Supercritical Fluid Extraction Vessel

Supercritical drying of Aerogels

SCFE Flow Diagram for Lab Scale Model

PFD for Commercial Scale SCFE Plant with CO2 Recycling

Salient Features

  • Supercritical fluid extraction systems with pressures upto 700 bar for lab scale units & upto 450 bar for commercial plants
  • Semi or fully automated PLC based plants with CO2 recycling
  • PED, U stamp, CE, CSA, UL certification optional
  • Customizable designs as per client requirements

World-class technology for natural products

  • There is a tremendous demand for high purity & residual solvent free extracts of natural products. Also there is increasing requirement of eco-friendly manufacturing processes for the extraction of natural products
  • Supercritical fluid extraction technology provides an economical solution toproviding a safe & eco-friendly way for extraction of natural products. Its superiority over the conventional technologies of extraction, especially for natural products in the food and pharmaceutical industry is well recognized
  • Supercritical CO2 textile dyeing is an emerging innovative waterless technology for dyeing of textile fabrics that will revive the textile industries

Commercial Applications of SCFE extractor systems

  • Extraction of natural products such as spice oil & oleoresins, flavors, fragrances, colors
  • Decaffeination of tea & coffee
  • Production of uniform &ultra fine particles
  • Supercritical CO2 (SCO2) textile dyeing of fabrics
  • Supercritical CO2 (SCO2) cleaning of high precision metal components
  • Drying of aerogels

Advantages of SCFE system

  • Extract with delicacy & freshness close to natural
  • High potency of active components
  • Longer shelf life extracts
  • Eco-friendly & green technology with no residual solvent & effluents
  • High flexibility of process conditions
  • Simultaneous fractionation of extracts
  • High yields compared to solvent extracted products
  • Low batch times for extraction
  • Recycling of CO2
  • Low operating cost

Advantage of CO2 as a solvent

  • Carbon dioxide is generally regarded as safe (GRAS) for food products
  • Inexpensive & easily available
  • Non-toxic, non-flammable and inert to most materials

Process description for lab-scale plants

The Carbon dioxide gas from the cylinder is first liquefied & then pressurized above the critical pressure of CO2 (73.8 bar) to the required pressure necessary for extraction. This high pressure liquid CO2 is then heated above the critical temperature of CO2 (31 °C) to the required temperature. CO2 which is now in supercritical phase (SCCO2) enters the extractor where the raw material is fed in powder form & the extraction is achieved on the basis of solubility. The compounds dissolved in SCCO2 finally come to the separator at atmospheric pressure & get precipitated. CO2 leaving the separator is then measured by passing it through a CO gas flow meter.

Process description for commercial scale plant

The raw material in powder form is fed to the extractor. The liquid carbondioxide from the CO2 tank is precooled by passing it through the precooler. This precooled liquid carbon dioxide is then pressurized by means of a positive displacement plunger pump to a pressure above the critical pressure of CO2 (i.e. 73.8 bar). High pressure liquid CO2 is then heated above the critical temperature of CO2 (i.e 31 °C) by passing it through preheater. CO2 which is now in the supercritical state enters the extractor in which the raw material is loaded. The SCCO2 dissolves substances on the basis of solubility, depending on operating conditions. The SCCO2 with soluble extracts enters the separators where the pressure & temperature are reduced sequentially so that solubility decreases & extract precipitates in the separators. Finally the clean CO2 without any traces is recycled back to the CO2 tank via condenser.

Amar make high pressure reactors are a critical part of supercritical fluid extraction equipment designed and manufactured by us. These units are used for various purposes including Extraction of natural products such as spice oil & oleoresins, flavors, fragrances, colors, Decaffeination of tea & coffee, Production of uniform &ultra fine particles, Supercritical CO (SCO ) textile dyeing of fabrics, Supercritical CO (SCO ) cleaning of high precision metal components, Drying of aerogels, etc. As opposed to the traditional solvent extraction systems, these systems are eco-friendly, more reliable, efficient and safer. End product of very high to ultra high purity can be obtained with the help of accurately designed SCFE systems.

SCFE extractor standard models

Model No. Working Volume (ltr) Feed Capacity* (kg/day)
E1331 0.1 0.24
E1431 0.25 0.6
E2131 0.5 1.2
E2331 1 2.4
E2431 2 4.8
E2531 5 12
E3131 10 24
E3331 25 60
E3431 50 120
E3531 100 240
E3631 200 480
E3731 500 1200
E3831 1000 2400

Material of Construction: SS316

Volume (ltr) Design Pressure (bar) Design Temperature (°C)
Standard Optional Standard Optional
0.1 to 2 350 500, 700 100 200
5 to 25 500
50 to 100 NA 150
200 to 1000
  1. *The feed capacity is assuming bulk density of 0.4 kg/ltr of feed, 6 batches/day & one extractor. 5 ltr & above can be offered with 2 extractors & the feed capacity shall double the above given capacity.
  2. 5 ltr & above systems are offered with CO2 recycling & PLC controls.
Gas Pressure Regulator (FPR) To manually charge different gases at desired pressures upto 140 bar / 2000 psi or higherinto the reactor from gas cylinder. Nitrogen, Oxygen & Hydrogen can be charged throughsame regulator (with special adaptor). The regulator is made from SS316 & comes with inlet -outlet pressure gauges & flexible SS braided Teflon PTFE high pressure hose pipe (4m long) with non return valve. Optional Regulators upto 350 bar, automated regulator Regulator for other gases like NH , CO etc. & MOC of Hastelloy C Pressure reducing station with auto changeover
Digital Pressure Indicator / Controller (DPI)

It consists of SS316 pressure sensor (transmitter) & digital pressure indicator/ controller (mounted on common control panel) with pressure alarm & optionally heater cut off for safety. Digital pressure indicator has pressure reading in bar & psi, where as controller reads any one ofthe units. The controller is normally used with mass flow controllers (MFCs) or solenoid/flow control valves to maintain constant pressure inside the autoclave. With MFC, gas flow indicator & totalizer are also provided on the same panel. The pressure sensor has temperature limitation upto 100°C & hence the same is provided with water cooling jacket. Optional Intrinsically safe pressure sensor. Pressure sensors with Hastelloy C / Inconel wetted parts can be offered on request.

Auto Cooling System (ACV)

This system is useful to control temperature overshoots for highly exothermic / out of control / runaway reactions as well as for faster cooling upon completion of reaction. The control panel of the autoclave gives 230V, 1Ø output to connect external auto-cooling system. Options available are: Solenoid valve (ACV) for autoclaves upto 25 ltr or Pneumatically actuated ball valves (ACV) for autoclaves above 25 ltr connected at the inlet of the internal cooling coil with external source of water supply. This is standard for 50 ml – 250 ml autoclaves, however for bigger autoclaves if the cold water line pressure is less than 2 bar then it is better to opt for external pump & tank water cooling system. Normal tap water cooling is not effective at higher temperatures due to steam back pressure whereas pump & tank auto cooling system gives positive pressures & faster cooling. Pump & Water Cooling Tank (ACP): It consists of a SS 304 water tank & pump to circulate water in the internal cooling coil of reactors. Cooling starts automatically if the rate of heating rises suddenly. It comes with monoblock pump, tank, pipeline & flexible hose pipes with quick release coupling & is mounted on the autoclave trolley itself. Ice can be put in the water or the hot water can be discharged & fresh water replenished on continuous basis for more effective and faster cooling. Optional: Ex-proof group IIC pump

Reflux Condenser (RC) It is a jacketed single tube SS-316 heat exchanger with packing material inside used to reflux the condensate back into the reactor & vent off the uncondensed vapours. It is connected directly on the autoclave lid & works under full autoclave pressure. A receiver pot can be connected at the bottom of the reflux condenser with valve for reflux take off. It is available in 0.01, 0.02 or 0.05 m² area. Optional: Reflux condensers can be offered in different materials & area.
Pressure Safety Valve (PSV)

High pressure autoclaves are provided with built in safety rupture disc, however additionalsafety can be offered by providing pressure safety valve for which release pressure can be setmanually by increasing or decreasing the spring tension or by simply changing the spring. Theset pressure should normally be around the design pressure. Safety relief valves are standardsupply for glass autoclave & shaker hydrogentor where rupture discs are not available for lowpressures. These valves come with PTFE / Kalrez O-rings. Optional: Materials: Hastelloy C, inconel

Catalyst Basket (CBS/CBD) It is provided to improve the efficiency of the catalysts & for holding the catalyst so that it willnot be destroyed or changed by the stirring action of impeller. The baskets are made from SS316wire mesh & connected to the stirrer so that they rotate with the stirrer. It is available for 450 ml-100 ltr autoclaves. The catalyst basket can be static which is stationary (CBS) or dynamic (CBD)which rotates with the impeller.
Catalyst Slurry Charging System (CSC)

It is a pressure reactor with magnetic drive stirring, inlet & outlet valves, pressure gauge &nitrogen/vent. Solvent & catalyst are charged in the vessel & the slurry formed by mixing istransferred under nitrogen pressure into the reactor. The pressure rating & volume of thissystem is designed depending on the quantity of catalyst, pressure & temperature rating of theautoclave. Specially designed control system developed by Amar can be offered to charge thecatalyst slurry in continuous mode at a pre-defined flow rate under pressure. This is very usefulfor CSTR, where no suitable pumps are available for slurry. This system is available for anyreactor volume, pressures upto 350 bar & for a wide range materials.

In Situ FTIR Spectroscopy (IR) In situ high temperature, high pressure infrared (IR) probe is offered for real timechemical reaction monitoring. It provides specific information about reaction initiation,conversion, intermediates & end point. Suitable for 1 ltr to 100 ltr reactors upto 100 bar& 200°C.
Torque sensor Torque sensor for accurate measurement of the motor torque, where change in torqueindicates change in viscosity of the reaction.
Gas Booster (GB)

Gas boosters are useful when the cylinder pressures are much lower than the autoclave ratedpressures. In such case the booster takes gas at lower pressure from cylinder & compresses thesame to deliver at higher pressures. They are generally pneumatically operated. Special gasbooster pumps are available for liquid CO used in supercritical fluid extraction system. The 2booster systems are supplied with air filter regulator, pressure relief valves, inlet-outlet pressuregauges, valves & flexible hose pipe. Optional Boosters upto 700 bar pressure

Liquid / Slurry / Gas Charging High Pressure Pot (HPP)

It is used to transfer liquids, slurries or gases in to the autoclave under pressure. It consists of high pressure SS-316 pot designed for working pressure 100 bar or higher with port for nitrogen gas (N ), liquid / slurry inlet with valve & funnel, outlet valve, pressure gauge, pressure safety 2 valve, high pressure hose & NRV. The liquid to be charged is fed into the pot from top funnel & pressurized with N gas until its pressure is higher than the autoclave pressure & then under 2pressure the liquid is charged into the autoclave. The quantity & rate of flow of liquid charged is not known precisely in this system. However a level indicator or sight glass or weighing balance or flow meter can be provided optionally to measure the liquid charged or its flow rate. Pots of different pressure, M.O.C. & sizes can be offered. These pots can also be used for storage of gases when gas cylinders are located at a far away place. With this option approximate quantity or flow of gas consumed can also be determined by measuring the pressure drop. Volume: 250 ml, ½ ltr, 1 ltr, 2 ltr, 5 ltr, 10 ltr Optional: Forward pressure regulators can be provided at the outlet of (FPR) pot if they are used as gas charging. Pots upto 200 bar / 350 bar Pots in MOC Hastelloy C, Inconel, Monel, Titanium

Magnetic Drive & Pressure Sensor Cooling System (MCS) It is a simple 10 ltr SS 304 tank with submersible pump to circulate water in the magnetic drive & pressure sensor jacket to prevent temperature rise beyond 80°C. It is useful if tap water connection is not near the autoclave & when water needs to be condensed.
Condenser (CN)

It is a SS-316 shell & tube reverse flow heat exchanger for distillation/condensing vent vapours from the autoclave upto 10 bar pressure. It is offered in different surface areas such as 0.1, 0.2, 0.5, 1 & 2 m². The condensate can be collected separately in a receiver or optionally refluxed back into the reactor. Higher area & pressures upto 350 bar Different materials Corrugated tubes heat exchangers for better efficiency / compact size

Chain Pulley / Hydraulic Head Lifting System (PL/EL/HL) For autoclave volumes from 10 ltr to 250 ltr & removable head design, the head & vessel are tooheavy to lift manually. Hence chain pulley block mounted on same trolley with SS Stand can beoffered for lifting the head with minimum efforts. Optional: Electric (EL) chain pulley lift Hydraullic lid (HL) lifting arrangement can be offered on request for any reactorvolume. Refer page 8 for picture of the same
Catalyst Filters (CF)

These are small 7 microns SS 316 sintered cup filters which are threaded to bottom of thesampling dip tube so that the catalyst does not come out while sampling liquid. It is very usefulwhen the catalyst is expensive or pyrophoric. These filters may reduce the rate/ flow of thesampling liquid due to the resistance offered by the fine mesh, hence they need regularcleaning to prevent choking. Filters are available for 500 ml – 100 ltr autoclaves. Optional: Different micron sizes Materials: Hastelloy C

Catch Pot (CP)

It is used to collect the vent vapours / gases from the autoclave vent / rupture disc /safety valve port, when the vapour / gas is highly hazardous & cannot be releaseddirectly into the atmosphere. It is a pressure vessel, designed depending on volume ofautoclave & its design pressure. It is provided with inlet, outlet, vent, dip tubes, pressuregauge, safety valve & optionally a flame / flash back arrester. It is normally filled withwater. The gases / vapours collected are safely released through the flame / flash backarrester to avoid any hazard. It is suitable & available for any autoclave volume.

Level transmitter (LT) / switch (LS)

Level transmitter (LT) / switch (LS) with indicator to measure or maintain level inside thereactor under high pressure. Used mainly in CSTR.

Ultrasound Transducer High pressure ultrasound transducer for high frequency mixing.
Thermal Gas Mass Flow Meter (MFM) / Controller (MFC)

MFM can be used to measure accurate mass flow rate of gas (in gm/hr or LPH) & totalized quantity of mass / volume (in gms/ltr) charged in the autoclave at any point. Mass flow controller (MFC) is used to charge the set flow rate of gas into the autoclave at high pressures up to 100 bar or it can be used in pressure control mode to indicate the gas flow & total gas uptake to maintain desired set pressure inside the autoclave (ideal for hydrogenation). The same MFM / MFC can be used for multiple gases by just entering the conversion factor for different gas densities provided the gases are inert to each other. The MFM/MFC comes with high pressure flexible hose, inlet filter with digital gas flow indicator cum totalizer & additional pressure PID controller with pressure sensor if the MFC is used in pressure control mode. User has to specify the maximum flow rate range, pressure, gas & mode (flow control or pressure control) for ordering MFM/MFC. Optional Ex-proof MFM / MFC can be offered on request MFM/MFC upto 300 bar pressure

Ethylene EO/Polypylene PO Oxide Pot (EPP)

It consists of SS 316 (EO/PO) horizontal pot with inlet, outlet valves, gas inlet with dip tube, thermowell, pressure gauge & high pressure hose pipe for 10 bar working pressure. It is used for ethoxylation / propoxylation. Volume: 1 ltr, 2 ltr & 5 ltr Optional: Ex-proof weighing balance to measure the quantity of EO/PO charged.

Heating Cooling Circulators Open Bath Heating Circulator It is used to heat jacketed autoclave from ambient to 150°C by circulating thermic fluid inside thejacket. It consist of bath, pump, level switch, heater & internal cooling coil for cooling from hightemperature to ambient temperature using chilled water or brine solution.It is suitable for reactors up to 5 liter volume. Optional Ex-proof heating bath Closed Loop Heating Circulator (CLH) It is used to heat jacketed autoclave from ambient to 350°C by circulating thermic fluid. Itconsist of a closed pressure withstanding tank, magnetically coupled pump, heater, levelindicator & internal cooling coil for cooling from high temperature to ambient temperatureusing chilled water or brine solution. Suitable for reactors up to 100 ltr volume. Optional Ex-proof circulator Low temperature open bath circulator (CB) It is used to cool or control reactor temperature to -50°C by circulating thermic fluid cooled toup to -75°C inside the jacket or internal coil. It consists of a bath, pump, compressor, condenser& level switch. Suitable for reactors up to 100 ltr volume Heating Cooling open bath circulator (HCB) It is used to heat, cool & control reactor temperature by circulating thermic fluid in theautoclave jacket. It consists of a bath, pump, heater, compressor, condenser & level switch. Temperature range: -25°C to 175°C. Suitable for reactors up to 5 ltr volume Closed loop heating cooling circulator (CLS) It is used to heat, cool & control reactor temperature by circulating thermic fluid in theautoclave jacket. It consists of a bath, pump, heater, compressor, condenser & level switch. Temperature range: -35°C to 200°C / -80°C to 180°C. Suitable for reactors up to 1000 ltr volume.
Receiver Pot (RP) <p< SS 316 receiver pot can be connected at the outlet of the shell & tube or reflux condensor to collect the condensate separately. It is also provided with a port to apply vacuum & offered in 250 ml, 500 ml, 1 ltr, 2 ltr & 5 ltr volumes. Higher volumes & other materials can be offered onspecial request. It can be optionally provided with level indication.
SCADA Software for remote operation & recording (SCD)

SCADA is a supervisory control & data acquisition software with all controllers / indicatorshaving RS 485 modbus communication port or PLC & HMI / touch panel, for online display, setpoint changes & data logging of various parameters like pressure, temperature, motor RPM,motor current / torque, liquid / gas flow rate with totaliser, heater temperature, level, pH, ORP,turbidity, IR etc. remotely from PC as well as locally from panel. It gives continuous online datalogging at predefined (variable) time interval, online graphical representation as well ashistorical data & graphs on PC for single or multiple autoclaves. RS 485-232 convertor & cableupto 50 m or higher is also supplied. Optional: Wireless data communication from PC to panel or mobile alerts can be supplied onrequest

Catalyst Addition Device (CAD) It is used for one time catalyst charging under pressure during the reaction. It consists of a 3 ml to150 ml (depending on Autoclave size) small container with airtight cap, which is openable. Thepowder is filled in the container which is then threaded to the autoclave head from below to aseparate port with needle valve on the top. Under atmospheric & pressurized conditions thepowder remains inside the container as the cap remains closed. One has to apply gas pressure greater than autoclave pressure from the needle valve on thatport so that the cap opens & releases the catalyst inside the autoclave under pressure.Depending on the optional accessories selected, the catalyst addition device may not bepossible due to space constraint on the head. Available for autoclave sizes 100 ml – 100 ltr & upto250°C.
Vacuum Pump (VP)

Suitable rotary vane or diaphragm oil fee vacuum pumps can be supplied for vacuumfrom 100 mbar upto 0.001 mbar in the reactor. It is used either before starting the batchor for high vacuum distillation. Suitable analogue or digital vacuum indicator withcontroller can be offered on request. The reactor fittings would change for very highvacuum & this may limit its pressure rating

pH/ turbidity (TB) / DO / ORP sensors pH/ turbidity (TB) / DO / ORP sensors with indicators & controllers for high pressure &temperature application. pH can be controlled automatically by variable speed acid & basemetering pumps.
Gas Purge Panels

Ex-proof certified gas purge panels for electrical accessories / utilities like heating coolingcirculators etc.

Coriolis Gas – Liquid Mass Flow Meter / Controller (CFM / CFC)

These are used for higher & accurate gas or liquid flow rate indication or control in cases where thermal mass flow meters are not suitable. A common meter can be used for different gases & liquids for a particular range of flow. Optional Ex-proof CFM/CFC can be offered on request

Liquid Metering Pump System (LMP)

This system is used to charge liquid at a desired rate from as low as 1 ml/hr to 100 ltr/hr, when the autoclave is under pressurized condition. The system comes with a metering pump, flow indicator, controller, liquid sump, pressure gauge, strainer & high pressure hose. Pressure safety valve, flow totalizer can be offered on request. Types of pumps offered are: Diaphragm metering pumps for pressures upto 100 bar & minimum flow range of 60-600 ml/hr to maximum 10-100 lit/hr. The flow rates are varied by varying the motor speed with variable frequency drive. Materials: SS316, option: Hastelloy C, Titanium, PTFE High pressure more accurate HPLC type low flow metering pumps for high pressures upto 350 bar & flow range from 0.01 upto 100ml/min. These pumps can be used along with precision weighing scales to measure the total liquid charged at any point of time. Materials: SS316, option: Hastelloy C, Titanium High pressure syringe, PTFE diaphragm, gear, peristaltic pumps can be offered for pumping corrosive chemicals at low / high pressures for specific application & flow rate condition. In line flow meters can be connected to measure & control the flow of the liquids.

Flow Control Valves (FOV / FCV) These valves can be connected at jacket inlet for controlling flow of steam/ hot oil/ water fortemperature control from PID or at the inlet or outlet of the autoclaves for control of pressure. Optional (FOV) On/off pneumatic ball valve actuated by 230V output from panel to solenoid valveinline of air supply (FCV) Pneumatic proportionate flow control valves with I to P convertor (for accuratetemperature / pressure control)
Back Pressure Regulator (BPR)

It is SS 316 regulator mounted on the vent line of the autoclave & is used for maintainingconstant pressure inside the autoclave upto 350 bar. The pressure is maintained by releasing theexcess pressure into the atmosphere or through a hose to safe area. The pressure can be setinitially on the gauge, by manually varying the knob until the gas comes out. Once the setpressure is exceeded the excess pressure is released until the autoclave pressure becomes equalto or below the set pressure. The pressure release is slow & gradual & the set pressure can bevaried at any point. Optional Electronic actuated digital pneumatic back pressure regulator, where the pressureis set digitally & can be released at preset rate of pressure release (6 bar air supplyis required) Pneumatically actuated pilot operated back pressure regulator (air / N gas supply 2for rated pressure is required to activate the same) Electronic control unit & forward pressure regulator with 4 mtr. hose for activating (b) above Materials: Hastelloy C, PTFE etc.

Liners (LN) Removable PTFE / Metal / Glass liners can be offered for autoclaves from 100 ml – 25 ltr. Theseliners can be used for reactions that are corrosive, to prevent the autoclave body from corrosion.PTFE & glass liners can be used upto 200°C & metal upto 500°C. The heat transfer is poor withPTFE & glass liners. Glass liners cannot be fabricated accurately. Hence, Amar recommends theuse of completely corrosion resistant metal autoclaves made from special alloys like Hastelloy,Inconel, Titanium etc. over glass/teflon liners. Liners should be used only if cost is the constraintor corrosive chemicals are to be used sparingly. Metal liners can be offered in Hastelloy C ,Inconel , Monel , Titanium etc.
Catalyst Filtration & Recycling System (CFR)

It consists of vertical SS sintered filter cartridges in a SS housing. After the batch is over thereactor liquid is transferred to the catalyst filter under reactor/nitrogen pressure. After filtrationis over, catalyst is taken back in to the reactor by back washing, thus recycling the same & makingit available for the next batch. Thus catalyst is never exposed to atmosphere & is reused.Generally this system is suitable & available for 2 ltr to 2000 ltr reactor volume. These filters areavailable with zero hold-up volume.

View Windows / Light & Sight Glass (SG) These are quartz / sapphire view glass windows / light & sight glass of small diameter oralong the length of the vessel with special cameras & software for continuous onlineviewing / recording in jacketed vessels to see the reaction. Suitable for high pressuresupto 200 bar & any autoclave / reactor volume.
Sampling Pot With Condenser

Sampling pot with condenser for cooling / condensing & collecting the sample taken at highpressure & temperature