All posts by Rushabh Parekh

Reactive extraction by Asymmetric Rotating Disc Contactor type Liquid-Liquid Extractor

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

15

Aug 2022

Reactive extraction by Asymmetric Rotating Disc Contactor type Liquid-Liquid Extractor

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

In Pharmaceuticals industry, various reactions are done to produce API in conventional batch kettles. Based on process requirement, required reaction time is provided to complete the reaction. Once the reaction is completed, suitable solvent is used to extract API. Kettles are agitated and jacketed to provide required heating. In most cases, product extraction is followed by water washing for impurity removal. This entire process requires large number of batch reactors of higher capacities. These batch mode operations have inherent disadvantages as given below:

    • Complete process involves lot of manual operation. This gives inconsistent product quality and batch failures.
    • Increasing product capacity to manyfold has lot of challenges. This means many new batch reactors with higher capacities. This arrangement will have a huge space demand and requires lot of manpower.
    • When extraction is carried out in a conventional batch kettle, fresh solvent for extraction is added several times in the same vessel. Each washing cycle would incrementally extract the desired product from the aqueous phase, producing dilute extract in each subsequent cycle. As a result, the solvent use is high and a large volume of extract leads to higher recovery costs and solvent losses.
    • These issues can be overcome by converting batch process into continuous mode. For this, Technoforce make Asymmetric Rotating Disc Contactor (ARDC) type Liquid-Liquid Extractor can used for reaction followed by extraction in continuous

Figure 1 : Asymmetric Rotating Disc Contactor with cross section

ARDC is a vertical cylindrical shell having eccentric rotor. Inside ARDC has a series of mixing & settling zones created by alternating rotating and stationary baffles (see figure 1). Top and bottom of ARDC has decantation zones to decant raffinate and extract phases. The feed/solvent having higher density will be fed from top and feed/solvent with lower density will be fed from the bottom of ARDC. One of the phases will be continuous and other phase is dispersed. Both phases will be effectively mixed and settled using rotating and stationary baffles within ARDC shell. After extraction, Both the extract and raffinate will be collected in tanks after passing through settlers. ARDC will have following advantages:

    • ARDC provides adequate mixing and residence time for the reaction to occur continuously.
    • The two phases can be fed at calculated rate to give the required time for the reaction to happen.
    • As the reaction required a specified temperature, both the phases can be preheated online and the extractor which is equipped with a jacked can be also kept hot by circulating hot water at the required temperature.
    • ARDC require less power as compared to batch reactor.
    • This efficiently designed extractor provides adequate mixing between the phases. This leads to lower feed to solvent ratios. overall requirement can get reduced by ~50 % as compared to batch extraction.
    • One Liquid Liquid extractor can replace all Reactors. This leads to 70% space saving.
    • No manual intervention.
    • Reaction / Extraction and water washing keeps on working continuously without any involvement of manpower.

Typical Asymmetric Rotating Disc Contactor plant

Technoforce has already designed and built several ARDC type Liquid-Liquid Extractors for various industrial sectors. We also offer other evaporation technologies like Agitate Thin Film Evaporation, Short Path distillation and Drying, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Centrifugal Extraction and Crystallization technologies.

Technoforce is ISO 14001:2015, ISO 45001:2018, ISO 9001:2015 certified company with decades of experience in construction under ASME U stamp and PED/CE mark certification. Technoforce also have Pilot Plants facility in The Netherland and India. Sales office in India and Germany. For more details, visit Technoforce website www.technoforce.net

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


Agitated Thin Film Evaporator for Cardanol recovery

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

09

Aug 2022

Agitated Thin Film Evaporator for Cardanol recovery

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

Cardanol is the main component of cashew nutshell liquid (CNSL), a byproduct of cashew nut processing. This nutshell liquid contains mainly anacardic acid and a smaller amount of cardol and its methyl derivatives. CNSL can be decarboxylated and distilled to yield high purity cardanol, a highly desirable alkylphenolic compound in the chemical industry. Cardanol finds use in the chemical industry in resins, coatings, frictional materials, and surfactants used as pigment dispersants for water-based inks. With the increased desire in the chemical industry to replace petroleum-based materials and move away from toxic substances, cardanol end-uses continue to expand as a diluent and intermediate for various derivatives and applications.

Cashew nutshell

Batch kettle distillation is commonly used as industrial method to evaporate Cardanol from CSNL. However, batch process has inherent disadvantage of long distillation time. Cardinol is heat sensitive product. Long distillation hours at high temperature catches color in Cardinol. This reduces the Cardinol quality and subsequent reduction in market value. Longer distillation hours can reduce Cardinol yield to 50-60%.

Considering heat sensitive properties of cardanol, its recovery and color can be improved if contact time to heating surface is reduced. Agitated Thin Film Evaporator (ATFE) is best fit for this requirement.

In ATFE, a thin film is formed on inside diameter of shell which is intensely agitated by rotor. The small holdup in the film reduces residence time to a few seconds. The turbulent flow within this thin film narrows the spread in residence time distribution. Required evaporation is achieved in a single pass, avoiding recirculation and repeated exposure of the product to the heated surface. These features provide big benefits while processing heat sensitive products. Also, ATFE can operate at high vacuum [maximum 1 mbar] to keep process temperature low. The product can be distilled with the help of hot oil/Steam heating on the jacket side. The product vapors flow counter currently to the feed and condense in a suitable cooling water condenser. The concentrate from ATFE and distillate from the condenser will be discharged continuously by pump.

Benefits of using ATFE for Cardanol evaporation
Improved evaporated Cardanol colour as compared to batch kettle.
Increased rate of cardinol recovery to 80% and more, due to high rates of heat transfer achieved in ATFE combined with low residence time and high vacuum which limits polymerization.
Better handling of the highly viscous and tarry residue with ATFE rigid rotor design which add value to the customer as the un-polymerised residue is a suitable by- product.
Technoforce has already designed and built more than 300 Agitated Thin Film Evaporators for various industrial sectors. We offer evaporation technologies like Agitated Thin Film Evaporation, Short Path Distillation and Drying, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction and Crystallization technologies.

Technoforce is ISO 14001:2015, ISO 45001:2018, ISO 9001:2015 certified company with 2 decades of experience in construction under ASME U stamp and PED/CE mark certification. Technoforce also have Pilot Plants facility in The Netherland and India, sales office in Germany. For more details, visit Technoforce website www.technoforce.net.

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


Removal of aromatics from oil fractions

30

Aug 2022

Removal of aromatics from oil fractions

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

In the processing of petroleum crude oils, vacuum distillates and de-asphalted oils (DAO) are among the partial streams. These can be further processed into high quality base oils.
The first step is the removal of aromatics by extraction, which produces Distillate Aromatic Extracts (DAE) and Residual Aromatic Extracts (RAE) as extracts. DAE and RAE are important process oils used in the production of rubber products (tyres, inner tubes, floor coverings).
The polycyclic aromatic hydrocarbons (PCA) contained in DAE and RAE are now classified as highly harmful to health.
EU Directive 2005/69/EC limits the permissible limit value for polycyclic aromatic hydrocarbons (PCA). Limit values are benzo(a)pyrene < 1 mg/kg and total PCA < 10 mg/kg.
In order to fall below these limits, DAE and RAE are further treated by means of a extraction step. The extracts obtained in this way are called Treated Distillate Aromatic Extracts (TDAE) and Treated Residual Aromatic Extract (TRAE).
The market for TDAE and TRAE is growing strongly while DAE and RAE are in decline.
Figure 1: Market development TDAE

A possible technical solution for the extractive removal of aromatics is the Asymmetric Rotating Disk Contactor (ARDC) from Technoforce Solutions. Here, the series counter current circuit of several mixers/settlers (see Fig. 2) of a conventional extraction is transferred to an extraction column.

Figure 2: Conventional arrangement of three mixers/settlers

Figure 3: Structure of the ARDC

The ARDC consists of an axis with rotating discs that ensure mixing of feed and solvent and flow- calmed settling zones in which raffinate and extract can separate. The separate settling zone of the ARDC has significant advantages even against symmetrically designed conventional rotary extractors. The separation is significantly more controlled and thus more effective, as unwanted flow entrainment is avoided.

Approximately 6 mixer/settler stages are realised in one ARDC. The name comes from the off-centre axis of rotation of the mixing zone.
For the removal of aromatics from the DAE, furfural or NMP are used as solvents. While the NMP tolerates higher process temperatures, the possible process temperature for furfural is limited due to the higher partial pressure. However, furfural has a higher selectivity towards mono-aromatics than NMP and can therefore be used in a lower solvent to feed ratio. The process-relevant data are determined in advance by piloting in pilot plants of Technoforce Solutions. Figure 4 shows the settling zones in a glass column, which is used to adjust the flow conditions. Figure 5 shows one of the piloting plants.

Figure 4: Settling zones in an experimental column

Figure 5: ARDC Pilot Plant in Geleen, The Netherlands

Even at lower temperatures, the removal of aromatics to values far below those required by EU Directive 2005/69/EC can be achieved by getting a good TDA yield.

Technoforce has already designed and built more than 60 Asymmetric Rotating Disk Column Units for Petrochemical industry, Fine chemistry, Pharma and other industrial sectors. Within the scope are also other extraction technologies as well as other technologies like Short Path Distillation, Agitated Thin Film Evaporation and Drying, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction and Crystallization.

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


Crystallization of a Monomer from a Waste Depolymerization Process

12

Aug 2022

Crystallization of a Monomer from a Waste Depolymerization Process

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

Recycling of polymer products (“plastics”) is an important contribution to reduce the amount of waste that can turn into microplastic and pollute the environment for decades, and for an improved carbon dioxide balance in production of new polymers. The latter can be achieved by depolymerization of polymers by either thermal pyrolysis or in case of polyesters by interesterification in a suitable medium. However, the recovered monomer usually must meet strict quality requirements. Therefore, besides yield, the purity achieved is an essential criterion for the economy of the overall process. Depending on the properties of the monomer, different separation processes are available for this purpose. In addition to distillation methods, crystallization is one possibility for achieving high quality products. Using crystallization, it is also possible to not only have a strict control of purity but also on the crystal morphology and size distribution. In addition, customers are looking for continuous processes rather than batchwise operation. This is where the Technoforce Plug Flow Crystallizer (TPFC) comes into play.

The Technoforce Plug Flow Crystallizer consists of a horizontal cylinder fitted with one or more separate double jackets. This allows the crystallizer to be individually tempered in different sections to create a graduated temperature profile. In cooling crystallization, for example, an 80°C solution could be cooled to 60°C, then to 40°C and further to 20°C to control crystallization. A specially designed rotor ensures good mixing within a section, however from section to section (i.e., from temperature level to subsequent temperature level) the system forces a plug flow without significant back-mixing. The rotor design also minimizes mechanical energy transfer into the crystal slurry to avoid breaking of mature crystals into fines. By this, unwanted secondary nucleation and uncontrolled crystal growth can be reduced considerably.
Technoforce Plug Flow Crystallizer with cross section

By optimizing the crystallization process with our pilot size Technoforce Plug Flow Crystallizer, we were able to maximize yield with a narrow crystal size distribution for the monomer. The solution was directly coming from the upstream depolymerization at elevated temperature and was gradually cooled down at two different cooling media temperatures in one single TPFC. Thus, in one step we achieved the desired separation, while for demands of even higher purity it is always possible to repeat the crystallization by using either the same or a different solvent, a process known as re-crystallization.
In our laboratories in Nashik/India or Geleen/The Netherlands we can offer our customers bench scale and pilot scale crystallization trials in our continuous Plug Flow Crystallizers. Choice of suitable solvent as well as some pre-investigations regarding solubility curves should be performed by the customer beforehand to speed-up the project.
Technoforce has already designed and built several hundred skids of process intensification technology for oils and fats applications, fine chemistry, polymers, food and pharma products and other industrial sectors. We also offer other evaporation technologies like Short Path Distillation, Agitated Thin Film Evaporation and Drying, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction in columns or centrifugal systems.

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


Energy efficient drying of high TDS wastewater by Sludge Dryer

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

09

Aug 2022

Energy efficient drying of high TDS wastewater by Sludge Dryer

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

Industrial wastewater is a generated from the various manufacturing processes and cleanup operations. As water is required for nearly every step of production across a multitude of industries, it can pick up a variety of contaminants that require removal to acceptable levels before discharge from an industrial manufacturing facility. Typical constituents requiring treatment may include suspended solids (TSS), dissolved solids (TDS), fats-oils-grease (FOG), pH, bacteria, selenium, heavy metals and other regulated chemicals and substances.

Typical wastewater treatment involves primary, secondary, and tertiary treatment to remove mainly contaminates, followed by concentration of high TDS stream by evaporation technique. Treatment of this concentrated stream is the last part of wastewater treatment. Sometimes concentrated stream generates directly from plant operation.

Various types of methods are used to treat concentrated wastewater. Most conventional methods operate in batch mode, which involves filtration or kettle drying. In filtration method, mother liquor has to be recycled for concentration, which involves repeated use of energy to evaporate same liquid. Also, sludge from the filter contain high amount of water, which is expensive to dispose. In kettle drying method, kettle filled with wastewater is heated indirectly with hot utility on jacket side. This technique involves high energy consumption and longer hours for drying. Also removing sludge after drying become difficult task which involves lot of manual work. This leads to unsafe and messy operation.

Commonly used continuous method is spray drying. This is direct contact drying where hot air is in direct contact with wastewater droplets. In this case, energy efficiency is low because of inefficient contact with hot medium. Also size of the plant is huge and number of equipment involve are more. Evaporated water along with flue gases discharged to outside air. Hence evaporated water cannot be recovered. This technique is not environment friendly and less energy efficient

The Technoforce Sludge dryer is example of indirect contact drying method. Agitated Thin Film Drying technology is used in this type of dryer. Sludge Dryer consists of a vertical cylinder fitted with a heating jacket. The feed material is pumped continuously to the feed nozzle on top of the equipment. By gravity it flows down and is spread uniformly to a thin film on the inner wall of the Sludge Dryer by a fast-rotating agitator. The heating jacket is heated by steam or thermal oil and transfers the heat to the evaporator. Evaporated vapors from feed film travel to an external condenser while the feed material turns into slurry, sludge, paste and finally dry powder that is collected at the bottom. For wastewater applications, the dryers are often run under atmospheric pressure. This leads to ease in powder collection.

Rotor design is crucial to be successful in the wastewater drying process. Most wastewater feeds are sticky in nature. During drying process, solids stick to the inside wall of Sludge Dryer should be removed continuously to keep surface clean. For this purpose, Zero clearance rotors having hinged blades are used. These hinge blades can touch the shell and wipe the solid built up. (Refer figure 3) Blades are sturdy in design and can handle various types of wastewater.

Figure 3: Zero clearance blade in Sludge Dryer

Agitated Thin Film Drying is highly energy efficient process. Because of the compact design, good control over operating parameters; Sludge dryer become very easy to operate and require less space. One can vary dryness of the solids from dryer based on requirement by simply changing the feed rate or heating temperature. Evaporated water can be condensed and reused.

The indirectly heated sludge dryer eliminates air pollution and gives unmatched thermal efficiency of more than 90 % which is way higher than spray dryer. Overall, 75% space saving can be achieved as compared to similar size spray drying plant.

Technoforce has two types of Sludge Dryers based on their orientation, i.e., vertical and horizontal. Sludge Dryer – Vertical suits well for feeds in the form of solutions or slurries which are pumpable. Sludge Dryer- horizontal is versatile alternative. It is suitable for solutions, dilute slurries, thick slurries, pastes or filter cakes.
Technoforce has already designed and built more than 150 Sludge Dryers for various industrial sectors. We also make Agitated Thin Film Dryers (ATFD) specially designed for product drying applications. We offer other evaporation technologies like Agitate Thin Film Evaporation, Short Path Distillation, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction and Crystallization technologies. Technoforce is ISO 14001:2015, ISO 45001:2018, ISO 9001:2015 certified company with decades of experience in construction under ASME U stamp and PED/CE mark certification. Technoforce also have Pilot Plants facility in The Netherland and India. Sales office in India and Germany. For more details, visit Technoforce website www.technoforce.net

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


[:en]Case Study - Agitated thin film dryer: vertical[:de]Fallstudien - Aufgerührter Dünnschichttrockner - vertikal

Pesticide Removal from Fish Oil by Short Path Distillation

14

Aug 2022

Pesticide Removal from Fish Oil by Short Path Distillation

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

Fish oil is a valuable nutrient and well-known for its high omega-3 fatty acid content. In general, the fatty acid spectrum is considered to have a positive impact on health, especially EPA (eicosapentaenoic acid) and DHA (docosaheaxanenoic acid). High EPA/DHA oils are highly sought after and achieve high market prices. However, depending on the source of the oils, they typically contain a considerable amount of so-called POPs (persistent organic pollutants) that are not easily bio-degradable and thus accumulate in nature. Many of these POPs are quite toxic even in extremely small concentrations below ppm levels, including PCBs, halogenated furans and dioxins, brominated phenyl ethers, DDT etc.

Specifically, fish liver oils have relatively high concentrations of POPs which exceed the limits given by legislation of many countries. In this case, Short Path Distillation can help to reduce the content to an acceptable level.

Short Path Distillation (sometimes referred to as Molecular Distillation) is a wiped film technology that can operate at extremely low absolute pressures down to 0.001 mbar. This is achieved by eliminating all usual pressure drops that occur in classical distillation equipment. By continuously feeding into a heated vertical evaporator and spreading the feed to a very thin film on the inner evaporator wall by a specifically designed rotor, no hydrostatic pressure hinders the evaporation, taking smoothly place from the surface of the wiped film. The generated vapors will then have a quite short path from place of evaporation to the place of condensation, as the condenser is packed concentrically inside the evaporator shell. By this construction, the usual pressure drop by vapor mass flow to an external condenser is also removed, thus the equipment can operate at the extreme low vacuum conditions. This in turn enables to distill at temperatures that are reduced by 150-200 K compared to a distillation at ambient pressure. Short Path Distillation can therefore be considered the gentlest distillation process, which opens distillation to separation tasks that would not otherwise be possible.

SPDU with cross section

SPDU roller type rotor top view

By optimizing the crystallization process with our pilot size Technoforce Plug Flow Crystallizer, we were able to maximize yield with a narrow crystal size distribution for the monomer. The solution was directly coming from the upstream depolymerization at elevated temperature and was gradually cooled down at two different cooling media temperatures in one single TPFC. Thus, in one step we achieved the desired separation, while for demands of even higher purity it is always possible to repeat the crystallization by using either the same or a different solvent, a process known as re-crystallization.

In our laboratories in Nashik/India or Geleen/The Netherlands we can offer our customers bench scale and pilot scale crystallization trials in our continuous Plug Flow Crystallizers. Choice of suitable solvent as well as some pre-investigations regarding solubility curves should be performed by the customer beforehand to speed-up the project.

Technoforce has already designed and built several hundred skids of process intensification technology for oils and fats applications, fine chemistry, polymers, food and pharma products and other industrial sectors. We also offer other evaporation technologies like Short Path Distillation, Agitated Thin Film Evaporation and Drying, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction in columns or centrifugal systems.

Typical SPDU skid unit

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction


Drying of a Chemical Intermediate by Agitated Thin Film Drying

12

Aug 2022

Drying of a Chemical Intermediate by Agitated Thin Film Drying

It’s no secret that the digital industry is booming. From exciting startups to global brands, companies are reaching out to digital agencies, responding to the new possibilities available.

For drying of natural or chemical products several technologies are available on the market. It varies from belt dryers, drum dryers, freezing dryers to spray dryers etc. Many customers approach Technoforce for a drying process of a product that is going from development into industrial production, or to seek a better technology than their existing one. Better could mean higher quality, less residual moisture, lower drying temperature, or higher energy efficiency. In many cases the Technoforce Agitated Thin Film Dryer is the best solution to achieve the desired goal.

Phograph 1: Powder after drying in ATFD

The Technoforce Agitated Thin Film Dryer (ATFD) consists of a vertical cylinder fitted with a heating jacket. The feed material is pumped continuously to the feed nozzle on top of the equipment. By gravity it flows down and is spread uniformly to a thin film on the inner wall of the ATFD by a fast-rotating agitator. The heating jacket is heated by steam or thermal oil and transfers the heat to the evaporator. From the feed film, the volatiles evaporate. Vapors travel to an external condenser while the feed material turns into slurry, sludge, paste and finally dry powder that is collected at the bottom. To ease the powder collection, the dryers are often run under atmospheric pressure, however solutions for vacuum drying including semicontinuous discharge via a double chamber receiver are also available.

Rotor design is crucial to be successful in the drying process. Different rotor types are available with different properties:
– Fixed clearance rotors with a defined clearance/gap between rotor blade tip and evaporator wall. The blades may be rigid or hinged and are usually made from stainless steel.

Phograph 2: Fixed clearance blade in ATFD

– Zero clearance rotors have hinged blades that touch the evaporator wall. During the process the product film typically works as a kind of lubricant between blade an evaporator, however a small amount of wear and tear particles is usually found in the bottom product. In some cases, this can be avoided using PTFE tips for the blades. This design transfers mechanical force into the film, breaking up any build-up of solids on the evaporator.

Phograph 3: Zero clearance blade in ATFD

In our pilot plants in Nashik/India or Geleen/The Netherlands we can offer our customers bench scale and pilot scale drying trials in our continuous ATFD systems. We are happy to send a process questionnaire to be filled by the customer beforehand to speed-up the project.
In this specific case, a customer approached Technoforce to replace their existing spray dryer for a chemical intermediate which was not flexible enough for variations of feed rates and consumed too much energy. After successful pilot trials we could design an ATFD plant skid fulfilling these requirements.

Phograph 4: Typical ATFD skid

Technoforce has already designed and built several hundred skids of process intensification technology for oils and fats applications, fine chemistry, polymers, food and pharma products and other industrial sectors. We also offer other evaporation technologies like Short Path Distillation, Agitated Thin Film Evaporation and Drying in a horizontal ATFD, Falling Film, Rising Film and Forced Circulation Evaporation, as well as Liquid-Liquid Extraction in

Our Expertise
Evaporation
Drying
Crystallization
Short Path Distillation
Zero Liquid Discharge Systems
Extraction