brief comparison of harvesting technologies mainly focusing on chemical and biological flocculation has shown that integrating physical and biological harvesting methods are more reliable and efficient. Overview of downstream processing has indicated that biomass processing in a cascading manner offers the complete biomass valorization in a zero-waste paradigm. Summary Assessment of cultivation-to-production technologies highlighted that zero-waste algal biorefinery has the potential to become reality by integrating the industry 4.0 and phenomics approaches with eco-friendly cultivation, harvesting, and processing technologies. Hybrid methods based on integrated cascading processing offer complete biomass valorization in a circular bioeconomy paradigm.

Automated summary

This review assesses the prospects of emerging technologies for sustainable algal biorefinery development, with a focus on the processing issues. The findings show that high-rate algal ponds and integrated carbon capture and transformation technologies offer the possibility of waste valorization into eco-friendly algal production. Integrating physical and biological harvesting methods proves to be more reliable and efficient. Biomass processing in a cascading manner offers complete biomass valorization in a zero-waste paradigm. The integration of industry 4.0 and phenomics approaches with eco-friendly cultivation, harvesting, and processing technologies has the potential to realize a zero-waste algal biorefinery.