The Study Of Kinetics And Model Of Daqing Oil Shale Pyrolysis

Energy, the basic driving force of the development of the world and economy, is the fundation of human survival. In recent years, energy issues become the main problem of restricting China’s economic development with conventional fossil fuels drying up increasingly such as oil, natural gas and coal. Looking for alternatives to conventional energy becomes imperative. Oil shale is a kind of unconventional oil and gas resources. Oil shale can obtain shale oil that is similar to natural oil through pyrolysis. According to relevant data, the oil shale reserves is abundant in our country with the world’s second after the United States. If the oil shale can generate shale oil, the problem of China’s conventional fossil energy shortage will be solved. Therefore, the experiment and simulation of Daqing oil shale pyro lysis has the vital practical significance.The basic properties of oil shale and char have important role for the analysis of composition, structure and calorific value before and after oil shale pyrolysis. At the same time, the definition of unconventional component also needs some basic properties of oil shale and char during using Aspen Plus software. Proximate analysis, ultimate analysis, calorific value, carbon dioxide of carbonate and IR spectra were determinated for Daqing oil shale and char.The temperature and the constant temperature time are the most important factors in the process of oil shale pyrolysis. Under ordinary conditions of pressure, the yield of shale oil increases with the temperature and then decreases slowly. The higher the temperature is, the more intense the pyrolysis reaction is. Meanwhile, the secondary cleavage reaction of the pyrolysis products is also intense with the increasing of the pyrolysis temperature. Certain conditions, the yield of shale oil increase and then level off with the constant temperature time. Under nitrogen atmosphere, the pyrolysis of Daqing oil shale were carried out in a fixed-bed reactor in order to study the influence of the pyrolysis temperature (400～540℃) and the constant temperature time (0-30min) on oil shale pyrolysis characteristics. The pyrolysis reaction kinetics of oil shale was studied combining the experimental data of fixed-bed pyrolysis and the mechanism of the oil shale pyrolysis. The yield curve of shale oil changing with the temperature was fitted to compare with the measured value with the constant temperature time for20min according to the pyrolysis kinetic parameters. The qualitative and quantitative analysis for Daqing shale oil were conducted through two methods of the acid and alkali wash and column chromatography with GC-MS analysis method and TLC (thin layer chromatography) method.The fixed-bed pyrolysis process for Daqing oil shale was simulated using Aspen Plus software. The process defined components as the mixtures of conventional components, unconventional components and conventional inert solid components. The mixtures through preheating system removed the moisture in the Daqing shale. The dried shale was into RCSTR reactor and reacted to form shale oil, retorting gas and char. The char was out of the system directly. The retorting gas and the shale oil were into the oil-gas separation system for the separation of oil and gas. In the simulation, during the pyrolysis temperature of360～580, the change rule of mass flow rate and the pyrolysis products was analyzed for shale oil, char and water. The effect of the temperature on the mass flow rate and composition of retorting gas was analyzed.