Recent advances in chemical, thermochemical, and biochemical processing of algae

Considering today’s challenges regarding climate change and rapid depletion of conventional fossil fuels, algae-based fuels seem to be promising and sustainable alternatives via various conversion methods. Despite growing interest in algal-based applications, the full potential of algal biomass as a versatile and sustainable feedstock remains underutilized as it is abundantly available when compared to terrestrial plants. The biomass from algae can be used for producing biofuels and chemicals as they are high in proteins, carbs, and lipids. Producing fuel from algae remains commercially challenging because cultivation and harvesting demand significant energy and incur high costs. At the pilot scale, these challenges often create major bottlenecks in converting algae into biofuels or biochemicals. Adopting an integrated algae biorefinery approach can help lower both energy use and expenses. Such systems enable the simultaneous recovery of biopolymers, biochemicals, biofuels, and biofertilizers with better cost-effectiveness than traditional processes. Ultimately, making algae-based production more economically feasible strengthens its potential role in advancing a green economy. This review articulates recent advances in chemical, thermochemical, and biochemical conversion processes of algae-based biomass. Chemical transesterification, thermochemical processes such as gasification, pyrolysis, and hydrothermal treatments, and biochemical conversion methods like fermentation, anaerobic digestion, and photobiological techniques are discussed in this review. For biochemical conversion methods such as fermentation, anaerobic digestion and photobiological techniques are mentioned towards the end of this review.