Calculation of Pyrolysis Zone in Installation of Activated Carbon Production
Activated carbon can be obtained in a variety of ways. The most promising in terms of resource conservation and economic benefits is the method of producing activated carbon from organic waste. The production of activated carbon by this method is based on the process of pyrogenetic decomposition of pre-crushed and dried waste. As a result of thermochemical processing, activated carbon and pyrolysis gas are formed. Conductive waste pyrolysis is a high-temperature process that runs without oxygen. The temperature regimes of the pyrolysis process are described by the differential heat transfer equation. The calculation of the specific masses of the waste, coal and steam-gas mixture formed during the decomposition is carried out according to the differential equations of mass transfer by complicated ongoing chemical reactions. The hardware design of the pyrolysis process is a set of complex design and technological solutions. When developing equipment designed for the pyrolysis of crushed waste, it is necessary to carry out calculations related to the optimization of the hardware design and operating parameters of the process of thermal decomposition of waste particles, which make it possible to obtain a high-quality product. A pyrolysis zone of crushed waste has been developed for an energy- and resource-saving continuously operating unit for the production of activated carbon. Heating of waste to a temperature of 450-550 ° C is carried out by non-condensing combustible gases obtained during the separation of the steam-gas mixture. Waste flue gases enter a recuperative heat exchanger, and then serve as a heat carrier for drying a new batch of waste. The paper describes a method for calculating the pyrolysis zone in an activated carbon production unit. A mathematical model of the pyrolysis process is presented, by which it is possible to determine the optimal height of the layer of waste particles and the specific mass of the formed coal and gases during the decomposition of organic waste. An algorithm for calculating the pyrolysis zone has been developed. The following characteristics are shown: the dependence of the heating temperature of the layer of wood particles in the pyrolysis chamber on the layer thickness and the kinetic dependence of the specific mass of the solid residue of wood particles during pyrolysis. The calculation of the coal pyrolysis zone for the activated carbon production unit is presented.