共查询到17条相似文献,搜索用时 78 毫秒
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以中低温煤焦油沥青质为原料,采用NiMoW/γ-Al_2O_3商业催化剂,在反应温度380℃、反应压力8 MPa和反应时间1.5 h条件下,分别在不同剂油质量比(1∶25、1∶20、1∶15、1∶10)条件下进行加氢实验,通过采用元素分析、FT-IR、XRD、~1H-NMR和XPS等分析表征手段,考察不同剂油质量比对中低温煤焦油沥青质加氢转化过程的影响。结果表明,随着剂油质量比的增加,沥青质转化率提高,加氢产物分布也发生大幅变化,沥青质和芳香分轻质化转化为饱和分。但随着剂油质量比的进一步提高,同时也发生了更多的裂化反应和缩合反应,剂油质量比在合适范围能够很好地起到加氢轻质化且抑制结焦的效果。 相似文献
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《化学工程》2015,(8):62-68
综述了原油沥青质在加氢处理中结构组成变化的研究现状。现有的研究主要针对沥青质加氢过程中H/C原子比随加氢条件变化如何变化,S,N,V,Ni脱除状况,以及加氢处理中沥青质相对分子质量及分子结构的变化,沥青质晶体结构参数的变化。结果表明:加氢处理后沥青质C,H质量分数降低,H/C原子比且随加氢条件变化苛刻而降低。沥青质的S较易脱除,由于N,V,Ni位于沥青质芳环系中,所以难以脱除,且随着反应条件的苛刻,其质量分数增加。反应中沥青质烷基侧链变短、侧链数变少,芳环数减少,芳核缩合度增加,芳香度增加,沥青质平均相对分子质量降低,总环数增加。加氢转化后沥青质芳香层层数M减少,芳香层层间距dm和芳香层堆积高度Lc降低。通过这几方面的研究结果分析,对解决加氢处理中沥青质引起的催化剂生焦及轻质油收率低等不利影响具有重要的理论指导意义。 相似文献
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对沥青质和胶质的分离与表征是低温煤焦油科学开发和综合利用的重要突破口之一。笔者借鉴原油三组分分离法将样品分离为沥青质、胶质和轻质组分3个组分,前两者的质量分数为53%~63%。由^1H—NMR谱图信息计算获得的结构参数可知,沥青质芳香度较高,芳香环缩合度较低,环烷烃含量较高,链烃含量较少;胶质芳香度较低,芳香环缩合度较高,环烷烃含量较少,链烃含量较高,碳链较长。 相似文献
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以中低温煤焦油为原料,采用小型固定床连续加氢反应装置进行2 500 h全馏分加氢实验,研究煤焦油加氢沥青质组成与性质随加氢反应器运行时间延长的变化规律。结果表明:随反应时间的延长,催化剂活性逐渐降低,煤焦油沥青质脱除率降低,加氢沥青质S和N杂原子含量以及Fe和Ca金属含量均增加,脱除率均降低,在一定温度范围内,提高反应温度可以提高煤焦油沥青质加氢转化性能,但也促进大分子量的沥青质生成;此外,随反应时间的延长,加氢沥青质芳香度(f_A)增大,H和C原子比降低,说明加氢沥青质缩合度提高,另外,加氢沥青质分子量逐渐增大,甚至超过原生沥青质,说明部分沥青质发生缩聚反应;反应后期,沥青质缩聚反应加剧,金属Fe和Ca易沉积在催化剂上,催化剂失活严重。 相似文献
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煤焦油通过溶剂分析可定量分离为三部分:甲苯不溶物、沥青质和油相。本文主要研究了煤焦油在此分离过程中芳烃溶剂类型、萃取方法、甲苯溶液浓缩量、烷烃溶剂类型和正庚烷溶剂与甲苯溶液浓缩量的添加比例对煤焦油沥青质沉淀量的影响。结果表明,甲苯溶液浓缩量、正庚烷与甲苯溶液浓缩量的添加比例对沥青质沉淀量的影响较大,萃取方法次之,将苯替换成甲苯影响最小。当选择甲苯溶解煤焦油,超声萃取3h,甲苯溶液浓缩量9mL,正庚烷与甲苯溶液浓缩液的添加比例为20∶1时,煤焦油沥青质的沉淀量为13.4%。本实验表明煤焦油的分离工艺会影响沥青质沉淀量,故在研究煤焦油沥青质性质和结构时需注明沥青质的沉淀分离条件。 相似文献
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Asphaltene prepared from a Japanese coal (Akabira, 81.2 wt% C) and coal tar pitch were heat treated under nitrogen or hydrogen. Under nitrogen the initial thermal decomposition produced radicals which abstracted hydrogen from other molecules to stabilize and to produce smaller molecules and gas. The molecules from which hydrogen was abstracted as well as other radicals polycondensed to produce heavier solvent-insoluble fractions. Under hydrogen the radicals were stabilized by hydrogen gas to produce smaller molecules avoiding the production of a heavier fraction. The higher the hydrogen pressure, the smaller was the yield of heavier fraction and the larger the yield of lighter fraction. Higher temperature accelerated the production of the heavier fraction. Donor solvents could reduce the production of the heavier fraction. 相似文献
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The molecular structure of asphaltene: an unfolding story 总被引:6,自引:0,他引:6
From detailed chemical and thermal degradation studies, a host of structural units have been identified in Alberta asphaltenes. It has been shown that the extent of aromatic condensation is low and that highly condensed pericyclic aromatic structures are present in very low concentrations. From the available data reported to date, it is concluded that petroleum asphaltenes were mainly derived through the catalytic cyclization, aromatization and condensation of n-alkanoic, probably fatty acids, precursors. 相似文献
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The chemical structure of the oil from hydrogenation of Miike caking coal using red-mud and sulphur in a batch autoclave has been investigated. The oil was separated into compound-type concentrates in a silica-alumina dual-packed liquid-solid chromatographie column. The effects of reaction temperature (400 and 450 °C), and nominal reaction time (0–120 min) on the chemical composition of each compound-type of oil were studied. The chemical compositions of these compound types were investigated by means of 1H-n.m.r. spectroscopy, elemental analysis and molecular weight measurement. Under mild reaction conditions (400 °C) there were slight changes in the yield and composition of the oil with the reaction time. Under more severe conditions (450 °C) short alkyl-substituted aromatics and cycloalkyl aromatics in each compound-type of the oil were observed. The oil may be produced by splitting of the bridges connecting unit structures. 相似文献
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针对陕北榆林地区中低温煤焦油利用率低、环境污染严重等问题,以陕北榆林地区中低温煤焦油轻质油为原料,丙三醇水溶液为萃取剂,采用超声萃取法萃取中低温煤焦油轻质油中的酚类化合物,考察丙三醇添加量、丙三醇水溶液质量分数、超声温度等工艺条件对酚类化合物萃取率的影响。结果表明,丙三醇添加量对萃取结果影响最大,其次是丙三醇水溶液质量分数,超声温度对萃取结果的影响较小。最佳萃取条件为:丙三醇与轻质油质量比3.5∶1,丙三醇水溶液质量分数25%,萃取温度55℃,超声频率25 k Hz,酚类化合物萃取率高达93.9%。 相似文献
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为获得高品质高产率热解油气,以榆林长焰煤为研究对象,采用1 kg/h外热式回转炉,研究不同热解温度下榆林长焰煤的产品产率、半焦强度及煤焦油品质。结果表明:随着热解温度的升高,榆林煤裂解程度加深,有机质剧烈分解,气体、液体产物不断析出,半焦产率下降,煤气产率增加;热解水量受温度影响不大,仅随温度升高略有增加。随热解温度升高,榆林煤热解半焦结构强度和半焦微孔均增大,温度越高,气孔结构越发达。煤焦油中脂肪族和芳香族含量与热解温度成正比,极性物含量与热解温度成反比。长焰煤适宜热解温度为600℃,此时煤焦油产率达到极大值8.66%,为格金焦油产率的79.5%;半焦结构强度在78%以上,煤焦油中脂肪族和芳香族含量在50%以上,极性物含量32.9%,族组成较为理想。 相似文献