Hydrogen Pyrolysis Performance And Its Char’s Microcosmic Structure Of Doped Shengli Lignite

This article selects the Shengli lignite as the research object which was pyrolysised at H₂ atmosphere,and then characterized with different methods such as proximate analysis,elemental analysis, IR spectra, Raman spectra and x-ray photoelectron spectroscopy.In order to test the effect of alkali on structure and properties of lignite during pyrolysis, different strength grades of alkali were added to the lignite which was pretreated with hydrochloric acid. The result shows that the alkali adding damage the hydrogen bonds and stability of lignite, which lead to the promotion of reactivity in hydrogenated pyrolysis. The addition of NaOH hindered the formation of carbon lattice cell and graphitization, reduced the carbon crystal size、degree of carbon matrix order and stability and improved the quantity of activity on coal surface and reactivity in heating process.By adding different sodium salt after pickling, we have researched the effect of Na⁺ and its alkalinity on hydrogenated pyrolysis performance and structure variation after pyrolysis of demineralizd lignite. Results showed that different sodium salt has different catalytic effect during hydrogenated pyrolysis of lignite, but the strong alkaline decreased graphitization and exhibited significant catalytic activity in pyrolysis process, especially in NaOH catalyzing.By adding different nitrate after pickling such as Ca²⁺, Na⁺, K⁺ 、Ni²⁺ and Fe³⁺, we have researched the effect of the metal ions on hydrogenated pyrolysis performance and structure variation after pyrolysis of demineralizd lignite. Results showed that the addition of Ca²⁺, Na⁺ and K⁺ made char had hinder graphitization, and promote the hydrogenation pyrolysis reaction reactivity at the same timeIn order to investigate how the alkalinity or acidity and pressure affect the process of pyrolysis, we test the reaction activity of three samples（raw coal 、raw coal with acid pretreatment and raw coal with NaOH addition） in different pressure（ordinary pressure and 2Mpa）. Results showed that the higher pressure made the coal structure exhibit higher graphitizing degree and the better performance of hydrogenated pyrolysis; Raw coal with NaOH addition exhibit higher graphitizing degree after hydrogenated pyrolysis,but acid pretreatment show heopposite effect. Raw coal with NaOH addition exhibit the best reaction activity in all those three samples.