The effectiveness of modified sodium bicarbonate in the purification of exhaust gases from HCl and HF

Abstract

The effectiveness of gas purification depends on the sorption properties of sorbents. The aim of the research was to determine the ability of sodium sorbents to remove gaseous pollutants such as HCl and HF. The research used baking soda subjected to mechanical and thermal activation, which was introduced into the hot flue gas circuit, similar to the dry flue gas cleaning method used in all kinds of boilers. In almost all cases, mechanical and thermal treatment of baking soda allowed for a significant improvement in the reduction of hydrogen chloride and hydrogen fluoride concentrations in the exhaust gases produced during the combustion of polyethylene terephthalate (PET) bottles. The preparation of sorbents must consider the optimum development of the material's specific surface area, especially during thermal activation, to prevent pores from sintering. In wet and dry flue gas cleaning processes, sodium compounds are used in the power industry. Appropriate preparation of the sorbent allows for improving the effectiveness of reducing the concentration of harmful substances and reducing investment and operating costs. From the point of view of process optimisation, the results obtained will contribute to the identification of optimal operating conditions in dry sorbent injection systems to prevent the pores on the surface of the sorbent from clogging when injected into hot flue gases.