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

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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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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Laboratory evaluation of modified cashew nut shell liquid as oilfield wax inhibitors and flow improvers for waxy crude oils

Upstream Oil and Gas Technology ◽

10.1016/j.upstre.2022.100068 ◽

2022 ◽

Vol 8 ◽

pp. 100068

Author(s):

William Iheanyi Eke ◽

Ekemini Ituen ◽

Lin Yuanhua ◽

Onyewuchi Akaranta

Keyword(s):

Laboratory Evaluation ◽

Crude Oils ◽

Cashew Nut Shell Liquid ◽

Waxy Crude ◽

Cashew Nut ◽

Cashew Nut Shell ◽

Waxy Crude Oils

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Comparative Study of Cashew Nut Shell Liquid and a Commercial Demulsifier for Treating Crude Oil Emulsions

Chemical Science International Journal ◽

10.9734/csji/2019/v28i430148 ◽

2020 ◽

pp. 1-17

Author(s):

C. O. Victor-Oji ◽

U. J. Chukwu ◽

O. Akaranta

Keyword(s):

Crude Oil ◽

Water Content ◽

Raw Materials ◽

Synergetic Effect ◽

Test Method ◽

Cashew Nut Shell Liquid ◽

Water Separation ◽

Cashew Nut ◽

Oil Emulsions ◽

Cashew Nut Shell

Cashew Nut Shell Liquid (CNSL), a natural phenolic liquid extracted from locally sourced raw materials, and Phasetreat-4633 (a commercial demulsifier) were diluted with xylene and butanol and used as demulsiﬁers in the treatment of crude oil emulsions. Laboratory simulated crude oil emulsions dosed with different concentrations of CNSL and PT-4633 were the basis for comparison of demulsifier performance via the bottle test method. Different factors affecting demulsiﬁcation efﬁciency such as; water content, demulsifier concentration, and solvent type were investigated at 10%, 30%, and 50% water content. The data obtained showed that the rate of water separation increases with increasing concentration and water content of the demulsifiers and emulsion respectively. Among the demulsifier-solvent combination employed in this study, Phasetreat-4633 in butanol recorded the most efficient water separation with optimal (100%) separation recorded after 5 minutes at 40 ppm and 50 ppm concentration, 50% water content and 60℃. From the obtained results, the investigated demulsiﬁers have great potential with butanol as a solvent in the resolution of crude oil emulsions in shorter times. This behavior can be attributed to the synergetic effect of butanol as a solvent. Hence, butanol can be regarded as a better solvent substitute to xylene, due to its attributive synergetic effect, low cost and toxicity levels, unlike xylene which is more toxic and expensive.

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Synthesis and Evaluation of Ethanolamine-Cashew Nut Shell Liquid Products as Crude Oil Emulsion Breakers

Asian Journal of Applied Chemistry Research ◽

10.9734/ajacr/2019/v4i430122 ◽

2020 ◽

pp. 1-33

Author(s):

C. O. Victor-Oji ◽

U. J. Chukwu ◽

O. Akaranta

Keyword(s):

Crude Oil ◽

Water Content ◽

Synergetic Effect ◽

Anacardic Acid ◽

Cashew Nut Shell Liquid ◽

One Pot ◽

Water Separation ◽

Oil Emulsion ◽

Cashew Nut ◽

Cashew Nut Shell

Cashew Nut Shell Liquid (CNSL), a natural phenolic liquid, was extracted from cashew nut shells using acetone and derivatized using Ethanolamine (EA) and Diethanolamine (DEA) in varying molar ratios via a one-pot process into anacardic acid-based ethanolamine esters and evaluated for use as crude oil emulsion breakers. The CNSL extract was characterized for its physico-chemical properties, FTIR spectral analysis for CNSL and the derivatives confirmed its chemical modification. Medium heavy crude and seawater sampled and characterized with ASTM standards were used in producing laboratory-simulated crude oil emulsions at varying crude oil: water mixing ratios of 90:10, 70:30 and 50:50. Performance of the anacardic acid-based CNSL extract and derivatives as demulsifiers were evaluated based on variation in dosage (10 ppm – 50 ppm), water content (10%, 30% and 50%), and solvent types (xylene and butanol, BuOH) at 60℃ within a 3-hr period via bottle testing. The performance of effective demulsifier formulations were compared with a commercial demulsifier, Phase Treat-4633, PT-4633, under similar conditions. Results obtained showed that water separation increases with demulsifier concentration and emulsion water content respectively, though water seperation varied among the demulsifiers as concentration and water content increased. PT-4633 in butanol achieved efficient water separation with an optimal seperation (100%) observed after 5 minutes at 40 ppm and 50 ppm, 50% and 60℃. In conclusion, the evaluated ethanolamine-CNSL products possess emulsion breaking potential using BuOH as solvent at shorter times. This behaviour may be due to the synergetic effect of BuOH as a solvent, thus, BuOH should be considered as solvent substitute for xylene due to low cost and toxicity levels, unlike xylene which is toxic and expensive.

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