Study Of Melt Crystallization Of Octyl Phenol

Octyl phenol is an important fine chemical intermediate material, which is widely used in producing chemical products such as surfactant, bond, resin and industrial fiber. Because the quality of octyl phenol made in our country can not meet the demand, the markets of octyl phenol in China are occupied by the products from other countries such as Japan. In the paper, a new melt crystallization technology was developed to purify octyl phenol, which can provide the basic data and theoretical instruction for industrialization and engineering design.Firstly, differential scanning calorimeter (DSC) was used to measure the solid-liquid phase diagram of octyl phenol, which is appeared as solid-solution system according to the experimental result. Wilson model were introduced to simulate the experimental data combined with the generalized equilibrium relationship. In the above experiment, it is found that the melting points of the samples before the DSC experiment are different from that after the experiment. Infrared spectrum (IR), x-ray powder diffraction (XPRD) and DSC are used to characterize the samples.The kinetic behavior of the static melt crystallization of octyl phenol was investigated by means of DSC. Nonisothermal crystallization kinetic models such as Avrami model, Ozawa model, improved Ozawa model and Kissinger model were firstly introduced to process the kinetic experimental data of Octyl phenol system. The results of all the models were compared and the kinetic parameters of the models were obtained which reveal the mechanism of static melt crystallization of octyl phenol. Based on the study of the phase diagram and the crystallization kinetics of octyl phenol, the process of melt crystallization for purifying the octyl phenol was systemically investigated. The effects of the material component, crystallization temperature, crystallization time, sweating temperature, sweating steps and sweating time on the yield and quality of octyl phenol product were studied. Finally a new melt crystallization technology for purifying the octyl phenol was developed. By using of the new developed technology and the material with purity of octyl phenol > 98% and 4 –(t-Octyl) phenol content > 95%, the quality of octyl phenol would be up to the international advanced standard, namely, the purity of octyl phenol > 99.5% and the content of 4 –(t-octyl) phenol > 98%. Summarily, this new melt crystallization technology for purifying the octyl phenol has a good foreground of industrial application.