Fast pyrolysis of biomass into fuels and chemicals

Two first commercial size pyrolysis plants for renewable energy production in the world have been commissioned 2014-15: one in Joensuu, Finland, by Fortum and Valmet, and the other in Hengelo, the Netherlands by BTG-BTL/EMPYRO [1,2]. The aim of both of these installations is to produce high-quality renewable heating bio-oil from woody biomass, e.g. forest residues. Valmet has integrated the bio-oil demonstration plant to an existing 200 MWth Fortum combined heat and power (CHP) plant in Joensuu, Finland [13]. The nominal output of the pyrolysis plant is 30 MW of bio-oil with a planned annual output of 50,000 tons which equals to 210 GWh of energy. The demonstration plant will utilize 225,000 solid cubic meters of forest residue and sawdust annually. At the moment the main market for the fast pyrolysis oil is to replace heavy fuel oil (HFO). Standardisation towards boiler fuels under CEN is going-on [3]. The same technology may also be developed further for the production of transportation fuels and chemicals. One of the challenges in bio-oil storage and use is to avoid the phase-separation into aqueous and lignin-rich phases [4]. This phenomena could be applied as advantage for chemical production. If a wet feedstock is used for thermal fast pyrolysis, a spontaneous phase-separation of the aqueous and lignin-derived phases is obtained (Figure 1). Figure 1. Fast pyrolysis as a fractionation process for fuels and chemicals. [15].