Chemical Speciation Of Victory Lignite Oxygen Functional Groups And Removal Of Its In Liquefied Pre-reaction

Lignite is a low rank coal with high reactivity. It is easily liquefied under mild condition which is favourable for security and stability of liquefaction plant operation. But during liquefaction the oxygen in lignite will be moved into water which conduce higher hydrogen consumption and liquefaction cost. Among the coal in China suitable for direct liquefaction, about half is the lignite. Higher hydrogen consumption must be overcome while lignite reactivity is well used for liquefaction. So, characteristics of the oxygen functional groups in Sheng Li lignite and their release form during preliquefaction are studied in the paper in order to find out optimum conditions of deoxidization. The release of more of oxygen in lignite in the form of CO and CO2 will decrease hydrogen consumption caused by forming the water during lignite liquefaction.In the paper empirical formula and X-Ray Photoelectron Spectroscopy is chosen to study the characteristics of organic oxygen functional groups in Sheng Li lignite. There are about three kinds of oxygen functional groups: single-bond(including ether link C-O and hydroxyl group O-H),carbonyl group and carboxyl group. The content of these groups in Sheng Li lignite decrease in turn. The release limit of oxygen functionalgroups in gas form is obtained. It lays strong foundation for the following experiment conclusion.Secondly, the deoxidizing degree at different temperatures in the process of non-catalytic and 4 kinds of catalytic liquefaction of Sheng Li lignite is studied respectively. The 4 kinds of catalysts include MnO₂ MoO₃ Fe2O3 and pyrite. A series of autoclave texts had been done. The series of autoclave experiments indicate that the difference of deoxidizing degree in lignite between reactions with and without catalyst used in the paper is little, but deoxidizing degree is higher in the presence of MnO2. The deoxidizing degree in non-catalytic reaction increases obviously under hydrogen pressure from l0MPa to IMPa. Satisfied deoxidization degree at pressure IMPa, temperature 360⁴00, non-catalysts is obtained; The experiment provides a thought of decrease of hydrogen consumption ( coal slurry is heated to 360 400 and enters a prereactor and separator before it enters reactor, during which the oxygen in lignite release in the form of CO_X farthest.) for the improvement of lignite liquefaction process.Compared with liquefaction process results, the text provides valuable experimental date for the improvement of liquefaction process. Hydrogen is saved by 0.32 percentage points, which accounts for 4.1% of hydrogen consumption of liquefaction process by theory calculation. Themeaningless consumption caused by the combination of hydrogen andoxygen in lignite into water is decreased. The utilization efficiency ofhydrogen is improved and the cost is reduced.