Process Developent Of PVB Power Production In Homogeneous Phase Method

In the existing process of PVB, it has disadvantages of unsteady aldehyde groupdistribution, low content of aldehyde acetal group. So the homogeneous stagealcoholisms-condensation process, the dimethyl sub-sulphone process, as well as thepolar match alcohol process have studied systematically.In the stages alcoholisms-condensation homogeneous process, the effect of thereaction temperature, the catalyst amount and material proportion on the alcoholisms andcondensation reactions is discussed systematically. Owing to the research on theinteraction of alcoholisms and condensation, the best reaction time needed in stagealcoholisms reaction and the condensation reaction was obtained. The optimum time werethat: alcoholisms of 15 minute, condensation of 60 minutes in the first stage; alcoholismsof 30 minute, condensation of 60 minutes in second stage; alcoholisms of 50 minute,condensation of 90 minutes in the third stage.The experiment revealed that PVB ,which is made in stage alcoholisms-condensationcraft, was steady in the aldehyde group distribution and contain aldehyde acetal groupwhich was gained 75% at the most.In the dimethyl sub-sulphone homogeneous process, reaction temperature, time,material proportion, the catalyst type and quantity in the condensation reaction wereoptimized. Final condensation fluid processing method was discussed. PVB, whichproduced by homogeneous process with dimethyl sub-sulphone as solvent, achieved 82%of aldehyde acetal group. The recycling of dimethyl sub-sulphone using rectifyingconsumed 7.30×10⁷ kJ per hour. In the alcohol method homogeneous process, the appropriate water entrainer wasdesignated through research on solubility and solution behavior of the polymer. To makesure that the polymer and the solvent can match in polar aspect in the reacting system,entrance speed of water entrainer was determined. On the basis of determination reactionrate, The kinetics equation was obtained as follows: r=kC_Aⁿ₁C_Bⁿ₂=573.59e^{5769.78／T}C_A^2.08C_A^20.8C_B^0.31.Some craft parameters as reaction temperature, reaction time, material proportion areoptimized by the orthogonal experiment preliminarily. The results show that the contentof PVA solution is 20%, material ratios of three kind of feedssm_pvA∶m_丙醇∶m_H2O=2∶3∶5, the dissolving temperature is 85-90℃, the aldehydetemperature is 55℃, mass ratio of the sulfuric acid as catalyst to PVAis m_H2SO4∶m_pvA=0.12∶1, the molar ratio of hydroxyl in the butyricaldehyde to PVA isn_丁醛∶n_羟基=1.1∶2, the reaction time is 3h. PVB, making from alcohol methodhomogeneous process, contained 83% of aldehyde acetal group and steady aldehydeacetal group distribution. The recyciing of propanol using first extraction then rectifyingneeded 4.34×10⁶ kJ per hour.