The Catalyst Used in Nitric Acid Production: Process Guide

You need to know the catalyst used in nitric acid production before going to other steps. There are many ways to produce nitric acid. Most methods give us a weak acid. It is crucial to make high concentration nitric acid as concentrated nitric acid is a need for many scientific processes. We can produce nitric acid from ammonia by oxidation. You need to follow four steps to produce nitric acid.

Ammonia Oxidation

Platinum is the catalyst for nitric acid production. The process starts with ammonia and air as you need to insert ammonia and air into the catalytic chamber. The ratio of ammonia and air should be 1:8. For every part of ammonia, there should be eight parts of air. The reaction will start when you place these gases at 800 degrees celsius. The pressure of the chamber has to be five times the air pressure. This reaction should consume 95 percent of the ammonia gas. You need to keep these gases at high temperatures and pressure till 95% of the raw materials are converted to products. You will get NO gas as a result of this reaction.

Cooling Chamber

When ammonia reacts with oxygen, it will release energy. It can increase the temperature of the NO gas. You need to cool this gas for the next step. In the second step, there is no catalyst used in nitric acid production. There are many ways to cool a gas. If you keep it for some time, it will lose heat. Most industries cannot wait for a long time. They use specialized refrigerators to cool the NO quickly. Once the gas is cooled, we can send it to the next oxidation chamber.

NO Oxidation

When you combine oxygen with NO, you will get NO2. It is better to keep the gas cool at this stage. If the chamber temperature increase, it can break down NO2. The reaction cannot go forward in this case. It is essential to ensure that all NO has reacted with oxygen to make the NO2. If you send the gas to the next step before reaction completion, it will lead to low concentration HNO3 production. You may also get many by-products when the reaction has not finished in this chamber. When the gas is cooled we need to recover the catalyst from it. Some catalyst particles can enter the gas and go through the cooling process. The catalyst used in nitric acid production is expensive. After the cooling chamber, they recover the catalyst particles and use them again. This method will help avoid losses.

HNO3 Production

We can get a 65 percent concentration of nitric acid from this reaction. NO2 enters the chamber from one side. Water is sprinkled on this gas repeatedly to make HNO3. Compressed air is also part of the reaction. If there is some NO remaining in the chamber, it will convert to NO2. It increases the process efficiency. Water combined with the NO2 at high pressure. This chamber has a pressure of 10 atm. The temperature will increase as a result of this reaction. It can decrease the concentration of nitric acid to 60%. If you reduce the temperature, you can get 65% HNO3.

Dehydration

Most commercial nitric acid solutions have a 65% concentration. When you get this concentration, you can sell it in the market. If you get a demand for high concentration HNO3, you have to treat it with H2SO4. Sulphuric acid can take up the water content of nitric acid. It can increase the HNO3 concentration to more than 90%. This reaction is not a part of the HNO3 production process. It is an extra step to increase the concentration of nitric acid.

Conclusion

It is easy to produce nitric acid commercially. The catalyst used in nitric acid production will make the process faster. You may have to spend some time setting up the equipment. There is no need for extensive effort once the equipment is ready. You can feed the raw material and the process will continue automatically. It is essential to add an extra step of dehydration in the production when you want an acid concentration of more than 65%. You cannot produce more than 65% HNO3 using the first three steps.