Opportunities Surrounding the Use of Sargassum Biomass as Precursor of Biogas, Bioethanol, and Biodiesel Production

Abstract

Climate change (along with other factors) has caused an increase in the proliferation of brown algal mats floating freely along the Atlantic Ocean since 2011. These brown algae mats are composed of sea plants from the Sargassum genus. The gargantuan agglomeration of biomass flows alongside currents and lands in beaches belonging to the Eastern coasts of the Mexican Caribbean and several other countries in the region. These events, dubbed golden tides, harm the local economy and environment. Current elimination approaches involve the mechanical harvesting of the Sargassum and ultimate landfill disposal. However, explorations into the commercial application of other brown algae have elucidated the potential of Sargassum as a feedstock for valorization. This review informs the trends, challenges, and opportunities presented by the coastal invasion of this biomass. Primarily, the potential use of this material is as a precursor in biorefineries where multiple value-added products are generated concurrent with the ultimate production of biofuels.

Sea‐weeding: Manual removal of macroalgae facilitates rapid coral recovery

“…Disposal of the by‐product algae can create opportunities for circular economies and carbon sequestration. In the Caribbean, episodic influxes of pelagic Sargassum are posing a management issue (Smetacek & Zingone, 2013), with a current focus on harnessing potential economic benefits (Davis et al, 2021; Milledge & Harvey, 2016), including use as biofuels (Orozco‐González et al, 2022), bioplastics (Lim et al, 2021), agricultural fertilisers (Sembera et al, 2018) or in other ecosystem restoration programs (e.g. dune plants (Williams & Feagin, 2010), mangroves (Trench et al, 2022)).…”

Brown algae invasions and bloom events need routine monitoring for effective adaptation

“…the nearshore or have made land, the most common management approach is in situ removal (in ocean or beaches) [67,74,[77][78][79][80]. Mechanical removal has been used, although it is increasingly criticised as this can damage coastal habitats leading to erosion, dune destruction or loss of critical nutrients [81,82].…”

Escape from Sargasso Sea: Tremendous Sargassum Blooms Challenge Caribbean and Atlantic Communities

“…Better solutions are urgently needed, and proposed options include using Sargassum as a raw material for commercial products such as animal feed, 35 cosmetics, 36 drugs, 37 plastics, 38 and biogas. 39 In many places, Sargassum has long been used to supplement nutrient-deficient soils. 40 The challenge for all these applications is to ensure that arsenic and other toxic constituents do not pose unacceptable risks, according to Devault, who is first author on an extensive review of Sargassum contamination and its consequences for downstream uses.…”