Lab-scale mixing of Oxygen with Hydrocarbon

[leejs]

I'm preparing a lab-scale catalytic combustion system. Oxygen, steam, and hydrocarbon are feeded separately into in-line static mixer, and then into the combuster. The tempearture of feed streams is very high, over 600?. The feeds are flammable over a certain concentration of oxygen. If there existed high-oxygen-concentration area caused by incomplete mixing, it would exploded, and cause serious problems (like a burn, economic loss, dismissal, and etc.).

The problem is that the flow rate of feeds are very low, under 1 g/min. How can I guarantee the safety of my system, not to be exploded during the operation over 2 weeks?

 

[Montemayor]

leejs:

I have to give you credit for being honest and up front in detailing what you are proposing to do. My basic question is: Are you doing this on your own - or are you working for an organization that has employed you to do the experimentation?

If you are proposing to do this on your own, without technical, engineering assistance then my advice to you is simply that you shouldn't attempt what you have described.

If you are employed by an organization who can afford to have research and experimentation, then that same organization should furnish you with technical assistance and know-how in what is being attempted - as well as safety standards, training and expert supervision.

I seriously doubt if any experienced, knowledgeable, and responsible engineer on this forum is going to offer advice that would "guarantee the safety of your system". This is not only impossible to do, but would be foolhardy since we don't know you, your training, experience, and capabilities. To do so would be risking liability as to the results as controlled by you. Sorry.

 

[kenvlach]

This sounds like a dangerous design but maybe some details you haven't mentioned.

The inline mixer is a likely place for explosions, with point of ignition at the entrance to the catalyst bed. Maybe use a Y-shaped mixer filled with catalyst. Feed the hydrocarbon and steam from one side, the oxygen from the other, and have check valves on each feed to prevent flashback.

Maybe recycle some of the exhaust through the oxygen side to keep the catalyst hot.

You probably have a zirconia oxygen sensor and thermocouples to monitor the experiment, so maybe add a controller and electronic (solenoid) valve on the hydrocarbon feed to shut off if get outside the design parameters. Use a 'normally-closed' valve, which shuts off automatically in the event of electrical failure.

Good luck.