Assessing antifouling coatings in microalgal photobioreactors through LCA

Biofouling poses a critical challenge to scaling up microalgal biomass production, significantly reducing productivity,
increasing costs, and impacting environmental sustainability. This study evaluates the feasibility of an
amphiphilic antifouling coating in closed photobioreactors (AFC-PBRs) through life cycle assessment (LCA) and
economic evaluation. Coated systems demonstrated superior performance, with coated tubular PBRs (CT-PBR)
achieving a 32 % increase in productivity and a 71.4 % reduction in global warming potential compared to
noncoated systems. Antifouling coatings reduced biofouling effects by limiting cell adhesion, thus enhancing
biomass production and extending the productive period. Coatings showed minimal influence on toxicity-related
impact categories, and their use proved both environmentally sustainable and economically viable, with tubular
PBRs (T-PBR) outperforming flat panel PBRs (FP-PBR) in coated scenarios. Electricity was the dominant environmental
contributor in all systems, accounting for more than 80 % of the environmental impacts, emphasizing
the need for energy-efficient operational practices and integration of renewable energy. Biofouling management
in closed photobioreactors remained costly in non-coated systems, with biomass production costs being 1.2 and
3.6 times higher in flat panels and tubular PBRs, respectively, due to cleaning stoppages and reduced productivity.
This study addresses a key research gap by presenting, for the first time, a life cycle and economic analysis
of standard versus newly coated photobioreactors, providing an environmental perspective on coating technologies
that has not previously been examined through LCA.