steam distillation

Types of Steam Distillation

Steam distillation can be done in three main apparatuses: the direct method, the separation apparatus, and the indirect method.

• The direct method

This involves passing steam directly through the biomass material in a stainless steel vessel. The steam heats the plant material, vaporizing the essential oil and aqueous solution. The steam and the vaporized oil are then channeled through a condenser, where the temperature drops, and the steam condenses into liquid form. The oil and water are then separated based on density differences, with the oil floating above the water.

• Separation apparatus

This method involves using a separator or a trap before the distilled steam is cooled down in the condenser. A typical separator like a Florentine flask relies on the actual density differences of the essential oil and water to stratify the two liquids, allowing for easy separation. Usually, the oil will float above the water in the separator, preventing the mixing of the two fluids and enabling the distillation of essential oils from botanical extracts.

• The indirect method

The indirect method uses steam transferred from a separate boiler to a still containing plant material. In this method, a heat exchanger or another device heats the plant material through indirect contact. The still in which the plant material is located may also contain a cooling coil through which cooling water is circulated to condense the vapor containing the essential oil into liquid. An advantage in the use of indirect steam distillation is the ability to extract essential oils from heat-sensitive materials without overheating them in the still, according to some authors.

Specification and maintenance of steam distillations

Understanding the maintenance requirement for a steam distillation apparatus is important in ensuring effective extraction and getting valuable essential oils. Here are a few things to know about the maintenance requirement and specifications of steam distillation equipment for sale.

• Material

  The main apparatus for steam distillation is usually made from stainless steel. The materials are resistant to corrosion and rusts, so easily the equipment will be able to withstand the harsh operating environment.

• Temperature control

  For efficient steam distillation to occur, the boiling temperature of water has to be maintained. Therefore, the equipment used for steam distillation has to have the proper temperature control mechanisms. Thermostats, pressure gauges, and valves are examples of temperature-controlling devices in a distillation apparatus.

• Water supply system

  In the steam distillation apparatus, there must be a constant and stable supply of water. Therefore, the water supply system of the steam distillation apparatus includes a pump, piping, and any other water treatment devices required.

• Storage tank

  Absorption or separation vessels may also be a specifications part of a steam distillation apparatus. This is where the essential oils are separated, absorbed, or stored post-distillation.

Maintenance Tips

Here are simple maintenance tips for steam distillation apparatus buyers:

• Regular Inspection:

  Regularly check and inspect all major steam distillation apparatus parts. Some major parts to pay attention to include the water supply system, the distillation pot, the absorption or separation vessels, and the collecting flask.

• Clean-up:

  After the distillation and extraction processes, residues remain in the distillation equipment. Failure to clean the equipment properly will affect the quality of the subsequent distillation processes. Therefore, it is important to properly clean the apparatus after use.

• Avoid Overload:

  Users should not overload the distillation equipment beyond its available capacity. Overloading may put a strain on the equipment, leading to a faster rate of wear and tear. It may also get damage.

• Follow Manufacturer Guidance:

  Every brand manufacturer will have a unique way of constructing the steam distillation apparatus. Therefore, it is important to familiarize with the specific maintenance requirements and installation tips provided by the manufacturer of the apparatus used.

scenarios of steam distillation

Steam distillation apparatuses are commonly used in laboratories, industrials, and food and beverage production.

In labs, scientist use steam distillation apparatus to separate chemical compounds or purify chemicals substances that are likely to be heath risk when undertaking process with more than one chemical reaction. These chemical substances are likely to be toxic, which means they shouldn't be exposed to users; therefore, they have to use these apparatus to gain pure and safe substances for their research. Also, some chemicals have high boiling points. The lab users will have to use low boiling points apparatus such as steam distillation to avoid ruining the chemical at high temperature.

Industrials such as oil refineries use the steam distillation method to separate oils. They distillate crude oil into natural gas, diesel, benzene, kerosene, propane, and other substances. The method can also be used to separate essential oils from plant materials. In the food industry, it can be used to distillate alcohol from fermented yeast mash.

Heathcare facilities like hospitals and clinics use steam distillation apparatuses to purify water. The distilled water is used in laboratories for research and testing purposes. It's also used to produced medical equipment like autoclaves, which sterilize surgical instruments and provide coolant in lab equipment.

Some essential oil companies extract oil using the steam distillation method. They place plant materials in stills and pass steam through them. The steam activates the essential oil components, which evaporate and condense into the collecting vessel.

How to choose steam distillation equipment

• Distillation volume demand analysis:

  First, users need to analyse the required distillation quantity to determine the appropriate vessel volume and processing capacity. Consider factors like production flow, single batch distillation volume and distillation frequency.

• Raw material and product characteristic matching:

  Choose the suitable material and structure of the distillation equipment according to the properties of the raw material and distillation product.

  For example, an indirect heating steam distillation apparatus with an anti-explosion setup should be selected for flammable or explosive substances.

• Automated control functions:

  User should select appropriate equipment according to their actual needs and level of knowledge.

• Space and layout considerations:

  Users need to ensure that the size of the distillation device selected matches the available space. Also, consider how well the equipment integrates with other pieces of processing equipment.

• Safety and compliance considerations:

  Choose steam distillation apparatus compliant with relevant safety and regulatory standards. Pay attention to the safety devices, protection mechanisms and operating guidelines that come with the equipment.

Steam distillation Q&A

Q: What are the benefits of steam distillation?

A: The main advantage of steam distillation is that it can extract the final material from substances with high boiling points. In addition, lower temperatures are used, so the product does not degrade.

Q: What type of plants can be processed by a steam distillation machine?

A: Almost any plant with a succulent structure containing essential oils can be processed with this method, such as rosemary, thyme, peppermint, lavender, and citrus peels.

Q: How pure is the product obtained with steam distillation?

A: The essential oils extracted by steam distillation are up to 95% pure. Further processing could increase purity levels.

Q: Is steam distillation energy-efficient?

A: While steam distillation has several benefits, it is not energy efficient, as it requires large amounts of energy in the form of steam.

Q: What other types of distillation are there?

A: The other essential oil extraction method widely used is solvent extraction. It uses lower temperatures, but the final product may contain harmful chemical residues.