How is the exhaust gas from hydrogenation reactions in fine chemical manufacturing monitored?
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Hydrogenation reactions in the fine chemical industry are considered high-risk processes; according to regulatory requirements, it is necessary to monitor the exhaust gases generated by these reactions. I wonder if everyone is doing this monitoring, or if there are other methods available?
Hydrogenation reactions in the fine chemical industry are generally carried out in a batch mode at certain pressures; therefore, the vent valve is usually not opened during the reaction process. The vent valve is only opened at the end of the reaction to release the exhaust gases. Since these exhaust gases are simply vented, their composition is generally not analyzed. Only continuous hydrogenation units are capable of detecting exhaust gas composition.
That’s the key point, but the crucial question is: can it be emptied directly? Is there a risk of explosion upon contact with air in the vent pipeline?
A flame arrester needs to be installed on the vent pipeline.
According to the design firm, the exhaust gas should flow directly into the organic solvent through an exhaust pipeline; a flame arrester is sufficient on the equipment side. The exhaust gas first passes through a condenser to recover the organic solvents, and then through an exhaust gas absorption tower before being released into the atmosphere at high altitude
When the volume concentration of hydrogen in air is between 4.0% and 75.6%, it will explode upon contact with a fire source. However, when the hydrogen concentration is less than 4.0% or greater than 75.6%, no explosion occurs even in the presence of a fire source, but other dangers may arise. Therefore, when converting this volume percentage into ppm, hydrogen will explode at concentrations ranging from 40,000 ppm to 750,000 ppm in air. Hydrogen detectors can be used; portable hydrogen detectors are capable of continuously monitoring the hydrogen concentration in the working environment as well as any changes in it. Hydrogen detectors can operate by means of natural diffusion to detect gas concentrations, or they can use electrochemical sensors, which offer high sensitivity and excellent repeatability ； It features simple operation, comprehensive functions, and high reliability; available options include Dräger hydrogen detectors, Messgerät hydrogen detectors, Honeywell detectors, and Riken detectors.