蜡碳数分布和蜡含量对结蜡层分层的影响研究

Effect of Carbon Number Distribution and Wax Content on Stratification of Wax Deposit Layer

利用Couette结蜡装置,对不同蜡碳数分布和蜡含量的纯蜡油和含沥青质蜡油开展结蜡实验,研究蜡碳数分布和蜡含量的改变对结蜡层分层的影响。通过外观形貌观察和DSC热分析发现:随着油样蜡分子碳数的升高,纯蜡油结蜡层厚度增大,蜡含量减少;含沥青质蜡油结蜡表层厚度和蜡含量减小,底层厚度增大而蜡含量减小。随着油样蜡含量的升高,纯蜡油结蜡层、含沥青质蜡油结蜡表层和底层的厚度及蜡含量均增大。且蜡碳数分布和蜡含量的改变不会导致结蜡层分层,沥青质加入是结蜡层分层的主要原因。通过蜡晶微观形貌观察发现:纯蜡油结蜡层、含沥青质蜡油结蜡表层和底层中,蜡晶形貌分别为:线状、枝状和片状。且随着油样蜡分子碳数的升高,结蜡层蜡晶尺寸变大,数量减少;随着油样蜡含量的升高,蜡晶尺寸变大,数量增多。

The effects of carbon number distribution and wax content on stratification phenomenon of wax deposit were studied by the experiments on pure wax oil and asphaltenes-containing wax oil samples with different carbon number distribution and wax content using Couette device.The macroscopic morphology and DSC curves of wax deposit show that as the carbon number of wax molecule of the samples increases,the thickness of the wax deposit of pure waxy oil increases and its wax content decrease;the thickness and wax content of the outer layer of the wax deposit of asphaltenes-containing wax oil decrease,and the thickness of the inner layer increases and wax content decreases.As the wax content of samples increases,the thickness and wax content of the wax deposit of pure wax oil and the thickness and wax content of the outer layer and inner layer of the wax deposit of asphaltenes-containing wax oil increase.The change of carbon number distribution and wax content will not lead to the stratification of the wax deposit,and the addition of asphaltene is the main reason for the stratification of the wax deposit.The observation of wax crystal microcosmic morphology shows that the wax deposit of pure way oil and the outer layer and inner layer of the wax deposit of asphaltenes-containing wax oil are needle-like,branch-like and sheet-like separately.As the carbon number increases,the size of wax crystal increases and its number decreases.As the wax content increases,the size of wax crystal increases and its number increases.