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为研究不同分子筛催化剂对生物油催化裂解特性的影响,该文采用稀土元素La、非金属元素P以及活泼金属元素Ni对ZSM-5分子筛催化剂进行改性,在连续式固定床反应器中对乙酸乙酯、二丙酮醇、糠醛和愈创木酚等生物油模型化合物进行催化裂解试验,进而对比HY、HZSM-5、ZSM-5催化剂以及改性后ZSM-5催化剂对模型化合物的催化裂解反应特性以及脱氧效果。试验结果表明:在反应温度为400℃、反应质量空速为4/h条件下,经La/P/Ni改性ZSM-5分子筛催化剂,模型化合物有机相收率提高,结焦率下降;HY分子筛所得有机相收率最低,结焦率最高。模型化合物各组分裂解难易程度由易到难为二丙酮醇>乙酸乙酯>糠醛>愈创木酚;改性后ZSM-5分子筛使组分单一转化率和总转化率均出现下降;HZSM-5分子筛作用下,反应转化率达到最高。模型化合物催化裂解脱氧产物以芳香烃为主,经La改性ZSM-5分子筛作用后,其芳香烃选择性较ZSM-5略微上升;P和Ni改性后,芳烃选择性下降;HZSM-5对于芳香烃选择性最高,达7.36%;HY对于芳香烃选择性最低,仅为3.15%。通过液体产物组分分析进一步探讨模型化合物反应路径,从而为生物油的催化裂解提供一定的理论基础和科学依据。
In order to study the effect of different molecular sieve catalysts on the catalytic cracking of bio-oil, ZSM-5 zeolite catalysts were modified with rare earth elements La, non-metallic elements P and active metallic elements Ni. In a continuous fixed-bed reactor, acetic acid Ethyl acetate, diacetone alcohol, furfural and guaiacol. The catalytic cracking reactions of the model compounds with HY, HZSM-5 and ZSM-5 catalysts and the modified ZSM-5 catalysts were compared. Characteristics and deoxidation effect. The experimental results show that the yield of organic phase of the model compound increases and the coking rate decreases with La / P / Ni modified ZSM-5 zeolite catalyst at a reaction temperature of 400 ℃ and a space velocity of 4 h / h; HY molecular sieve The resulting organic phase yield the lowest coking rate highest. The degree of cracking of each component of the model compounds is easy to difficult from the diacetone alcohol> ethyl acetate> furfural> guaiacol; the modified ZSM-5 molecular sieve components single conversion rate and total conversion rate decreased; HZSM- 5 molecular sieve, the reaction rate reached the highest. The aromatics selectivity of the model compound was higher than that of ZSM-5 after La-modified ZSM-5 zeolite. The selectivity to aromatics decreased with P and Ni modification. The highest selectivity for aromatics, up to 7.36%; HY for the lowest aromatic selectivity, only 3.15%. Through the analysis of liquid product components to further explore the model compound reaction path, which provides a theoretical basis and scientific basis for the catalytic cracking of bio-oil.