Dear Friends

Plant biomass burning is discouraged for obvious reasons. Plant biomass can be converted into useful compost or can be used for alternate purposes. Distillation techniques currently employed to produce essential oils from aromatic plants use large quantities of plant biomass often derived by cutting trees. With advances in solar power technology, it is theoretically possible to produce steam and use it for essential oil production. Solar-power home/office water heaters are already in use. It is time for some one to conceptualize and develop solar-power distillation units for essential oil production. Your ideas, views, suggestions and remarks are welcome.

In Mexico becomes bioplastic from the avocado seed...

Regards.

http://www.freshfruitportal.com/2012/12/27/mexican-company-converts-avocado-waste-into-environmental-plastic/?country=mexico

https://www.polymersolutions.com/psi-newsletter-archive/september-2014/

 Distillation, in general, is energy-intensive &  is accompanied by loss of material. It may also involve undesirable changes on the oils to be isolated even though the temperature in steam distillation is below 100 oC. Upon the suggestion of some colleagues, our students were directed to separate citrus oil from orange peel by steam distillation but the % recovery was very low over 4 semesters. I think that solvent extraction is generally better than steam distillation (if it works) & research will be better directed towards increasing its efficiency.

Dear Dr. Jaime

Thank you for your very interesting links on production of bioplastics from renewable agricultural waste materials.

Best wishes

Dear Dr. Sergei

This is what I am exactly looking for. I am happy that some one has already designed solar powered distillation units for production of essential oils from aromatic plants. I hope these units will become popular in future in all the countries where aromatic plants are cultivated commercially.

Dear Prof. Nizar

Solvent extraction and super critical fluid extraction techniques are already in use for extracting flower concretes and spice oleoresins. Solvent extraction of essential oils from aromatic herbs is expensive and technology/capital intensive. Most of the aromatic plant cultivators are illiterate, resource constrained, small and medium farmers. Solvent recovery and disposal pose problems for large-scale production of essential oils.

Thank you for your contribution.

Dear Friends

Tractor or truck mounted distillation units have been experimentally used but to the best of my knowledge have not attracted farmers' attention possibly due to cost factor. In the distillation process, lot of water is consumed for steam generation and for condensing steam and essential oil vapors in the condenser. Instead of water-cooled condensers if we have air-cooled condensers akin to automobile radiators lot of water (extremely precious and limited resource) can be saved. can any one have any references, reprints, photos or ideas for constructing an air-cooled condenser?

Dear Ali

Thank you for your informative links.

Dear Prof. Mario

Thank you for your information on super critical fluid extraction. Distillation is simple, affordable and requires no special skills. SCFE on the other hand is expensive, needs technical people to run it and is useful for costly essential oils or spice oleresins. I am looking for a distillation technology where we can do away with burning biomass for steam generation and an air-cooled condenser to save water.

I really learned a lot of information from the responses of professional scientists. Now, I know a little more about rhis process.

Dear Vladimir

Thanks for the post. If you are interested in the subject please read the attachments.

Dear Professor Rao, thanks for helping to understand some plant technology features. All the best. Vladimir

Thanks for understanding.

Welcome dear @ Vladimir. Let us keep in touch for scientific exchanges on common subjects.

Dear professor Rao,

Your answer is very helpful. Our aim is develop drugs using local aromatic plants. The plant we started with showed good biological function and high d-limonene content. However when we repeat, the material could not give consistent d-limonene content. Seasonal changes may be a reason. Now I understand,for our purpose, it is to easier to screen other plants which we know have higher content of d-limonene.

Dear Ping

Check the following in your plant (s):

1. Different plant parts.

2. Different ages of leaves if leaf is your material. In most plants young and expanding leaves are biosynthetically more active than fully expanded old leaves

3. Different stages of plant. In some flowering stage is appropriate.

4. Different plants or phenotypes, they may differ in yields.

5. Seasonal variation of course is another

6. Different times in day or night may also sometimes give variable results.

7. D-limonene distills early in distillation time. Collect different fractions at different times and check the content of these fractions. Early fractions are likely to contain more limonene.

8. Solvent extractions generally yield more essential oil but not necessarily limonene. You can still check.

Good luck.

Steam distillation usually uses fossil  and  electrical sources of energy but I am struggling with generation of biogas from crop wastes and human wastes  to power gas heaters. This mat enhance reuse of plant and animal materials for energy production . The plant residues from the aromatic plants are potential sources of biogas and hence reduces the waste plant materials.after steam distillation.

Good luck

Depending on how the plant and what her body is a raw material provides various so-called waste residues, certainly exist a possibility to use them especially when we are talking about a large amount of residue after distillation. Such quantities often arise in large mills and it miejsu so there kad plants are harvested (crop field). Then, when distillation is used fresh feedstock can use it as biomass to power field. This gives the results in the form of nitrogen but also proteins and aromatic available residues of soil disinfectant properties.

Please tell me, who can tell us about ancient secrets of cooking oils. This is what we know only of the delicious oriental tales.

The Directorate of Oil Seeds Research in Hyderabad and the Oil Technological Research Institute of Jawaharlal Nehru Technological University, Anantapur are 2 national level Indian institutes exclusively working on edible and non-edible oil seeds and their oils. Indian Institute of Chemical Technology, Hyderabad has also an oils and fats division. They may throw light on the secrets of cooking oils. 

Dear Jondiko

Biogas plants running on cattle excreta exist in India and other countries. While the energy is generally used for domestic lighting and other purposes, the slurry is used as manure. Crop wastes are generally converted into compost or vermicompost by farmers. Biomass based energy generation units are also in operation in different parts of the world including in India. They use both crop residues and municipal solid waste.

Electricity operated distillation units are uneconomical in developing nations, therefore small and marginal farmers use distilled biomass or firewood as fuel. In large farms oil fired boilers can be used for steam generation.

Theoretically biogas production from crop wastes is a good idea. As far as I know no commercial biomass-based biogas plants are in operation.

Thank you for your interesting contribution.

Microwave-assisted hydro-distillation and solvent-free microwave-assisted distillation techniques have been successfully demonstrated in the laboratory. This has reduced the time of distillation and in some cases improved the essential oil yield and its composition.

I am day dreaming that in future automated units may become affordable. Tractor mounted harvesters harvest the biomass and transport it to the distillation units. The biomass is cut into small pieces to increase the volume and expose the oil glands to the action of heat. The cut biomass is conveyed through conveyor belts into a field-scale microwave-assisted or solar-powered distillation unit. Essential oil vapors are condensed in air-cooled condensers to collect near-pure (moisture-free) essential oil (moisture present in the plant biomass may also get condensed). The distilled biomass is conveyed to drying units operating on solar energy. This biomass can then be used for other purposes.

Any comments?

I think we all dream about such a process of distillation, which will be fast and yet extremely cheap, efficient and cost-effective also in relation to the raw material, which also have a smaller quantity of waste. But if it will not, and certain complications and protests from the branch of the essential (because the final product will be cheap), perfume (consumers no longer spend a fortune on the coveted, favorite scent), power plants (which raise from the sale of their income) and so on ...

Along with the simplification of the process of production scale seems to me that will change completely the ratio of this product, which are essential oils. I do not want to say that I am not in favor, but when we look at how to develop a small drop of oil in the machine which involves so many entities for which it is often to be or not to be, I wonder if it's worth working on until this simplification.

Engineers are working on developing energy efficient, multipurpose designs. Tractor or truck mounted, transportable distillation units and semi-automated units are already in use but are not yet affordable by small and marginal farmers. Research efforts by government funded institutions will continue to improve efficiency, yield and bring down cost and waste. Change may not always be welcomed by all the stakeholders but is the way of life. 

Our former president Dr. Abdul Kalam who is a missile scientist is fond of children and told them to dream and dream big and try to convert them into reality.  

Aromatic plants are harvested when the essential oil is at the peak percentage in the flower, leaves, root, peel or wherever the plant stores its oil. After cleaning and sorting, the aromatic plant material is loaded into a still for the steam distillation process. Water is heated that rises through the plant material, helping to evaporate the essential oils that are carried out with the steam. As the steam recondenses, the oil and water naturally separate. Typically the oil floats and is skimmed off the surface of the water

What makes the difference in quality?

The most prevalent myth is that if an essential oil is 100% pure, then it can be used for Aromatherapy. The truth is that purity is relatively easy standard to meet, but the quality of pure essential oils varies wildly.

http://terrapinfamily.com/Web/Aromatherapy.html

Dear Prof. Krishnan

Thank you for your contribution. This is the popularly used distillation method for isolation of essential oils from aromatic plants. Purity and quality are differently viewed. A pure natural essential oil of an aromatic plant is the one which is not adulterated or reconstituted (essential oils are fortified by synthetic constituents or synthetic essential oil) or some of its constituents removed (deterpenated essential oils, dementholised menthol mint essential oil etc.). The quality of an essential oil is evaluated by its physico-chemical properties (color, odor, specific gravity etc.) and its chemical composition (assessed through GC-FID and GC-MS). The quality of an essential oil is influenced by several factors some of which you mentioned in your post.

During steam or hydro-cum-steam distillation of aromatic crops both heat energy and water are wasted. I have seen several distillation units fired by either dried distilled biomass or firewood. The furnace is open and the heat efficiency is low. The distillation tanks are not covered and during distillation can not be touched. In few cases the distillation tanks were pasted with a thick layer of mud held by coconut rope tightly tied over the mud covering the entire length and breadth of the tank. In other cases only rope was tied. Farmers who are economically rich used glasswool packing held employing tin sheet and GI wire.

Two types of condensers are in use. Coil condensers immersed in a pool of water or tube and shell condensers where water is circulated. In the second type which is more common the water outlet releases the hot water into the adjacent area thereby wasting a precious resource. Only few farmers or distillers recirculate the water used for condensation.

Slight modification of the distillation equipment with an extra cost can save energy, fuel, time taken for distillation, water and cut down expenses on distillation.

Dear friends

Check these interesting publications on distillation techniques:

Dear friends

Although this is not a new technique for distilling aromatic plants for isolating essential oils, this is a new technique (utilization of handheld Raman spectroscope) for distinguishing essential oils and detecting their adulteration. 

Here is another method for extraction of essential oils from aromatic biomass.

This is a very important area in research, i had this in mind too, designing of an essential oil distiller using solar energy for extraction of essential oil, will be very glad if we would work together.

i really appreciate the literature you have posted.

Dear Dr. Rao,

I am very much pleased to know your interest in the use of solar distillation technique for essential oil extraction. I have used hydro-steam distillation method for aromatic plant leaf essential oil extraction. Could you develop the solar technique for the same? Please do share as I am also interested in the same. 

I really appreciate your interest in the development of new techniques.

Dear Ms. Nigam

The technique you used is very common. Yes it is possible to develop solar technique provided funds are available for research.

I have asked this question when I was in service. I have retired from service 2 years ago and my interests have changed.

Good luck

I thank that microwave the most effective method for distillation essential oil .

Under lab conditions may be. Under field conditions it is not feasible at present for the farmers for bulk distillations.

Dear Dr. B.R. Rajeswara Rao ,

I had worked microwave technology on the magmatic rocks. It's heating effect were useful for rocks. Maybe it helps obtain essential oils effectively from aromatic herbs. But unfortunately, generating microwave energy is expensive way. I agree with you about get an energy from solar panels. This way is not only cheaper way but also make sustainable energy production circle and enviromental conditions.

Kind Regards