Development of new methods for energy technology processing of Kyrgyzstan coals

Introduction. This study explores methods for determining the yield of volatile matter from Kyrgyz coal and obtaining ultra-pure carbon for potential applications in modern carbon nanotechnologies used in the construction industry. Both organic and inorganic components of various coal types were analyzed, along with the composition of the released volatile substances. Methods and materials. We used in the research empirical methods (observation, experimentation, measurement, and comparison), alongside chemical methods involving acid treatment (for the removal of metallic impurities) and a transport reaction method (for the removal of silicon oxide impurities). The study focused on obtaining ultra-pure carbon from bituminous coal deposits in Kyrgyzstan. The tested raw materials included grey and brown coals from deposits in the southern region of Kyrgyzstan. Pre-weighed samples were placed in a stainless-steel reactor and subjected to slow pyrolysis under sealed conditions across specific temperature ranges. For brown coal, pyrolysis was conducted between 100 °C and 550 °C, while for bituminous coal the range was 100 °C to 1100 °C. The process continued until all liquid and gaseous pyrolysis products ceased to be released. Results. Pyrolysis was used to remove volatile liquid and gaseous impurities from the coal samples. The qualitative and quantitative composition of the volatile gases was determined. During pyrolysis in the 100 °C to 850 °C range, pyrogenetic water was formed, and gaseous products such as NO, CO₂, CO, H₂S, CH₄, and others were released. For brown coal, the yield of volatile substances at 150–170 °C was 61.9%. For bituminous coal, at 380–400 °C, the yield was 15.5%. Post-pyrolysis, the remaining coal contained only solid impurities – primarily metallic elements and silicon dioxide (SiO₂). These were removed using a chemical method involving a mixture of concentrated sulfuric and nitric acids in a 1:3 ratio. Silicon dioxide impurities were removed via a transport reaction facilitated by gas convection. As a result of this two-stage purification, ultra-pure carbon consisting solely of carbon atoms (C–C–C–) was obtained. Conclusion. The proposed experimental setup and technological scheme for impurity removal and carbon purification – including the use of transport reactions – enable industrial-scale production of ultra-pure carbon from coal. This purified carbon can be used as a component in advanced construction nanomaterials. The use of such materials significantly enhances the performance characteristics of construction structures and coatings, while also reducing the environmental impact of combustion by-products, ultimately lowering costs associated with environmental protection.