The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great difference...The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great differences,static melt crystallization was applied to separate and purify durene from its isomers.Crystallization experiments were carried out under various operating conditions.The effects of cooling rate,crystallization temperature,sweating temperature and sweating time on the yield and purity of crystal were investigated.Orthogonal experimental design method was adopted to analyze the factors that may affect the yield of durene.Under the optimal crystallization conditions,the purity of durene could reach as high as 99.06%with the yield of 75.3%through one crystallization process.By fitting purification data based on sweating time in isothermal operations,the purification rate coefficient was obtained.展开更多
Based on heat and mass transfer characteristics of spontaneous combustion of coal,Arrhenius equation and the Ranz-Marshall correlation,a novel approach was proposed in this paper to estimate oxygen consumption rate of...Based on heat and mass transfer characteristics of spontaneous combustion of coal,Arrhenius equation and the Ranz-Marshall correlation,a novel approach was proposed in this paper to estimate oxygen consumption rate of self-ignition of coal at high temperature.Compared with the conventional methods,this approach involves not only kinetic properties of self-ignition of coal and temperature,but also the ambient air flow characteristics and diameter of coal particle.To testify the proposed approach,oxygen consumption rates at high temperature were measured by the programmable isothermal oven experiments.Comparisons between experimental and theoretical results indicate that the rates of oxygen depletion calculated by the proposed approach agree well with those measured from laboratory-scale experiments,which further validates the proposed approach.展开更多
基金Supported by the National Natural Science Foundation of China(21176172)Top Talents Program of Yunnan Province,China(2011HA010)
文摘The purification and separation of durene from the mixture containing durene isomers were studied.Since the boiling points of tetramethyl benzene isomers are very close but their melting points are of great differences,static melt crystallization was applied to separate and purify durene from its isomers.Crystallization experiments were carried out under various operating conditions.The effects of cooling rate,crystallization temperature,sweating temperature and sweating time on the yield and purity of crystal were investigated.Orthogonal experimental design method was adopted to analyze the factors that may affect the yield of durene.Under the optimal crystallization conditions,the purity of durene could reach as high as 99.06%with the yield of 75.3%through one crystallization process.By fitting purification data based on sweating time in isothermal operations,the purification rate coefficient was obtained.
基金Project(51534008) supported by the National Natural Science Foundation of China
文摘Based on heat and mass transfer characteristics of spontaneous combustion of coal,Arrhenius equation and the Ranz-Marshall correlation,a novel approach was proposed in this paper to estimate oxygen consumption rate of self-ignition of coal at high temperature.Compared with the conventional methods,this approach involves not only kinetic properties of self-ignition of coal and temperature,but also the ambient air flow characteristics and diameter of coal particle.To testify the proposed approach,oxygen consumption rates at high temperature were measured by the programmable isothermal oven experiments.Comparisons between experimental and theoretical results indicate that the rates of oxygen depletion calculated by the proposed approach agree well with those measured from laboratory-scale experiments,which further validates the proposed approach.
