What is the Catalytic Process?
The process of modifying chemical reaction rates by the addition of a catalyst, which cannot change itself during the chemical reaction is known as the catalytic process. These catalysts are generally used to ensure that the rate of production of a desired product is higher than the rates of production of undesirable by-products. And, also ensures that the pressure rates are low enough for manufacturers to use economically priced equipment, so that chemical reactions can occur at those temperatures.
For the production of purified terephthalic acid (PTA) Dürr Air Pollution Control System Division in India presents high-pressure catalytic systems, which are often used to control air pollution. They are used for all exhaust gases produced under high pressure and are based on the Cat.X PH (high-pressure catalytic) systems.
Common Usage of Cat.X PH
The Cat.X PL system is generally used in chemical and pharmaceutical industries and helps in purifying exhaust air from surface treatment plants and automotive paint shops.
Benefits of Cat.X PH
From the expansion of the purified process gas, for e.g., in a turbine, energy is recovered.Cat.X PH removes volatile organic compounds (VOCs) with the help of catalytic oxidation. The benefits of Cat.X PH are:
- The device has autothermal operation
- Anti-corrosive design of Cat.X PH are easily available
- The Cat.X PH and production systems have similar maintenance cycle whether they are long or low
- In the area of PTA, DürrCat.X PH has ample experience
- Customers have the flexibility to select the most effective catalyst material (no need to use a particular producer), if they are using the Cat.X PH
- The device has a comprehensive service portfolio and is operated by local engineers
In India, the Cat.X PH system developed by Dürr Air Pollution Control System Division has a small footprint. At a high pressure, the exhaust gas can be drawn directly from the production line, which will lead to a reduction in size of the overall system and individual components.
Operating principle of the Cat.X PH
Without prior expansion, the high-pressure exhaust gas, which comprises methyl bromide, carbon monoxide and methyl acetate, can be cleaned directly and passed into the high-pressure catalytic system.
Powered by pre-heated air or steam, the exhaust gas is heated using a heat exchanger. The device is used to improve the energy efficiency of the system and when the gas reaches the operating temperature of the catalyst, the temperature of the exhaust gas rises using an air-to-air heat exchanger, which is heated with purified air. The heat is recovered in the air-to-air heat exchanger after the organic pollutants have been turned in the catalyst and the cleaned exhaust gas has cooled down. The purified and cooled exhaust gas returns to the production system and is still under pressure. From a downstream expander, the energy released from the gas is recovered.
Application areas of the Cat.X PH
Dürr’s Cat.X PH high-pressure catalytic system is the ideal solution for the production of purified terephthalic acid (PTA) and for other applications that give rise to exhaust gases at high pressure. High-pressure catalytic systems are generally used where PTA is produced in the petrochemical industry.
Technical specifications of the Cat.X PH
The exhaust gases, which comprise pollutants like methyl bromide, carbon monoxide and methyl acetate are produced at high pressure and managed for use by Cat.X PH high-pressure catalytic systems.
Within a very narrow range, the Cat.X PH high-pressure catalytic system’s pollutant burden fluctuates in the PTA production process. An integral characteristic of the design of the Cat.X PH system is that it allows long production cycles when the customer is given the options to select the correct catalyst bearing the pollutant burden.
Construction of the Cat.X PH
At the heart of the high-pressure catalytic system, lies the catalyst, which removes the organic pollutants from the exhaust gas. Before reaching the catalyst, the exhaust gas is heated to the required temperature with the help of upstream heat exchangers that allow the catalyst to operate within its ideal temperature window. Without any modification, the exhaust gas transferred from the production process is purified due to the arrangement of the components in a high-pressure catalytic system. After the exhaust gas is cleaned, it returns to the manufacturing process at its existing overpressure. In case of VOC or volatile organic compounds, extra heat can go around the heat exchanger and be released directly into the chimney without being utilized. This happens when concentration of heat is so high and excess energy is produced for the reaction to occur. Therefore, the design of the device is extremely systematic and ideal.
