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The velocity of nearly spherical mono-sized PVC powder in a cold-flow rotating cone reactor (top angle π/3 rad, height 0.43 m) was measured under variation of the particle diameter (140 –780 μm) and the cone rotational speed (up to 1800 rpm). Derived residence times for these particles vary from 0.05 to 0.3 second. The gas velocity distribution near the cone wall appeared to have a considerable influence on the velocity of particles smaller than 200 μm. Next to the experimental work a mathematical model is presented, using a single-particle description and a gas-flow description near the wall according to the universal velocity profile [1]. The conversion of biomass can be calculated by combining the hydrodynamic model together with a proper heat transfer and pyrolysis model. Particles smaller than 200 μm may pyrolyse completely in the present rotating cone flash pyrolysis reactor.

Analysis and characterisation of liquids from fast pyrolysis processes is an important area of research. Data on the physical and chemical properties of the liquids may give important indications about process parameters, quality, toxicity and stability of the pyrolysis liquids. Based on the growing interest in the utilisation of pyrolysis liquids as fuel for heat and power production as well as a source for chemicals, several analytical methods have been applied and modified to meet the special requirements of pyrolysis liquids. This paper will describe new achievements and developments in the physical and chemical characterisation of pyrolysis liquids. Two international working groups, Pyrolysis Network for Europe (PyNE) and the IEA activity on pyrolysis (PyRA) are currently active in reviewing, assessing, harmonising and developing standard procedures for pyrolysis liquids analysis. These activities will be presented and discussed.

Liquid-phase thermochemical processing of tall oil soap has been experimentally investigated. The organic matter of tall oil soap, which is a by-product of kraft pulping, originates mainly from wood extractives. Conventional processing of tall oil soap involves acidulation to yield crude tall oil and subsequent distillation of the oil at centralised refineries. Because tall oil originating from birch wood is far less valuable than that from pine, there is an economic incentive in the Nordic countries to develop alternative conversion processes for the tall oil soap produced at pulp mills where birch is widely used as feedstock.

The drying and the pyrolysis section of an updraft biomass gasifier is considered by using a numerical model. The drying and the pyrolysis usually occur simultaneously inside wood particles, since the particle size used in gasifiers is quite large. The effect of different parameters such as wood moisture content, particle size, gas flow velocity and gas and wood mass flow rates on the dimensions of the drying and pyrolysis section and on the gas outlet temperature is examined by model calculations.