https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:37723 2 and polyaromatics during lignite pyrolysis under pressurized entrained-flow conditions. The pyrolysis temperature and pressure ranged between 600-900 ℃ and 0.1-4.0 MPa, respectively, and were found to greatly influence the yield and composition of pyrolysis products. The results showed that the concentration of H₂ in the light gas fraction increased drastically with pyrolysis temperature and pressure, reaching 91.69 vol% at 900 ℃ and 4.0 MPa, which corresponded to H₂ generation of 0.27 m³/kg coal. The yield of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, biphenylene, fluorene, phenanthrene, pyrene, and fluoranthene was also promoted at elevated pyrolysis temperatures and pressures. The highest PAHs concentration of 90.4 area% in the pyrolysis oil was obtained at 900 ℃ and 4.0 MPa. It was also found that the changes in the hydrogen distribution under pressurized entrained-flow conditions mainly took place during the secondary pyrolysis reactions. It was postulated that hydrogen was formed via aromatization, condensation, aromatic ring growth mechanism, and direct cleavage reactions. The findings of this study showed that lignite could be efficiently converted to H2-rich gas, PAHs as chemical raw materials, and energy-dense lignite char via a novel poly-generation system based on pressurized entrained-flow pyrolysis.]]> Thu 25 Mar 2021 12:33:52 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:43652 2H₂ addition (HACA) was postulated to be the mechanism of the formation of PAHs. The 4-ring PAHs (pyrene, fluoranthene) and 3-ring PAHs (phenanthrene, fluorene) were found to dominate the lignin bio-oil, while the bio-oil from cellulose and xylan mainly contained 2-ring PAHs (naphthalene). Elevated pressures and temperatures were also found to significantly increase the selectivity of H₂ in the bio-gas.]]> Mon 29 Jan 2024 17:50:37 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:42309 c), interlayer spacing (d₀₀₂) and lateral size of the graphite structures (L_a) were used to evaluate the graphitic structures in chars. The results showed an increase in L_c,, L_a, and the average number of graphene sheets with pyrolysis pressure, indicating a more ordered carbon structure at elevated pressures. The d-spacing of char was in the range of 3.34-3.37 Å, similar to typical graphitic structures.]]> Mon 22 Aug 2022 09:14:19 AEST ]]>