Synthesis, characterisation and pre-evaluation of a novel terpolymer as pour point depressants to improve the Malaysian crude oil flowability

Ibrahim Elganidi,Norhayati Abdullah,Norida Ridzuan,Basem Elarbe

doi:10.1007/s13202-021-01445-2

Ibrahim Elganidi, Norhayati Abdullah + Show 2 more

Open Access

https://doi.org/10.1007/s13202-021-01445-2

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Abstract

Wax deposition is considered one of the most serious operational issues in the crude oil pipelines. This issue occurs when the crude oil temperature decreases below the temperature of wax appearance and paraffin wax starts to precipitate on the pipelines’ inner walls. As a result, the crude oil flow is impeded because of the precipitated wax. The use of polymeric pour point depressants has obtained significant interest among researchers as an approach of wax control for enhancing the flowability of the waxy crude oil. PPD of poly(behenyl acrylate -co-stearyl methacrylate-co- maleic anhydride) (BA-co-SMA-co-MA) was facilely synthesised by the use of free radical polymerisation. The variation of the PPD structure was studied by choosing several essential parameters like monomers ratio, reaction time, initiator concentration, and reaction temperature. Furthermore, viscosity measurement, pour point, and cold finger apparatus have been employed to evaluate the efficiency of the synthesised Polymer. The chemical structure of poly(BA-co-SMA-co-MA) has been identified through the use of Fourier transform infrared as well as nuclear magnetic resonance. The experimental findings demonstrated that the ideal conditions for obtaining the highest yield were 1.5% initiator concentration, reaction time and temperature of 8 h and 100 °C, respectively, and monomer ratio of 1:1:1 (BA:SMA:MA). Under these ideal conditions, the prepared terpolymer reduced the crude oil viscosity at 30 °C and 1500 ppm from 7.2 to 3.2 mPa.s. The cold finger experiment demonstrated that after poly(BA-co-SMA-co-MA) was used as a wax inhibitor, the maximum efficiency of paraffin inhibition of 45.6% was achieved at 200 rpm and 5 °C. Besides, the best performance in depressing the pour point by ΔPP 14 ℃ observed at the concentration of 1500 ppm, which can change the growth characteristics of wax crystals and delay the aggregation of asphaltene and resin, thus effectively improving the flowability of crude oil.

Highlights

It is widely acknowledged that the main components of the crude oil mixture consist of resins, asphaltenes, paraffin, and aromatic hydrocarbons
The result shows that methacrylate moiety, a moiety of maleic anhydride, and alkyl chain moiety are present in the synthesised terpolymer
The most excellent poly(BAco-Stearyl methacrylate (SMA)-co-maleic anhydride (MA)) yield was 90 wt%, which was observed at the following optimum polymerisation reaction environments: reaction time of 8 h, reaction temperature of 100 °C, and initiator concentration of 1.5 wt% and monomers ratio (BA:SMA:MA) of 1:1:1

Summary

Introduction

It is widely acknowledged that the main components of the crude oil mixture consist of resins, asphaltenes, paraffin, and aromatic hydrocarbons. Polymers containing long linear alkyl chains and a polar component such as acetate, acrylate, and methacrylate groups have an increased ability to interfere with crude oil crystal wax below their cloud point (Yao et al 2016). These additives can co-precipitate with the wax, causing steric hindrance during the crystallisation process, interfering in the growth and aggregation of wax crystals. API and viscosity were computed with a Micromeritics AccuPyc II 1340 pycnometer and Brookfield DV-III viscometer, respectively

Evaluation performance of terpolymer

Results and discussion

Conclusion