Pour point depression and flow improvement of waxy crude oil using polyethylene glycol esters of cashew nut shell liquid

AbstractWax crystallization and deposition is a major flow assurance problem in production and transportation of waxy crude oil. Conventional flow improvers are mainly high molecular weight synthetic polymers, many of which are eco-toxic. Bio-based flow improvers derived from natural products are promising as inexpensive, eco-friendly alternatives to existing products. In this study, natural cashew nut shell liquid (CNSL) extracted from waste shells of Anacardium occidentale was esterified with polyethylene glycol (PEG). CNSL derivative reduced the pour point of waxy crude oil by 12 °C at 1000 ppm. The effects of CNSL derivatives on wax crystal morphology and micro-structure were studied by cross-polarized microscopy. Micrographs were processed and analyzed with ImageJ software. Addition of CNSL derivatives to oil resulted in changes in wax crystal morphology and micro-structure evidenced by a reduction in average crystal Feret diameter and aspect ratio and increase in boundary fractal dimension, indicative of formation of increasing number of smaller, rounder crystals. Effect of the additives on flow properties of the waxy oil was determined using a co-axial cylinder rotational viscometer. Dynamic viscosity of oil at shear rate of 17 s−1 was reduced by 79.7–90.5%. CNSL-PEG esters show good prospects as low-cost additives for production, storage and pipeline transportation of waxy crude oil.

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Glycerol-modified cashew nut shell liquid as eco-friendly flow improvers for waxy crude oil

Petroleum Science and Technology ◽

10.1080/10916466.2020.1849284 ◽

2020 ◽

pp. 1-14

Author(s):

William Iheanyi Eke ◽

Ozioma Achugasim ◽

Joseph Ajienka ◽

Onyewuchi Akaranta

Keyword(s):

Crude Oil ◽

Waxy Crude Oil ◽

Cashew Nut Shell Liquid ◽

Waxy Crude ◽

Cashew Nut ◽

Cashew Nut Shell

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Evaluation of Cashew Nut Shell Liquid Borate Ester as Pour Point Depressant for Flow Assurance of Waxy Crude Oil

Letters in Applied NanoBioScience ◽

10.33263/lianbs113.36113625 ◽

2021 ◽

Vol 11 (3) ◽

pp. 3611-3625

Keyword(s):

Crude Oil ◽

Pour Point ◽

Pour Point Depressant ◽

Waxy Crude Oil ◽

Cashew Nut Shell Liquid ◽

Cashew Nut ◽

Point Depressant ◽

Borate Ester ◽

Cashew Nut Shell ◽

Flow Improvement

The development of chemical solutions to wax problems by modifying renewable natural products is an innovative response to the need for cheaper, eco-friendly pour point depressants for waxy crude oil flow improvement. Natural cashew-nut shell liquid (CNSL) was extracted from shells of Anacardium occidentale and derivatized into the borate ester. Pour point of oil doped with 500ppm CNSL borate ester was reduced by -24oC. The effect of borate ester addition on wax morphology was studied by cross-polarized microscopy. Analysis of micrographs using ImageJ software showed a decrease in Feret diameter, aspect ratio, and boundary fractal dimension of wax crystals in doped oil and increased crystal circularity and solidity, indicating the evolution of smaller, rounder, regular structures with smoother, even surfaces. At 10oC, oil shear stress and dynamic viscosity were reduced by 27.6% and 24.6%, respectively. Pour point depressant and flow improvement effects of additive were related to changes in crystal morphology.

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A study on cashew nut shell liquid as a bio-based flow improver for heavy crude oil

Journal of Petroleum Exploration and Production Technology ◽

10.1007/s13202-021-01162-w ◽

2021 ◽

Vol 11 (5) ◽

pp. 2287-2297

Author(s):

Sivakumar Pandian ◽

Patel Chintan Dahyalal ◽

Shanker Krishna ◽

S. Hari ◽

Deepalakshmi Subramanian

Keyword(s):

Crude Oil ◽

Pour Point ◽

Optimum Dose ◽

Heavy Crude Oil ◽

Cashew Nut Shell Liquid ◽

Remarkable Improvement ◽

Cashew Nut ◽

Heavy Crude ◽

Cashew Nut Shell ◽

Flow Improver

AbstractTransportation of heavy crude oil through pipelines poses a great challenge in oil and gas industry. Crude oil chokes the pipelines when the temperature drops below the pour-point temperature. In the present study, a bio-based additive, i.e., Cashew Nut Shell Liquid (CNSL) has been tested as a flow improver for heavy crude. CNSL was obtained from waste cashew nut shell by means of mechanical extraction, and it was completely characterized. Similarly, the crude oil used in the study was characterized for its physio-chemical properties. Also, the crude oil was subjected to Saturates, Aromatics, Resins and Asphaltene analysis and Fourier Transform Infra-Red analysis. The raw and additive-treated crude oil with different CNSL dosages were subjected to pour-point and rheology measurements and optical micro-imaging analysis which indicated a remarkable improvement in flow whereby an optimum dose of 2000 ppm was observed. Furthermore, the effects of different parameters like shear rate, concentration of the flow improver and the effect of temperature on the crude oil flowability were studied. The process variables were optimized by means of Taguchi method, and the percentage contribution of each parameter was identified with the help of ANOVA table. The results indicate that a remarkable improvement in flow was observed at an optimum dose of 2000 ppm. The contribution of the concentration was found to be around 53%, whereas the contributions of the shear rate and the temperature were only 18.08 and 28.91%, respectively. Therefore, it has been observed that CNSL flow improvers extracted from cheap reasonable resources are more effective as they are cost-effective and eco-friendly when compared to conventional additives.

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Synthesis and Properties Measurement of Pour Point Depressant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.616-618.948 ◽

2012 ◽

Vol 616-618 ◽

pp. 948-953 ◽

Cited By ~ 2

Author(s):

Ying Xu ◽

Rui Guo

Keyword(s):

Crude Oil ◽

Pour Point ◽

Crystal Morphology ◽

Flow Properties ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Depressant ◽

Result Show ◽

Pour Point Depressants ◽

Maleic Anhydride Copolymer

The amidation grafted copolymers derived from styrene-maleic anhydride copolymer were prepared and characterized by FTIR. Their intrinsic viscosity and crystal morphology were measured. The prepared polymers were investigated as pour point depressants (PPD) and flow improvers for waxy crude oil, and it was found that the depression effect of PPD modified by mixture amines was more effective than single amine, and the maximum depression was obtained by the sample that modified by mixture amines from 13 °C to 4 °C (ΔPP = 9 °C, at 3 000 ppm). The effect of the PPD modified by mixture amines on the flow properties of waxy crude oil was investigated. The result show that the viscosity decreased from 1 223 mPa.s to 81.3 mPa.s at 13 °C and 3 000 ppm. In addition, the crystal morphology have also been improved for the same sample and conditions.

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Effect of Pour Point Depressants on the Impedance Spectroscopy of Waxy Crude Oil

Energy & Fuels ◽

10.1021/acs.energyfuels.0c03378 ◽

2020 ◽

Vol 35 (1) ◽

pp. 433-443

Author(s):

Hongying Li ◽

Chaohui Chen ◽

Qian Huang ◽

Yifei Ding ◽

Yu Zhuang ◽

...

Keyword(s):

Impedance Spectroscopy ◽

Crude Oil ◽

Pour Point ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Pour Point Depressants

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Effects of 4-vinylbenzyl trioctylphosphonium- bentonite containing poly(octadecylacrylate-co-1-vinyldodecanoate) pour point depressants on the cold flow characteristics of waxy crude oil

Fuel ◽

10.1016/j.fuel.2020.118817 ◽

2020 ◽

Vol 282 ◽

pp. 118817

Author(s):

M.A. Betiha ◽

Tahany Mahmoud ◽

A.M. Al-Sabagh

Keyword(s):

Crude Oil ◽

Pour Point ◽

Flow Characteristics ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Cold Flow ◽

Pour Point Depressants

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Application of Synthesized Novel Biodegradable Pour-Point Depressant from Natural Source on Flow Assurance of Indian Waxy Crude Oil and Comparative Studies with Commercial Pour-Point Depressant

SPE Journal ◽

10.2118/208578-pa ◽

2021 ◽

pp. 1-13

Author(s):

Biswadeep Pal ◽

Tarun Kumar Naiya

Keyword(s):

Interfacial Tension ◽

Crude Oil ◽

Pour Point ◽

Microscopic Analysis ◽

Proton Nuclear Magnetic Resonance ◽

Flow Assurance ◽

Pour Point Depressant ◽

Waxy Crude Oil ◽

Waxy Crude ◽

Point Depressant

Summary Pour-point depressants (PPDs) were synthesized from natural sources and used in waxy crude oil transportation to reduce the pour point and improve flow. A biodegradable PPD (BPPD) was synthesized and tested to mitigate crude oil flow assurance problems in the present work. The transesterification process was used to synthesize coconut oil ethyl ester (COEE, termed as BPPD). Fourier transform electron spectroscopy (FTIR), proton nuclear magnetic resonance (H-NMR), and microscopic analysis were performed for better understanding of mechanisms for both BPPD and a commercially available PPD named PPD-A. The pour point of crude oil was reduced by 12 and 9°C after the addition of 800 ppm BPPD and PPD-A, respectively. The microscopic analysis confirms that the crystals of wax converted to very fine and dispersed particles during mixing of additives, which in turn increase flowability. BPPD performs better to reduce interfacial tension than PPD-A. The maximum reduction of 19% in interfacial tension was observed after the addition of 800 ppm BPPD. BPPD alters the wettability of the pipeline surface from intermediate wet to water-wet within 60 seconds, which results in reduced slip velocity and consequently lessens the deposition of wax. As a result, crude oils will not stick to the wall of the pipe surface and will experience less resistance to flow through pipelines. FTIR analysis indicated that long-chain alkane and aromatic groups are responsible for a higher pour point, and their concentration level was reduced after the addition of BPPD. The viscosity of crude oil was reduced by almost 94% after the addition of 800 ppm BPPD with crude oil, which in turn minimizes pumping costs for crude oil. As a result, the total project cost was reduced substantially. Biodegradability tests confirm that the BPPD is biodegradable and nontoxic. Due to its biodegradability and nontoxic nature, BPPD has a promising capacity to be used in the petroleum industry for easier pipeline transportation of waxy crude.

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