Download Turpentine Oil Hydration using Trichloroacetic Acid as Catalyst

 American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
Turpentine Oil Hydration using Trichloroacetic Acid as Catalyst
N. Wijayati1,2*, H. D. Pranowo3, Jumina3, Triyono3
1. Student of Doctorate Program, Department of Chemistry, Universitas Gadjah Mada, Yogyakarta
2. Department of Chemistry, Semarang State University, Jl. Raya Sekaran Gunungpati Semarang
3. Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta
Corresponding Author Email: [email protected]
Abstract:
Trichloroacetic acid (TCA) was used as catalyst for the hydration of α-pinene from turpentin oil
using water as hydroxyl donor. The reaction was performed in batch reactor at 70oC, using
aquous aceton as solvent. The TCA catalyst converted α-pinene into hydrocarbons, while the
TCA catalyst was active and selective for producing alcohol, α-terpineol with selectivity of
87,56%.
Keywords: Turpentine; Hydration; Terpineol; TCA
1. Introduction
Turpentine is generally produceed in places having vast tracts of pine. Chemically, turpentine is
a mixture of cyclic monoterpene hydrocarbons, C10H16, such as α-pinene, camphene. β-pinene
and 3-carene being α-pinene the predominant constituent [1]. The chemical reactivity of
turpentine varies with its composition but generally is the characteristic of α-pinene.
α-pinene is known to react readily in the presence of acids through reactions involving either
expantion to derivatives of bornane or fenchane, or ring opening to derivatives of p-memhane.
Upon treatment with aquous mineral acids, complex mixtures are obtained resulting from
isomerization and hydration [2-4].
The hydration of terpenes via acid catalysis is an important method for alcohol synthesis, and has
several applications in the perfume and pharmaceutical industries. α-Terpineol, 4-terpineol and
terpineol hydrate are from commercial viewpoints, the most interesting derivatives of α-pinene.
α-Terpineol exhibits antimicrobial activity and is used for wound healing and insect bites [5-8].
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American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
Hydration and isomerization of the α-pinene to several alcohol or terpenic hydrocarbons have been
studied since the 1940s. Román-Aguirre et al. [9] utilised oxalic and chloroacetic acid for the
transformation of α-pinene and obtained conversion of 80% with selectivity of 70% for α-terpineol after 4
h but the dissolved acid had to be separated. Robles et al. [10] used HPW12O40 as catalyst and mixtures of
acetic acid and water as solvent for hydrating limonene, b-pinene and a-pinene, obtaining selectivity to
terpineol near to 30%, with 90% of a-pinene conversion after 3 h of reaction at 25oC. Pakdel et al. [11]
used aqueous solutions of sulfuric acid as catalyst in the presence of acetone to obtain terpineol from
crude sulphated pine oil, they reported 67% of selectivity to terpineol although conversion was not
reported. The systems before mentioned need the manufacture of catalytic supports; nevertheless,
diffusivity is altered in the course of the reaction, or they present environmental problems by the
disposition of the used homogenous catalysts..
The objective of this work is to study the role of trichloroacetic catalyst to hydration α-pinene to terpineol
using water as the hydroxyl group donor.
2. Experimental Section:
2.1. Materials
α-Pinene was obtained from isolation of turpentine oil. The trichloroacetic acid (TCA), aceton and
deionized water were e-Merck products. The reagents were not purified before its use.
2.2. Instrumentation
Analysis of the reaction products was performed by Gas Chromatography (GC) (Hewlett Pacard
5890 Series II equipped with flame ionization detector/FID). The column used was HP5 (%
Phenyl Methyl Siloxane). The temperature of the column was adjusted to be 70oC for 5 min and
then increased to 280oC by 10oC/min. The carrier gas used was helium (He) (0,1µL/min flow).
The injection and detection temperatures were set to be 280 and 300oC, respectively and the split
mode was 1/100. The various components were characterized by FTIR and GC-MS instrument.
2.3. Procedure
The catalytic tests were performed in a 100-cm3 three-necked-glass reactor with condenser and
thermocouple. The reactor was submerged in thermostatic bath with silicone oil and magnetic
stirring. In batch experiment, 3.6 mmol of α-pinene, 18 mmol of water and 10 mL of aceton were
first placed. After heating to the desired temperature, 32 mol of the trichloroacetic acid catalyst
was added. Aliquots were extracted with a micropipette and immediately analyzed with GC.
3. Result and Discussion:
3.1. Effect of catalyst
Acids catalyze the hydration reactions of alkenes in aqueous solution. The acid transfers a proton
to double bond of the alkene, forming an intermediary carbocation that reacts with water to form
a protonated alcohol. The loss of H+ from the protonated alcohol generates the neutral product and
the recovery of the catalyst. In the hydration of terpenes, a variety of products may be obtained
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American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
depending on the catalyst and reaction conditions (Fig 1). To study the effect of acidity strength
and organic/inorganic nature of trichloroacetic acid on the pinene hydration, reaction test were
made at 70oC with reaction time of 30 min.
+
H+
Hydration
-H+
OH
α-pinene
Isomerization
α-terpineol
camphene
limonene
terpinolene
Figure 1. Hydratian reaction α-pinene using trichloroacetic catalyst
The hydration of α-pinene with trichloroaceticacid catalyst leads to a complex mixture of
monoterpenes (alcohols and hydrocarbons). When the hydration reaction is carried out in the
presence of water with acid catalysts, in addition to the products mentioned above, alcohols such
as α-terpineol. Alpha-terpineol, an important monoterpenic monocyclic alcohol, is industrially
obtained through the hydration of α-pinene with an aqueous mineral acid, giving rise to the cisterpene hydrate, followed by a partial dehydration to α-terpineol [2]. The formation of these
compounds supports the above mentioned, and trichloroacetic acid could promote the
water/pinene interaction, so protons at organic phase promote mainly pinene rearrangement
isomerization like in the isomerization process of pinene to produce camphene.
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American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
100
90
80
70
C and S (%)
Cα-pinene
S α-Terpineol
60
50
40
30
20
10
0
30
60
120
240
time, min
Figure 2. Conversion (C) and Selectivity (S) over trichloroacetic catalyst vs. Time
As shown in Fig. 2 and Table 1, the conversion obtained using trichloroacetic acid as catalyst was
88.20% and the selectivity to terpineol was 87.85%, this result is notable for industrial purposes,
other advantages with this catalyst are the absence of chlorinated by-products, and the capability
to recover catalyst by simple recrystallization. Trichloroacetic acid is miscible with pinene and
also soluble in water, due to these two factors, this catalyst, besides the formation of the proton to
form the carbocation, favors the transfer of OH- to organic phase and as a result, hydration yield
is the highest of the studied catalysts [9].
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American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
Table 1. Turpentine oil hydration using TCA catalyst
conversion
Selektivity, S (%)
time
(min)
α-pinene
(%)
camphene
limonene
terpinolene
terpineol
others
30
88,21
1,80
6,21
2,87
87,56
1,55
60
89,73
9,14
22,47
9,31
23,10
10,35
120
90,74
9,59
23,95
8,44
22,71
35,31
240
94,53
7,52
25,00
7,80
25,05
34,63
3.2. Effect of temperature
Fig 3 shows the effect of temperature on the conversion, plot under otherwise similar conditions.
Selectivity of terpineol increases significantly with an increase in temperature. Hydration of
α-pinene is an exothermic reaction and the equilibrium shift in the reverse direction with a rise in
temperature.
100
Concentration (%)
80
60
α-Pinene
α-Terpineol
40
others
20
0
50
60
70
Temperature, oC
Figure 3. Efect of temperature for turpentine oil hydratioan using trichloroacetic catalyst
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American Journal of Oil and Chemical Technologies;
ISSN (online): 2326-6589; ISSN (print): 2326-6570
Volume 1, Issue 9, November 2013
4. Conclusion
The chloroacetic acid catalyst was active and selective for producing alcohols, with a
conversion of 88,21% and showed 87,56% selectivity for α-terpineol at 30 min. The good
results were due to its strong acidity during reaction and its easy separation from reaction
products. The yield obtained by using this catalyst was interesting for industrial application.
5. Acknowledgements:
The authors would like to thank to Directorate General of Higher Education (DIKTI), Department
of National Education Republic Indonesia for the Fundamental Research grant.
6. References:
[1] Avila, M. C., Nora A. C., Castellon E. R., Lopez A. J., 2010, J.Mol.Catal. A:
Chemical, 322,(1-2),:106-112.
[2] Vital J., A.M. Ramos, I.F., Silva, H. Valente., J.E., Castanheiro, 2001, Catal. Today, 67,
217-223
[3] Castanheiro J.E., I.M., Foseseca, A.M. Ramos, R. Oliveira, J.Vital, 2005, Catal.Today, 104,
296-304.
[4] Mochida T., Ryuichiro O., Naoto H., Yuichi K., Toshio O., 2007, Micropor.Mesopor. Mat.,
101: 176-183
[5] Bhatia, S.P., 2008, Food.chem.toxicol., 46 : 5275-5279.
[6] Martino L.D., Vinzenco D.F., Carmen F., Enrico M., and Felice S., 2009, Molecules, 14,
2735-2746.
[7] Moreira,M.R., Cruz, G.M.P., Lopes, M.S., Albuquerque, A.A.C. dan Cardoso, J.H. L., 2001,
J.Med.Biol.Res., 34: 1337-1340
[8] Bagheri S. M, Amirhossein S, Ahmad R. G., Soodabeth S, Maryam M, and Mehrdad I, 2010,
Pharm. Biol., 48(3): 242-2463.
[9] Roman-Aguirre. M.R., De la Torre-Sáenz, Wilber A.F., A. Robau-Sánchez, A.
AguilarElguézabal, 2005, Catal. today, 107-108 :310-314
[10] Robles-Dutenhefner, Patricia A.,, Kelly A., da Silva, M. Rafiq H. S., Ivan V. Kozhevnikov,
Elena V. G., 2001, J. Mol. Catal A: Chem, 175, 33-42.
[11] Pakdel, H., Sharron, S., and Roy, C., 2001, J. Agric. Food. Chem., 49, 9, 4337–4341.
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