What is a Glass Reactor and how does it work? In-Depth Guide To Glass Reactors

• Posted on 23 August 2023
• Posted in Buyers Guides, Glass Reactors, How To Guides
• 0

What is a glass reactor?

Scientific and research labs require controlled environments to conduct certain studies and processes. In order to facilitate this entirely controlled environment, researchers will employ glass reactors. These are vessels that range from small (500 milliliters) to large (150 liters+) sizes depending on the volume of the experiments. By connecting a glass reactor to external equipment such as heaters, chillers, vacuum pumps, and stirrers, researchers are able to control every aspect of their experiment. We will go over the exact components, variations, and uses of glass reactors throughout this article.

How does a glass reactor work?

A laboratory glass reactor is used to facilitate chemical reactions with air and temperature control. They implement a lid that caters to a number of accessories like stirrers, condensers, and thermometers. Solutions and reactants are loaded into the glass reactor body and the reaction process is monitored through the clear glass for visual cues. As the reaction progresses, it is adjusted by altering certain variables like temperature, stirring speed, and pressure.

Components of a Glass Reactor

The main component of glass reactor vessels is the body of the reactor. This is usually a cylindrical shape glass piece with varying sizes from tabletop reactors to large scale, 150 liter reactors that are mounted onto a metal frame. Every glass reactor will come with some sort of lid equipped with a number of ports or valves. These ports connect to a number of accessories such as an over head stirrer, condenser, or thermo-probe.

At the bottom of the reactor there will be a drain port. Being fairly self explanatory, the drain port is used to empty the liquid contents of the glass reactor and move it to another vessel or recirculate the solution, depending on the application.

Jacketed Glass Reactors

A jacketed glass reactor vessel can potentially have multiple outer layers. Some reactors have no external layers and the glass body is exposed to the ambient air, these are single layer glass reactors. To control temperatures with this style of reactor, users will commonly employ an electric heat blanket that wraps around the entirety of the glass body. These are ideal for certain applications but cannot be used with volatile solutions due to the risk of fire or electric shock associated with heated blankets. They also block the view into a glass reactor making it much harder to monitor a reaction mixture.

For use with volatile solvents and other solutions that will not work with a heated blanket, there is an option for jacketed glass reactors. In order to connect the vessel to an external heater or chiller, users need at least a double layer glass reactor. A double layer glass reactor uses an outer layer with hose connections to hook up to a recirculating heater for example. By using an external heat source, there is no risk of electricity starting any ignition because the heater is set up far enough away from the reactor to allow for safe usage. Still, this outer layer is exposed to ambient air and loses heat energy to the room it is in, but there are ways to mitigate this loss of energy.

Double jacketed glass reactors (also known as triple layer reactors) have two additional outer layers on the glass vessel. The inner layer is equipped with inlet and outlet ports for a heater or chiller to connect to for temperature control. The second, outermost layer has a connection port for a vacuum pump. By having this outer layer and connection, the pump is able to remove the air from inside the jacket and use vacuum insulation to preserve the energy to the vessel. This can prevent any burns and hot surfaces on the outside of the glass reactor, while also preventing condensation when the vessel is chilled that could impede the transparency of the glass.

Stirring Mechanisms

For glass reactors, especially larger ones, there is usually a wide opening in the center of the lid. This opening is meant to house the bearings for an overhead stirrer. Often, a ptfe bearing will house the stirring rod while doubling as a seal for the top of the reactor. The stirring motor is mounted on the frame holding the rest of the reactor.

Paired with these stirring motors are a number of different impellers. These rods have different shaped fins to facilitate a specific type of stirring reaction. Material type is key to selecting the correct stirring rod, ptfe stirrers would be better for chemical reactions as they are mostly inert and will not react with the solution. While stainless steel stirrers are more suited for high temperature applications that would otherwise compromise a ptfe coated rod.

Vacuum system

Some applications require a certain pressure or lack thereof to create ideal conditions for their experiments. A vacuum pump can be hooked up to the lid of the vessel to remove air. This usually cannot be used with a stirring mechanism as most stir bearings do not create an air tight seal that can hold vacuum. So there is often a trade off of vacuum vs stirring when deciding what a reactor needs.

Condenser

There are a huge variety of condensers each with their own purpose, we could easily write an extensive blog just on the different styles of condensers and what they are used for. The two main variations of condensers are determined by their orientation on top of the reactor. A reflux condenser is placed upright, directed vertically above the vessel. This allows any gases to enter the chilled condenser, re-condense into liquid, and fall back into the reactor. When a condenser is placed sideways at an angle, it is meant to remove the gases from the reactor and collect them elsewhere. Warm gases will evaporate and turn to liquid in the condenser, which is angled to have the liquids drip away from the reactor and into a separate collection.

Temperature sensors

Temperature sensors are vital to control the thermodynamics of a reaction. These are long, metal rods that are inserted into the top lid and travel down the length of the reactor until it is submerged at the bottom of the main tank. They are often connected to a temperature control device that can regulate the flow of heat from an external heater.

Pressure Sensors

A pressure sensor can be as common as a pressure or vacuum gauge connected to the top of the vessel that will demonstrate what pressure the reactor is at. We have also equipped different distillation setups with vacuum gauges that connect to a computer via USB or blue-tooth for data logging purposes. Reach out for more information.

Features of Glass Reactor

Any glass reactor worth its salt is made of high quality borosilicate glass. Goldleaf glass reactors for example are made from 3.3 borosilicate glass that is highly resistant to water and most solvents. Still, as with any glass container, thermal shock must be accounted for. Be cautious about rapidly heating or cooling a reactor to prevent thermal shock that could compromise the vessel.

Most reactors have a modular design. At Goldleaf, we carry custom and standard components that can be interchanged. We can fashion custom sized glass joints to connect with whatever glass piece a user needs. Since reactors can come blank with empty ports, it is up to the user to decide if they want to plug any additional holes or use them with a condenser, thermometer, pressure gauge, or anything they see fit. This creates a highly modular piece of equipment that can be fitted for specific applications.

Advantages of Glass Reactor Equipment

Glass reactors are ideal for a number of applications that require chemical reactions because the glassware is chemically inert and will not interfere with a chemical process like stainless steel might. They are also great for high quality mixing because there is no splashing out of the sealed container and stirrers can reach a very high rpm.

If a user has one of our electric lifting reactors, it is extremely easy to clean as the stand will help tilt and hold the reactor in place while it is being cleaned. Besides cleaning, there is not much regular maintenance that needs to be done unless something is broken.

Glass Reactor Models

Here are a few models of Goldleaf glass reactors to give an idea of what options are available. All of our reactors come with an overhead stirrer, controller, and condensers with size options from 10 liters to 150 liters. Lids are sealed with chemically resistant ptfe gaskets.

Goldleaf Single and Double Jacket Glass Reactor

Our standard, base model reactor, the single jacket has an outer layer allows for a connection to a recirculating chiller or heater. A well priced, versatile unit that can fit a number of needs from L2L extraction, distillation, and bulk heating and cooling.

A step up from our single jacketed glass reactor, the double jacketed model comes with everything the base model has but with an extra layer. This second, outermost jacket can have vacuum pulled on it to completely insulate the inner layers and prevent energy loss to the surrounding environment.

Optional Air Powered Motor

For those using volatile substances, our reactor have an optional C1D1 rated air motor that is powered by an external air compressor rather than electricity. An important thing to keep in mind when buying and setting up this reactor, is having a proper sized air compressor that is far enough away from the vessel for safe use. Size of the air compressor depends on the size of the reactor.

Goldleaf Jacketed Explosion Proof Glass Reactor

When dealing with any flammable substance, an explosion proof motor is almost always required. The electronics on this model are UL rated and marked for use in C1D2 environments. This reactor uses a brushless geared DC motor. When paired with a fume hood and other safety precautions, this reactor is well suited for use with volatile and flammable substances. Always check with the regulatory licensing agency in your area to ensure you meet local fire codes. Goldleaf can always help with making sure your reactor is up to code. 

Goldleaf Triple Layer Lifting Reactor

To make a users life easier, this reactor is equipped with an electric lifting motor that can lower and raise the reactor body into place. This allows for much easier cleaning as the glass body can be lowered away from the lid and tilted slightly for easier access, all with just the push of a button.

Goldleaf Triple Layer Explosion Proof Lifting Reactor

Like our jacketed explosion proof glass reactor, this model is equipped with a C1D2 rated electric motor, while the lifting motors are also explosion proof and rated for flammable use in a sealed electrical box. This allows the reactor to be used with flammable substances in a controlled environment, while still having the convenience of a lifting motor.

Equipment Used With Glass Reactors

There are numerous different pieces of equipment that can be paired with a glass reactor set up. We will likely create an in depth article about selecting things like the proper heating and cooling systems in the future. This is mainly because the ancillary equipment needed is determined entirely by the application of the end user, which you will see later in this article can be a number of different uses.

Let's start by breaking down the different types of equipment that can be used with reactors. For starters, there is the equipment that is included with a Goldleaf Reactor purchase, such as stirrers, feed flasks, and condensers.

As stated in the above section about available Goldleaf models, there are several types of stirring motors. A stirrer with standard components is used for aqueous solutions like testing soil solubility in water. Explosion proof stirrers are commonly paired with a fume hood for use with volatile solvents like ethanol. These are electric stirrers with sealed components that can withstand flammable fumes and not give off a spark. For extremely volatile compounds like pentane and other hydrocarbons, air powered stirrers are connected to a compressor so there is no electricity near the reactor at all. Reactors with air powered stirrers are often placed in C1D1 explosion proof booths with fire suppression systems, exhaust vents, and gas detectors.

Feed flasks are used just as the name implies, to feed solution into the reactor. This glassware can have multiple uses such as drip feeding more solvent into a mixture and measuring feed stock before loading.

The condenser that comes with a Goldleaf reactor is meant to be used as a reflux condenser. Placed vertically above the reactor, any fumes created in a reaction mixture will travel upwards through the chilled glassware, re-condense, collect, and drip back into the reactor. Depending on the gas being released, a certain type of chiller cooling system will be required.

Chiller Cooling Systems

A recirculating chiller will serve a number of purposes for a glass reactor. Not only for chilling any condenser, but mainly cooling the jacketed layer of a reactor. A smaller, 10-20 liter reactor that will only require cooling, can utilize a benchtop chiller, for example a Polyscience 40C to -20C LS Benchtop Circulating Chiller. With the ability to reach -20c with slight heating power up to 40c (104f), this unit will be able to cool smaller reactors with no heat load and even raise temps above the ambient room temperature if needed.

Larger reactors are regularly used for multiple purposes, especially in testing and research labs. Meaning these setups will require both heating and chilling to accommodate certain applications. For applications that require mainly chilling, there are units equipped for high strength cooling with some heating. This Lauda Ultracool UC14 Chiller has a very strong cooling capacity at -20C and will easily cool a larger, 100 liter reactor system.

Recirculating Heaters

Depending on the application, a strong heater may be needed for distillation, decarboxylating, and dissolving certain solutions. Users who are trying to mix small batches of viscous solution may need slight heat to make a substance easier to work with. Volumes around 10-20 liters will suffice with a Polyscience 7L Open Bath Recirculating Heater, which can reach up to 200C with 1kw of heating power. This unit would be great for keeping things warm and even boiling small amounts of solvent.

As things begin to scale up to 50 liter and large reactors that demand high temperatures for distilling gases and de-carbing oils, a much more powerful heater is needed. Not necessarily a larger heater, but certainly one with more kw heating power. A Huber CC-315, open bath heated circulator has 3.5kw of heating power with a 300C range. Reactor kits that demand constant high temperatures will benefit from a heater like this or stronger.

Use of Glass Reactors Across Different Industries

The versatility of these machines is expansive when discussing their wide range of uses across multiple industries. Pharmaceutical, biochemical, and food production industries can all benefit from the use of glass reactors. Here is a list of different uses.

Chemical Industry

-Chemical Synthesis: Glass reactors are extensively used for the synthesis of a wide range of chemicals, including organic compounds, intermediates, and specialty chemicals. Researchers can control reaction parameters such as temperature, pressure, and stirring speed to optimize yields, selectivity, and reaction kinetics.

-Reaction Screening: Glass reactors enable efficient screening of different reaction conditions for exploring new chemical transformations. Researchers can test multiple variables simultaneously to identify the most promising conditions for desired outcomes.

-Temperature-Sensitive Reactions: Glass reactors are equipped with precise temperature control systems, making them ideal for temperature-sensitive reactions. Chemists can carry out reactions at specific temperature profiles to optimize reaction rates and product quality.

-Hydrogenation and Oxidation: Glass reactors are employed in hydrogenation and oxidation reactions, where precise control over pressure and temperature is crucial. These reactions are common in the production of pharmaceuticals and fine chemicals.

-Photocatalysis and Photochemical Reactions: Specialized glass reactors equipped with light sources are used for photochemical reactions. These reactions leverage light energy to initiate chemical transformations and are employed in various chemical synthesis processes.

Pharmaceutical Industry

-Drug Synthesis: Glass reactors are used to synthesize active pharmaceutical ingredients (APIs) through various chemical reactions. The controlled environment of a glass reactor allows researchers to optimize reaction conditions, yields, and product purity.

-Formulation Studies: Glass reactors are used to study and develop drug formulations, including solid dispersions, emulsions, suspensions, and liposomal formulations. Researchers can adjust reaction conditions to achieve the desired physical properties and stability.

-Crystallization Studies: Glass reactors facilitate the study of crystallization processes for pharmaceutical compounds. Researchers can control temperature and other parameters to optimize crystal forms, particle size distribution, and dissolution rates.

-Biopharmaceutical Production: Glass reactors are utilized in the production of biopharmaceuticals such as proteins, enzymes, and vaccines. They provide a controlled environment for cell cultures, fermentation, and downstream processing.

-Photochemical Reactions: For photo-sensitive compounds, specialized glass reactors equipped with light sources are used for photochemical reactions, enabling the synthesis of complex molecules under controlled lighting conditions.

Petrochemical Industry

-Catalyst Development and Testing: Glass reactors are used to study and develop catalysts for various petrochemical reactions, such as cracking and hydrocracking. Researchers can test different catalyst formulations and reaction conditions to optimize yield, selectivity, and overall process efficiency.

-Hydrocarbon Synthesis: Glass reactors are employed in the synthesis of hydrocarbons from feedstocks like methane or ethylene. Researchers can simulate and optimize the reaction conditions required for hydrocarbon formation.

-Polymerization Studies: Petrochemical industry relies heavily on polymer production. Glass reactors are used to study polymerization reactions, optimize reaction conditions, and control molecular weight and distribution of polymers.

-Distillation and Fractionation: Glass reactors can be used for distillation and fractionation experiments to understand separation processes involved in refining crude oil and separating different components of petrochemical mixtures.

-Environmental Analysis: Glass reactors are used to study and develop processes for the treatment and disposal of waste products generated during petrochemical production, contributing to environmental sustainability.

Food Industry

-Flavor and Fragrance Synthesis: Glass reactors are used in the synthesis of flavor compounds and fragrances that enhance the taste and aroma of food products. Researchers can control reaction conditions to optimize the production of desired flavors and scents.

-Food Additive Production: Glass reactors are utilized in the production of food additives such as preservatives, coloring agents, and stabilizers. Researchers can test different reaction conditions to ensure the safety and effectiveness of additives.

-Extraction Processes: Glass reactors are used for extraction processes to isolate natural compounds from food sources. This includes extracting essential oils, aromas, and bioactive compounds from herbs, spices, and fruits.

-Enzyme and Fermentation Studies: Glass reactors are employed in the study of enzymatic processes and fermentation. They provide a controlled environment for the production of enzymes, probiotics, and other biologically active components used in food processing.

-Beverage Production: Glass reactors are used in the production of beverages, including alcoholic beverages and non-alcoholic drinks. They allow for the controlled synthesis of flavor compounds, coloring agents, and other additives used in beverages.

-Aroma and Flavor Encapsulation: Glass reactors are used in the encapsulation of flavors and aromas to protect them from degradation and release them slowly into food products, improving overall taste and aroma.

-Nutraceutical and Functional Food Development: Glass reactors are used in the development of functional foods and nutraceuticals. They facilitate the production of bioactive compounds and ingredients that offer health benefits.

Biotechnology Industry

-Biopharmaceutical Production: Glass reactors play a crucial role in the production of biopharmaceuticals such as monoclonal antibodies, recombinant proteins, and therapeutic enzymes. They provide a controlled environment for cell culture, fermentation, and downstream processing.

-Vaccine Production: Glass reactors play a role in vaccine production processes, including the cultivation of viral vectors and recombinant organisms used in vaccine development. They enable researchers to monitor growth and expression of vaccine components.

-Bioremediation Studies: Glass reactors are used for bioremediation studies, where microorganisms are employed to remove pollutants from the environment. Researchers can study the growth of pollutant-degrading microorganisms and optimize conditions for effective remediation.

-Continuous Bioprocessing: Glass reactors can be used in continuous bioprocessing, which offers advantages such as improved productivity, reduced footprint, and enhanced process control. This is particularly important in biotechnology where long-duration processes are common.

Safety Considerations

As with any lab application, glass reactors require a degree of safety. For starters, always ensure chemical compatibility with glassware, stirring rod, and hoses to prevent unwanted degradation. When working with potentially hazardous vapors, a fume hood or other form of explosion proof ventilation should be used to evacuate said vapors and pull in fresh air.

When installing a reactor system always consult with a professional about electrical requirements, ventilation needs, and other potential safety hazards to mitigate any risks later down the road. Goldleaf will always be available to customers who need assistance in any installation or training for their team.

Goldleaf Glass Reactors

At Goldleaf we work to ensure the safety and ease of use with our systems. That is why we provide options for explosion proof equipment when there is any volatile chemical use. Lifting reactors make loading, cleaning, and setup achievable with one operator. Any purchase of our reactors comes with a 1 year warranty and lifetime support from Goldleaf for installation, repairs, and upgrades, just let us know about anything you need help with.

Conclusion

As laboratory processes and research facilities expand, Goldleaf will be there to support the industry. Our reactors cater to an extensive range of industries and the modular options make these a versatile tool that can change as a facility changes. Call us at (510)487-1390 or email us at [email protected] for more details about glass reactors and their availability, we would be happy to speak with you.