【Polypropylene】Discussion on the quality of polypropylene products
Thread Content
This post was last edited by Xiao Gong 1985 on 2016-2-18 at 10:59. In the recently produced polypropylene, small lumps have appeared, something that has not occurred before in the production process. Adjustments were made throughout the process, from the use of the various reagents to the reaction conditions, yet the lumps still appear. All routine analysis results for the polypropylene are within the specified ranges. Additionally, the amount of hydrogen used has been increased; experienced experts are requested to provide guidance
The presence of small lumps indicates local overheating; considerations should be given to the water flow conditions at the beginning of the reaction as well as the possibility of scorching in the reactor. Additionally, the formation of crusts inside the reactor and scaling on the jacket are also factors to take into account. .
Thoroughly check whether there are any issues with the equipment itself.
Which factories are still using small reactors to produce PP? It seems to have been phased out a long time ago~~
Due to raw material constraints, there is still about 1.8 million tons of production in China for small-scale units.
If there is no issue with the raw materials, the heat removal from the polymerization reactor should be considered; it’s likely the reactor itself that is the problem
When products clump together, several factors need to be considered: 1. Whether the reaction kinetics curve is normal； 2. Check whether there are thermocouples at the temperature measurement points in the reactor; excessive local heating can lead to caking ； 3. Due to catalyst issues, it is recommended to try using a new batch of catalysts.
Will flashing occur when 2.6 MPa propylene enters the heat exchanger? How much temperature drop can be caused by flashing, and what should be considered as the minimum design temperature for the heat exchanger? Please give me your advice. Thank you
Vaporization occurs when a high-pressure saturated liquid enters a container at a lower pressure; the sudden drop in pressure causes this saturated liquid to turn into both saturated vapor and saturated liquid at the pressure of that container. How much the temperature drops depends on how much material vaporizes
How to measure hydrogen feed for a 20-liter polymerization reactor?