Study On Physical Properties Of Heavy Oils And Heat Transfer Calculation In The Process Of Fluid Catalytic Cracking

With growing demand for light oil and the gradual depletion of high-quality crude, heavy and poor-quality fuel oil including oil-sand bitumen is gradually becoming important source for oil processing.At present, China is still lack of systematic processing technology ans experience of heavy and poor-quality fuel oil.As foundation and precondition of heavy and poor-quality fuel oil processing, reliability and accuracy of evaluation on crude oil is of greatest importance.In the evaluation of crude oil, fractions cutting directly decides the reliability of simulation. In the existing process simulation software, although there have rich property database and related experience formula to support fractions cutting and analysis.Around the world, especially in the western countries, the processing of heavy and poor-quality fuel oil is still at the start stage, and the accumulation of data and empirical formulas are not sufficient. Therefore it is necessary to conduct study on the physical properties of heavy oil in order to lay the foundation for the further processing of heavy oil;Fluid Catalytic Cracking(FCC) technology of heavy oil is one of the current technologies handling heavy fuel oil.In this thesis, study is conducted on two aspects:the oil basic properties and heat transfer in the FCC.As the crude oil component is complex, the former researchers studied the nature of the mixture from the perspective of the virtual components.In this thesis, the complexity of crude oil is first analyzed. A comparison of virtual component division method on the crude oil is conducted. Based on the current state, the best virtual component division method is used to conduct division and cutting on crude oil, a series of virtual components are obtained. These virtual components can be regarded as a "pure substance"for study convenient in the investigation of their related properties.On the base of virtual components and the calculated physical properties, the technology of FCC of crude oil is researched and analyzed. In the process of FCC,vaporization rate of the raw material oil is a key factor. Through establishing a pre-lift section black box model, factors that influenced the vaporization rate are analyzed.The higher temperature of regenerated catalyst, preheating temperature of feedstock can increase vaporization rate of feedstock,and provide a gas phase for the next FCC reaction.Through establishment of a single oil droplet vaporization model, vaporization properties of feedstock are studied. The gasification of feedstock is more associated with the particle size of feedstock and environmental temperature.