The Study Of Three Phase In Multicomponent Complex Systems

Central and western regions have abundant natural gas resources in China,while the eastern coastal region is the main consumption area of energy as the large populations and development industry.We must balance the relationship between energy and development of east and west,with transport and storage problems.Currently,LNG has become the main mode of short distance transportation of natural gas.Natural gas and equipment are in low temperatures in gas liquefaction process,while the heavy hydrocarbons deposited freeze at low temperatures,thereby clogging the pipeline and equipment.So estimate the temperature and pressure conditions of the heavy hydrocarbons deposited freeze by studying the natural gas,liquid and solid phase equilibrium is essential.But the foreign companies package their natural gas liquefaction process trictly,we can not get the heavy hydrocarbon thermodynamic conditions.According to China's natural gas properties,we select the PR equation and calculate the mixed system of three phase model for gas mixing system,in order to predict and calculate the thermodynamic properties of heavy hydrocarbons.And prepare the corresponding calculation software,as to realize its application in engineering.The paper calculate one mixing gas system,and select the correct mixing rule for PR equation.Determined the rule of mixtures of interaction factor Kij values by comparing the calculation results with the Aspen.We calculated the gas-liquid equilibrium constant and make the phase diagram.Then we calculated the fugacity coefficients of three phases,to determine the benzene,toluene and cyclohexane freeze temperature and precipitation other conditions effect the freeze temperature.This study make us not over-rely on foreign sources,it provide reliable data base and appropriate research directions and methods for the study of heavy hydrocarbons in natural gas.