Misr J. Ag. Eng.

, 36 (3): 953 - 968 PROCESS ENGINEERING

EXTRACT THE AROMATIC OIL OF THE

ROSEMARY PLANT BY STEAM DISTILLATION AND
HYDRO-DISTILLATION METHODS
Arafa. G. K.*
ABSTRACT
Pure essential oils are extracted from various parts of plants and are
widely used in various fields of industries, such as perfumery and
pharmaceutical industries. These essential oils have a high commercial
value because of their therapeutic properties. The objective of this study is
to study the behavior of rosemary oil extraction by using both steam
distillation and hydro distillation method including quantity, components
and ratios of distilled oil analysis and oil analysis. Gas chromatography
for the effect of extraction time (5, 10, 15, 30, 60, 90 and 120 min) on yield
and composition of essential oil obtained by water distillation method and
steam distillation method at three different levels of water vapor flow (3 l /
min, 6 l / min and 9 l / min) was also investigted. This research revealed
different behaviors of the main components of rosemary oil. α-pinene and
1.8-cineole and camphor in the treatment with the amount of vapor flow
rate. Experience has shown that steam distillation method is better than
water distillation based on the ratio of oil and its components.
1. INTRODUCTION

E ssential oils of plants have many applications in medicines,

cosmetics, food stuff and pharmaceutical industries. They are
present in plants at low concentration which would require high
performance extraction techniques in order to achieve high yield.
Generally, essential oils are produced by different methods, including
solvent extraction, supercritical fluid extraction, hydro-distillation, steam
distillation, use of superheated steam and combinations of the previous
techniques with others such as ultrasound and microwave-assisted
processes (Chemat et al. 2006 and Masango 2005). Rajeswara (2002)
showed that the steam distillation is one of the most popular methods
because of its low cost in comparison with advanced methods such as
supercritical fluid extraction and its green approach compared to solvent
extraction.

*Ag. Eng. Res. Institute., Ag. Res. Center

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This method has been actively pursued since the beginning of the 1980s.
In the literature there are some studies of oil extraction by steam
distillation.Masango (2005). studied the effects of increasing the steam
flow rate and steam jacket as well as appropriate insulation of distillation
column in extracting essential oil from Artemisia and Lavender plants by
steam distillation, optimizing the consumption of energy and increasing
the final yield of extraction. Romdhane et al. and Tizaoui ( 2005)
presented a mathematical model for optimizing the steam distillation
process for preparation of Pimpinella anisum oil. Chemat et al. (2006)
Using a microwave heater instead of an electric ovn decreased the time of
extraction and improved the quality of Artemisia oil. In another study the
effect of crushing of the plant and time of extraction on the yield and
chemical composition of Coriander oil was reported by (Smallfield
2001).Rosemary (Rosemarinuse officinialis L.) is an aromatic, medicinal
and condiment plant that belongs to the family labiatae, reaching a height
of 1.5 meters. Essential oil of rosemary, known as rosemary oil, is
obtained by steam distillation method of the fresh leaves and twigs. The
yield ranges from 0.5 to 1.5 % (w/w) (Mateus et al 2006). Chemical
composition and physicochemical characteristics have been reported for
rosemary essential oil. It is an almost colorless to pale yellow liquid with a
characteristic, refreshing and pleasant odor. Major components
characterized for the oil are α-pinene, 1,8-cineole and camphor
(Boutekedjire et al. 2003). The effect of extraction time on the yield and
composition of rosemary oil has been reported in two different methods;
steam distillation and hydrodistillation (Masango 2005) . The composition
of oil may vary to a large extent depending on the extraction method used.
Steam distillation process was modeled as an inevitable step to project
industrial plants with good operational condition (Cassel et al. 2009 and
Bimakr et al., 2011). showed that conventional soxhlet extraction of
flavonoids of spearmint took 6 hr for 3 g of dried and ground plant at 40°C
using solvents such as ethanol, methanol. So, they proposed supercritical
extraction with CO2 to obtain high efficiency (Bimakr et al 2011).
Therefore, solvent extraction does not perform well. In the present study, a
column was designed and constructed in order to evaluate the steam
distillation process for the extraction of rosemary oil. Optimal operating

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conditions were determined in order to achieve high extraction yields.

Also, it can be analyzed the effect of different parameters on chemical
composition of the extracted rosemary oil. The novelty of the process is
introducing multistage beds of plant in order to achieve a better extraction
of target materials through enhancing mass transfer operation.

2. MATERIAL AND METHOD

2.1- Plant material
The rosemary samples were collected obtained from the farm of the
Medicinal and Aromatic Plants Research Department, Dokki, Giza, in
2018. Fresh plant materials were carefully separated into leaves and stems.
The samples were dried in the shade for 5 days for use in the research
experiments and the primary moisture of the leaves was 60.2%(w.b). For
the extraction of essential oils, 100 grams of each powder sample was
used and then the essential oils isolated by hydro distillation and steam
distillation are isolated for 5, 15, 30, 60 and 120 minutes. Then separating
essential oils from the water layer and drying them over anhydrous sodium
sulphate, and calculating the average yield of aromatic oil.

2.2- Essential oil extraction

Essential oil was extracted from each of the plant parts by two extraction
methods:

2.2.1- hydro distillation

The Clevenger-type apparatus hydro distillation was used for this purpose for
is shown in Fig. (1). A mixture of Rosemary leaves or powder (200 g) and
1000 ml of water was put into a 2000 ml round bottomed flask. The
temperature was set at 80C for the extraction of essential oil. The process in
Clevenger-type apparatus was run for the time till no further oil could be
extracted. The essential oil was vaporized with the steam. Condensation
occurred as the vapours of essential oil and steam mixture passed through a
condenser. The condensate, a mixture of oil and water, was then separated.
Essential oil being lighter settled above water and it was collected. To study
the kinetics of extraction of oil, essential oil was collected at regular intervals
during the extraction process.

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Fig. (1 ). Essential Oil hydrodistillation

2.2.2- Steam distillation apparatus and procedure

A schematic diagram of the steam distillation apparatus used for essential
oil extraction is shown in Fig. (2).The apparatus has a cylindrical Pyrex
body (6 cm inside diameter and 60 cm height). A batch of 100-200 g of
dried and ground leaves of rosemary was packed in the column with 2000
ml water in steam source. The raw material forms the packed bed. The lid
was closed and the process of distillation began with the injection of steam
to the bottom of the column. Each plant bed was exposed to several flow
rates of steam. Steam and essential oil were condensed and collected in
time intervals of 5, 15, 30, 60 and 100 minutes. Following condensation,
the mixture was decanted to separate phases of oil and water. The essential
oil was collected, dried with anhydrous sodium sulfate and stored at 4oC
until analyzed. In these experiments, the steam jacket of the column was
insulated by foam cover having 1 cm thickness. After doing the
experiments and determining the yield of each experiment, the obtained
samples from the three experiments with steam flow rates of 3, 6 and 9
l/min and a packed bed of 100 g that were collected at five intervals,
namely 5, 15, 30, 60 and 100 minutes, were analyzed by GC-MS and GC

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instruments. Each experiment was repeated at least three times and mean
of results was reported.

Figure 2. Schematic diagram of the steam distillation apparatus.

2.3 -Volatile oils:

The essential oil yield was estimated according to the dry vegetal matter
by using the following equation:
Moil
Y= s M × 100………………………………..……….(1)
Where: Y: Percentage of Essential oil yield [w/w].
Moil: Mass of essential oil [g].
MS: Mass of dry plant [g].
The percentage of volatile oil of different plants was measured at the end
of drying process and calculated as follows:-
volum of distillati on vlatile oils
Volatile oils % = x 100… (2)
weight of leaves sample
2.4 - Gas chromatography-mass spectrometry identification
GC analyses were carried out using a Hewlett-Packard 6890 with HP-5
capillary column (phenyl methyl siloxane, 25 m×0.25 mm, 0.25 μm film
thickness) and a DB-1 capillary column (30 m ×0.25 mm, 0.25 μm film
thickness). The temperature of oven was programmed to 60–240°C at
4°C/min; injector temperature, 250°C; detector temperature, 260 °C;
carrier gas, He (1.5 ml/min); split ratio, 1:25. GC–MS analyses were
carried out applying a Hewlett-Packard 6859 with a quadropol detector, on

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a HP-5 column (see GC), operating at 70 eV ionization energy, using the

same temperature programmer and carrier gas as above.
3. RESULTS AND DISCUSSION
The results obtained from the extraction of essential oil from the rosemary
plant in two methods of extraction as follows:
3.1- hydro distillation
The yield of the hydrodistillation was 0.44%. The essential oil yield as
a function of time is shown in Fig. 3, and all oils are recovered after
30 min. In addition, the yield increases quickly at the beginning of the
extraction, its evolution becoming slower thereafter. whereas for the
hydrodistillation it takes at least 30 min to extract 88% of the oil.
Analysis by gas chromatography of the oil recovered with regular
time intervals enabled us to follow the evolution by time of the
relative content of some major components of oil belonging to
various known chem- ical families: 1,8-cineol, camphor, borneol, α-
terpineol, bornyl acetate,β-caryophyllene and δ-cadinene,as shown in
Fig.4. Also Fig.4 shows a rapid evolution of the content of the
considered components, and those recovered in the ascending order of
their boiling points. then the β-caryophyllene follows them with a
maximumcontent after 15 min The fact that the components
considered are recovered in the ascending order of their boiling points
The 1,8-cineol and camphor are recovered in greater proportion after
10 min hydrodistillation, as shown in Fig. 3. it can be observe
thereafter the simultaneous extraction of borneol, α-terpineol, bornyl
acetate and β-caryophyllene, which reach their optimal contents
after 20 min of the process. After 30 min, only traces of these
components are recovered. In addition, the considered components are
not recovered in the order of their boiling points. Indeed, 1,8-cineol
is collected at the same time ascamphor, whereas it is more volatile.
The same happensfor other components which have different boiling
points.
3.2 - Steam distillation
The isolation and concentration of essential oils were performed in single
stage and multistage column with three steam flow rates. The yield was

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calculated from the relation between the mass of obtained oil and the mass
of raw material used in the experiments.
0.16
0.14
The yield of essential oil

0.12
0.10
0.08
0.06
0.04
0.02
0.00
0 10 20 30 40 50 60 70 80 90 100 110 120
Time

Fig.(3) Evolution of essential oil yield as related to extration time.

10 min 20 min 30 min

35
30
25
Relative content %

20
15
10
5
0

Components of oil

Fig.(4) Evolution of the content of some conponents of rosemary essential

oils during hydrodistillation proccss

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The three different steam flow rates (3, 6 and 9 l/min) and a packed bed of
100 g were used. The results are shown in Fig. 5. It can be seen from this
figure that as steam flow rate decreases, the amount of oil increases
monotonically in each of the five intervals. The greatest yield was
obtained for the steam flow rate of 3 l/min, which was 1.074. Also, from
the sharpness of the slope during the first 30 minutes, it can be observed
that the highest extraction rate occurs in the first 30 minutes of extraction
time. In general, in most cases of the experiments, between 85 and 95
percent of total oil was extracted during this interval. The effect of height
of packed bed on the extraction yield of essential oil was considered for
two steam flow rates of 3 and 6 l/min and packed beds with the heights of
30, 45 and 60 cm. These heights were equal to 100, 150 and 200 g of
plant, respectively.

1.20 y = 0.1563ln(x) + 0.3722

R² = 0.9125
The essent oil yield (%)

1.00

0.80
y = 0.1273ln(x) + 0.3768
0.60 3 l/min
R² = 0.9335
0.40 y = 0.1231ln(x) + 0.3167 6 l/min
R² = 0.8889 9 l/min
0.20

0.00
0 20 40 60 80 100
Time (min)

Fig.(5) Extraction yield as a function of processing time under different

steam flow rates.
The results of these experiments are presented in Figs. 6 and 7. It was
evident from these experiments that with an increase in the mass of the
packed bed, a sharp decrease occurred for the total yield of the extraction,
depending on the steam flow rate. Furthermore, the slope of the curves for
the packed beds of 45 and 60 cm of height were less during the 30 minutes
in comparison with that of 30 cm height of bed. It revealed that the

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amount of extraction was less in this interval for higher heights of single
packed bedAn increase in the height of the packed bed caused higher
pressure drop. As a result, the total yield of the extraction decreased. To
avoid this problem, steam redistributors were used between every two
successive beds of the column.

1.40 y = 0.1823ln(x) + 0.3234

R² = 0.9437
1.20
The essent oil yield (%)

1.00

0.80
100 g
0.60 y = 0.1351ln(x) + 0.3225 150 g
0.40 R² = 0.9618
200 g
y = 0.1156ln(x) + 0.3405
0.20 R² = 0.9245
0.00
0 20 40 60 80 100
Time (min)

Fig.(6).Yield curves of rosemary oil samples for different masses of packed -

beds for steam flow rate of 3 l/min.
1.20 y = 0.1214ln(x) + 0.4235
R² = 0.9521
1.00
The essent oil yield (%)

y = 0.104ln(x) + 0.3206
0.80 R² = 0.9957

y = 0.0976ln(x) + 0.2974
0.60 R² = 0.986

0.40

0.20
100 g 150 g 200 g
0.00
0 20 40 60 80 100
Time (min)
.
Fig.(7). Yield curves of rosemary oil samples for different masses of packed
bed for steam flow rate of 6 l/min.

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As seen in Figs. 5 to7, using two or three stages of beds caused an increase
in the total yield of the extraction, and the yield of such process in one-
stage column with a mass of 150 g and a steam flow rate of 6 l/min
reached from 0.776 to 1.03 % in a three stage column with the same
condition Fig. (8). As shown in Fig. (9). Reduction of total mass of beds at
the same steam flow rate of the previous condition enhanced the yield.
With respect to Fig. 10, a decrease in the steam flow rate and also a
decrease in the mass of the packed plant with the same height of column
caused a yield increment up to 1.36 %. However, using more stages does
not cause any increase in the total yield. With a decrease in the height of
the packed bed, a decrease in the steam channeling was observed. But,
here the contact between steam and the internal walls of the column
increased, which in turn caused the steam condensation on the internal
walls of the distillation column which returned to the packed bed The
results of GC-MS analysis showed that rosemary oil has 61 components
with the concentration between 0.01 and 15.47 percent.

1.40 y = 0.176ln(x) + 0.47

R² = 0.9541
1.20 y = 0.1274ln(x) + 0.5235
R² = 0.8747
The essent oil yield (%)

1.00
y = 0.142ln(x) + 0.3407
R² = 0.9307
0.80

0.60

0.40 One-stage column

Two-stage column
0.20 Three-stage column

0.00
0 20 40 60 80 100
Time (min)

Fig.(8). Yield curves of rosemary oil samples for multistage column with
steam flow rate 6 l/min and packed bed of 150 g.

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1.60 y = 0.2051ln(x) + 0.4745

R² = 0.9401
1.40
y = 0.1886ln(x) + 0.4468
The essent oil yield (%)

1.20 R² = 0.9727

1.00 y = 0.2115ln(x) + 0.2437

R² = 0.953
0.80

0.60

0.40 One-stage column

Two-stage column
0.20 Three-stage column
0.00
0 20 40 60 80 100
Time (min)

Fig.(9). Yield curves of rosemary oil samples for multistage column with
steam flow rate 6 l/min and packed bed of 100 g.

1.60 y = 0.2051ln(x) + 0.4745

R² = 0.9401
1.40
y = 0.1886ln(x) + 0.4468
1.20 R² = 0.9727
The essent oil yield (%)

y = 0.2115ln(x) + 0.2437
1.00 R² = 0.953
0.80
One-stage column
0.60 Two-stage column
Three-stage column
0.40

0.20

0.00
0 20 40 60 80 100
Time (min)

Fig. (10). Yield curves of rosemary oil samples for multistage column with
steam flow rate 3 l/min and packed bed of 100 g.

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The results of gas chromatography were analyzed for three experiments

with steam flow rates of 3, 6 and 9 l/min and a packed bed with a mass of
100 g. The three most important components (α-pinene, 1,8-cineole, and
camphor) were selected and changes in their concentration in relation to
the time of extraction were studied during 5, 15, 30, 60 and 100 min
intervals (Figs. 11 to 13). For α-pinene a maximum extraction occurred in
the first 5 minutes, following a decrease during 15 minutes and an increase
in the further 30 minutes of extraction was observed. For 1,8-cineole,
decrease in extraction amount occurred during the time of extraction. Low
extraction was observed for camphor in the first 5 minutes; a maximum
extraction occurred at 15 minutes and was followed by decreasing with
time. Varying steam flow rate had no effect on the behavior of each
component.

Generally, Experiments showed variations in the amount of components

with time. The results indicated weak effect of steam flow rate on the
essential oil components. In other words, a change in the amount of steam
flow rate does not lead to either increase or decrease in any considerable
components of Rosemary essential oil. However, the time of distillation
has an effect on the constituents of essential oil. This effect was studied
for three important components of Rosemary essential oil: α-pinene, 1,8-
cineole, and camphor. Each of these components showed different
behavior in contact with steam flow rate during time intervals. First,
barrier effect, and second, the boiling points of components. In the case of
α-pinene, barrier effect is active and for camphor and 1,8-cineole, the
boiling point is effective.

It should be noted that some of the α-pinene is present in the cell of plant
walls and some exists inside these cells. This increase and decrease is due
to evaporation of compounds that exist between these cells. Another
reason is the time needed to destroy the cell walls that contain essential
oils. But in the case of camphor and 1,8-cineole, this trend is the result of
their boiling points. 1,8-cineole has the boiling point of 176 C, and
camphor has the boiling point of 209 ̊C. Each of these components showed
different phenomenon in contact with steam flow rate during time
intervals.

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0.40
α-pinene Component(%) 0.35
0.30
0.25
0.20 4 l/min
0.15 7 l/min
0.10 9 l/min
0.05
0.00
5 min 15 min 30 min 60 min 100 min
Time

Fig.(11).Change of alpha-pinene concentration in terms of time for different

steam flow rates.

0.18
0.16
1,8-cineole Component(%)

0.14
0.12
0.10
4 l/min
0.08
7 l/min
0.06
0.04 9 l/min

0.02
0.00
5 min 15 min 30 min 60 min 100 min
Time

Fig.(12).Change of 1,8-cineole concentration in terms of time for different

steam flow rates.

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12

10
Camphor Component (%)

6 4 l/min
7 l/min
4
9 l/min

0
5 min 15 min 30 min 60 min 100 min
Time (min)

Fig.(13).Change of camphor concentration in terms of time for different

steam flow rates.

4. REFERENCES
Bimakr, M., R.A. Rahman, F. S. Saleena, A. Ganjloo, L. Md Salleh, J.
Selamat, A. Hamid and I. S. M. Zaidul (2011). "Comparison of
different extraction methods for the extraction of major bioactive
flavnoid compounds from spearmint (Mentha Spicata L.) leaves",
Food and Bioproduct Processing, 89, 67.

Boutekedjiret, C., F. Bentahar, R. Belabbes and J. Bessiere (2003).

"Extraction of rosemary essential oil by steam distillation and
hydrodistil-lation", Flavour and Fragrance J., 18, 481.

Cassel, E., R. M. E. Vargas, L. Martinez, N. D. and E. Dellacassa

(2009) "Steam distillation modeling for essential oil extraction
process", Industrial Crops and Products, 29, 171.

Chemat, F., M. Lucchesi, J. Smadja, L. Favretto, G. Colnaghi and F.

Visinoni (2006). " Microwave accelerated steam distillation of

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essential oil from lavender: A rapid, clean and environmentally

friendly approach", Analytica Chimica Acta, 555, 157.

Rajeswara, R., B. R. Kaul, P. N. Syamasundal, K. V. and S. Ramash

(2002). "Water soluble fractions of rose-scented geranium
(pelargonium species) essential oil", Bioresource Technology,
84,243.

Romdhane, M. and C. Tizaoui (2005). "The kinetic modelling of a steam

distillation unit for the extraction of aniseed (pimpinella anisum)
essential oil", J. Chem. Technol. Biotechnol., 80,759.

Mateus, E. M., C. Lopes, T. Nogueira, J. A. A. Lourenco and M.

Curto, R. Rajeswara, B. R. Kaul, P. N. Syamasundal, K. V. and
S.Ramash (2006). "Water soluble fractions of rose-scented
geranium (pelargonium species) essential oil", Bioresource
Technology, 84,243.

Masango, P. (2005). "Cleaner production of essential oils by steam

distillation", J. Cleaner Production, 13, 833.

Smallfield, B. M., J. W. Van Klink, N. B. Perry and K. G. Dodds

(2001) ."Coriander spice oil: Effects of fruit crushing and distillation
time on yield and composition", J. Agric. Food Chem., 49, 118.

‫الملخص العربى‬
‫استخراج زيت نبات حصالبان بواسطة التقطير بالبخار والتقطير المائي‬
*‫عرفه‬ ‫ جمال كمال‬/‫د‬

‫يتم استخراج الزيوت العطرية النقية من أجزاء مختلفة من النباتات والتى تستخدم على نطاق واسع‬
‫ وهذه الزيوت‬.‫ مثل صناعة العطور والصناعات الدوائية‬، ‫في مختلف مجاالت الصناعات‬
‫ والهدف من هذه الدراسة هو دراسة‬.‫األساسية لها قيمة تجارية عالية بسبب خصائصها العالجية‬
‫تأثير استخراج زيت حصالبان من خالل استخدام كل من التقطير بالبخار وطريقة التقطير المائي‬
‫على كميتة ومكوناتة ونسب تحليل الزيت المقطر و تحليل الزيت كروماتوجرافيا الغاز‬

‫ مصر‬-‫ مركز البحوث الزراعية‬- ‫ معهد بحوت الهندسة الزراعية‬-‫* باحث أول‬

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‫لمعرفة تأثير وقت االستخراج (‪ 90 ، 60 ، 30 ، 15 ، 10 ، 5‬و ‪ 120‬دقيقة) على المحصول‬

‫وتكوين الزيت العطري الذي يتم الحصول عليه بواسطة طريقة تقطير الماء وطريقة‬
‫التقطير بالبخار لثالثة مستويات مختلفة من تدفق بخار الماء (‪ 3‬لترات) ‪ /‬دقيقة ‪ 6 ،‬لتر ‪ /‬دقيقة‬
‫و ‪ 9‬لتر‪/‬دقيقة)‪ .‬اظهر هذا البحث عن سلوكيات مختلفة للمكونات الرئيسية لزيت‬
‫حصالبان ‪ 1.8 -cineole ، α-pinene‬و ‪ camphor‬في المعالجة مع مقدار معدل تدفق البخار‪.‬‬
‫أظهرت التجربة أن طريقة تقطير البخار أفضل من طريقة تقطير الماء بنا ًء على نسبة الزيت‬
‫وكميته وكذلك مكوناته‪.‬‬

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