Effect of bio-based flow improver on the microscopic and low-temperature flow properties of waxy crude oil

Abstract

Wax formation creates flow assurance problems in the production and transportation of waxy crude oil. Flow improvers are added to waxy crude in order to reduce handling cost. Bio-based flow improvers derived from cheap renewable resources are attractive as cost-effective, eco-friendly alternatives to the conventional additives. Natural cashew nut shell liquid extracted from waste biomass (Anacardium occidentale shells) was derivatized and applied as flow improver for waxy crude oil. Effect of the additive on wax formation in crude oil was studied by cross-polarized microscopy, while the change in oil flow properties was evaluated using a rotational coaxial cylinder viscometer. Micrographs of the waxy crude were processed and analyzed with image J software. The microscopic properties of the wax crystals were characterized using Feret diameter, crystal area, aspect ratio, circularity, solidity and boundary fractal dimension. The pour point of doped crude oil was depressed by − 18 °C and the wax area fraction reduced by 40% due to wax inhibitive effect of the additive. The presence of the additive resulted in evolution of smaller, rounder and more regular wax crystals with smoother and more even surfaces indicated by reduction in the Feret diameter, aspect ratio and boundary fractal dimension of wax crystals in doped oil, and an increase in crystal circularity and solidity. The shear stress and viscosity of doped oil were reduced by 86.8% and 85.0%, respectively. The flow improvement effect of the CNSL derivative is linked to its effect on morphology and microstructure of wax crystals in the crude oil.

Gamma radiation-induced grafting of poly(butyl acrylate) onto ethylene vinyl acetate copolymer for improved crude oil flowability

“…Additionally, the grafting of p(BuA) Homopolymer on EVA copolymer results in increased bulkiness and heightened likelihood of intermolecular interaction, thereby diminishing its effectiveness. Consequently, the pour point exhibits a subsequent increase 92 – 94 . Additionally, as shown in Fig.…”

Research Status and Outlook of Mechanism, Characterization, Performance Evaluation, and Type of Pour Point Depressants in Waxy Crude Oil: A Review

“…The main component of CNSL extracted from waste biomass is anacardic acid. Eke et al , reacted CNSL with diethanolamine and sulfuric acid to produce sulfonated cashew nutshell liquid ester amine (CNX), and found that CNX caused the wax crystals to become tiny and rounded with a smooth, homogeneous surface. Since CNX was similar to wax molecules, aliphatic chains containing C15 interacted with wax molecules and were adsorbed onto wax crystals.…”

“…The nonpolar extended-chain alkyl groups of PPD molecules interact with wax molecules to change their wettability and increase the solubility of wax molecules in crude oil, thus reducing the amount of wax precipitated, decreasing the wax precipitation rate and hindering the growth of wax crystals. Most surfactants (quaternary ammonium salts, sulfonates, , etc.) inhibit wax deposition through solubilization mechanism. ,, …”

Advances in and Perspectives on Strategies for Improving the Flowability of Waxy Oils

“…They compared them with EVA pour point depressant and found that palm oil additives were more effective in viscosity reduction. Eke et al 216 extracted natural cashew nut (Anacardium occidentale) shell liquid from waste biomass and subjected it to derivatization reaction. The obtained material was used as a waxy crude oil pour point depressant with a mixture of alkyl and alkenyl phenols as active ingredients, including cashewic acid (6-pentadecylsalicylic acid), 3cashewol (3-pentadecylphenol), 5-cashewol (5-pentadecylresorcinol), and 2-methyl-cashewol (2-methyl-5-pentadecylresorcinol).…”