We are currently using a Parr 4564 Mini Bench Top Reactor (equipped with a gas inlet valve, a liquid sampling valve and a gas outlet valve). Within this reactor, we plan to run some liquid-based reactions at high pressure and high temperature. During the reaction process, we would like to take the liquid sample out for analysis. Can someone kindly help advise us how can we manage the sampling? Plus, how can we be sure that the sample we take is representative of the whole liquid in the vessel, given that the liquid is a mixture of solvents with different boiling points?
Thank you very much!
The sample representative of the whole liquid in reactor if the reactor is mixed perfectly.
You could use a 3-way valve at the bottom of the reactor to create a sample lock. Install a fixed volume dead end on position 1 (normally the inlet of the valve). Connect the reactor on port 2. The reactor pressure will fill the sample volume quite reproducible, switching to the open outlet at port 3 drains the sample.
Thanks, Arnoud and Duraid.
We are thinking about adding en extended tube to the liquid sampling valve with additional two valves (denoted as A and B valves, A is closer to reactor). Open A, the pressure inside the reactor will help fill the tube with liquid sample, then close A and wait until it's cool. Open B and drain the liquid.
However, we are still questioning the uniformity of the liquid inside the reactor.
Your reactor should be provided with a mixer/stirrer which ensures a homogenous mix within the reaction medium during sampling. A solenoid valve with the inlet end dipped into the reactor is connected. The outlet of the solenoid valve is connected to your sampling container. The solenoid valve is programmed to release your samples at preset times or it can be triggered manually to release the samples at the desired times. This way progress within the reaction mix can be monitored.
Thanks to Dr. Kūn Guō for his question. We have the same problem. How did you solve this problem? Could you upload some drawings about how to implement a good system for sampling to be used for kinetic analysis?
Hi Dr. Kūn Guō, I have a question regarding taking of liquid samples during high pressure and temperature conditions. While draining the samples, there is a chance of reducing the set pressure. How can I maintain set conditions in that situation? Please help me.
Thank you in advance.