Economic production of monoclinic bismuth vanadate from waste vanadium ions: Process design and cost-benefit analysis

Abstract Carbon black waste generated in Singapore oil refinery contains a high concentration of vanadium (>14000 ppm on dry weight basis). Considering the high market value of the waste vanadium component, in this work, an economic and eco-friendly production strategy of monoclinic bismuth vanadate (BiVO4) has been developed based on vanadium recovery from carbon black waste leachates. The total recovery of vanadium from the carbon black waste can reach 99%. Importantly, the BiVO4 could be utilized as photocatalysts to degrade organic dyes under visible-light irradiation. Further economic analysis on the industrial-scale production of BiVO4 was studied after scaling up the production process and evaluating the profitability associated with operations over a 10-year period. Considering a 30 tons/day processing rate of wet carbon black waste feed, the estimated discounted payback period at 8% discount rate is 1.36 years after plant commissioning.