What is a high pressure reactor?

20 November 2021

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What is a high pressure reactor?

A high pressure reactor is a chemical reaction vessel that can carry out a reaction while under pressure. The pressure can be generated by the reaction or by an external source. The reactor can be used to modify samples with hydrogen and carbon diox.

Description

Advantages

A pressure reactor has several advantages over a standard round-bottom flask. For starters, it can carry out a reaction above a solvent’s boiling point. Second, pressure can reduce the reaction volume, including the liquid phase, increasing concentration and collision frequency, and thus accelerating a reaction.

Temperature increases can hasten the desired reaction but also hasten the decomposition of reagents and starting materials. Pressure, on the other hand, can accelerate the desired reaction and only has an effect on decomposition when it involves the release of a gas or a reaction with a gas in the vessel. Competing reactions are minimised when the desired reaction is accelerated. In general, pressure allows for faster reactions with cleaner reaction profiles.

The above advantages of a pressure reactor have been demonstrated in microwave chemistry. For example, if a Suzuki Coupling takes 8 hours at 80°C, a microwave synthesiser takes only 8 minutes at 140°C. The microwave effect is a contentious subject. Later experiments reveal that some of these early reports were merely artefacts, and that rate enhancement is solely due to thermal effects.

If a pressure reactor is properly designed, it can meet four of the twelve green chemistry principles.

1, Less waste is produced as a result of less solvent and a cleaner reaction profile.
5 – Less solvent is required
6, a short reaction time can save up to 92 percent of the electricity and 200 gallons of cooling water per refluxed reaction[citation required].
12, a closed vessel can prevent toxic gas leaks and explosions.

Types of pressure reactors

Standard glass pressure reactor

Glass Pressure reactors are commonly used when an operator needs to see how a reaction occurs. Although the pressure ratings on these systems are lower than those on most metal pressure reactors, they are still an effective means of reaching responsible pressure limits. The ratings on glass vessels are proportional to the vessel’s diameter. The lower the allowable pressure, the larger the diameter. Pressure ratings can also be affected by integrated bottom valves. A bottom valve on a glass vessel is usually associated with a lower allowable working pressure. All of these variables are influenced by the process and parameters of each individual reaction.

Inert applications can also benefit from the use of glass pressure vessels. These vessels are used in a variety of reactions, including but not limited to hydrogenations, polymerizations, synthesis, catalytic, petrochemical, crystallisation, and others. One disadvantage of a standard glass pressure reactor is the possibility of explosions due to unpredictable excessive internal pressure and a lack of a relief mechanism. However, with proper safety implementation provided by the high pressure reactor manufacturers, the operator can safely perform the majority of reactions.

Fish-Porter tube

A Fisher-Porter tube, also known as a Fisher-Porter vessel, is a glass pressure vessel used in chemistry laboratories. The reaction vessel is made up of a lipped heavy-wall borosilicate glass tube and a stainless steel lid. The lid is held in place by a coupling and is sealed with an o-ring. The advantage of stainless steel autoclaves is that the progress of a reaction can be observed visually. The maximum pressure achievable is much lower than that of a metal bomb. For example, a large 335 mL Fisher-Porter vessel has a pressure rating of 7 bar, and a small 90 mL vessel has a pressure rating of 15 bar, whereas the typical type of bomb is safe to use at 200 bar.

Metal pressure reactor

Metal pressure reactors are commonly used for high-pressure reactions. They can withstand much higher pressures than glass reactors. Despite having a higher pressure rating, they have their own set of flaws. One of them is that metal vessels are more prone to corrosion. During the design phase of a metal pressure reactor, the material of construction (MOC) is especially important. The proper MOC can reduce or even eliminate corrosion in the vessel, but depending on the material used, it may raise the price of a system. Metal vessels are also significantly heavier and must be handled with care when performing maintenance.
Metal high pressure reactors are used in reactions such as hydrogenation, polymerization, synthesis, catalysis, petrochemicals, and others. They are also used in research, such as Upstream, Biomass, Biopolymer, Zeolite, and so on. Setup, maintenance, and corrosiveness are the disadvantages of a metal pressure reactor (bomb).

Microwave synthesizer

Microwave chemistry is the study of the use of microwave radiation in chemical reactions. Microwaves are high frequency electric fields that can heat any material that contains mobile electric charges, such as polar molecules in a solvent or conducting ions in a solid. Polar solvents heat up because their constituent molecules are forced to rotate with the field and lose energy in collisions. When ions or electrons within a semiconducting or conducting sample form an electric current, energy is lost due to the material’s electrical resistance.
Microwave heating in the laboratory gained widespread acceptance following papers published in 1986, despite the fact that microwave heating has been used in chemical modification since the 1950s.

Conclusion

High-pressure reactors are multi-purpose laboratory reactors that are simple to use and designed for the synthesis of organic compounds, hydrogenation, polymerization, and other chemical reactions under pressure. They can also be used in petrochemical research, new material testing, and other areas of research and industry that require high pressure reactor manufacturers,