Comparative Analysis of Thermally Enhanced Biobased Phase Change Materials: A Critical Review of Factors Governing Thermal Conductivity Enhancement

• TE-BPCMs are presented as a green alternative to paraffin-based PCM. • Effect of enhancer’s morphology (OD, 1D, 2D, 3D), composition (metallic, carbon-based, hybrid) and integration technique (foams, fins, dispersion) on TCE is analyzed. • Comparative dataset of enhancers with maximum TCE ratio and lower LH loss is presented. • BPCM from families of fatty acids, alcohol, esters, fats and oils with maximum enhancement potential are pinpointed. • Biomass derived additives are presented as potential next-generation green enhancers. Phase change materials (PCM) are promising solution for thermal energy storage (TES), yet widespread utilization of non-biodegradable paraffinic materials negates sustainable development goals. Conversely, biobased PCM (BPCM) are green TES materials though limited by low thermal conductivity (TC). Numerous strategies are reported to increase their TC; however, literature reveals divergence in efficacy of enhancers utilized. This study focuses on comparative assessment of these techniques by critically analyzing the factors affecting enhancement ratio mainly additive’s morphology (0D, 1D, 2D, 3D), composition (metallic, carbon-based, hybrid), pristine TC, weight percent concentration and employment methodology (dispersion, soaking in preformed frameworks, fins, aerogels). BPCMs were selected from families of fatty acids, alcohol and esters. Analysis revealed high enhancement ratios were found for preformed frameworks delivering TCE ratio of 30-90 folds. Amongst distinct nanostructures, 3D materials outperformed delivering TCE ratio of 240-1300 percent. Minimum reduction in latent heat was observed for 0D and 1D materials with 1-3 percent decline only. Amongst the BPCM families investigated palmitic acid, erythritol and polyethylene glycol revealed maximum TCE ratio. In hybrid configurations, expanded perlite formed effective composites with silicon carbide and expanded graphite delivering TCE of 419 and 402 percent respectively. Alongside conventional enhancers, biobased additives revealed TCE ratio of 150-280 percent showcasing a green alternative to metallic and carbon-based enhancers. The findings of this critical analysis will serve as foundation dataset for future studies on TE-BPCMs promoting sustainability in TES field.