Global Trends and Prospects of Black Liquor as Bioenergy

Abstract

Black liquor from kraft pulp mills is a valuable bioresource that can be used to generate renewable energy and to recover cooking chemicals. Consequently, black liquor must not be regarded as a nonrecyclable waste. Kraft pulp mills are known to generate 1.4 to 1.5 tons of black liquor (measured as dry content) per ton of pulp, representing a potential energy source ranging between 250 MW and 500 MW. The effective heating value of black liquor is relatively low at 12 MJ/kg to 13 MJ/kg, compared to fossil fuels. The combustion of black liquor is well controlled according to strict regulations, in order to meet RPS and to obtain renewable energy credit (REC) that equal the percentage requirement for electricity sold. To date, however, Korea has seen no REC benefits in relation to black liquor bioenergy generation, though, in most other countries that produce kraft pulp, surplus renewable energy transactions benefit from black liquor combustion. Only one company produces kraft pulp in Korea, contributing to the consistent growth of the domestic paper industry. As such, it is strongly suggested that the relevant ministries in Korea consider black liquor a valuable resource for generating renewable energy.