The question for discussion is not directly expressed. We needed to know the type of reactor, wether continuous, batch or plug flow or even batch Continuous by design. Secondly what is the nature of the reaction? The useful information here is the reaction must be void of water. Hydrated state. The reaction phase is it reversible kinetics? Is it in gaseous phase or heterogenous. If possible specify the reaction equations. These will give a clue to answering your questions. Now if you can decrease your reactor Volume, you can increase pressure of the reaction in a case where the reaction must be void of atmospheric pressure. An inert gas can be used along the feed streams to increase the pressure. Agitation another approach to increasing the frequency of collision of reactant molecules thus increasing pressure. Increasing the temperature of the reactor can also lead to an increase in pressure. Bet, the challenge grossly depend on the reaction activation energy, enthalpy and other factors. If you specify conditions clearly. The a concrete answer can be issued here. My thought.

You have not mentioned the reactant detail and flow type PFD or CSTR, mixed flow etc. what is the process, catalytic reaction etc, the pressure controlling device purge etc. you can used Nitrogen for maintaining pressure.

Thank you for your response Prosper Ovuoraye and Prem Baboo sir. I sent details in messenger.

Another aspect to be looked at is safety. Is your reactor and your piping designed to withstand such high pressures? Do you need a safety valve or how you can control the pressure in the reactor. I would also suggest to use either notrogen or a gaseous raw material if feasible.

Thanks for your suggesstion Bernhard C. Seyfang. The vendor said, maximum pressure should be less than 10 bar. In reactor they have given one valve to depressurize. My friend said, you cant pressurize the reactor to 15 bar with nitrogen. Is it right?

If the vendor gives you a max pressure it definitily contains a safety factor, so your colleague's statement is informally correct. Nevertheless I would be very careful if it is a glass reactor and would do first experiments @ pressures

There is no problem either to remove the moisture from the air, or to compress the gaseous substrates. Of course, it is also possible to increase a pressure over the reaction mixture if desired.

Hydrogenation is commonly performed in a fixed-bed catalytic reactor performed at elevated temperature and pressure to increase the density of the hydrogen and increase the rate of reaction.

Yusuf Kedir It is not an hydrogenation reaction. So I cant use hydrogen to pressurize the reactor.

Narayanan Subramanian, Maybe you better state what the process is, at least we won't have to guess. It is also worth mentioning what reactor it is. I also have a question, what is the "corversion reaction"? Do you know a reaction in which there is no conversion of the substrates?

The most common ways to increase pressure:

* Use a pump

* Use a compressor

* Close the valve that controls the pressure