Journal of Scienti fic & Industria l Research

Vol. 61 , November 2002, pp 952-960

Portable Mini Essential Oil Distillation Apparatust

Kiran G D Babu , Vijay K Kaul * and P S Ahuja

Natural Pl ant Products Di vision, Institute of Himalayan Bioresource Technology. Post Box No. 6, Palampur 176 061

Rece ived: 24 August 200 I: revised: 06 September 2002: accepted: 12 Septemher 2002

Production of essenti al oil s and hydrosols by common hydrod istill ation prompted and fac il itated deve lop ment of a low cost, ponable. mini di still ati on apparatu s (MDA) made of stainl ess stee l (SS) with a modul ar design for easy and rapid install ati on components de pcnding on need. MDA can di still 1- 10 kg pl ant materi al per batch of a var iety of hedvy and li ght essenti al oil s hy different heating modes, such as direct firing by fu el wood in easil y constructibl e count ry made furnaces at the site, LPG sto ve, other heating devices like steam spu rger. or elect ri cal heaters. The ex trac ti on efficiency of MDA was compared with that of Clevenger type apparatus (CA ) for essenti al oil uctcrminati on by dis tilling Geranium and Tagetes oil s. MDA yielded more essenti al oil wi th better and more comple.te 'eompone.nt make up ' or sensory pro file qu alit iat ively. The GC and GC- MS studi es furth er co nfi rmed the findin gs. Similarl y, the CJuality of rose water produced by MDA was al so better. The co mbination of cost-clTecti veness and Il ex ibility with hi gher yield of better quality essential oil s or 'waters' offe r multipl e options of ut ili ty in new agri culture produ cti on of hydrosols systems where di versificati on is the need and MDA may se rve as a catalyst of change. M DA's patent has heen fi led in Indi a, Arge nti na. Indones ia. USA , Brazil. Bulgaria. China and Tu rkey (NF No 041 NF 2000. Appli cation No. 1004 DEL 2000, Filing date 10 Nove mber 2000).

Introduction

India has enormous natural aromatic plant wea lth. Some of the aromatic plants of commercial importance contribute significantl y to essential oil industry as India rank s third in the production of essential oil s. The essential o il industry shoulders the responsibility, but not much efforts have gone in simplifying the apparatus used for small-scale entrepreneurs, farmers. aromatherapi sts or the hobbyists. Many methods are known for the extrac ti on of essential oil s, such as hydrodi stillali onl, mi crowa ve di s lillati o n ~, solvent ex tracti on" .j

enn eurage, macerati on and supercritical CO2

extracti on5 However. hydrodi still ati on remained a widely used method of essenti al oil s extrac ti on. According to Guenther(' there are three types of hydro-di still ati ons v i ;: ., (i) Water di stillation , (ii ) Water and steam di stillation , and (iii ) Stea m di still ati on. Majority of aromati c crops are di stilled at commerc ial level by any of the three methods li sted above for obtaining better qualitative and quantitati ve

"i" IHBT Publi ca ti on No: 2 125: Its patent has been li led in Indi a. Argentina, In dones ia. USA, Brazil , Bulgari a, China and Turkey (NF No.04 1 NF 2000, Appli cati on No. 1004 DEL 2000, Filing da te 10 Nove mber 2000).

*Au thor l'or correspondence. e- mail : vk auI 2002@yahoo.co .in

results. Based on these methods, several di still ati on units of commercial- , pilot- and sma ll-scale were deve loped that are used the world over. However, pilot scale essential oil di stillation units involve hi gh capital in ves tment which small growers and marginal farmers generally can ill-afford . particularl y at the beginning of setting up of plantation. Hence. a simple, portable, fi e ld di still ation unit, working on agro-waste or LPG was conceived. designed and assessed for economi c viability. The eX lstlllg laboratory sca le glass Clevenger type7 apparatus (CA) may not give the exact simulated results because of its limitations in the appli cation of other methods of d isti lIations such as water and steam d ist i Ilation, and stea m di still ati on, and its inability to produce quality grade aroma di stillate (hydrosols) and the mode of heati ng, etc . Disti Ilation of essential oil s at different temperatures and press ures is not poss ibl e in such a glass apparatus. Small sca le di stil la ti on units of capacities 5, 10, or 40 kg/batch were deve loped and reported by Dutta et (li. 8 These units, howe ver, are not compact and have different parts such as sti II/retort, condenser si mi lar to that of a pi lot pl ant unit and separator (a separate entity not included in the design). The oil yield of CYlIlbofJogonflexuosus in such units of 5, 10 and 40 kg di stillati on units were 0.332, 0.337 and 0.28 per cent, respecti ve ly, whi ch are lower than 0.45 per cent obtained in the

BABU ('/ al. MINI ESSENTI AL OI L DISTILLATIO APPARATUS 953

laboratory using CA. The quality of oil di stilled in these units is al so poor with respect to the methyl eugenol leve l as compared to that of CA. Another portable di stillati on unit of 300 L capacity made up of mild steel (MS) was fabricated by Theagarajan el af .')

which di stilled 26-50 kg fo li age of Eucalyptlls hybrida/batch with recoveries of 1.0-1. 8 per cent oil , which is hi gher than that obtained with stati onery still s of large dimension. No compari sons were made with the CA.

Another mobile di stillati on pl ant, developed by Anglian Essenti al Oil s Ltd . of East Anglia , for the di still ati on of Chamomile (A lIlhemis nobilis)l o is permanentl y mounted on a truck fo r transportati on to the sites. The still ca n accommodate a pair of round one-tonne ba les that produce up to one liter of di still ate each. The plant materi al is di still ed by stea m, which is generated fro m a boiler mounted separately on a truck along with water-so ftening pl ants. Thi s set up is extremely elaborati ve and expensive. There is no report on qualitati ve and quantitative yields of oil s thus produced.

The methods of hydro-di still ati on, viz, stea m di still ation and water di still ati on at both mac ro- and micro-scales are we ll known. Mac ro-di still ati ons require about 200 g fresh plant material. Micro- and semi-micro di still ations require 1-10 g fresh pl ant materi al. Similarl y, Kerven el al. 11 developed a semi­micro stea m-powered di still ati on unit for iso lating oil from indi vidual small sa mples. This system was a direct fl ow di stillati on with no recycling of the di still ati on water as it was fe lt that the recyc ling would remove some of the oi I.

To overcome the preva iling limitati ons and to meet the needs of small and marginal farmers, educati onal and research institutes, and entrepreneurs from aromatherapy groups who wish to start essenti al oil di still ati on at small sca le and learn the art , skill and science of essential oil producti on within affordable price, a mi n i essenti al oi I di sti Il at ion unit was developed. The system has been des igned and tested to di still a wide range of light and heav ier essential oil s with batch capac ities of 5-10 kg plant material hav ing good reproducibility at all levels. The apparatus can be heated by external and integral heating dev ices viz., by direct firing by fuel wood, LPG stoves, burners-operated by petro leum products, by stea m, or elec tri c heating. An optional feature allow ing di still ati on of materi al with or without recyc ling was inc luded in thi s mini di still ati on

apparatus (MDA) des igned and reported for the extracti on of essenti al oi I.

Design of the Apparatus

The system, as shown in Figure 1, is di vided into three parts: vessel, cohobation column, condenser and recei ver-cum-separator.

Th e Vessel

A cylindrical vessel of fl at bottom end made up of stainless steel (SS-304) fo r holding pl ant material and water is with wide-open top or mouth for eas ier charging and di scharging of materi al. An adju stable false bottom is al so prov ided for di stilling the charge by either hydro-di stillati on methods of: (i) Water and

Cf!)----

(0--~--i

(~>-~ ~ "

Figure I- Mini disti ll ation apparatus I - Cyli nd rica l vessel; 2 - Bottom end: 3 - Con ical top end: 4-- Quick li t jo int/nut bo lt system: 5 - False bottom: 6 - Th readed rod: 7 - Cleats ; 8 - Cohobati on head co lumn : 9- Union : 10 - Bend : II - Condenser: 12 - Condensate outl et: 13 - Rece iver-culll-separator; 14 - Buu joinl : IS-Air ven t; 16 - Recyc ling pi pe line; 17 - Flex ib le tube: 18 - Oil dra in Ollt va lve: 19 - Recycl ing ON/OFF valve: 20 - Tempe­rature/pressure gauges: 2 1 - Safety valve; 22 - Flanges welded to item nos. I and 3: 23 - Capillary tube: 24 - Steam spurger

954 J SCIIND RES VOL 61 NOVEMBER 2002

steam di stillation , or ( ii) Stea m di stillation. The minimum weight of the plant materi a l, which can be charged into the vesse l w ith minimum or no loss is I and 2 kg for I and LO kg capacity system, respective ly . A flange is welded with the vessel upon which cone shaped lid is placed and ti ghtened with nut bolts. The cone is equipped w ith a safe ty valve thermomete r to monitor temperature . A gas ket is provided to prevent the leakage from the flange. A provi sion for steam inj ect ion is also made by providing a stea m spurger with suffic ien t pipe and ho le di amete r to ensure even di stributi on of steam. A drain-out port is welded at the bo ttom for taking out the spent water afler completion of distillation process .

The Coho/;(/Iioll Head CO/IIIl111 alld COlldellser Sectioll

These two are considered as a s ing le entity as both are welded togethe r with a bend in between. A uni on connects the sa id part with lid . The inte rnal diameter of the cohobation column is 50 mm with sufficient he ight. Dimens ion s (he ight and di amete r) of the cohobation column vary with capacity of the still , nature of plant mate rial to be di stilled and many other paramete rs . The exact number of theore tical plates in the cohobation column can be calculated from the vapour-liquid equilibrium (V-L-E) of a particula r essential o il and water to be di stilled . No such stud ies ha ve been reported in literature as yet. However, by the hit and trial method and with ava ilable data , the diameter and height o f the cohobation column were standardized for some essentia! o il s and water system. The condenser is a shell and tube heat exchanger type hav ing 12 tubes with 8 mm internal dia meter and 250 mm length with 25 pe r cent cut baffles in between. The dimens ion and number of tubes va ry with the s ize of st ill. Two ports are provided in she ll s ide for water inlet and outle t, which can be connected to a sink tap by tubing for circulat ion of water for condensation of vapours during di stillation. An a ir vent and condensate outlet is provided on the rear end bonnet of the condenser. A recycling tube of 8 mm internal diameter is welded to the cohobation column, which is again connected to the receive r-cum-separator by a flexible tube with a va lve.

Recei ve r-culI1 -Sepa rator

It is made up of Borosil g lass o r any transparent material compatible w ith essential oi ls to keep track

of the wate r and oil level and the rate o f distillati o ll . which is an important facto r during di stillati on. Thi s g raduated column has two ports; one for recyc ling the di stillate water, which is sa turated with the oil and the o ther to drain out the essential oi IIwater at the end of di stillation process by opening the valve. Depending upon the product of inte rest these va lves can be closed or kept open. The uniqueness of this des ig n is that distillation of heavie r as we ll as ligh te r essential o il s is possible in the same apparatus.

Materials and Methods

The pl ant material along w ith wate r is charged into the vessel through the open top in the rati o of 1 :0- 1 :2, depending upon the method of distillation. Depending upon the moisture level in fresh o r a ir­dried material and its bulk porosity, the load va ri es from 2.5-4.25 kg/batch for the water and steam di stillation me thod in the 25 L capacity vessel. The gasket is placed properly o n the face of the flan ge. of the vessel. above which the conical lid is fixed by known means. The lid is attached t the cohobation column with a union. The rece ive r-cu m-separato r is then connected to the condensate o utle t of the condenser welded to cohobation column, with nut­bo lts. In fact, the lid , cohobation column, condenser and receive r-cum-sepa rator are always attached to one another till o the r essential o il is d ist ill ed . After ensuring prope r setting of all the gaskets, heat ing is started o r steam is injected , as the case may be, to commence the di stillati o n. The she ll s ide of the condenser is filled with water, which ca n be s uppli ed from a sink tap by adapting the inl et port of the condense r w ith hose. The water o utlet of the condenser port is also adapted in the hose for prope r drainage of the coolant/wate r. The air vent on condenser is kept open throughout the process, so that plant mate ri a l is distilled at atmospheric pressure , o r c losed if the plant mate rial is to be extracted unde r pressure . After a few minute s, vapours coming out from the vessel are condensed in the heat exchanger. The condensate is collected in the recei vel' where the essential oil settl es as an upper o r lower layer. depending on the density difference. The aqueous part of the di st illate is recycled to the vesse l through the cohobation column from the receiver-c ull1-separator. To di still hydrosols, the di stillate from the condenser is collected in a container by o pening the bottoll1 valve on the receiver and the va lve on the recyc ling pipe is c losed . To recover di sso lved o il in the sa turated di stillate the process is continued fo r 3-5

--....--

) '-- -

BABU el al.: MINI ESSENTIAL OIL DISTILLATION APPARATUS 955

h, requiring 5-10 kg fuel wood depending upon the charge size, type of plant material and the method of distillation, etc. After the completion of process, the oil is collected through capillary tube by opening the drain out value. The oil collected is dried over anhydrous sodium sulphate and stored as per standard procedures.

Experimental Procedure

Distillation of Geranium (PelargoniulII graveolens) Leaves

In the beginning 6 L fresh water is charged into a well sterilized or rinsed vessel of capacity 25 L along with 3.5 kg fresh leaves of P graveolens cultivar Kelkar. The false bottom in the v~ssel is adjusted over a threaded rod so that the distance between fal se bottom and water level is sufficient to extract the plant material by water and steam distillation method. The vessel is heated, by direct firing to commence the distillation, after the lid and cohobation column-cum-condenser are fitted onto the vessel. The flange of the graduated glass tube is also fixed properly with the condenser. A silicon tube is used to connect the glass receiver tube and the recycling line. In fact , al l the fittings starting trom lid to silicon tube are always fixed as one unit, unless it is required to be cleaned or for distillation of another aromatic material.

After 15-30 min , water be low the false bottom starts bo iling and comes out along with essentia l oil in the form of vapour, which is condensed in the condenser and collected in the receiver where the oil is separated. The following process is continued for 3 h by maintaining a consistent flow rate of the di stillate. Using the same processing parameters the experiment was repeated twice. At the end of the process, the oil thus obtained was dried over anhydrous sodium sulphate and subjected to GC analysis. Simultaneously, 2 kg sample of geranium leaves, from the same batch, were also distilled in a Clevenger type glass apparatus (CA).

Distillation of Wild Marigold (Tageles minula)

The vessel of capacity 25 L was charged with 3 kg fresh plant material of wild marigold (Tageles m.inuta) along with 4 L water. All the components were attached and fastened by means of nut-bolts and union as mentioned in the operational procedures. Then the vessel is heated over a furnace and fuel wood i:; fired. Initially about 1.5 kg fue l wood is charged in parts to commence the distillation . The

actual distillation starts 15-30 min of firing depending upon factors such as the temperature of water charged, condition of fuel wood and fire intensity. After that, small pieces of fuel wood are charged as and when required for maintaining the di stillation rate. The process is continued for 3 h. The oi l collected in the g lass column was separated and dried over anhydrous sodium sulphate, stored at 0 °C for GC analysis. The experiment was repeated twice with the same process parameters. Simultaneously, 2 kg sample was distilled in CA for 3 h and the oil thus obtained was also dried over anhydrous sodium su lphate and kept at 0 °C for GC analysis.

Distillation of Rose Water

About 5 kg fresh Damask rose (Rosa damascena) flowers were charged into the vessel along with 10 L water. Before charging the material the perforated fa lse bottom was kept at its minimum height from the bottom. The charged vessel is kept above the furnace. The furnace was so constructed that three-fourths size of the vessel remains in side it and the rest outside. The gasket was placed on the flange welded to the vessel. Water distillation was used to distill roses . The conical lid coupled with cohobation column was placed carefully above the gasket and tightened by a quick fit joint to prevent the leakage of the vapours formed . The condenser was provided with water connection . The valve on silicon tube remains closed throughout the process. The furnace was fired slowly with agro-waste. After 30 min, vapours started forming and condensing in the condenser. The condensate started accumulating in the glass tube receiver. The valve at the bottom of the recei ver was kept open to collect the condensate known as rose water. The rose water was collected at the rate of 2 Llh , maintained by controlling the furnace fire. In al l, 5 L rose water was collected in 2.5 h and then the distillation process was stopped . The rose water thus col lected was subjected to GC ana lysis. The results were compared with rose water di sti lied on a pi lot plant.

Analysis

GC analysis of essentia l oi l samples was performed on Shimazdu Gas Chromatograph GC-14B, on SE-30 column, 30 m x 0.25 mm internal diam, with nitrogen as carrier gas at 40 mLimin . The equipment was fitted with Fill and C-R7A Chromatopac printer. Analysis with tempera ture programming was performed from 40-200° C at 10

956 J SC II ND RES VOL 6 1 NOVEMB ER 2002

°C/min, with initia l 2 min ho ld at 40°C and fin a ll y 15 min at 2000 C. Sample inj ec ti on and de tec tor tempera tures were kept at 250 and 230 °C, respec ti ve ly. Rose oil , ex trac ted fro m rose water, was analyzed on 30 m long Carbowax 20M co lumn , keeping other conditions the same as he ld for ana lysis on SE-30 column .

GC/MS analys is was cond ucted on Perkin­Elmer 910 model equipped with SE-30, 30 m x 0.25 mOl internal di am column using the sa me conditi ons as in GC analys is. He lium was used as a carrie r gas . Identif ica ti on of constituents was carried out by compari son of mass spec tra with the data g iven in I· 1'_1 -1 d h NIST I' b IS Ite rature - an t e l rary · .

Results and Discussion

From the experiments, it was o bserved that the recoveries are higher in the M DA the apparatus des igned and be ing reported , than in CA (Clevenger apparatus) as shown in Table 1 and 2 . The re lati ve

effi c iency over three batches of di ffe rent size, as reported in Table 1 and 2, varied due 10 combined effect of the amount of mate ria l handled/batc h, way of charg ing/pac king the mate ri a l in the vesse l, contro l over heating by direct firing by fuel wood and the di still ati on rate . For example, in T abl e I , the MD A was c harged wi th 3.0 and 4.0 kg material in batch I and 3 with re lati ve effi c ienc ies of 1. 35 and 1.08, respec ti ve ly, which are less when compared to ba tch 2. T hi s could be due to over charg ing (in the case of batch 3) and operating the apparatus in under ca pac ity ( in the case of batch I ). T hus, the ' opt i mum batc h capac ity fo r di stilling ge rani um leaves was 3.5 kg. T he ba tc h capac ity may also change depe nding upon the lype of p lant materia l viz . rhi zomes, f lowers. seeds, who le pl anl mate ri a l f resh or dr' ied , degree of drying, etc. The chemi ca l components identi fied in T abl es 3-5 have commerc ial ' importance. Other compo unds of no-commerc ia l imparlance have not been reflec ted .

Table 1- Distil lation of geranium leaves in MDA and CA.

Descript ion

CA

Pl ant material charged for di stil lation. kg 2.0

Water charged. L 4.0

Disti ll ation time. h 3.0

Oi l coli cued. rnL* 3.4

Oil yield . per cent 0. 17

Relative effic iency MDA (oi l yield) vis-a-v is CA 135

MDA-mini disti llation appara tus. CA-Clevenger type glass apparatus. *-Results arc hased on two repl icatcs

MDA

)0

6.0

3.0

6.9

0.23

Batch

2

CA MDA

2.0 3.5

4.0 6.0

3.0 3.0

1 2 3. 1

0.06 0.09

1 50

Tab le 2 - Distill ation of wi ld mari gold (Tagefes //IiI/ilia ) in MDA and CA

Description Batch

2

CA MDA CA MDA

Plant material charged for di stillation . kg 2.0 3.0 2.0 3.0

Water charged. L 4.0 4.0 4.0 4.0

Distill at ion ti me. h 3.0 3.0 3.0 3.0

Oi l recove red. mL * 6.0 16 14 22

Oil yield. per cent 0.3 0.53 0.7 0.73

Rel at ive cfli ciency MDA (oil yield) vi s-a-vis CA 1.76 1.04

MDA- rn in i dis till ation appara tus. CA-Clevenger type glass apparatu s. *-Results arc based on two rep li cates

3

CA MDA

2.0 4.0

4.0 6.0

3.0 3.0

3.5 7.6

0. 175 0.19

108

3

CA MDA

2.0 3.0

4.0 4.0

) 0 3.0

12 20

0.6 0.67

1. 12

,

Constituents

cis-Rose ox ide

trans-Rose oxide

Iso menthone

Ci tronell yl formate

Geranyl form ate

Citronellol

Geraniol

10-Epi- ,-eudesmol

Geranyl tiglate Colour of oil

Sensory profiel

BABU ef at.: MINI ESSENTIAL OIL DISTILLATION APPARATUS

Table 3 - Comparative quality analysis of geranium oi l

MDA, per cent

0.09

0.02

5.30

5.70

6.00

23.30

28.60

540

1.70 Amber to greeni sh yell ow

Rosy, varying minty note. fruity

CA, per cent

0.09

0.02

5.20

4.80

3.00

2140

22. 10

5.30

1.60 Li ght straw yellow to greeni sh

Herbaceous, leafy. less minty. rosy dryout

Results are based on six samples. NS-not significant (p >0.05)

Tab le 4 - Comparative qu ality analysis of wi ld marigold oil

Constituent MDA. per cent

Ocimene 38.10

Dihydrotagetone (DHT) 28.60

E-Tagetone 1.00

Z-Tagetone 9.90

E-Ocimenone 10.90

Z- Ocimenone 11.20 Colour of oil Yellow to reddi sh

Sensory profile Strong fruity, herbaceous

The results are based on six samples, NS-not significant (p > 0.05 ) MDA-mini di sti ll ation apparatu s. CA-Clevenger type glass apparatus

CA, per cent

3640

13.90

0.90

9.50

7.30

6.20 Yellow to orange

Green fruity. woody

Table 5 - Comparative quality analysis of rose water

Constituents Pilot plant. per cent MDA , per cent

Linalool

Ci tronellol

1erol

Geraniol

Phenyl ethyl alcohol

Methyl eugenol

Eugenol

cis-Rose oxide

f rall s-Rose oxide

Colour

Sensory profil e

4.59

4.88

4. 16

9.38

68 .66

0. 10

0.03

Courless

Fresh rosaceous, floral herbaceous

Results are based on six samples. NS-not significant (p > 0.05 ) MDA-mini di sti ll ation apparatus

3.50

4.50

4.30

9.00

76.00

0.20

1.40

0. 10

0.05

Courless

Sweet, fresh green, fruity

Paired t-tes t. 5 per cent

NS

NS

NS

3.67

17.89

7.56

6.71

NS

NS

957

Paired t-test, at 5 per cent

5.34

18.97

NS

3. 12

6.6 1

12 .53

Paired t-test, at 5 per cent

NS

NS

NS

NS

5.68

18.97

20.48

NS

NS

958 J SCIIND RES VOL 61 NOVEMBER 2002

Geranium oil

From Table 1, it is evident that the optimum charge size for geranium leaves in MDA of 25 L vessel capacity was 3.5 kg/batch for di stillation by water and steam which gave high relative yields of 0 .09 pe r cent compared to 0.06 pe r cent obtained in

CA. If the vesse l is charged with more or less than 3.5 kg material , the yie ld decreased , as in the case of batch 1 and 3. Hence, standardization of the apparatus has been worked out at the load capacity of 3.5 kg/batch which g ives the maximum relative efficiency of 1.50. The diffe rence in average level of some minor constituents suc h as cis and trails rose oxides, isome nthone, lO-epi-y-eudesmo l and geranyl tig late present in the oils di still ed by MDA and CA was not much over the s ix samples analysed. However, in other minor constituents s ignificant diffe rences were recorded in oils di still ed in the two

apparatuses, viz, citronellyl formate (5.7 pe r cent in the oil di still ed by MDA was hi ghe r than 4 .8 pe r ccnt in the oil distilled by CA), ge rany l formate (6.0 pe r cent in the oil di still ed by MDA that was doubl e the quantity of 3.0 per cent in the oil di still ed by CA).

The main constituents of o il a re ge raniol and citronellol for which the plant is cultivated on la rge scale for commcrcc. In thcse components also morc geraniol (29 .0 pe r cent) was present in the oil distill ed by MDA than 22. 1 pe r cent in the oil di still ed by CA (22.1 per cent). Other maj o r chemical constituent viz., c itrone ll o l in the oil was al so hi ghe r in the oil distill ed by MDA (23.3 pe r cent) than by CA (2 1.4 pe r cent). Thus, both the yie ld and quality of oil di stilled by MDA was hi ghe r and bette r than the o il di stilled by CA as revea led by the res ult s presented in Tabl e I and 3.

Tagetes o il

The re lative efficiency o f MDA with respec t to CA was a lways above 1.0. The comparati ve leve ls of chemi ca l constituents of the essential o i I of Tagetes sample di still ed by MDA and CA is g iven in Table 4. The oc imene in the o il di still ed by MDA was 38. 1 per cent and that of CA was 36.4 pe r cent. The diffe rence is no t la rge. However. othe r maj o r constituent viz., dihydro tage tone (DHT) was 28.6 per cent in the o il di still ed by MDA and 13.9 pe r cent by CA showing a la rge diffe rence as double the alllount was present in the MDA di still ed o il. S imil a rl y, Z-oc imenone was

present at higher le vels in MDA (11 .2 per cent) compared to CA (6.2 per cent) distilled oiL that is, almost double the quan tity of it was present in the oil distilled by MDA. Similarly, E-ocimenone (10.9 per cent) was higher in the oil distilled by MDA than by the CA (7 .3 per cent). Marg inal variati ons were found in the case of E- and Z-tagetones, the quality­determining constituents of Tagetes oil. T hus the oil di stilled by MDA was of much improved quality as compared to that disti lied by CA, as seen from the res ults given in Table 4.

Rose Water

CA is no t s uitable fo r the produc tion of rose water. MDA was the Illost suitable apparatus for the production of rose water as it contained a li the qua lity de termining constituents as g iven in Table 5 . Pheny l e thy l alcohol, one of the main quality determining chemical constituent in rose water, was present in large r proporti on in the rose water di st illed by MDA (76.0 pe r cent) than that di still ed in a pil ot plant (68.7 pe r cent). M ethyl e ugenol and eugenol could no t be identified in the rose wa te r produced in pilot plant while the sa me were found in good amounts in sa mples di still ed in MDA. Thi s emphasizes that , MDA can produce a bette r quality rose water. Rosc water is o ne of the important natural products, which is used in foodstuffs and in many medicina l preparations.

Better quality and hi ghe r yie lds o bta ined in MDA can be ex plained due to improved des ign of the di stillation apparatus, method s of hydro-di stillation used, be tte r hea t transfe r rates, process paramete rs and othe r des ign fac tors l6 such as standa rdi sing the he ig ht and diamete r of coho bati on column , fo r the di stillation of spec ified aromatic pl ant mate ri a l. in order to accommodate required number of theore tical pl ates.

Applicatioll s alld Uses

This po rtable mi n i essenti a l oi I d isti Il at io n

apparatus working on fu e l wood aV3ilabi e in the

forest is useful fo r field di stillati on of wide va ri e ti es

of aromatic plants, avoi ding costl y tran sportation of

bulky fo liage and fuel wood to di sti llati on uni ts

stati oned at one pl ace. The comparati ve expe rimental

tri a ls and analysis reveal that the apparatu s prod uces

\

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,

BABU el al.: MINI ESSENTIAL OIL DISTILLATION APPARATUS 959

quality grade essential oils with higher recoveries without any res trictions on the mode of heating, as it can be heated: (i) On a country made (temporary) furnace constructed by clay and bricks, (ii) On household LPG burner, (iii) Burners operated by other petroleum products , (iv) By electric heat ing elements, and (v) By stea m spurger depending on the available source and conveni ence It can also di still material by any of the hydrodi stillation methods : (i) Water di stillati on, (ii ) Steam di stillation, and (iii ) Water and steam distillation as thi s cannot be done on any available laboratory sca le essential oil determining Clevenger apparatus. Easy charging and discharging of plant material s is possible because of wide mouth . This apparatus has been designed to withstand against pressure or vacuum, as some of the aromatic plant material s are required to be di stilled

17 18 ·f b · . d under pressure or vacuum or eUer recovenes an quality grade essential oil. This apparatus can be used to di still hyd rosols such as rose, {(jowan water and basil water. The quality of these hydrosols was better than the hydrosols di still ed on pilot plants. The reported des ign is al so capable of di stilling heav ier essential oil s as well. This apparatus with low initial capital investment is of hi gh utility in the area of new agricultural production practices for rural development , education institutes, and to the farmers. The des ign is also useful to small cottage industries , housewives, and to aromatherapi sts.

Conclusions

It is ev ident that the re lati ve efficiency of oil yields from MDA vis-a-vis CA was always greater than 1.0, as show in Table I and 2. As far as the quality of oil is concerned, the paired t-tes t comparison reveal ed that some of the chemi ca l constituents were present in significantly higher amounts in oil s di stilled by MDA than those di stilled by CA. As is ev ident from Table 3, some chemical compounds viz .. citronell yl formate. geranyl formate. citronell ol and geran iol were present significantl y in higher amounlS in geranium oil di still ed by MDA. Similarly, data given in Table 4 revealed that among chemica l constituents of Tagetes oi l viz., oc imene, dihydrotagetone. Z-tagetone, E-ocimenone and Z­oc imenone di stilled by MDA were also present in significantl y hi gher amounts. Similarly, some of the

chemical constituents were present 111 significantly higher proportion in rose water distilled by MDA vis­a-vis that di stilled in pilot plant as evident from data in Table 5.

With the above promising results and versatility of the design the apparatus is being manufactured on commercial scale by Mis Andel Equipment Pvt Ltd , Mohali (Punjab) india, under license given by thi s institute. Some of the units have already been so ld to the entrepreneurs for distillation of various essential oils and hydrosols from aromatic pl ants with encouraging results. This newl y developed desi gn is also useful to rural population for additional income generation and can be taken as one of the major activities for rural development programmes.

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