Photo Coupled Thermo-oxidation Of Shenfu Coal

This article intended to provide theoretical foundation and basic data for preparation fine chemicals from coal in mild condition studied by the reactivity of shenfu coal in photo coupled thermo-oxidation and high effective extraction humic acid and fine chemicals from the photo-thermo-oxidation coal.The research object shenfu coal which was treated with alkali solubilization and acid precipitation to remove primary humic acid and with hydrochloric acid and hydrofluoric acid to remove minerals. Finally obtained the FHMC. The photo coupled thermo-oxidation mechanism of photo-thermo-oxidation coal was studied in the photo coupled thermo-oxidation fixed bed reactor. Humic acid was extracted further from this coal in the slurry fluidized-bed reactor. The influence of different extracted factors on humic acid yield and structures of oxidation products and humic acid were analyzed to investigate the photo coupled thermo-oxidation mechanism. The reactivity of shenfu coal in photo coupled thermo-oxidation using FTIR, GC, SEM, GC-MS instruments and methods of total humic acid, total acid was researched to analyse the oxidative products and the photo coupled thermo-oxidation mechanism in photo coupled thermo-oxidation.The effects of ultraviolet, reaction atmosphere and temperature on composition of photo coupled thermo-oxidation products in the photo coupled thermo-oxidation fixed bed reactor. The results show that: The main gas products are CO and CO2, with some CH4, and the release amount of CO2 greatly increase under oxygen atmosphere. The concentration of gas products is CO2>>CO>CH4. The CO2 concentration increases with increasing temperature, and reaches maximum after 2 h. UV irradiation can obviously promote the release of CO2 and CO. The release rates of CO and CH4 increase with increasing temperature. Photo coupled thermo-oxidation improve the selectivity of gas products and demonstrate obvious synergistic effect to increase humic acid of coal, meanwhile, lead to the formation of phenolic hydroxyl. Dichlormethane extracts from photo-thermo-oxidation FHMC obviously improve the selectivity of products. The GS-MS analysis suggests that the main difference between their products is the long chain alkane. The latter contains lots of long chain alkane, as the relative content of dioxaphetyl butyrate is up to 44.562%, while the former contains hardly any.The slurry fluidized-bed reactor with alkaline medium was used to treat photo-thermo-oxidation FHMC in deep oxidation and reactivity extraction, to separate and purify humic acid. And methods of FTIR, UV-vis and GC-MS were used to analyze changes of humic acid structure. The results show that factors of extraction time, atmopheres and ultraviolet have great influence on the extraction yield and distribution of humic acid. The extraction yield of humic acid from photo-thermo-oxidation FHMC reaches the maximum of 9.6% under liquid aerobic conditions and UV irradiation. The amount of three humic acid improve that with reaction time increasing, the yield of ulmic acid outclass fulvic acid and pyrotomalenic acid.The FTIR analysis shows that Fulvic acid with numerous hydroxyl groups associates hydroxyl easily. It is easy to genrate new absorption peaks of humic acid under O2, which altraviolet irradiation weekens absorption peaks. The GC-MS analysis about extracts of fulvic acid by ethanol in the slurry fluidized-bed reactor shows that the quantity of compound reduces and the yield increases markedly under O2, especially coexistence of O and UV. The content of some phenanthrene derivative reaches up to 50.422%.Form the experiments we can see that photo-oxidation mainly shows free radical reaction mechanism with photosensitive activity groups of coal, while thermo-oxidation shows free radical chain reaction mechanism. The present of photo improves the reaction selectivity and thermo-oxidation increases reaction speed. The photo coupled thermo-oxidation mechanism is free radical chain reaction mechanism of photosensitive activity groups.