Sinokrot farms produce several culinary plants for exportation to European countries. These culinary plants are: basil, chervil, chives, coriander, lemon thyme, mint, oregano, parsley, rucolla, rosemary, sorrel, tarragon, and thyme.  30%-50% of these products only meet the export standards. The residue (the loss) which is in high quality are gathered and used as animals food.  This project is designed to reuse the loss of culinary plants by rendering them into economical articles. At the first part of the project drying experiments were carried out to produce spices while at this part of graduation project the work is continued to produce essential oils from aromatic plants    . 

Extraction of essential oils from different aromatic plants such as Rosemary, Thyme, Minta and Orange is a promising business.  The extraction method used was Steam Distillation which was applied to isolate an Essential Oil from These plants. The steam distillation was successful and the produced oil quantity and quality are identical to that found in literature. The oil color is transparent faint yellow with refractive index is about 1.422 .

A sample of approximately 1000(g) of wet green plant was placed in the distiller. The water content in these fresh herbs were about 85-93% and the extracted oil was ranged between (1_3) ml.

In general different samples of dried products are used for preparation of pastes, macaroni and pizza sauces, while the essential oil may be used for hundreds of therapeutically and flavoring formulations. 

It's important to say that the obtained products are pure organic, free from chemicals, this because pesticides and fertilizers were not used at cultivation process.

Finally, exploitation of culinary plants by products at PAPA production site is a promising project for different perspectives and it was found that the salvage value of the project after five years is about 6192100NIS.

 

 

 

 

 

 

 

 

Table of Contents                                                                              Page

Abstract:……………………………………………………………………………. 1 

Problem:.....................................................................................................................5   

Methodology:………………………………………………………………………………………………………..5    

Introduction:…………………………………………………………………………6

Theoretical background:……………………………………………………………19

Experimental part:………………………………………………………………….20

Results:……………………………………………………………………………..22

Discussion:…………………………………………………………………………………………………………..28  

Conclusion &Recommendations:…………………………………………………..29

References:………………………………………………………………………….31                                                                                                                                               

Appendices:…………………………………………………………………………32                                                                                                                                           

 

 

 

 

 

 

 

 

 

 

 

List of figures:

 

 

 

 

 

 

 

 

 

List of tables:

 

 

 

 

 

 

Problem

This project is based on the cultivation of plants under certain conditions to be exported to Foreign countries like Europe,America and Russia by Jordan, also 70% of these plants don’t meet export standards  that specified by the importing countries. This percentage has an economical value, so we are seeking for a solution to convert them to an economical article such as spices, flavors, or liquid food additives.

This project is obeying the interests of the different parties. The producing company will increase its profit by exploiting the herbal loss through processing to valuable product. The processing creates jobs for chemical engineers, and reduces the spice import. 

Four varieties of natural medicinal plants are included in this project as mentioned here:

1) Mint Bunches

2) Rosemary Bunches

3) Sage Bunches

4) Thyme Bunches

In addition, Orange peels are included too. 

 

Methodology 

This project is designed to be achieved through the following stages.

1-      Bringing the plants to the laboratories of chemical engineering departments for processing.

2-      The processing is achieved by:

Drying:  This require  the establishing of the optimal conditions of drying , so, there is a need to find the equilibrium moisture content, the rate of drying , the time of drying  and selection of economical drying method. This part was done in the first part of the graduation project.

3-      Extraction of essential oils from green herbs by steam distillation, A steam distillation unit was subjected to different modifications and improvement to increase the separation efficiency .

4-      After finishing all trials and extracted the liquid matter Oil’s composition was analyzed by measuring its refractive index. 

5-      Working out rough feasibility study for 100kg herbs/charge unit

Beside all mentioned steps literature survey must be carried out to learn from other experiences.

 

Introduction 

It is worth to give short description on  the plants used in the project containing their medical and culinary benefits .

Sage:

  

Figure(1) :Sage herbs [9].

 

Medical uses:

Sage used for a variety of conditions including mouth inflammation, gingivitis and sore throats [1]. 

 

Culinary uses:

Because Sage has such antibacterial and antioxidant properties, it has been used for centuries as a flavoring and natural preservative for cheeses, meats and meat products, especially sausage [2].

 

 

Mint: 

  

 

Figure(2):Mint herbs [10].

 

Medical uses [3] :

1. Mint tea relieves from menstrual cramps and heavy menstruation.
2. According to traditional medicine mint is a contraceptive. Infusion made with mint leaves is useful for cold, flu, hiccups and flatulence.
3. Keep  breath fresh by chewing some mint leaves.
4. Mint cures from dog bites, scorpion and beestings.
5. Infusion of mint is good for hypertonic diseases, atherosclerosis, and kidney and liver diseases.

Culinary uses :

Mint has numerous applications in the kitchen, being used all over the world as flavoring as well as key ingredients to foods and drinks. Peppermint makes an excellent flavoring for ice cream, chocolates, and other deserts [4].

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rosemary:

 

 

Figure(3):Rosemary herbs [11].

Medical uses :

Rosemary has been around for a long time, and therefore has a long list of claims regarding its medicinal uses, including use as a tonic, a digestive aid, to treat depression, headaches, and muscle spasms, and stimulant for production of bile.  Also it is good to stimulate hair growth [5]. 

Culinary uses [6] :

The leaves and flowers of rosemary can be used in many different dishes such as:

1) The flowers can be used in desserts e.g sprinkled over ice cream or mousses.

2)  Making rosemary flavored oil or vinegars.

3) Add chopped leaves to soups, sauces, salads, pasta and bread .

 

 

 

 

 

 

Thyme:

 

Figure(4):Thyme herbs [12].

Medical uses :

It has been used through the centuries as a remedy for many ailments, from epilepsy to melancholy. Nowadays, it is prescribed by herbalists for intestinal worms, gastrointestinal ailments, bronchial problems, laryngitis, diarrhea, and lack of appetite  [7].

Culinary uses :

This herb is great when used fresh. Thyme also is a great complement for many vegetables, including tomatoes and roasted potatoes [8].

 

The main objectives of this part of the project are:

a.       The development of the existing steam distillation equipment by carrying out some modifications to increase the efficiency of essential oils separation process.

b.      Extraction of essential oils by using this equipment.

c.       Making rough feasibility study for extraction of essential oils.

 

 

 

 

 

 

 

Essential Oils:

Essential oils are very important economically article because of different uses in aromatherapy and as flavor in food. So it's worthy to give some introduction on it.

An essential oil is basically the life blood of a plant. It can be found in the glandular hairs, glands, veins or sacs of a plant, grass or tree. The 'oil' is extracted from flowers, trees, fruits, roots and leaves. It is the actual aroma which is extracted and it is this aroma which is used in aromatherapy to treat a number of ailments.

Essential oils are volatile; that is, they evaporate at, or above, room temperature. It is the factor of heat which releases the aroma and fragrances. True essential oils are non-oily, despite their name. They are never identical by their very nature; variations can be caused by temperature, soil conditions, the altitude grown at and the country grown in.

The chemical make-up of each individual essential oil is complex but they are nearly all comprised of some combination of alcohols, phenols, aldehydes, ketones, acids, esters, oxides, lactones, coumarins and furocoumarins. The result of this means that most essential oils are anti-inflammatory; anti-viral; anti-fungal; detoxifying; circulatory; anti-spasmodic; analgesic and decongestant. All essential oils are able to be absorbed by the human body; they are all non-greasy; they are only partially water soluble; they are all inflammable; they are all volatile; they are all soluble in both alcohol and carrier oil (which are used to blend essential oils and be absorbed by the skin.

In addition ,all essential oils are capable of being antiseptic; all essential oils are balancing to the mind, emotions and various systems of the body; all essential oils are pro biotic, that is, they help the body fight infection and disease and build up the body's natural defenses to further attack [13].

All essential oils [13]:

• Are prophylactic – they are all intended to prevent disease.
• Are stress relieving – they balance emotions and certain essential oils have a pronounced sedative and calming effect on the nervous system, for example, Lavender (lavandula angustifolia).
• Are synergistic – the different chemical components complement each other within an essential oil and when blended together their effectiveness is greater than when used singly.

Finally, it is worth mentioning that all essential oils are quenching, meaning they 'satisfy' each individual component of an essential oil or blend of oils. For example, the high proportions of ketones in Sage (salvia officinalis) are 'made safe' by the presence of the other components. On their own, they would be toxic; without them, the other components would not function as expected.

 

Literature review

Essential oils physical and chemical properties :

It is worth to give short description of  the physical and chemical properties of the essential oils that were extracted from different herbs  in the project :

 

1)      Sage [14]:

Product Name: Clary Sage Oil.

Oil properties: Sage oil has a sharp, herbal smell, and is watery in viscosity.

Chemical composition: The main chemical components of sage oil are a-pinene, camphene, b-pinene, myrcene, limonene, 1,8-cineole, a-thujone, b-thujone, camphor, linalool, bornyl acetate and borneol.

Table(1) :Physical & Chemical Properties of Sage herbs [14]:

 

2)      Mint(menthol) [15]:

Product Name:  Peppermint Oil.

Oil properties : Peppermint oil has a fresh, sharp, menthol smell, is clear to pale yellow in color and watery in viscosity.

Chemical composition : The chemical components of peppermint oil are menthol, menthone, 1,8-cineole, methyl acetate, methofuran, isomenthone, limonene, b-pinene, a-pinene, germacrene-d, trans-sabinene hydrate and pulegone.

Table(2) :Physical & Chemical Properties of Mint herbs [15]:

 

 

3)      Rosemary [16]:

Product Name:  Rosemary Organic Essential Oil.

Oil properties : Rosemary oil has a clear, powerful refreshing herbal smell, is clear in color and watery in viscosity.

Chemical composition : The main chemical components of rosemary oil are a-pinene, borneol, b-pinene, camphor, bornyl acetate, camphene, 1,8-cineole and limonene.

 

 

 

Table(3) :Physical & Chemical Properties of Rosemary herbs [16]:

 

 

4)      Thyme [17]:

Product Name:  Thyme Essential Oil (White).

Oil properties : It has a rather sweet, yet strongly herbal smell and is reddish-brown to amber in color.

Chemical composition : The main chemical components are a-thujone, a-pinene, camphene, b-pinene, p-cymene, a-terpinene, linalool, borneol, b-caryophyllene, thymol and carvacrol.

Table(4) : Physical & Chemical Properties of Thyme herbs [17]:

 

Oranges oil :

The Oil of Orange is an Essential Oil derived from the rind of oranges and some other citrus fruits. It is composed of Limonene, α and βPinene, Myrcene, Octanal, Decanal, δ-3-Carene, and Linalool; with Limonene comprising over 90% of the Oil derived from common orange varieties. Because it is non-polar, Limonene makes a good, environmentally friendly solvent.

 

 

Figure (5): Orange oil chemical structure [18].

Limonene:

Limonene is concentrated in the peel of an orange. The orange peel has two distinct layers, the skin and the pith. Limonene is not distributed evenly between these two layers. Experimentation has shown that only minimal quantities of limonene can be extracted from the white pith.

The yield of limonene is about 1% using this outer skin. This is a large yield compared to other essential oil extractions, where yields can range from 1-0.01 % by mass [18].

 

 

 

The production of natural perfumes from essential oils [20]:  

The existence of a volatile oil, however, is by no means confined to the inflorescence, but frequently occurs in other parts of the vegetable organism.

                               

 Table (5) : The part of plants that may contain essential oils:

 

 

Separation methods of essential oils [20]:

The manufacturing processes employed may be conveniently classification as follows:

1.      Distillation ( thyme, rosemary, menthol, Geranium, Lavender, Neroli, Rose, etc)

2.      Expression  ( Citrus oils )

3.      Extraction by mean of :

 (a) enfleurage.

 (b) maceration.

(c) volatile solvents.

1) Distillation:

This processes in a crude form dates back to the times of the ancients, when fire was regarded as a supernatural element. Among the earliest type of apparatus were the cucurbits, the Alembic, and the Bercbile, from which has gradually been evolved the distilling apparatus of modern time. Also it was known that the Arabian alchemist (and physician) Ibn Sina - also known as Avicenna, who lived 980 - 1037 AD, was the first one who designed perfect steam distillation , and his process was so good that it stayed unchanged for a couple of hundred years.

The processes of evolution were slow up to the middle of the last century, but was hastened in later years, largely on account of the remarkable advance made in the perfume industry.  During this period the improvement in the construction of steam and vacuum stills has only increased and cheapened the yield of oil, but has materially enhanced the purity of the product.

Volatile oils, as a general rule, are a highly odorous, mobile liquid and may be obtained from plants by stream distillation without undergoing decomposition. They usually contain numerous individual bodies, differing in chemical constriction and tow one or more of these the characteristic odor of the oil is due. 

Different distillation processes are employed for separating the essence from the plant, and choice of method depends upon the nature of the product and the yield that can be obtained. Several factors contribute towards the amount of essential oil that can be won from the plant, in many cases, of course, the plant grows wild, and no effort has been made to study the particular kind of manure that could be used to materially increase the yield of oil. In a few instances, however, the of this part of the process has been realized, and the case of lavender proved by the experiments of professor Zaccharewitz, of Avignon, who found the yield of oil could be more than double by use of an artificial manure consisting of sodium nitrate 1, potassium chloride 1, calcium superphosphate 3. Another important factor is the preparation of the plant for the still, and upon this will depend not only the yield of oil but also the rapidity with which the process may be completed. The state of the raw material must be such that the steam or water can completely permeate the mass and carry over with it into the condenser every particle of essential oil present. In many cases, such as flower, leaves, and grasses, the raw material requires no special treatment, but sometime the complete extraction of the volatile oil would be impossible without its previous preparation.

The processes of distillation may be divided broadly under the tow following heads:

1.      By boiling with water.

2.      By means of steam(dry or live)  

The first method is the oldest and the easiest. It is still applied by the peasant who grows his own plants and is too far from the factory to convey them there. With carful application good results are obtained, but if a part of the raw material should not be covered with water and come in contact with the hot sides of the apparatus, destructive distillation takes place with the production of obnoxious bodies and a consequent impairment of the odor of the final product.

This last danger is overcome by the application of the second method, when the steam is produced in a boiler or other vessel away from the still. In this case the apparatus is fitted with a steam jacket or a steam coil (for dry steam distillation), and also with a live steam inlet.

The rate of distillation of the essential oil depends mainly on the condition of the raw material and the rate at which the volatile oil is liberated from it. This is influenced to some extent by its vapor pressure and the molecular weight of its constituents.

Condensation is effected by means of water-cooled coils or vertical tubes, the latter being very efficient and rapid for many products. If they are too fast, however, air cooling is resorted to as in the case of ores oil. To save the space and the cost of the enormous length of tube necessary for air cooling, warm can be inserted in warm water kept at any specific temperature by means of a thermostat and condensation efficiently effected.

Many ingenious forms of receivers are in  use where by the oil flows from one exit and the condensed water run back into the still automatically. Florentine flasks are also used, both singly and in cascade. In the case of crude oils rectification is effected by redistillation with stream.

In a number of instances, notably in those of orange flower and rose, the oil, or some of its constituents are slightly soluble in the aqueous distillate, and even by the volatile oil is difficult and frequently impossible. Such water enter commerce as Aqu-Trip.

 

2)      Cold Pressing method (Expression) :

Cold pressing requires a rind, so it can only be used with citrus fruits and certain seeds. The rind is ground into small pieces and then pressed. Under the pressure, the oil will be squeezed out along with trace amounts of the rind. The oil is then allowed to separate and harvested [19].

There are three main processes for the separation of so-called citrus oils the peel of the lemon, orange, bergamot, and lime.

They may be described as:

(a)    Sponge process.

(b)    Ecuelle method.

(c)     Machine process.

The first is applied to lemon and orange oils; the second was at one time employed for lemon oil but is now little used; the third on a large scale is applied mainly for the production of bergamot oil, but as described below, machines have been devised to deal efficiently with lemon oil also.  A small quantity of oil of limes is prepared by the sponge process, but is as well known the major portion of the oil of commerce is obtained as a by-product of distillation in the West Indies.

A)    The sponge process :

The oil cells of the rind of any of the above fruits are easily broken, as can be shown by turning a piece of lemon peel backwards. This process on a large scale, therefore, does not offer any serious difficulty, nor does it require very heavy pressure for the extraction of the oil. It may divided into three stage:

1.      The preliminary operation of the peel.

2.       The expression of the oil.

3.       The clarification of the oil.

      B) The Ecuelle method:

The Ecuelle method is practiced in the north of Italy, and consists of rolling the fruits about in hollow vessels, the walls of which are covered with spikes. The oil cells are punctured, and the liquid flows to the bottom, being collected in a receptacle situated in the handle of the vessel. The product is then clarified as described above.

C)    Machine processes:             

Machine processes have been applied in the manufacture of lemon and bergamot oils during recent years. One for the production of lemon oil consists of a mechanical adaptation of the sponge process, when the pressure is applied with a liver.

Machine consists of two channels between which the fruit is rolled; skin is lacerated by means of spikes, and the mixture of oil and juice is collected and subsequently  and then the rind is placed between two rotative wire sieve-like plates.

 

3)  Extraction:

Reference has already been made to the separation of volatile oils from plants (and their flowers) by means of distillation, and in several instances this process yields oils of exceptional purity and of very fine aroma. In a large number of cases, however, the application of this method does not yield products which are entirely satisfactory because many unstable aromatic substances are damaged or completely destroyed by the high temperature of steam, while in other cases the quantity of essential oil that could be obtained would be negligible. In view of these facts, other methods are used for the separation of the fragrant bodies from the flowers, and they are known as extractions by means of solvents. The materials used for this purpose are broadly classified as volatile and non-volatile, while the latter are again sub-divided according to the conditions of temperature appertaining during the process. These distinctions are clearly indicated as follows:

1.      Extraction by means of non-volatile or fixed solvents such as animal fats or vegetable oils.

(a)    At normal temperatures-Enfleurage.

(b)   With the application of heat-Maceration.

2.      Extraction with volatile solvents such as petroleum ether, etc.

The choice of process depends upon several factors, the more important being:

(a)    That certain varieties of flowers produce fragrant materials when placed in such a condition that their vital functions may still be exercised.

(b)   Those other varieties of flowers contain all their odoriferous principles in the free state, and are unable to produce new fragrant materials, even if still living.

 

Theoretical background [21]:

In our case the steam generator is connected directly to the a steam distillation unit as shown  below:

 

Figure(6) : Steam generator system and steam distillation unit

 

 

Steam distillation works because the Water and the Oil are immiscible. Hence, they boil independent of each other.

 

So, boiling occurs when the sum of the pure vapor pressures equals the atmospheric pressure:

Patm= PWato+ POilo                                                 (Eq. 1)

Thus, a mixture of two immiscible liquids boils at a temperature lower than the Normal Boiling Point or either component of the mixture. Because PWato>>POilo, the mixture will boil at a temperature slightly less than the normal boiling point of Water. This means the Oil will vaporize under very mild conditions.

However, this methodology leaves us with one complication; the distillate is a mixture of Oil and Water. The relative numbers of moles (n) of each component of the distillate will be given by:

nOil/ nWat= POilo/ PWato                                                     (Eq. 2)

If we know the average molecular weigth (M) of the Oil, then we can estimate the mass (m) of Oil that will be obtained in a given amount of Water:

mOil/ mWat= (POiloMOil) / (PWatoMWat)                          (Eq. 3)

 

 

Experimental part

Many extraction experiments are carried out to investigate the behavior of different herbs by using steam distillation unit .

Steam Distillation process of Essential Oils:

1)      Place fresh plant matter or dried botanical in the bottom chamber of distiller. Loosely pack the chamber.

2)      Turn on the hot plate of your distillation unit. As the water heats, the steam begins to rise up from the lower chamber. It should take about a half an hour for the steam to pass through the chamber into the condenser.

 

 

3)      Wait between one to two hours before finishing the process. Most of the oil will come off plant matter within the first hour of the distillation process.

 5) Turn the distillation unit off. Wait for the entire unit to cool down by using ice-bath. At this point the essential oil will have risen to the top of the water in the cooling tank.
 6) Skim the oil off the top and put it in a bottle for storing. Some distillation units have valve at the bottom of the cooling chamber. Slowly open this valve and release just the water. Close the valve leaving the oil in the cooling chamber.

7) A new style of receiver was developed which allow to separate the oil from the condensed water.

8)  Get collection bottle and open the valve to drain the oil into the collection bottle.

9) It is also known that different cases may be faced, oil is very slightly dissolve in water, or some polar organic constituents dissolve in water. Other ways were not applied to use in the project but may be needed to extract the Essential Oil from the co-distilled Water. Oil is soluble in non-polar solvents like Diethyl Ether (CH3CH2OCH2CH3). Ether is added to the Oil-Water mixture in a Reparatory Funnel. This funnel allows the two solvents to layer and subsequently we can drain one solvent layer away from the other.

After a few moments of shaking, the Oil will Partition into the Ether layer. Draining the Water layer from the Ether removes the Oil from the Water. The partitioning is almost never complete, so an Extraction is usually carried-out multiple times. The resulting Ether layers are collected and combined. (Caution must be observed when shaking the system. First, the system must be vented continuously because of vapor build-up that occurs within the flask. Second, the shaking cannot be too vigorous or else the system will emulsify. If emulsification occurs, separation of the two layers will become very difficult.) , then a mixture of Oil and Ether that must be separated. However, this is not a major problem. The Ether will boil at a low enough temperature that it can simply be boiled off from the Essential Oil. After the Ether is stripped off, isolation of the Essential Oil is complete.

 

 

 

 

 

 

Results

Those results were documented during the extraction of the essential oils from Rosemary, Sage, Mint, Thyme and Orange shells which represented the amount of oil_in ml_extracted from a sample of 1000g of fresh herbs deposited inside the distiller.

Steam distillation experiments data :

 

Table(6):Thyme steam distillation data

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table(7):Rosemary steam distillation data

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table(8):Sage steam distillation data

 

 

 

 

 

 

 

 

 

 

 

 

 

Table(9):Orange shells steam distillation data

 

 

 

 

 

 

 

 

 

Marketing survey about oils prices in Nablus for different sellers:

 

Table(10): Arafat’s shop for oils(Nablus)

 

 

Table(11):Breek shop for dry herbs(Nablus)

 

 

Table(12):Arafat shop for herbs(Nablus)

 

 

Table(13): Mahmood AL_Deerawy squeezor for oils(Jenen)

 

 

Table(14): Habayeb shop for oils (Tulkarm)

 

 

Table(15):King of perfumes shop(Tulkarm)

 

 

Rough estimation of production cost of essential oils :

Assumption:

1-100NIS/month cost of electricity and water.

2-we don't include the operation cost of raw material.

3-the price of 1Kg from rosemary oil =1000$.

4-1$=3.5NIS.

5-work 15 day/month .

6-number of years(n)=5 years=60 months.

7- heat content of 1 kg of cooking gas=  .

 

           Cost of production for 1 kg of steam:

Assuming 70% efficiency of burning .

Usable energy or energy transferred to the system for steam generation = 0.7 * 28000

                                                                                                                   =19600 kJ /kg

Enthalpy of steam = 2676  kJ /kg at 100 ᵒC.

The amount of saturated steam produced from 1kg of cooking gas =

                                                                 =7.32kg steam

Price of 1 Kg gas =

                             = 5.27 NIS/kg gas.

The cost of 1 Kg of steam = 5.27/7.32 = 0.7 NIS .

We could estimate the cost of electrical energy and water is about 100NIS/month.

 

 

 

 

 

 

Figure(7): Cash flow diagram

Capital cost:

CC= cost of the devise +cost of two pumps(0.5KW) +cost of two tanks (5m³) .

CC=30000 +1000+ 3000=

                                        =34000(NIS)

Operating cost(OC)= salary + water & electricity .

OC=5000+2500= 7500 NIS/month.

3.5*1000= 3500NIS/Kg.

For one charge: 100Kg Rosemary yield 700 g oil=0.7Kg.

0.7*1000=700$/Kg=2450NIS/Kg.

For 3 batches: 

3*2450=7350NIS/Day.

For 1 month:

Salvage value(SV)=7350*15=110250NIS/month.

OC /yr=7500*12=90000NIS/yr.

SV/yr=110250*12=1323000NIS/yr.

Future worth(FW)=-capital cost(F/P,i%,n)-OC(F/A,i%,n)+sulvage value(F/A,i%,n).

i=0.5% .

FW=-34000(F/P ,0.005,5)-90000(F/A ,0.005,5)+1323000(F/A ,0.005,5).

From appendix ().

FW=-34000(1.02525)-90000(5.05025)+1323000(5.05025).

FW=6192100NIS.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Discussion

The discussion is limited to experimental work that was carried out to obtain informative results. The extraction of oils was started on August where the weather was dry and hot so that the   herbs were exposed to air before starting the distillation, this action was allowed the evaporation of large percentage of water content from the porous of the plants, so that the most of the residuals were the volatile oils which needed to be extracted. On November the temperature and relative humidity of the air were approximately constant.

Many extraction experiments were done on Sage, Rosemary, Mint, Thyme and Orange shells to extract  available oils. In average about (2_3) g oil/1000 g   plants were distilled for each trial.

The time that needed for the extraction is very important parameter to make a comparison between the applied herbs, and it was determined as shown in tables (6-9) from steam distillation processing.

From the results, it was found that Orange shells yield volume of oil which was about 2 (ml) and the process required about 20(min) ,while Rosemary and Thyme yield about 2.5(ml) for 20 minutes of processing ,but Sage oils was formed as drops on the surface  of the condensed water .

Rosemary oil was very strong and produced a beautiful smell, so it could be used in the production of the perfume, its color was pale greenish and the refractive index was equal to 1.47 . These results were identical to the physical properties from the literature review in table (3) .

For Thyme oil the color ,odor ,and refractive index were  slightly yellow ,strong and 1.47 respectively ,as same as the physical properties from the literature review in table (4).

Different problems were happened during the process, one of it, that  the essential oil which collected in Plastic bottles(Polyethylene) made a dissolution in bottels due to the effectiveness of oil.

Other problem, when the color of the samples that stored in a plastic bottles became as same as the bottles color. To solve this problem glass test tubes were used to store the essential oils.

The collection of the oil was applied by skipping it from the surface of the water by a dropper  that interrupted the process , consumed time and few drops of oil was remaind in the dropper, also there was a loos of oils due to the exchanging of flask when the water over flow.The soluation was to design a new type of reciever which allowed the seperation of  the oil from the distilled water in easy way  . The reciever had two exits one for the excess water and the other for the oil  which float on the  top due to the difference in the density,then it will collected by a valve that was a part of the reciever component .

A modification was applied on the cover of the  chamber in order to increase the flow of the steam which came out to the condenser, so for this reason a cylindrical stainless

 steel connection of one inch diameter was constructed between the distiller and the condenser instead of the older one .

Based on our experiment it is needed to prepare (500-1000) gram steam for each one kg of solid material , or in average 0.7 kg .It means that we need to prepare 100 kg steam of 100 kg solid material.

Marketing survey was obtained from the  visting of differnt herbs shops in Nablus and Tulkarm cities . The results mentioned above in the tables (10-15) show the prices of the conducted plants in the project which were Thyme, Mint ,Rosemary and Sage whether sold  in kilograms or as essential oils but it is well known that the prices of the fresh herbs  or the related powders are less than the extracted liquids because oils separation is a complicated process which needs special equipments and specified conditions and its  cost  more than drying  . For example about 500(NIS) must paid for one liter of Sage oil while just 40(NIS) is the price of one kilogram .

 The project is successful because the capital cost will be covered after one month if we assume that the raw material costs and workers salaries  not included.

There are different previous experiences for the oil extraction from fresh herbs. At 2008 solvents extraction were carried out by Ala Naser and three graduated students from chemical engineering depatrment at An Najah university [22]. Also a feasibility study for the extraction of essential oils was achieved at 2009 which was also by steam distillation unit but they didn’t get satisfatory results as we did that is due to the applied modifications on the system [23].

 

 

Conclusion & recommendations

In this present project, a simple extraction method was applied by using a steam distillation system in the unit laboratory at An Najah university . The system consisted of four  main parts which were the chamber where the herbs placed, the condenser, the steam generator and a control panel. A cylindrical connection of 1(in) was constructed between the condenser and the distiller to increase the flow rate from the chamber to the condenser which was accelerated  the process ,this modification was designed instead of the smaller diameter connection. During each experiment the time of the extraction was documented to make a comparison between  herbs depending on the response time needed to produce the oil which was in average about 20 minutes for the trial.

 Experiments have been conducted on sage, mint, rosemary, thyme ,and orange shells. It was found that sage oils appeared as few drops on the surface of the condensed water which was a very small amount compared with other plants like rosemary and mint.

The effects of herbs weights that deposited in the distiller, the steam average flow rate and temperature  on the extraction characteristics have been kept on the same ranges.

It was proved that practically the essential oils of different Palestinian plants can be separated with satisfactory results which fitted with the literature data. 

 

The essential products from herb were obtained by oil extraction from  the leaves and sticks . The recommendations to achieve a good extraction rate are :

1.Based on our experience, it is recommended to store the herbs at hot windy place to spare the cost of extraction atconstant extraction rate period because that allowed the evaporation of a large percent of water content which accelerated the distillation process .

2.Extraction the liquid juice from the  herbs and carrying out  experiments on it  to use  as food flavors .

3. All extracted samples must be stored in glass bottles instead of plastic because it was  melt due to the  the effectiveness of oil’s components.

4. Steam distillation unit needed some improvements . For example the condenser must be controlled to reduce the amount of the volatile matter that escaped from the reciever for this reason poor condensation must be used in the system. The rate of condensation was about 500 ml/20 min ,so the solution was just to slow it down .

5. Extraction of oils using distillation unit is a method and it is better than other methods of extraction like solvents extraction.

6. Exploitation of culinary plants by products at PAPA production site is a promising   project for different perspectives .The extracted samples that were  used in different foods give strong indications that national organic flavoring spices can be produced in big amounts. This means profit for company and new jobs for engineers.

7. One of the main problems we faced that the availability of herbs to run experiments. It is not available when we needed it.

8. In the future we hope to continue the extraction of essential oils with the help of Sinokrot company.

 

 

 

 

References

Received on March, 8, 2013

 [1,2]: http://www.nutrasanus.com/sage.html

 [3]: http://www.bhg.com/gardening/plant-dictionary/

[4]: http://healthmad.com/alternative/15-wonderful-medicinal-uses-for-mint/

[5]: http://www.mintrubbing.org/themintplant.pdf

 [6]: http://www.gardensablaze.com/HerbRosemaryMed.htm

[7,8]: http://www.nutrition-and-you.com/thyme-herb.html

[9]: http://www.bhg.com/gardening/plant-dictionary/herb/sage/

[10]: http://www.bhg.com/gardening/plant-dictionary/herb/mint/

[11]: http://www.bhg.com/gardening/plant-dictionary/herb/rosemary/

[12]:http://www.bhg.com/app/plantencyclopedia/searchResults.jsp?searchType=quick&plantType=&zone=all&searchString=Thyme+

Received on November,12 , 2013

 [13]:  http://suite101.com/a/the-properties-of-essential-oils-a65106

 [14]: http://www.newdirectionsaromatics.com/msds/clarysagemsds.htm

[15]: http://www.sciencelab.com/msds.php?msdsId=9925523

[16]: http://www.essentialoilsdirect.co.uk/rosemary-rosemarinus_officinalis-essential_oil.html

[17]: http://www.essentialoilsdirect.co.uk/thyme-thymus_vulgaris-essential_oil.html

 [18]: http://infohost.nmt.edu/~jaltig/SteamDistill.pdf

[19]: http://www.ehow.com/about_5095563_oil-extraction-methods.html

 

[20]: George T Austin(1984), Shreve's Chemical Process Industries, 5th edition,  McGraw-Hill book company

[21]: Christie J. Geankoplis(1993), Transport processes and unit operations, 3rd edition, University of Minnesota, Prentice-Hall International

[22]: Alaa .A, Ramzi .Sh, Saeda .M(2008), Graduation project about extraction of essential oils from herbal plants, 41

[23]: Dalia .S, Doaa .B, Malak .A, Trab .A(2009), Feasibility study for extraction of essential oils, 51

 

 

Appendices

Procedure:

( Processing of steam generator):

The steam generator is able to supply steam to the systems needing it. Its potentiality enables to supply steam to two systems at the same time.

 

1.      Installation

·         Connect the softener to tap water end to a drain

·         Connect the valve V8 of steam generator to a drain

·         Open valves V4, V5, V6, V7

·         Close valve V1, V2, V3, V8

·         Connect the softener to the electrical supply

·         Connect the steam generator to the electrical supply

·         Drain the generator opening valve V8 and V9 until to the level of the water is at the medium of the sight glass of the level gauge LG1

·         Close valve V8 and V9

 

2.      Start up

·         Connect the steam distillation to steam generator

·         Press the pushbutton" RESET"

·         Switch the selector of pump G1 in position "AUT"

·         Switch on the heaters

·         Wait that the pressure on manometer increase up to 1 bar

·         Discharge the air opening partially valve V9

·         Repeat the operation till to steam exits through the valve V9

·         Close valve V9

·         When the pressure on manometer PI1 is about 4 bar, open the valve V1

 

 

 

3.      Shut down

·         Close valve V1

·         Switch off pump G1 position "0"

·         Switch off the heaters

·         For emergency shut down, push the red emergency pushbutton.

 

 

 

Steam distillation unit (Apparatus):

 

 

Figure(8): Steam generator and steam’s valve

 

 

 

 

 

Figure(9): Control panel for the steam generator

 

 

Figure(10): Water valves to supply the generator and the condenser

 

 

 

 

 

Figure(11): The distiller and the condenser

 

 

Figure(12): The receiver parts

 

 

 

 

Figure(13): Other type of receiver

 

 

Figure(14): Receiver‘s valve

 

 

Figure(15):  Sage oil

 

 

Figure(16): Thyme oil

 

 

 

 

 

 

 

Table(16): The common names for plants:

 

 

 

Table (17): List of some odorous oil found  in Palestine & its’ prices:

Table(18): Compound interest factors