How are the temperature and pressure in the polymerization reactor controlled?

This post was last edited by HEJIYUER on 2015-8-17 at 11:36. It depends on the individual; it’s the underlying principles of reaction, as well as the relationships between temperature and pressure, that determine everything in these processes. As the reaction temperature rises, the pressure does not necessarily increase. In the case of an exothermic reaction where the temperature is controlled by heat removal, an increase in temperature may require the absorption of heat from within, resulting in a decrease in evaporation rate = a decrease in vapor pressure. Temperature control can be flow control for heating/cooling, it can also involve control of the heat exchange area, or control based on temperature difference heat transfer; in mature processes, it may even be determined based on experience. Sometimes the heat transfer time is much slower than the reaction heating time, so it may be necessary to control the catalyst injection and stirring rates. Those with high requirements can create models for comparison in order to decide which control method is best: the simplest approach is the most effective (a quick solution) ； System robustness over a wide range ； Short convergence time and low overshoot. . . Anyway, it needs to be considered comprehensively. Pressure control can be achieved through the addition of N2 plus venting control (including negative pressure evacuation modes), or by controlling the amount of gas condensation. I guess that’s about it; it depends on the specific polymerization process and the composition of the materials. Even with the PP process, there will be differences. . . @jiaguoyun

First, I searched Baidu for “aggregation reactor”: L

Okay, thank you for your suggestion. Please share any information on this topic.

The temperature is adjusted by heating or cooling the water jacket, while the pressure is controlled using a pressure control valve as needed

The key is to control the reaction temperature properly; if the temperature rises too high, reactions that involve a gas phase can cause overpressure in the polymerization reactor. As the reaction proceeds, part of the gas phase gradually turns into the desired product, and the pressure inside the reactor then continues to decrease.

Control the reactor temperature; the reactor pressure follows the same trend as the reactor temperature and changes earlier than the reactor temperature. Control of the kettle temperature is achieved through cascade control using the return water temperature of the circulating water (secondary loop) and the kettle temperature itself (primary loop). It is basically kept within a range of plus or minus 0.1°C.

1. The reaction temperature is determined primarily based on the characteristics of the reaction; generally, polymerization reactions are exothermic, which means process control is necessary through reaction time and reaction stages. There are various ways to handle the heat generated, with jacketed reactors being a common approach at present. Another method is to use inert gases for rapid processing over short periods of time. 2. Pressure control is necessary due to the vaporization and liquefaction of the medium that occurs as a result of changes in reaction temperature. Since the speed at which pressure changes is much greater than that of temperature changes, the methods of pressure control also need to be adjusted according to the specific conditions of the reaction； Generally, there are many process operations involved, and methods such as vacuum extraction can easily lead to mutations in the reaction ； 3. In short, only an understanding of the manufacturing process can help handle the situations mentioned above; we are willing to participate, so please clarify this point, OP

In our production process, polymerization reactions also occur, and temperature control in the polymerization reactors is a very important aspect; the quality of the products depends largely on this. We use DCS for control. For pressure, we usually use normal pressure in our daily use, so it might not be of any help to you~

For polymerization reactions, if the molecular weight is greater than 10,000, it is considered a high-risk process. According to the requirements of the safety supervision agency, a safety instrument system must be installed to provide interlocks against over-temperature or over-pressure conditions, in order to stop the feed flow and add inhibitors to prevent polymerization.