重质原料油原位脱氮过程模拟及工艺优化

发布时间：2019-02-14 19:51

【摘要】：延迟焦化-催化裂化联合工艺是目前渣油利用的主要路线。但是,由于延迟焦化后焦化蜡油含氮量高,氮化物尤其是碱性氮化物在催化裂化过程中,会破坏催化剂的酸性活性中心,导致催化剂中毒失活,使得产出的汽柴油收率降低。同时,高含量的氮化物及硫化物易导致产品油氧化安定性差,燃烧后造成严重的环境污染。针对这一不利现象,目前国内外主要采用对焦化蜡油进行吸附脱氮,加氢脱氮,酸法脱氮,络合萃取脱氮等处理工艺。为了简化脱氮工艺,节约生产成本,本研究团队提出原位定向脱氮技术,即在延迟焦化工艺过程中加入脱氮剂,在重质原料油焦化过程中直接脱除氮化物,进入下道工序。本文根据结构导向集总的方法建立了描述重质原料油分子组成的模拟矩阵。通过编写反应规则及构建整个延迟焦化的反应网络,建立了关于DN-3脱氮剂的反应动力学方程组。同时以原料油分子组成矩阵作为初值,采用四阶龙格库塔法进行数值求解,从而获得了模拟延迟焦化的产物分布。本文设计了新型DN-5脱氮剂,同时考察了其在分馏塔底油模拟延迟焦化实验中的脱氮脱硫效果。在无需添加溶剂、相容剂并且省去了预焦化过程的前提下,进一步降低了脱氮剂的添加量,节约了生产成本。结果表明,DN-5添加量为3wt%时,焦化蜡油中氮化物含量由3120.0ppm降低至1450.3 ppm,总氮脱除率为53.5%。其中,碱性氮化物含量由1088.0 ppm降低至342.0 ppm,碱氮脱除率为68.6%。氮化物含量已满足催化裂化生产的常规要求。此外,DN-5对硫化物亦具有一定的脱除效果,硫化物脱除率为20%左右。
[Abstract]:The combined process of delayed coking and catalytic cracking is the main route of residue utilization at present. However, because of the high nitrogen content of coking gas oil after delayed coking, nitride, especially basic nitride, will destroy the acidic active center of catalyst, lead to deactivation of catalyst poisoning, and reduce the yield of gasoline and diesel oil. At the same time, high content of nitride and sulfides can lead to poor oxidation stability of oil and serious environmental pollution after combustion. In view of this disadvantage, adsorption denitrification, hydrodenitrification, acid denitrification, complexation extraction and denitrification are mainly used at home and abroad. In order to simplify denitrification process and save production cost, the research team proposed in situ directional denitrification technology, that is, adding denitrification agent in delayed coking process, removing nitride directly in the process of heavy feedstock coking, and entering the next process. In this paper, a simulation matrix for describing the molecular composition of heavy feedstock oil is established based on the structural directed set method. The reaction kinetics equations of DN-3 denitrifier were established by writing the reaction rules and constructing the whole network of delayed coking reaction. At the same time, using the molecular composition matrix of feedstock as the initial value, the fourth order Runge-Kutta method is used to solve the problem, and the product distribution of the simulated delayed coking is obtained. In this paper, a new DN-5 denitrification agent was designed, and the effect of denitrification and desulphurization in the simulated delayed coking experiment of the bottom oil of the fractionator was also investigated. Without adding solvent and compatibilizer and without the precoking process, the addition of denitrification agent is further reduced and the production cost is saved. The results showed that the nitride content in coking wax oil decreased from 3120.0ppm to 53.5% total nitrogen removal rate of 1450.3 ppm, when the addition of DN-5 was 3 wt%. The content of basic nitride decreased from 1088.0 ppm to 342.0 ppm,. The removal rate of alkaline nitrogen was 68.6%. Nitride content has met the conventional requirements of FCC production. In addition, DN-5 also has a certain removal effect on sulfides, and the removal rate of sulphide is about 20%.
【学位授予单位】：华东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TE624.5

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