大型藻类催化液化制备液体燃油的研究

【作者】 李晨；

【导师】 李金花；

【作者基本信息】 青岛大学 ， 分析化学， 2021， 硕士

【摘要】 世界经济的快速发展受益于传统化石燃料的利用。然而,这些不可再生的资源正在逐渐枯竭。此外,化石燃料的燃烧会产生大气污染物和温室气体,对环境造成严重的破坏。相比之下,生物燃料是环境友好且可再生的,是解决能源危机的有前景的替代能源。在众多可替代的液体生物燃料中,藻类生物燃料备受关注。不同的方法将海藻转化得到的生物油的组成和性质不同。本文以浒苔为原料,分别采用脱氧液化和水热液化技术制备两种液体燃油。通过元素分析和GC-MS对所得液体燃油进行表征,结果表明,脱氧液化得到的生物油的氧含量为6.25%,热值为40.84 MJ/kg,与水热液化生物油相比（10.29%,37.65 MJ/kg）,具有氧含量低和热值高的性质,因此脱氧液化技术更适合以海藻为原料制备高品质液体燃油。为了提高生物油的品质,可以在液化体系中加入适宜的催化剂。本文采用ZSM-5,MCM-41两种微孔和介孔分子筛催化剂,并采用单金属Ni、Mo和双金属Ni Mo分别对两种分子筛催化剂进行改性,通过SEM、BET、FTIR、XRD、NH₃-TPD等测试对催化剂的结构和性能进行表征,并将所有催化剂分别应用于浒苔的脱氧液化反应中。所得液体燃油的FTIR和GC-MS分析结果表明,在脱氧液化过程中加入催化剂可以降低液体燃油的氧含量和氮含量,提高液体燃油的热值等性能。其中,加入Ni Mo/ZSM-5催化剂得到的生物油的热值最高（43.66 MJ/kg）,烷烃和芳烃等碳氢化合物相对含量也最高（26.76%）。在海藻液化过程中应用微-介孔复合分子筛可以充分发挥微孔和介孔分子筛的优势互补和协同作用。本文合成了ZSM-5/MCM-41微-介孔复合分子筛催化剂,并采用单金属Fe,Cu,Co,Ni,Mo和双金属Ni Mo对ZSM-5/MCM-41复合分子筛催化剂进行改性,对上述催化剂的结构和性能进行表征,并将上述催化剂分别应用于浒苔的脱氧液化反应中。所得液体燃油的组分分析结果表明,加入Ni Mo/ZSM-5/MCM-41催化剂制备的液体燃油氧含量最低（2.22%）,热值最高（45.37 MJ/kg）。更多还原

【Abstract】 The rapid development of the world economy benefits from the utilization of traditional fossil fuels.However,these non-renewable resources are becoming exhausting.In addition,the combustion of fossil fuels produces large amounts of air pollutants and releases greenhouse gases,which lead to environmental pollution.More importantly,they are environmentally friendly and renewable,and are considered as promising alternative energy to solve the energy crisis.In recent years,as a kind of liquid bio-fuel,the liquid fuel obtained from algae has attracted much attention due to their potential applications in solving the serious threat of global warming on human beings.The compositions and properties of the bio-oil produced by different transformation methods are different.In this paper,Enteromorpha prolifera was used as raw material to prepare two kinds of bio-oil by deoxy-liquefaction and hydrothermal liquefaction,respectively.Elemental analysis and GC-MS characterizations were carried out of liquid fuels.The results showed that the oxygen content and high heating value of the bio-oils obtained by deoxy-liquefaction and hydrothermal liquefaction are 6.25%,10.29%and40.84 MJ/kg,37.65 MJ/kg,respectively.It is clear that the former possesses the lower oxygen content and the higher heating value.Therefore,deoxy-liquefaction technology is more suitable for the preparation of high-quality liquid fuel from macroalgae.The quality of the bio-oil can be improved by adding appropriate catalysts.In this work,ZSM-5 and MCM-41 zeolites were modified by the metals of Ni,Mo and Ni Mo,respectively and then they were used as catalysts during the liquefaction of Enteromorpha prolifera.The structures and properties of the catalysts were characterized by SEM,BET,FTIR,XRD and NH₃-TPD.The FTIR and GC-MS analysis results of the obtained liquid oils revealed that the catalysts can reduce the oxygen and nitrogen contents,and improve the heating value of the bio-oil.Furthermore,when using Ni Mo/ZSM-5 as the catalyst,we obtained the highest heating value（43.66 MJ/kg）and highest content of hydrocarbons（26.76%）including alkanes and aromatics.In the process of macroalgae liquefaction,the use of micro-mesoporous composite zeolite catalysts can perform the complementary advantages and synergy of microporous and mesoporous zeolites.ZSM-5/MCM-41 composite zeolite catalyst was synthesized and modified by Fe,Cu,Co,Ni,Mo and Ni Mo,respectively and then they were used as catalysts during the liquefaction of Enteromorpha prolifera.The structures and properties of the catalysts were characterized.The results of the composition analysis results showed that the obtained bio-oil using Ni Mo/ZSM-5/MCM-41 catalyst had the lowest oxygen content（2.22%）and highest heating value（45.37 MJ/kg）.更多还原