【作者】 马斌；

【导师】 胡浩权；

【作者基本信息】 大连理工大学 ， 化学工艺， 2010， 硕士

【摘要】 我国煤炭资源丰富,一直是主要的能源和化工原料,煤炭直接液化是解决石油短缺、保障能源供应安全的有效途径之一。提高煤的液化反应活性、缓和液化条件和增加油收率已成为当今煤直接液化领域的研究热点。本文以神华煤为原料,利用间歇式高压反应器考察了离子液体1-丁基-3-甲基咪唑四氟硼酸盐([BMIM][BF4])、1-丁基-3-甲基咪唑三氟甲基磺酸盐([BMIM][TFO])和其他溶剂对神华煤的热处理、水热处理、溶胀处理对神华煤液化性能的影响,并对铁系催化剂和助催化剂S的作用进行了考察。通过热重分析得出神华原煤最大失重速率在430℃左右,铁基催化剂明显促进了神华煤热解,使其总失重率由35%提高到60%,并且最大失重范围加宽。热处理时加入纳米Fe可以有效的减少煤中羟基形成的非共价键力,抑制循环油的热解缩合反应。预处理结果表明,热处理和水热处理能在一定程度上改变煤分子间的交联作用,尤其是非共价键作用形式和强度；伴随脱挥发分和热解反应,煤分子间产生了新的非共价键和共价键交联,适当温度的水热处理提高了煤液化转化率,如250℃水处理煤液化转化率较原煤提高了2.2%。溶胀作用改变了煤的结构,使煤中大分子骨架的网络结构交联缔合度降低,结构变得疏松。溶胀增加了神华煤的热解活性,NMP溶胀处理后煤的液化转化率提高了10.8%。使用1-丁基-3-甲基咪唑四氟硼酸([BMIM][BF4])对神华煤的预处理,可以有效改变煤的结构,提高神华煤热解活性,并且在低神华煤温液化的条件下,[BMIM][BF4]作为溶剂或催化剂的载体都可以生成更多的小分子液体产物。铁基催化剂在煤液化过程中促进了氢在反应体系中的转移,有效地增加了油产率和煤液化转化率。当以氢气为液化反应气氛时,催化剂对氢转移的作用是促进气相氢到溶剂的转移和溶剂氢到煤上的转移；而助催化剂S更有利于氢从气相到液相的转移,增加了活性氢的供给,提高了煤的液化转化率,促进重质产物向油的转化。更多还原

【Abstract】 At present it has been a main research issue to improve the liquefaction reactivity of coal to moderate the liquefaction conditions and increase the oil yield. In this paper, the experiments were carried out in an autoclave to investigate the effects of pretreatment by 1-Butyl-3-Methyl-Imidazolium Tetrafluoroborate ([BMIM][BF4]), 1-Butyll-3-Methyl-Imidazolium trifluoromethanesulfonate([BMIM][TFO]) and some other solvents on direct liquefaction of Shenhua coal as well as the iron, sulfur role in the process of liquefaction.TG/DTG curves show that Shenhua coal exhibits its maximum weight loss rate at about 430℃, and the existance of Fe catalyst increases the weight loss of SH coal pyrolysis from 35% to 60% and widen its major decomposition range. Addition of Fe in coal during the thermal treatment is benefit to break the hydrogen bond and other non-covalent bonds. Fe can also restrains regressive reaction occurs from oil.Results of The thermal and hydrothermal pretreatments of Shenhua coal change the cross-linking structure of Shenhua coal, especially the strength and distribution of non-covalent bonds such as hydrogen bond. The conversion increased by 2% after thermal treatment at 250℃due to the formation of new non-covalent and covalent bond cross link in the process of thermal treatment under higher temperature, in which the devolatilization and the pyrolysis occur obviously. Solvent swollen coals have much lower pyrolysis activation energies than raw coal. The liquefaction conversion of NMP swollen coal enhanced 10.8%. [BMIM][BF4] can effectively promote the reactivity of coal by changing the coal structure after thermal and swelling treatment. Much more light liquid products can be obtained at less severe liquefaction condition when [BMIM][BF4] serves as solvent or catalyst.The major role of the iron in coal liquefaction is promoting the formation of activated hydrogen and increasing the oil yield and coal conversion. The main sources of activated hydrogen include thermal and catalytic cracking of solvent and H2. The major transfer approach of activated hydrogen is from molecular hydrogen to solvent and then from solvent to coal. Sulfue has significantly positive effect on the liquefaction process. Addition of sulfur is helpful for converting heavy product to oil. Sulfur has also a favorable role in supplying more activated hydrogen from gas to liquid products.更多还原