Pre-loading Continuity Additive in Polymerization Reactors
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Gas phase polymerization reactors are vulnerable to sheeting and fouling during the initial stages of polymerization reactions, even when continuity additives are used, due to low concentrations of these additives introduced after the reaction has begun, leading to operability problems.
Innovation Solution
Pre-loading a continuity additive or a combination of a continuity additive and a flow improver into the reactor before the start of the polymerization reaction, along with a seed bed, to improve the continuity and reduce sheeting and fouling during the initial stages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If continuity additive is introduced after the polymerization reaction begins, then the reactor can operate with standard loading procedures, but sheeting and fouling occur during initial stages due to low additive concentration
Solution Approach 1:
The continuity additive is pre-loaded into the reactor before the polymerization reaction starts, ensuring that the additive is present at sufficient concentration from the beginning of the reaction to prevent sheeting and fouling during the critical initial stages
2Reliability
If continuity additive is pre-loaded into the reactor before polymerization starts, then sheeting and fouling are reduced during initial stages, but additional loading steps are required
Solution Approach 1:
The continuity additive is combined with the seed bed material into a single pre-mixed composition that is loaded into the reactor as one unit, eliminating the need for separate additive loading steps while ensuring proper distribution from the start of polymerization
3Reliability
If higher concentration of continuity additive is used, then sheeting and fouling are reduced, but the cost of additives increases
Solution Approach 1:
The continuity additive is pre-loaded at the optimal concentration before polymerization begins, ensuring sufficient additive is present during the critical initial stages without requiring excessive amounts throughout the entire reaction period
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
In some embodiments, a method in which at least one continuity additive ("CA") and a seed bed are pre-loaded into a reactor, and a polymerization reaction is optionally then performed in the reactor. In other embodiments, at least one flow improver, at least one CA, and a seed bed are pre-loaded into a reactor. Pre¬ loading of a reactor with a CA can significantly improve continuity of a subsequent polymerization reaction in the reactor during its initial stages, including by reducing sheeting and fouling. The CA can be pre-loaded in dry form (e.g., as a powder), or in liquid or slurry form (e.g., as an oil slurry). To aid delivery of a dry CA to the reactor and combination of the dry CA with a seed bed in the reactor, the dry CA can be combined with a flow improver and the combination of CA and flow improver then loaded into the reactor. Alternatively, the CA and flow improver can be sequentially loaded into the reactor, and then mixed together (and mixed with a seed bed) in the reactor after both the CA and flow improver have been separately loaded into the reactor.