Application
- Precise carbon balance
- Precise oxygen balance
- Selectivity near real-time
Process
Ethylene oxide (EO) is produced by direct oxidation of ethylene with air or oxygen over a silver-containing catalyst. For satisfactory catalyst operation the ethylene in the reactor feed concentration must be maintained between 5% and 10%. The relevant chemical reactions are:
(1) C2H4 + 0.5 O2 -> C2H4O
(2) C2H4O + 2.5 O2 -> 2 CO2 + 2 H2O
(3) C2H4 + 3 O2 -> 2 CO2 + 2 H2O
Output from the reactor is the desired ethylene oxide (C2H4O), carbon dioxide (CO2) and water (H20), along with the ethylene (C2H4) that was not oxidized. The operating conditions determine the proportion of ethylene oxide that is produced. For example, CO2 production should be minimized to maximize selectivity for ethylene oxide.
The MGA™ Process Mass Spectrometer can be used to monitor the ethylene input to ensure efficient catalyst operation by helping regulate the ethylene/air or ethylene/oxygen ratio. On the output of the reactor, an MGA can be used for real-time monitoring of ethylene oxide, carbon dioxide, ethylene and other gases. The operating conditions of the reactor can be optimized based on the ratios of these three components. This can lead to savings based on utilities costs, such as steam.
EO Reactor Input
Ethylene (C2H4) = 26%
Oxygen (O2) = 8%
Carbon Dioxide (CO2) = 7%
Argon (Ar) = 6%
Methane (CH4) = 50%
Nitrogen (N2) = 3%
EO Reactor Output
Ethylene (C2H4) = 0% to 40%
Oxygen (O2) = 0% to 10%
Carbon Dioxide (CO2) = 0% to 20%
Ethylene Oxide (C2H4O) = 0% to 5%
