| In the traditional coal liquefaction technology, direct H2 and cycle-oil are used as the hydrogen source and solvent. In this dissertation, the CO/H2O system was used to replace the traditional H2/cycle-oil or H2/tetralin systems. In CO/H2O liquefaction system, the H2 which comes from the water-gas shift reaction is much more active than the common H2 and it is easy to combine with radicals in the hydrogenation. CO is much easier to get, which represents a significant saving when the cost of operation with CO is much lower than the using of H2 in industry. The sub-supercritical or supercritical water plays a very important part in the CO/H2O system. As a substitute of the cycle-oil, supercritical water (SCW) is also a good solvent to the organics and it is much cheaper than the cycle-oil. Besides, the process using water as a medium does not require drying coal which will low down the cost and the energy consumption. This technology fits for the lower rank coal like the brown coal containting hige content of water.In this dissertation, firstly, the influences of Shengli brown coal liquefaction in CO/H2O system was studied including reaction temperature, residence time, ratio of coal and water, initial CO pressure, catalysts and the atmosphere. Liquefied products were analyzed using methods of FTIR, NMR, EPR, GC-MS, GC and MS; and the mechanism of Shengli brown coal liquefaction was inferred. Shengli brown coal, Xiaolongtan brown coal, Huainan bitmminous coal, Yanzhou bituminous coal and Shenhua coal were liquefied both in CO/H2O system and H2/tetralin system to investigate and compare their liquefaction behaviors.The optimized technology parameters of the Shengli brown coal in autoclave are as follow:350℃,3MPa (initial CO pressure),1.2 ratio of the coal and water,4wt% FeS catalyst. Under this condition, the total conversion, oil yield, asphaltene yield and gas yield are 67.28%, 44.49%,20.39% and 2.4%. The gas was analyzed by GC, and the main components are CO2, CO, H2, CH4, C2H6 and H2S. Through the 1H-NMR and 13C-NMR analyzing, it is found that the liquid products of the CO/H2O system contain many phenol and ether. The hydrogen and carbon distribution were calculated according to the NMR spectrum. The molecule model of Shengli brown coal and liquefaction mechanism were speculatedShengli, Xiaolongtan, Shenghuai, Huainan and Yanzhou coal were liquefied in CO/H2O and H2/tetralin system. The conversion in CO/H2O system is lower than it in H2/tetralin system. In CO/H2O system, the total conversion, oil yield of Shengli brown coal were the highest and it indicates that lower rank coal is fit for the liquefaction in the CO/H2O system.The hydrogen distribution of the oil and asphaltene of the 5 coals were calculated through the 1H-NMR spectrum and it is found that there is more hydroxyl and carboxyl in the oil and asphaltene obtained from Shengli and Xiaolongtan coal. These five coals and every step residues were analyzed by EPR and it is indicated that the g factor decrease with the increase of coal rank. The value of△H of Shengli coal decreases and the one of other 4 coal increase after liquefaction. The Ng value of Xiaolongtan coal is the lowest and the one of Huainan is higher. The Ng value increase after liquefaction and the amplitude of Shengli coal is the highest which indicates that the lower rank coal is easier to be liquefied because it may produce much more radicals.
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