Techno-economic evaluation of biofuel production from black liquor by hydrothermal liquefaction

Kraft black liquor, a side product of pulp and paper industry, is available in huge amounts at pulp mills in northern countries. Conversion of black liquor into transportation fuel via hydrothermal liquefaction is a promising pathway, which has been demonstrated in the laboratory scale in the LIGNOHTL project (2013-17)1. In this poster presentation, the techno-economic performance estimate of biocrude production from black liquor based on the measured laboratory scale yields is presented and the importance of different variables on the profitability is illustrated. According to the results, the cost of transportation fuels production from black liquor is roughly 1000 €/ton with mature production technology hence similar range than i.e. for Fischer-Tropsch or Methanol to Gasoline routes from lignocellulosic biomass. However, both the production technology and the profitability could be significantly improved if the organic losses particularly in the washing of the HTL crude product are reduced. Because the process has only been demonstrated in laboratory scale, the assumptions behind the techno-economic analysis particularly product yields should be verified in bigger scale and in continuous reactors.