Currently, the main prospects for improving the insulating means of respiratory protection are associated with the chemical method of oxygen reservation. Main arguments in favor of this choice are the high density of oxygen packaging and its self-regulating supply depending on physical activity of the person. However, the efficiency of using the protective resource of chemically bound oxygen is far from ideal. This is due to the presence of the so-called dead layer of chemisorbent based on potassium superoxide and pallets sintering under the effect of exothermic heat released when the exhaled carbon dioxide is bound.

To optimize the working process of the breathing apparatus using chemically bound oxygen, the formalism was developed that allows to simulate regeneration of the exhaled air by the layer of potassium superoxide oxide granules, the diameter of which gradually decreases in the direction of airflow filtration. It was shown that an increase of 1 mm in the granules in the frontal layer of chemisorbent reduces by 36 % the power of exothermic heat sources, preventing the sintering of the oxygen-containing product at heavy physical load of the person.  Dependence of the diameter of the granules on the depth of their occurrence in the regenerative cartridge is obtained, which ensures the uniform distribution of the thermal power of the dynamic chemisorption of carbon dioxide. Decrease in the diameter of the granules according to the found law to 2 mm, even in the absence of sintering in the uniformly equipped cartridge, ensures 27 % increase in protective action due to the resource of the dead layer of self-rescuing chemisorbent in heavy duty operation. The lower estimate of the dead layer resource during further grinding of granules is made and the ways of its use are indicated.