Ajwain (Carom) Spice Oil Distillation Plant
Ajwain (Carom) Spice Oil Distillation Plant
Ajwain (Trachyspermum ammi) essential oil is one of the richest natural sources of thymol (35–55%), a powerful antimicrobial phenol with broad applications in pharmaceuticals, dental products, and food preservation. India is the world's largest producer of ajwain seeds, making domestically manufactured distillation equipment critical for value-added processing. Mechotech's ajwain oil distillation plants are engineered for maximum thymol recovery, consistent batch quality, and compliance with food-grade and pharmaceutical-grade processing standards.
Mechotech designs ajwain oil distillation plants using steam distillation optimised for maximum thymol yield from Trachyspermum ammi seeds. The plant incorporates a SS 316L jacketed still pot, direct steam injection or external boiler connectivity, shell-and-tube condensers with chilled water circulation, and a Florentine flask for gravity-based oil-water separation. Typical oil yield is 2–4% from dry seeds, with thymol content of 35–55% and carvacrol as a secondary constituent. The modular design supports batch sizes from 100 kg to 2,000 kg of raw material per cycle. All wetted surfaces are SS 316L; the plant meets GMP layout norms for pharma-grade processing. Hydro-distillation mode is also available for operations without a dedicated steam boiler.
Manufacturing Process
Raw Material Preparation
Dried ajwain seeds (moisture ≤ 10%) are cleaned to remove dust, stalks, and foreign matter using a vibro-cleaner or aspirator. Seeds may be lightly cracked or coarsely milled to rupture oil glands and improve oil recovery by 10–15%, though whole-seed distillation is also practiced to retain top-note volatiles.
Loading the Still
The prepared seeds are charged into the SS 316L distillation vessel through a top manhole. A perforated false bottom keeps seed material above the water level or steam inlet. For steam distillation, the vessel is sealed; for hydro-distillation, demineralised water is added at a water-to-material ratio of approximately 4:1.
Steam Distillation
Live steam at 0.5–1.5 bar is injected through the false bottom and permeates the seed bed, volatilising thymol, carvacrol, p-cymene, and other aromatic constituents. Distillation runs for 2–3 hours at still-pot temperatures of 100–105 °C. Distillation progress is monitored by observing oil flow rate in the sight glass on the Florentine flask.
Condensation
The vapour mixture of steam and essential oil rises through an insulated gooseneck pipe into a shell-and-tube condenser fabricated from SS 316L tubes. Cooling water or chilled water circulates counter-currently on the shell side, condensing the vapour to a liquid mixture of essential oil and hydrosol at 25–35 °C.
Oil-Water Separation
The condensate flows by gravity into a Florentine flask (also SS 316L) where ajwain oil, being lighter than water (specific gravity 0.890–0.910), floats to the top and is continuously decanted into a collection vessel. Hydrosol (ajwain water, rich in thymol aroma) is collected separately and may be recovered or recycled.
Quality Testing & Packing
Finished ajwain oil is tested for specific gravity (0.890–0.910 at 25 °C), refractive index (1.495–1.505), thymol content (≥35% by GC-MS), optical rotation, and organoleptic properties. Oil meeting specification is filled into amber glass bottles or food-grade aluminium drums under nitrogen blanket to prevent oxidation.
Applications
- Pharmaceutical manufacturing — thymol extraction and antiseptic formulations
- Dental products — mouthwashes, toothpastes, and dental antiseptics (thymol as active ingredient)
- Food preservation — natural antimicrobial additive for baked goods, meat products, and pickles
- Veterinary medicines — antiparasitic and anthelmintic formulations
- Agrochemical sector — bio-pesticide and soil fumigant formulations
- Ayurvedic and herbal medicine manufacturing
- Flavour and fragrance industry — spice oil blending for food flavours
Key Features
High Thymol Yield
Optimised steam flow rate and bed depth ensure 95–98% extraction efficiency, achieving oil yields of 2–4% with thymol content consistently above 35% per batch.
SS 316L Construction
All product-contact surfaces — still pot, condenser tubes, Florentine flask, and transfer piping — are fabricated from SS 316L for corrosion resistance against thymol-rich condensate and full compliance with food and pharma GMP standards.
Hydro & Steam Modes
The plant can be configured for both hydro-distillation (water added to the still) and live steam distillation, giving operators flexibility to optimise for oil character, yield, or energy efficiency depending on batch requirements.
Corrosion-Resistant Condensers
Shell-and-tube condensers use SS 316L tubes with adequate heat-transfer area for full condensation even in high-ambient-temperature Indian conditions, maintaining condenser outlet temperature below 35 °C.
Multi-Crop Flexibility
The modular still design supports distillation of other seed spices (cumin, coriander, fennel, dill) in the same equipment with minor changeovers, maximising asset utilisation for multi-crop processors.
Frequently Asked Questions
What is the typical oil yield from ajwain seeds?
How long does one batch of ajwain distillation take?
What thymol content can I expect from Mechotech's plant?
Can the same plant be used for other spice oils?
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