## 1 Introduction
However, the mechanisms of physical and chemical processes occurring during the interaction of the products of thermal decomposition of the main components of mixed fuels (coal and wood) have not been reliably established [29; 47]. Therefore, the theoretical foundations of technologies for co-combustion of coal and biomass have not been developed. The main problem is that analysis of gaseous combustion products in many experiments (for example, [48; 49]) was carried out after the complete combustion of mixtures of dispersed coals and biomass. However, the composition of the flue gases changes quite significantly as the combustion process of the initial fuels is completed, depending on the combustion conditions. Therefore, an objective (statistically based) assessment of the composition of the pyrolysis products of coal and biomass particle mixtures at the stage of their intensive pyrolysis is important. One of the goals of the modern power engineering development strategy is to reduce the share of coal in the global structure of heat and electricity production, largely due to the fact that direct coal combustion causes significant harm to the environment. Creation of technologies that reduce anthropogenic load on the earth's atmosphere as a result of coal-fired power plants operation is one of the main tasks of the world community. A promising solution to the problem of air pollution by coal combustion products is to burn it together with biomass. This manuscript is aimed at substantiating the mechanisms of binding of anthropogenic gases during thermal decomposition of mixed fuels based on coal and woodworking waste. A completely new installation for registration of gas-phase pyrolysis products has been developed for research. In our previous works, studies were carried out usinga thermogravimetric analyzer with a mass spectrometric attachment. The weighed portions of mixed fuels for thermogravimetric analysis were no more than 20 mg. Based on the studies carried out in [50], a hypothesis was put forward about the processes that can occur during the joint thermal decomposition of wood waste mixed with coals of different grades, which contribute to the sequestration of anthropogenic gases. Thermogravimetric analysis showed a significant decrease in the temperature of the onset of thermal decomposition of mixed fuels with an increase in the proportion of woody biomass in a mixture with coal up to 50%. Gas analysis of the thermal decomposition of mixed fuels with a weight of up to 20 mg showed a significant decrease in the formation of nitrogen, sulfur, and carbon oxides. Technical analysis of the coals showed that their composition can differ significantly when examining samples with a low mass of fuel. As a result of the analysis of the results obtained, an installation was developed for determining the ignition delay times of the composite fuels. In [51], mixed fuel pellets weighing up to 1 g were investigated in various coal/wood mass ratios. Studies have confirmed the previously obtained results on the significant effect of woody biomass on a decrease in the temperature of the onset of thermal decomposition of mixed fuels with an increase in the share of the latter in wood pellets. All studies were carried out on brown coals of various deposits. In this work, a setup was used to study the gaseous products of thermal decomposition of mixed fuels based on thermal coal mixed with wood waste. The developed experimental setup made it possible, for the first time, to carry out uniform heating of a fuel sample weighing up to 5 g from 293 K to 873 K, continuously measure the temperature inside the reactor with fuel, and simultaneously monitor gases every 3 s.  
The volume of the ash residue obtained from the results of the experiments was sufficient for an analysis of the elemental composition by various methods, in order to establish the fact of a decrease in anthropogenic gases with the formation of agglomerates of calcium and aluminum sulfates in the ash of the fuel mixtures under study.