Mathematical modeling of thermal decomposition of resins in the process of reversed gasification of plant biomass
https://doi.org/10.30724/1998-9903-2020-22-5-83-93
Abstract
THE PURPOSE. Of this work is to estimate parameters for a sufficiently comlete thermal decomposition of tarry products of the fixed-bed gasification of wood fuel. METHODS. To this end, mathematical models are used in different statements: the decomposition of the tar is considered in the approximations of one- and two-reaction kinetic scheme; to assess the influence of the bed height and temperature, the convection-diffusionreaction equation with a given temperature distribution along the length of the reaction zone is used; the temperature of the gasification process is estimated from experimental data and thermodynamic calculations. Along with the numerical model of the decomposition of the tar, a simplified analytical expression (for large Peclet numbers) is applied, the limits of its applicability are determined. RESULTS. Of calculations show that the efficiency of the airblown gasification of wood is determined by the temperature level of the oxidation stage: in the range of modes in which the optimal values of efficiency are achieved, the conversion of tarry products does not proceed sufficiently completely due to kinetic limitations; an increase in the specific consumption of the oxidizer leads to a decrease in efficiency due to stoichiometric reasons. CONCLUSION. Physicochemical limitations do not allow reaching the limiting values of gasification efficiency, shifting the optimal modes towards increasing the specific air consumption; a decrease in the yield of tar requires, first of all, changes in the thermal modes of gasification (for example, external heating or an increase in the oxygen concentration).
Supporting agencies: The work is performed as a part of scientific project III.17.1.2 of Fundamental Research Program of Siberian Branch of Russian Academy of Scinces (reg. No. АААА-А17-117030310448-0) using equipment of the multi -access scientific center "High Temperature Circuit".
About the Author
I. G. Donskoy
Melentiev Energy Systems Institute of Siberian Branch of Russian Academy of Sciences
Russian Federation
Russian Federation
Igor G. Donskoy – Senior Researcher
Irkutsk
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For citations:
Donskoy I.G. Mathematical modeling of thermal decomposition of resins in the process of reversed gasification of plant biomass. Power engineering: research, equipment, technology. 2020;22(5):83-93. (In Russ.) https://doi.org/10.30724/1998-9903-2020-22-5-83-93
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