Modeling fast biomass pyrolysis in a gas–solid vortex reactor

A CFD study of biomass pyrolysis in a downer reactor equipped with a novel gas–solid separator-II thermochemical performance and products

“…[10]) (iii) multicomponent reactions model (e.g. [20,23,26]). The first option is the simplest and assumes that the biomass is thermally degraded to a final product of char, condensable vapour (bio-oil) and a permanent gas (NCG) and this can be represented by a single first order reaction and one global rate constant.…”

“…The study concluded that such a modelling approach is especially suitable for the design of fast pyrolysis reactors and their optimization to meet economic scales required for distributed or satellite units. Ashcraft et al [23] modelled a gassolid vortex reactor for assessing the potential of the centrifugal fluidization reactor technology and exploring its process intensification abilities using Eulerian-Eulerian approach with multi-component, multi-stages kinetics model. Xiong et al [24] investigated the effects of operating conditions on biomass fast pyrolysis in bubbling fluidized bed using Eulerian-Eulerian approach with Shafizadeh−Chin decomposition model [9], the prediction was found to be in good agreement with experimental data.…”

Classification and Separation of Granules in Vortex Granulators

“…The results of calculations are confi rmed by experimental investigations performed on a prototype of a suspended-layer vortex granulator. The optimum design of the work space of a suspended-layer vortex granulator as a function of the required fractional composition of the granulated product may be determined on the basis of results of theoretical and experimental investigations.Swirling of fl ows is one of the most effi cient methods of intensifying heat and mass exchange processes in chemical engineering [1][2][3].Through the use of vortex fl ows, it becomes possible to achieve stabilization of the hydrodynamic conditions in an apparatus and to equalize the temperature inside the apparatus.The introduction of suspended-layer vortex granulators into the technology employed in producing mineral fertilizers, granules with special properties, or multilayer granules has made it possible to raise the specifi c output of granulation plants and increase the degree of monodispersivity of the fi nished product, and to also realize production effi ciency [4].The creation of multifunctional apparatuses that can achieve several processes in a single work cycle (for example, granulation and cooling, granulation and drying, granulation and classifi cation) [5] represents a promising direction in the development of the technology of granulation.Granulators with constant cross-sectional area do not fully assure realization of processes of classifi cation and separation in view of the fact that in these types of apparatuses the ascending (fl ow) component of the total velocity of the gas fl ow is constant and equal to the working rate of suspension of particles of a given dimension (polydispersed system of narrow fractional composition). The value of the working rate of suspension for suspended-layer apparatuses is given by…”

Investigation of the kinetic laws affecting the organic suspension granulation in the fluidized bed

“…Drying process in the mentioned apparatuses using the active hydrodynamic mode, which provides an increase in the relative velocity of the interacting phases, provides the intensification of the process without reducing the economic efficiency of the apparatus. Other advantages of the active hydrodynamic mode are as follows [12,13]:…”