Thin Film Evaporators and Short Path Distillators How they work • Applications • Customer specific trial distillations

�

Stearic acidGlycerine monostearatGlycerine distearate

Glycerine tristearate

0 50 100 150 200 250 300 350

0,001

0,01

0,1

1

10

100

1000

Temperature °C

Vapo

r pre

ssur

e (m

m H

g)

Vapor pressure curve

UIC GmbH – Custom Vacuum Distillation Plantsturnkey distillation plants • capacity range: 100 grams to over 10 tons per hour • from UIC: a leading international supplier

Vacuum distillation plants are used in R&D labs, in pilot applications, and for full-scale industrial mass production.

Each plant can be configured to run around the clock, at feed rates ranging from ca. 0.1 kg/h to more than 10 t/h. In addition to the main com- ponents – the Thin Film Evaporators and the Short Path Distillators – all secondary devices are integrated to guarantee smooth and reliable operation.

While vacuum distillation plants cover large are-as of the process industry, common requirements of all applications are particularly gentle process conditions. The thermal load of heat-sensitive substances is minimized to avoid any deterioration of quality.

Food additives Oils and fats Flavors and fragrances Fine chemicals Pharmaceutical products

Separation of monomers and polymers Mineral oil products

The UIC Technology Center carries out test distil- lations with sample materials from our customers to provide reliable data on separation efficiencies, yields, and capacities – relatively quickly and with a minimum of effort. These parameters form an im- portant part of the customers’ investment decision.

Specialized in the engineering and delivery of turnkey plants, UIC designs each solution to meet specific customer requirements. Today, we are a leading supplier of vacuum distillation plants around the world.

Vacuum distillation plants

Applications

An overview of applications:

Test distillations

UIC: leading international supplier

�

How Thin Film Evaporators and Short Path Distillators Work

In the process industry, substances are usually not available as pure materials, but as mixtures. There are many reasons why substances or groups of substances are separated from mixtures:

to improve qualityto optimize the subsequent process stepsto reduce hazards (toxicity, environmental pollution,

or inflammable components, etc.)

The technologies to separate such mixtures make use of various che-mical or physical properties of the substances, e. g. the solubility (sol-vent extraction, supercritical extraction), the density (decantation) or the melting point (crystallization).

Distillation is a thermal separation technology and based on – in simple terms – the difference of the vapor pressures that individual components of the mixture have at the same temperature. “Vapor pres-sure” is the pressure achieved at a certain temperature in the state of equilibrium above the liquid phase of a pure substance.

A Pascal (Pa) is the official measuring unit of pres-sure – and also of vapor pressure. One Pa = 1 N/m² (Newton per square meter). The measuring unit bar or mbar (millibar) is also applied in vacuum technology, using the following conversion formula:

100 Pa (Pascal) = 1 hPa (Hektopascal) = 1 mbar

Even older is the Torr measuring unit (also cal-led “mm Hg”). One Torr corresponds to the pres- sure of a mercury column of 1 mm height. (1 Torr = 1.���� hPa = 1.���� mbar)

Vapor pressures rise or fall exponentially to the tem-perature. At a constant temperature, substances with a higher molecular weight often have a lower vapor pressure.

The diagram shown at the left side displays, in a semi-logarithmic scale, the above mentioned dependency

of substances often distilled in a typical Thin Film and Short Path Distillation application. It is evident that the vapor pressure for the four illustrated pure components differs in each case by about 1 to � de-cades at constant temperature.

The thermal separation by means of distillation is a composition of partial evaporation of a liquid mixture of substances and a partial or total condensation of the resulting vapors. In order to achieve econom- ically interesting evaporation rates, an evaporation temperature very close to the boiling temperature is aimed for. The boiling temperature is reached when the vapor pressure is equal to the ambient pressure.

High evaporation temperatures may have an extremely negative influ-ence on the quality of the substances to be separated by means of dis- tillation, e. g. due to thermal decomposition, disequilibrium of mono-mer / oligomer mixtures, polymerization, etc. The amount of such un-desirable chemical reactions increases both with the temperature and with the time of exposure to thermal load.

Many organic substances – such as vitamins, flavors, fragrances, pharmaceuticals, and similar substances – reach their thermal load limit at low temperatures. Due to the required high temperatures, a distillation at normal pressure (approx. 1000 mbar) would therefore re-sult in a loss of quality.

It is, however, possible to considerably reduce the boiling tempera-tures by lowering the pressure. This means carrying out distillation under vacuum. By finding a suitable operation pressure under vacuum, reducing the boiling temperature – compared to the atmospheric dis-tillation – by �00°C and more is possible.

The design of an appropriate distillation device must consider that the vapor volume will increase reciprocally in proportion to the decreasing pressure. A reduction of the pressure from 1000 mbar to 1 mbar results in a 1000-fold increase in volume.

Stearic acidGlycerine monostearatGlycerine distearate

Glycerine tristearate

0 50 100 150 200 250 300 350

0,001

0,01

0,1

1

10

100

1000

Temperature °C

Vapo

r pre

ssur

e (m

m H

g)

thermal separation technology • gentle distillation under vacuumturnkey distillation plants • capacity range: 100 grams to over 10 tons per hour • from UIC: a leading international supplier

Gentle Distillation

�

Thin Film Evaporator

The operating pressure for Thin Film Evaporators is mostly between 1 mbar and atmospheric pressure (1000 mbar), enabling a signifi-cant reduction in evaporation temperatures compared to atmospheric evaporation. The residence time of the feed material at evaporation temperature is very short – in most cases less than one minute. The combination of low evaporation temperature and short residence time results in a gentle distillation process with a low thermal load for the materials to be distilled.

The evaporation of the light volatile components of a mixture of substances is done from a thin liquid film (usually less than 1 mm thick). The mixture is fed from above onto the surface of a cylindrical evap-orator via a rotating distribution system, and then flows down-ward on the internal evaporator wall as a thin film. A mechanical wiper system, connected to the distribution system, uniformly distributes the mixture onto the evaporator surface area and permanently agitates the downward flowing material.

The cylindrical evaporator is jacketed to facilitate consistent heating of the evaporator surface area through a heat carrier medium (e. g. thermal oil or steam). Depending on the temperature of the liquid and the oper- ating pressure inside the evaporator, the volatile substances are evap- orated from the downward flowing liquid material film. In a reverse flow to the liquid film, the vapors led upward and exhaust through a nozzle. Particularly when using a Thin Film Evaporator for low oper-ation pressures, the above-mentioned increase in vapor volume must be considered when designing the apparatus. Cross sections as large as possible minimize the flow resistance, enabling low operating pres-sures.

Often, (partial and / or total) condensers or rectification columns are installed downstream from the Thin Film Evaporator. In the latter case, the Thin Film Evaporator works as a reboiler.

operating pressure range: 1 – 1000 mbar • short residence time • external condensation

Basic principles and Thin Film Evaporator design

motor with gearbox

driveshaft

vapor nozzle

feed nozzle

heating jacket

roller wiper

residue

�

The uniform distribution of the film material on the evaporator surface and the constant mixing of this film are of great importance for the efficiency of a Thin Film Evaporator.

Improves heat transfer from the evaporator wall to the film material

Brings the molecules of the light boiling substances to the film surface, where they evaporate more easily

Avoids non wiped areas that can thermally damage sensitive substances due to local overheating

Avoids direct contact between wiper elements and evaporator wall to avoid mechanical damages (e. g. scratches)

Has low wear and tear and long operating times without replacing the wiper elements

Contains only dynamic wiper elements (rollers) that rotate permanently and do not stick to one spot

Guarantees short residence times and a sharp residence spectrum

Minimizes the flow resistance of the vapors due to its open construction

The UIC wiper system consists of rollers aligned in segments, one on top of the other, beaded on guiding rods. The guiding rods are mechan- ically connected to each other and to the rotating distribution plate to form a wiper basket (see photo on the right). When the wiper basket rotates, the rollers are pressed into the downward flowing liquid film by centrifugal force and also rotate around their own axis. A “bow

Wiper rollers

The UIC Roller Wiper System

wave” forms in front of each roller, agitating and mixing the material due to turbulence forces.

Depending on the evaporator temperature and the mixture of materials, the rollers are, for example, made of pure PTFE, glass-fiber reinforced PTFE, graphite, or PEEK.

The UIC roller wiper system has proven to be the superior solution and is in use in over 1,000 distillation plants built during the past �0 years.

Installation of a wiper basket with wiper rollers into an RF 4500 Thin Film Evaporator (evaporation surface area: 45 m²)

optimal mixing of the film • self cleaning • low wear and tear

The UIC wiper system

�

Short Path Distillators

Operating pressures below 1 mbar can hardly be achieved in Thin Film Evaporators, as a certain pressure difference is required to transport the vapors from the evaporator to the external condenser. For a num-ber of distillation tasks, however, thermal damage to the material to be distilled can only be avoided with lower operating pressures – and thus lower evaporation temperatures.

For such tasks, a Short Path Distillator is the best choice. Providing the same advantages as a Thin Film Evaporator, Short Path Distillators allow operation pressures down to 0.001 mbar.

The pressure difference between evaporator and condenser must be minimized to use this range of operating pressures. This can be done by installing the condenser in the center of the evaporator. The vapors escaping from the liquid film flow only a “short path” (a few centi-me-ters/inches) before they hit the cold surface of the internal condenser, where they condense. The required pressure difference for the trans-portation of the vapors at this short distance is very low.

Of course, UIC Short Path Distillators are equipped with our roller wiper system.

operating pressures from 0.001 mbar • short residence times • internal condensation

Internal condenser

motor with gearbox

driveshaft

internal condenser

feed nozzle

heating jacket

roller wiper

vacuum nozzle

distillate nozzle

residue nozzle

�

The UIC Delivery Program

Thin Film Evaporator Short Path Distillator

Condenser alignment: External Internal

Typical operation pressures: 1 - 1000 mbar 0.001 - 1 mbar

Applications: Mainly as pre-stage upstream from Short Path Dis-tillators, e. g. separation of large amounts of solvents

For the thermal separation of mixtures of materials that can only be exposed to very low thermal loads

Construction materials are borosilicate glass (for laboratory plants) and stainless steels or highly corrosion resistant alloys (for pilot and industrial plants).

One of the outstanding features of all UIC plants is that each one is designed and built in accordance with the specific requirements of each and every task. This applies also to the secondary compo-nents, which are required for a perfect operation of the Thin Film Evaporators and Short Path Dis-tillators. Separate brochures are available for more information about the turnkey plants from UIC.

Both Thin Film Evaporators and Short Path Distillators are available in a variety of standard sizes with evaporation surface areas between 0.01 to �0 m² and capacities ranging from ca. 0.1 kg/h to more than 10 tons/h.

KDL 5 laboratory plant

Distillation plant with Thin Film Evaporator (22 m²) and Short Path Distillator (15 m²)

Short Path Distillator KD 300

capacities from 0.1 kg/h to over 10 tons/h • turnkey plants for industrial production and laboratories

driveshaft

internal condenser

�

Applications

The UIC Thin Film Evaporators and Short Path Distillators are used for the following tasks:

Concentration and depletion Removal of solvents Color improvement Separation of reaction side products Separation of excess educts Separation of monomers, dimers, trimers, oligomers

Thin Film and Short Path Distillation are ideal for:

Separation of mixtures of materials that contain at least one valuable product, with a minimal thermal load to avoid decomposition, deterioration of color, etc.

Separation of materials with high boiling points Avoidance of high temperatures that would disturb the reaction balance between individual components in an undesirable way

during distillation

Thin Film and Short Path Distillation plants are also successfully used for the following applications:

Food additives / oils and fats

Fish oil ethyl ester - concentration of Omega-� fatty acids (DHA, EPA)

Fish oils - separation of pesticides- physical de-acidification

Monoglycerides - concentrations up to >9� %

Tocopherol - separation of natural tocopherols from deodorizer condensate- concentration of synthetic tocopherols- color improvement

Carotene - separation from palm oil

Tocotrienol - separation from palm oil

Palm oil - gentle de-acidification without damnification of tocotrienol and carotene contents

Lactic acid - separation of water- concentration- color improvement

Free fatty acids - separation from vegetable oils

Oleoresine - separation of solvents- increase of the color bodies

Pharmaceutical products

Pharmaceutical intermediateand final products

- separation of solvents- separation of reactive by-products- color improvement

9

Flavors & Fragrances

Nootkaton - fractionation from grapefruit oil

Sinesal, Valencen - fractionation from orange oil

Patchouli oil / vetiver oil - concentration- color improvement

Wool waxes, wool alcohols - separation of pesticides- color improvement

Pepper, ginger, jasmine oils - color improvement- concentration

Fine chemicals

Synthetic vitamins - separation of reaction side products- color improvement- concentration

Silicone oils - separation of light volatiles

Fischer-Tropsch waxes - fractionation- color improvement

PE waxes - fractionation

Natural waxes - color improvement

UV stabilizers for varnishes - separation of solvents- concentration

Monomer / polymer separations

Dimer fatty acids - separation of monomers, trimers, and oligomers

Epoxy resins - separation of solvents- concentration of monomers

Polyurethane prepolymers - separation of solvents- separation of monomers (e. g. MDI, TDI, HDI)

Mineral oil products

Vacuum residues - characterization in laboratories (fractionation)- cuts up to �00°C AET- yield improvement

Used oil - recycling- color improvement

Waxes - fractionation- color improvement

10

Customer Specific Trial Distillations

Experimental research is recommended when infor-mation required for a good decision is unavailable or only partially available. In many Thin Film and Short Path Distillation projects the data for the com-ponents of the mixture of substances to be sepa- rated are unknown and calculations of the expected distillation results lead only to rough estimates.

We therefore offer comprehensive test distillation capabilities at the UIC Technology Center to inte-rested companies and persons with their own sam-ple materials.

Why do test distillations?

To clarify if a given separation task – with regard to its separation efficiency,

yield, thermal load, etc. - can be solved by Thin Film or Short Path

Distillation (feasibility studies)

Provide parameters required for the design of large industrial plants

(up-scaling)

Identify performance limitations to determine process guarantees

Produce product samples, e. g. for chemical analysis, physical tests or

forwarding sample materials to customers

Type of plant Degasser Falling Film Evaporator

Rectification Column

Thin Film Evaporator

Short Path Distillator

Typical sample quantities

Laboratory PlantsKDL 1KDL � x x

x x

0.� kg�.0 - �.0 kg

Pilot PlantsKD �Multi-stage plant

xx x

xx

xx

xx

�0 - 100 kg�00 - �00 kg

The UIC Technology Center

The UIC Technology Center distills sample quantities from 0.1 kg to 1000 kg. The following plants are available to perform test distillations:

feasibility studies • up-scaling • product samples

Modular distillation plant

Monitoring a trial run

11

Detailed information about our laboratory and pilot plants is available in a separate brochure.

Experienced distillation specialists supervise the plants and optimize the distillation parameters. Each and every part of the distillation plants is thoroughly cleaned after each distillation run to make sure no carry-over from one sample material to another occurs. When working under GMP conditions, an intermediate distillation run with a solvent is performed after the cleaning of the plant. This procedure is done as long as the material distilled previously can no longer be analytically traced in the solvent.

Prior to starting any trial distillation, a careful briefing is done with the customer. Our specialists benefit from the experience of over �,000 trial series runs made during the past years.

Both the KDL � laboratory plant and the pilot plants in our Technology Center run under a PLC control system. The operation parameters are represented in tables and as curves and are part of the test report given to the customer.

Because they know the products and the analytical methods best suited for the material examination, the analyti-cal examinations of distillate and residue samples obtained in the UIC Technology Center are usually done by the customers’ specialists.

laboratory & pilot plants • experienced distillation specialists

The analysis results and the operation parameters of the test plants are the basis for the up-scaling, i. e. the dimensioning of large plants for industrial production.

To prepare the trial distillations and ensure the safety of our staff and equipment, customers provide the following information prior to carrying out trial runs at the UIC Technology Center:

Detailed description of the distillation (a questionnaire is available from our website)

A material safety data sheet Special instructions regarding storage and transportation,

in particular for hazardous goods

Technology Center specialists carry out customer trial distillations

As a technology partner, we supply distillation solutions to our customers for the thermal separation of heat sensitive substances. UIC Thin Film and Short Path Distillation solutions operate under vacuum at pressures down to 0.001 mbar.

UIC GmbHProducts & Services

UIC GmbH

Am Neuen Berg � Telefon: +�9 �0�� 9�0 0 E-Mail: info@uic-gmbh.de

D-����� Alzenau Telefax: +�9 �0�� 9�0 ��0 www.uic-gmbh.de

UIC GmbH

Am Neuen Berg � Phone: +�9 �0�� 9�0 0 info@uic-gmbh.de

D-����� Alzenau Fax: +�9 �0�� 9�0 ��0 www.uic-gmbh.de

We offer

Feasibility studies

Distillation trials for laboratory and pilot plants performed at the UIC Technology Center

Basic and detailed engineering

Delivery of turnkey plants for R&D, pilot, and industrial applications

Plant start-up, commissioning, and process optimization

Leak detection, maintenance, and repair

Spare parts service

Consulting and support through our worldwide network

Ask for our other brochures

UIC GmbH – The Specialist in Vacuum Distillation Plants

Laboratory and Pilot Plants

Distillation Plants for Industrial Production