Chemical reactors form the core of all chemical processing plants. Enhancing their operation and design can result in substantial cost savings and potential revenue.
Continuous reactors are those that take in reactants in one place and allow the reaction to take place, and then remove the product continuously. They typically have lower cost of capital than batch processes.
Batch Reactors
Batch reactors are among the most basic kinds of vessels for chemical reactions. They are made up of tanks that have connections at the top that are used to add reactants as well as removing substances, and can be equipped with agitators as well as internal cooling or heating system. They are able to be utilized at temperatures up to 5,000 PSI.
The reactors are filled up with reactants, and heated to allow reactions to occur. After the reaction has been completed the reactor is then emptied and cleaned. It is now ready to be used again for the next batch of reactants that will be to be added. The batch process is typically adaptable and are used chemical reactors to make a range of chemicals.
Control of temperature is usually poor when working in batch reactors. The reason for this is that the temperatures of reactants vary in time because of reactions that are exothermic or endothermic. The temperature sensor on the vessel for reactors is typically ineffective at detecting these fluctuations in the process temperature. The result is hot or cold areas within the reactor, which could have negative effects on production quality.
In order to improve temperature control for batch reactors, a jacket is placed around the vessel. The jacket circulates the heat transfer fluid in order to remove or add heat generated by reaction in the reactor. The system has been designed to respond quickly to changes in cooling or heating loads, and to maintain a steady temperature of the jacket.
Continuous Reactors
Continuous reactors have advantages over batch methods, including higher yield as well as the ability to select. They are also more efficient and rely on newer technologies which can reduce costs. But, a reliable continuous process needs a thorough knowledge of reaction kinetics and the design for the channel. In particular, the flow distribution in the reactor can affect mixing efficiency, the transfer of heat and the pressure drop.
The best CSTR design ensures consistent reactions across the whole area of the reactor, which results in a consistent residence time distribution. This prevents dead space and short circuits which occurs when certain volumes of reactant are able to spend more time inside the reactor in comparison to others. However, in reality, the ideal performance of hydraulics is not often attained.
Tube, coil, and plate reactors (incorrectly called plug-flow reactors) are the most popular method of commercial manufacturing of chemical reactions that continue. They’re simple and have excellent mass and heat transfer capabilities and are utilized for gas-phase as well as liquid-phase reactions. They are however not suitable for the handling of solids, and are unable to handle expanding to pilot or production capacities.
A different option is using Continuous stirred tank reactors for sale, which can be designed to function as continuous reactors, but are able to handle solids as well as allow the use of additional chemicals during the process. They are typically smaller than CSTRs, and they can be constructed as pipes with or without baffles, or as a set of interconnected stages.
Microreactors
Microreactors are small size reactor which makes it simpler to conduct a reaction within the lab. It’s also more effective than traditional batches buy reactors and provides higher reactions rates. Additionally, it’s simple to regulate the speed of the reaction through adjusting the rate of feed. Microreactors are particularly suited for chemical reactions that are complex and have a an array of molecular characteristics.
Microreactors are made up of an opening that’s filled with a solution, and is sealed by a plate. The plate is etched with holes that are aligned with the top left, top right and bottom of the “T” design to permit fluids to pass through and out of. Reagents are introduced at the top left, and then withdrawn from the top right side in order to trigger a reaction. The reaction described above is typically isothermal and occurs in adiabatic environments.
Microreactors possess a large ratio of surface area to volume which means that the chemicals present in the solution may adsorb on the channel wall. This could reduce the concentration in the liquid. Microreactors also are more prone to rust than larger vessels.
The subject of continuously operated chemical reactors has experienced a increase in research papers in recent years. The reason for this is the realization that periodic processes have numerous advantages over those operating in steady-state processes, such as superior mean productivity and the ability to select. The benefits of periodic processes can be realized by using systematic design methods that consider the trade-offs that are involved in deciding on the operational conditions of a regular process.
Thermochemical Reactors
The thermochemical reaction uses an energy transfer medium, like a molten salt bath to provide energy in a uniform manner to the reaction substances. This medium allows the process to run at less temperature than what would be achievable with a high pressure hydrogen gas source. These thermochemical industrial reactors have the potential to run at very large energy density when compared to other methods that rely on electric power as an energy source.
Storage of thermochemical energy (TCS) is a storage device that stores energy from chemical reactions that endothermically occur and can be recovered at any moment through allowing the reverse reaction to take place. The process is able to release the thermal energy latent that is stored in the adsorption materials.
A good example of a TCS reactor is the solar reformer based on ceria (SRR). It can be utilized for either the water splitting redox cycle, or in the Hybrid sulfur cycle (HyS). Ceria’s ionic conductivity lets oxygen atoms move throughout the crystal structure of ceria many orders of magnitude more quickly than iron oxide. This allows SRR to operate at temperatures that are less than those required for HyS. HyS cycle.
