A value chain for large scale FT production: the case of Pyrolysis oil-char slurry gasifaction

Within the BECOOL project, value chains based on lignocellulosic biomass are developed and investigated biomass growth, harvest, transport, thermochemical conversion and !nally catalytic synthesis of liquid biofuels. Pyrolysis is included in the thermochemical conversion as it can provide a valuable feedstock upgrading step prior to gasification. Slow oxidative pyrolysis can provide both high quality charcoal and heat for the drying of biomass, ideal for decentralized upgrading of biomass before shipment to a centralized conversion plant. Char combined with fast pyrolysis bio-oil can provide a high-density fuel in the form of char/bio-oil slurries. This paper reports on the preparation and characterization of the char/bio-oil as intermediate energy carrier (IBC). The char concentration was varied from 0 to 20 wt% using ground char with a particle size of <100 and 100-250 micron. The increased energy density, low ash content and the rheological properties indicated an optimal weight ratio of 10/90 char/bio-oil for application as feedstock in gasification. Initial gasification experiments of the 10/90 slurry proofed challenging on lab scale due to blockages in the feeding system. However, fluidized bed gasification of the bio-oil at 770°C proofed successful and provided a producer gas at a cold gas efficiency of 81% with 18 g/nm3 of tar at an ER of 0.3 and a H20/C of 0.85