Analysis of Ionic Liquid Pretreated Low-Rank Coal via Equilibrium-Based Gasification Model
نویسندگان
1 Department of Chemical Engineering, NFC Institute of Engineering & Technology, Multan, PAKISTAN
2 Department of Chemical Engineering, NFC Institute of Engineering & Technology, Multan, PAKISTAN
3 Department of Chemical Engineering, NFC Institute of Engineering & Technology, Multan, PAKISTAN
doi
10.30492/ijcce.2024.2014793.6293چکیده
The utilization of vast coal deposits around the globe as an energy source is significantly limited in scope owing to environmental risks. In this context, ionic liquids (ILs) provide a novel solution as eco-friendly pretreatment agents. This work examined the effects of IL pretreatment on the gasification of low-grade coal using a simulation model in Aspen Plus®. Four ILs, 1-butyl-3-methylimidazolium chloride [Bmim][Cl], 1-ethyl-3-methylimidazolium chloride [Emim][Cl], trihexyltetradecylphosphonium chloride [P66614] [Cl], and tributylmethylammonium chloride [N1444] [Cl], were employed in this study. A comparative and sensitivity analysis was conducted on untreated and IL-pretreated coal samples using an equilibrium-based steam-O2 gasification model designed in Aspen Plus®. The model was validated and utilized to vary the oxygen/fuel (O2/F) ratio, steam/fuel (S/F) ratio, and temperature within the specified ranges (700-950°C, 0.1-0.6, and 2-4, respectively). The results showed that all the ILs increased CO and H2, and decreased CO2 and CH4, in the syngas produced by coal gasification. The biggest change was affected by [P66614] [Cl], which increased CO and H2 from 12 mol% and 42 mol % to 16 mol% and 50 mol %, respectively, and reduced CO2 and CH4 from 35 mol% and 3.5 mol% to 29 mol% and 2 mol%, respectively. The lower heating value (LHV) of syngas was increased from 7.37 MJ/Nm3 for untreated coal to 7.61, 7.56, 8.1, and 7.56 MJ/Nm3 for coal treated by [Bmim][Cl], [Emim][Cl], [P66614] [Cl], and [N1444] [Cl], respectively. As opposed to raw coal, [Bmim][Cl] and [P66614] [Cl] generated more CGE, ENE, and EXE. The highest CGE, ENE, and EXE of 19, 13.3, and 38.3% were achieved by [P66614] [Cl] treated coal. Syngas having higher H2/CO ratio and LHV were produced at low temperatures, low O2/F ratio, and high S/F ratio. The results of this investigation demonstrated that ILs composed of ammonium and phosphonium might be useful coal pretreatment agents in thermochemical conversion processes.
