Fast Pyrolysis of Pine Wood: The Influence of Process Parameters On the Quality and the Quantity of the Pyrolysis Oil

The thermal conversion of biomass into fuels and chemicals has been spurred by the interest in sustainable, environmentally friendly energy production. Among the many routes to the thermal conversion of biomass, fast pyrolysis provides a means of producing bio-oil, an intermediate envisioned for the production of fuels and commodity chemicals. In Maine, we have a significant biomass waste generated from the logging and lumber industry that has potential as a biomass feedstock. We have constructed a laboratory scale pyrolysis process that consists of a continuous biomass feeder, a bubbling fluid bed reactor, a hot gas filter, a condenser and an electrostatic precipitator to generate and separate bio-oil from pine sawdust. Process runs have been performed to establish the effects of process parameters such as reactor temperature, residence time, feed rate and moisture content on the product yield. The bio-oil has been characterized for water content, heating value, viscosity, and chemical composition. The hot gas filter, integrated with a cyclone for separating fine char generated during pyrolysis was particularly effective in removing fine particulates from the oil. Initial results on oil viscosity testing indicated that oil produced with the hot gas filter in–line was more stable over a two week period at room temperature when compared with bio-oil generated without the filter.