【作者】 门秀杰；

【导师】 石斌； 阙国和；

【作者基本信息】 中国石油大学 ， 应用化学， 2007， 硕士

【摘要】 为改进高含氮重油催化裂化性能,在模拟固定床微型反应装置(MAT)上考察了乙酸、甲醇、溴代正丁烷、添加物A等十种酸性添加物或添加物前驱体对含氮化合物-十六烷模型化合物体系和模拟高含氮体系(吡啶-克拉玛依减压蜡油)催化裂化的影响,将筛选的添加物用于高含氮的克拉玛依焦化蜡油的催化裂化。并尝试考察了克拉玛依焦化蜡油氧化预处理从体系内部产生酸性物质对其催化裂化的影响。主要结论如下:碱氮吡啶和喹啉,非碱氮吲哚均可使模型化合物体系催化裂化催化剂中毒,导致体系转化率降低,其中碱氮的作用更为显著。所筛选的添加物可以不同程度的减缓模型含氮化合物对催化剂的中毒,体系的转化率和轻质产物收率均得到提高,其中,几种具有明显作用的添加物的效果依次为:溴代正丁烷>甲醇>乙酸>添加物A,其作用机制可能涉及含氮化合物的Friedel - Crafts反应和提供活性氢两种方式。在模拟高含氮蜡油体系(吡啶-克拉玛依减压蜡油)中,甲醇、添加物A的性能较好,乙酸和溴代正丁烷效果不太明显。小分子醇(包括乙醇、乙二醇、丙三醇等)均具有类似甲醇的性能。添加物A使转化率基本不变,但降低气体、结焦产率,增加轻油收率,用量在200-500 g?g-1范围内效果最好。在高含氮的焦化蜡油体系中,添加物A和甲醇在一定程度上有利于改善其催化裂化的产物分布,其转化率和轻油收率最大可分别提高约1%和2%。所尝试氧化剂(高锰酸钾和叔丁基过氧化氢)氧化预处理焦化蜡油,不但产生含有-COOH或-OH的潜在酸性物质,而且使原料的分子量明显减小,从而有效减缓含氮化合物对催化剂的中毒,又能减缓催化剂结焦失活,还明显减少催化裂化的二次反应,反应产物的分布和转化率也有比较明显地改进。其中,汽油馏分收率和总转化率最大分别提高10%和4%,而干气、焦炭产率有明显减少。就氧化剂的作用而言,高锰酸钾优于叔丁基过氧化氢。更多还原

【Abstract】 In order to improve the catalytic cracking performance of heavy oil with nitrogen compounds, ten kinds of acid additives or acid additive precursors, which include acetic acid、methanol、n-butyl bromide、additive A and so on were applied into the model compound system comprised by some nitrogen compounds and hexadecane or the model heavy oil system made up of Kalamay vacuum gas oil(VGO) and pyridine or Kalamay coker gas oil(CGO) system in a simulated fix-bed catalytic cracking micro-reactor. Then their improvement was investigated in the two model systems and the CGO system. Besides the investigation of the external acid additives, the upgraded CGO FCC preceded by simple tentative pre-oxidizing, which could generate the internal acid function groups like–COOH and–OH in the CGO system, was evaluated and studied. The main conclusions can be drawn as follows:Both base nitrogen compounds including pyridine and quinoline and non-base ones (i.e. indole) could lower hydrocarbon conversions by poisoning the acid FCC catalysts. The acid additives in the model compound system allevated nitrogen compounds poisoning so that a conversion jump and a good product distribution could be achieved. Among the external acid additives, their upgrading effects were with the order : n-butyl bromide>methanol>acetic acid>additive A. The reason might relate to the Friedel-Crafts reaction and hydrogen donation. However, methanol and additive A showed better properties, while acetic acid and n-butyl bromide less effects in the model heavy oil system containing pyridine. Alcohol series including ethanol, glycol and glycerol gave the similar performance to methanol. As to the additive A, a substantial improvement on product distribution including the increase of gasoline and the decrease of the dry gas and coke on the same total conversion could occur with a 200-500 g?g-1 dosage. In the CGO FCC system, both methanol and the additive A were favorable to catalytic cracking with 1%the maximal increase of conversion and 1-2m% the light oil recovery.Pre-oxidization of CGO with potassium permanganate(KMnO4) and ter-butyl hydrogen peroxide(C(CH3)3OOH) not only generated the internal acid function groups like–COOH and–OH and“neutralized”base nitrogen compounds in the CGO, but also resulted in the decrease of molecular weight of CGO. After pre-oxidization treatment of CGO, nitrogen compounds poisoning in the CGO FCC could considerably be alleviated, and CGO conversion be increased and a good product distribution could be achieved. The jump of gasoline yield and the total conversion could be up to 10% and 4m% while the yields of dry gas and coke were clearly lowered. Between the two oxidants, KMnO4 showed better effect than C(CH3)3OOH.更多还原