碱土金属氧化物催化裂解酸化油及动力学研究

以碱土金属氧化物(MgO、CaO和BaO)作为裂解催化剂,在实验室自制的3 L裂解反应釜中对酸化油进行裂解脱氧制备烃类燃油。结果显示:3种碱土金属氧化物催化裂解酸化油所得液体燃油产率为70%~80%,特别是CaO和MgO作为裂解催化剂能够有效地脱氧,能够在较低的温度下获得更多的液体燃油,同时燃油的酸值低于20 mg/g。以硬脂酸钡、硬脂酸钙、硬脂酸镁为模型化合物研究废弃油脂裂解反应动力学,先进行热重分析,再利用分布活化能法对热重结果进行动力学参数计算,结果表明:硬脂酸钡、硬脂酸钙、硬脂酸镁的裂解活化能依次降低,分别为268,204和127 kJ/mol。以上结果表明:用MgO催化裂解酸化油能够在较低温度下收集更多的液体燃油,从而在较低温度下实现废弃油脂的裂解转化,有效降低反应能耗。

Catalytic Cracking of Acidic Oil by Alkaline Earth Metal Oxides and Its Kinetics Study

Alkaline earth metal oxides(MgO, CaO and BaO) were used as cracking catalysts, and a 3L cracking reactor made in the laboratory was used to crack and deoxidize acidic oil to prepare hydrocarbon fuels. The results showed that the yields of liquid fuel obtained from catalytic cracking of acidic oil by three kinds of alkaline earth metal oxides were 70%-80%; CaO and MgO as cracking catalysts could effectively deoxidize and produce more liquid fuel under lower reaction temperature and the acid value of the fuel was lower than 20 mg/g. Barium stearate, calcium stearate, and magnesium stearate was used as model compounds to study the kinetics of the pyrolysis reaction of waste oils, the thermogravimetric analysis was performed first, and then the kinetic parameters of the thermogravimetric results were calculated by using the distributed activation energy method. The results showed the pyrolysis activation energies of barium stearate, calcium stearate, and magnesium stearate decreased sequentially, which were 268, 204 and 127 kJ/mol, respectively. Above results indicated that the use of MgO as catalyst to crack acidic oil could collect more liquid fuel in the lower temperature section, and the waste oil was converted at lower temparture, which could effectively reduce the energy consumption during the conversion reaction.