Effect of polyaniline doped with dodecylbenzene sulfonic acid on pour point depressant of waxy crude oil

Abstract

The production, transportation, and storage of the crude oil below or near its pour point require a deep realizing the physical, chemical properties, and operating conditions of crude oil. Out of all the methods available for pumping waxy crude oil, the use of pour point depressant (PPD) is preferred economically. Chemical oxidative polymerization of polyaniline (PANI) doped with dodecylbenzene sulfonic acid (DBSA) was prepared and applied as a PPD for paraffinic crude oil. The prepared polymer was characterized using Fourier transform infrared, UV–Visible spectroscopy, photomicrographic analysis, and scanning electron microscope (SEM). It was found that the pour point of paraffinic crude oil reduced from +42 °C to −6 °C by treating this oil with 2500 ppm of PANI-DBSA dissolved in the heavy naphtha (PONA). This result was attributed to the innovative solvent (PONA) and represents a new achievement. In addition, the value of the crystallinity index of the paraffinic crude oil decreased from 80% to 74.7% after the addition of the PANI-DBSA. The conclusion is that the pour point of paraffinic crude oil decreases with decreasing the crystallinity index. This was mainly attributed to the effect of the polar groups of the prepared pour point depressant.