Improvement of efficiency of pyrolysis processing of municipal solid waste

Abstract

The disposal of waste by direct combustion method is prohibited in the Russian Federation due to the negative impact on the environment. An alternative option is solid waste pyrolysis technology, which allows not only to significantly reduce the amount of waste that requires disposal, but also to obtain various types of energy carriers. Existing installations allow recycling waste with humidity up to 30–35 %. An increase of humidity over 40 % requires additional energy sources for the drying process. To increase the efficiency of waste recycling by pyrolysis, it is necessary to improve the technology and to design an energy-efficient waste disposal plant. The use of the heat of combustion products in the heat exchanger to heat the air going into the drying chamber will increase the range of processing of wet waste. To determine the efficiency of the furnace for thermal waste disposal, the method of material and thermal balance is used. It allows determining the efficiency of the installation and selecting its operating mode with its maximum value. The paper proposes a new design of a waste disposal furnace with separate drying and pyrolysis chambers, as well as a mathematical model based on the equations of thermal and material balance. The design feature of the installation allows you to organize the controlled drying of wet waste and reduce losses with combustion products by using a heat exchanger for air heating. The proposed installation allows the waste recycling process to be carried out at a relative humidity of 0 to 60 % without additional energy sources. The efficiency of the waste varies from 61,5 to 80 % when the plant is operating on dry waste and from 42 to 62 % when operating on wet waste.