Title : Novel synthetic-based drilling fluid through catalytic and non-catalytic transesterification of linseed oil from CO2-enhanced super-critical fluid extraction process.
Abstract:
In this study, the optimum reaction parameters as well as the effect of catalyst concentration and type on the percentage yield and physico-chemical characteristics of linseed oil ethyl esters obtained from non-catalyzed (free catalyst system), super critical ethanol (SCE), homogeneous, heterogeneous and bio-catalytic (enzymatic) trans-esterification reactions were experimentally investigated. The catalysts under investigation are sodium hydroxide (NaOH), calcium Oxide (CaO) and lipase catalyst (Candida antarctica) from Novozymes biotechnology company. The crude linseed oil was extracted from its seeds by super critical fluid extraction (SFE) process using carbon IV oxide as the extraction solvent and an oil yield of 43.50% was obtained. The fatty acids compositional analyses of the extracted oil were determined by an Agilent 8890 gas chromatography system coupled with Agilent 5977B mass selective detector (GC-MSD) and thermal desorption auto sampler (TD sampler). A Fourier transform Infra-Red (FTIR) spectroscopic technique was used to detect and measure the complete conversion of the triglyceride to fatty acid ethyl ester (FAEE). The physico-chemical properties of the synthesized ethyl esters were evaluated by using the American petroleum institute (API), ASTM D 6751-07b and the European committee for standardization (EN 14214) recommended standard procedures and techniques.
The GC-MS analysis shows that the linseed oil contains essentially of poly-unsaturated fatty acids (about 53.15% of alpha Linolenic acid with 16.00% of Linoleic acid) and 20.80% of mono-unsaturated oleic acid. The major saturated fatty acids that were found in the oil GC-MS profile are 6.20% of Palmitic acid and 3.45% of Stearic acid with some traces of arachidic acid (0.30%). The Super critical ethanol (SCE) and the enzymatic ester production routes have the lowest quantities of free glycerine, water content, sulphated ash, carbon residue and total acid number as evident in their FTIR spectra because there was no production of soap and hence no washing steps were required. Though, with the former being more efficient than the latter in terms of ester yield, quality and superior cold flow, density, kinematic viscosity and oxidative stability characteristics. Finally, in comparison to catalytic reactions, non-catalyzed super-critical-alcohol trans-esterification process is faster with high triglyceride conversion efficiency in a very short time. However, the process requires higher temperature, pressure and alcohol to oil molar ratio when compared with the catalyzed reaction and hence higher cost of ester synthesis.
Key words: Bio catalyst (Candida Antarctica), ester yield and quality, Fatty acid ethyl ester (FAEE), Linseed oil, FTIR, GC-MS, heterogeneous catalyst, homogeneous catalyst, non-catalyzed, super critical fluid extraction (SFE), transesterification reaction.
Audience Takeaway:
- The research showed the technical viability and environmental friendliness potential of linseed oil as new discovery and promising candidate in the endless search for novel synthetic drilling fluid.
- The research article experimentally examined the effect of catalyst concentration and various catalytic routes as well as non-catalyzed transesterification reaction on the yield and physico-chemical characteristics of linseed plant oil fatty acid methyl ester (FAME).
- The research describes the optimum conditions under which production of Fatty acid methyl ester from linseed oil can be termed efficient.
- The article will serve as guide to researcher, scientist and various bio-energy operators on the consequence of increasing and reducing one parameter or the other on Fatty acid methyl ester ‘scold flow properties (cloud point and pour point) and critical fluid parameters (density, viscosity, acid number).
