Valorization of Prosopis Juliflora biochar for supercapacitor application: Techno-economic and lifecycle analysis

Prosopis juliflora (PJ) poses a significant concern to environmental engineers because of its adverse effects on the local communities and environment. The pyrolysis method was employed to recover value-added products from PJ biomass, producing biochar, bio-oil, and pyrogas. A 1:4 biochar-to-KOH ratio produced activated carbon (PJBAC-K4) with a specific surface area of 1140 m2/g and 80% mesopores. The electrode demonstrates a specific capacitance of 288 F/g at 1 A/g. Additionally, the results demonstrate a prolonged lifespan (at least 10,000 charge-discharge cycles), with a retention rate of 91.3% of the initial capacitance. Techno-economic analysis revealed that the net unit production cost of PJBAC-K4 is $18.41 per kg, which comes to around 0.006 cents/F, and the expected payback time is 5.16 years. Sensitivity analysis revealed that process economics is highly vulnerable to utility and raw material prices. The completed life cycle study revealed the environmental benefits of lower global warming potential compared to commercially available activated carbons.