Economic potential of black liquor electrolysis as a treatment option for small agro-based mills

Abstract

An economic simulation was performed to estimate potential costs and earnings associated with black liquor electrolysis for small agro-based paper mills. The results suggest that investing in low-potential black liquor electrolysis should give a payback of 0.6-4.2 years. Realistically, a payback period of less than 1.5 years is possible and would make economic sense. For high-potential black liquor electrolysis, the simulated payback period is 0.7 years in the best economic scenario. Under more realistic economic conditions, breakeven should be achieved within 2 years. Even with a lower selling price for hydrogen and higher electricity prices, a payback period less than 3 years could be possible. These are good propositions given the immense environmental benefits of the process. For low and high potential electrolysis the capital cost of the electrolyzer and the hydrogen selling price are the two most important economic indices affecting payback. Electricity price is expected to have a somewhat moderate influence.